$COF
CAPITAL ONE FINANCIAL CORP Stock $cof

$cof Overview Financials Valuation SEC Filings Company Website

2019 Q4 Form 10-K Financial Statement

#000092762821000094 Filed on February 25, 2021

Income Statement

Concept	2019 Q4	2018 Q4	2018 Q3
Revenue			$6.962B
YoY Change			-0.33%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development			$311.0M
YoY Change			5.78%
% of Gross Profit
Depreciation & Amortization	$905.0M	$675.0M	$589.0M
YoY Change	34.07%	-6.38%	0.17%
% of Gross Profit
Operating Expenses			$311.0M
YoY Change			5.78%
Operating Profit
YoY Change
Interest Expense			$1.109B
YoY Change			54.03%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$1.448B	$1.243B	$1.921B
YoY Change	16.49%	-4.97%	21.2%
Income Tax	$270.0M	-$21.00M	$420.0M
% Of Pretax Income	18.65%	-1.69%	21.86%
Net Earnings	$1.176B	$1.261B	$1.502B
YoY Change	-6.74%	-229.87%	35.68%
Net Earnings / Revenue			21.57%
Basic Earnings Per Share			$3.01
Diluted Earnings Per Share	$2.538M	$2.670M	$2.99
COMMON SHARES
Basic Shares Outstanding			477.8M shares
Diluted Shares Outstanding			480.9M shares

Balance Sheet

Concept	2019 Q4	2018 Q4	2018 Q3
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$13.75B	$13.49B	$11.63B
Short-Term Investments
Other Short-Term Assets
YoY Change
Inventory
Prepaid Expenses
Receivables
Other Receivables
Total Short-Term Assets
YoY Change
LONG-TERM ASSETS
Property, Plant & Equipment	$4.378B	$4.191B	$4.149B
YoY Change	4.46%	3.92%	4.91%
Goodwill	$14.65B	$14.54B	$14.51B
YoY Change	0.75%	0.08%	-0.13%
Intangibles	$174.0M	$254.0M	$289.0M
YoY Change	-31.5%	-39.67%	-39.92%
Long-Term Investments
YoY Change
Other Assets
YoY Change
Total Long-Term Assets
YoY Change
TOTAL ASSETS
Total Short-Term Assets
Total Long-Term Assets
Total Assets	$390.4B	$372.5B	$362.9B
YoY Change	4.79%	1.87%	0.42%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$439.0M	$458.0M	$391.0M
YoY Change	-4.15%	10.9%	29.9%
Accrued Expenses	$1.756B
YoY Change
Deferred Revenue
YoY Change
Short-Term Debt	$7.314B	$9.402B	$1.634B
YoY Change	-22.21%	1532.29%	113.04%
Long-Term Debt Due
YoY Change
Total Short-Term Liabilities	$2.195B	$458.0M	$391.0M
YoY Change	379.26%	10.9%	29.9%
LONG-TERM LIABILITIES
Long-Term Debt	$48.38B	$49.25B	$50.07B
YoY Change	-1.76%	-2.98%	9.91%
Other Long-Term Liabilities	$11.77B	$11.74B	$12.48B
YoY Change	0.19%	-6.56%	0.43%
Total Long-Term Liabilities	$60.15B	$61.00B	$62.55B
YoY Change	-1.39%	-3.69%	7.88%
TOTAL LIABILITIES
Total Short-Term Liabilities	$2.195B	$458.0M	$391.0M
Total Long-Term Liabilities	$60.15B	$61.00B	$62.55B
Total Liabilities	$332.4B	$320.9B	$312.3B
YoY Change	3.58%	1.23%	0.33%
SHAREHOLDERS EQUITY
Retained Earnings	$40.34B	$35.88B	$34.88B
YoY Change	12.45%	16.86%	9.19%
Common Stock	$7.000M	$7.000M	$7.000M
YoY Change	0.0%	0.0%	0.0%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$58.01B	$51.67B	$50.64B
YoY Change
Total Liabilities & Shareholders Equity	$390.4B	$372.5B	$362.9B
YoY Change	4.79%	1.87%	0.42%

Cashflow Statement

Concept	2019 Q4	2018 Q4	2018 Q3
OPERATING ACTIVITIES
Net Income	$1.176B	$1.261B	$1.502B
YoY Change	-6.74%	-229.87%	35.68%
Depreciation, Depletion And Amortization	$905.0M	$675.0M	$589.0M
YoY Change	34.07%	-6.38%	0.17%
Cash From Operating Activities	$4.120B	$3.940B	$3.351B
YoY Change	4.57%	-3.69%	9.22%
INVESTING ACTIVITIES
Capital Expenditures	-$256.0M	-$205.0M	-$240.0M
YoY Change	24.88%	-15.29%	-18.09%
Acquisitions
YoY Change
Other Investing Activities	-$16.86B	-$9.542B	-$2.016B
YoY Change	76.65%	168.49%	-71.83%
Cash From Investing Activities	-$17.11B	-$9.747B	-$2.256B
YoY Change	75.56%	156.77%	-69.72%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	9.204B	7.668B	-2.763B
YoY Change	20.03%	45.53%	-144.89%
NET CHANGE
Cash From Operating Activities	4.120B	3.940B	3.351B
Cash From Investing Activities	-17.11B	-9.747B	-2.256B
Cash From Financing Activities	9.204B	7.668B	-2.763B
Net Change In Cash	-3.788B	1.861B	-1.668B
YoY Change	-303.55%	-66.55%	-194.08%
FREE CASH FLOW
Cash From Operating Activities	$4.120B	$3.940B	$3.351B
Capital Expenditures	-$256.0M	-$205.0M	-$240.0M
Free Cash Flow	$4.376B	$4.145B	$3.591B
YoY Change	5.57%	-4.34%	6.84%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2020	dei	Amendment Flag AmendmentFlag	false
CY2020	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2020
CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2020	dei	Entity Central Index Key EntityCentralIndexKey	0000927628
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList	us-gaap:OtherAssets
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList	us-gaap:OtherAssets
CY2020Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	us-gaap:OtherLiabilities
CY2019Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	us-gaap:OtherLiabilities
CY2020Q4	cof	Depository Share Percent Interestin Preferred Stock DepositorySharePercentInterestinPreferredStock	0.025
CY2020	dei	Document Type DocumentType	10-K
CY2020	dei	Document Annual Report DocumentAnnualReport	true
CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-12-31
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	001-13300
CY2020	dei	Entity Registrant Name EntityRegistrantName	CAPITAL ONE FINANCIAL CORP
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	54-1719854
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	1680 Capital One Drive,
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	McLean,
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	VA
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	22102
CY2020	dei	City Area Code CityAreaCode	703
CY2020	dei	Local Phone Number LocalPhoneNumber	720-1000
CY2020	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2020	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2020	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2020	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2020	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2020	dei	Entity Small Business EntitySmallBusiness	false
CY2020	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2020	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2020	dei	Entity Shell Company EntityShellCompany	false
CY2020Q2	dei	Entity Public Float EntityPublicFloat	28300000000	USD
CY2021Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	459236740	shares
CY2020	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	24074000000	USD
CY2019	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	25862000000	USD
CY2018	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	24728000000	USD
CY2020	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	1877000000	USD
CY2019	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	2411000000	USD
CY2018	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	2211000000	USD
CY2020	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	82000000	USD
CY2019	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	240000000	USD
CY2018	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	237000000	USD
CY2020	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	26033000000	USD
CY2019	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	28513000000	USD
CY2018	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	27176000000	USD
CY2020	us-gaap	Interest Expense Deposits InterestExpenseDeposits	2165000000	USD
CY2019	us-gaap	Interest Expense Deposits InterestExpenseDeposits	3420000000	USD
CY2018	us-gaap	Interest Expense Deposits InterestExpenseDeposits	2598000000	USD
CY2020	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	232000000	USD
CY2019	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	523000000	USD
CY2018	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	496000000	USD
CY2020	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	679000000	USD
CY2019	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	1159000000	USD
CY2018	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	1125000000	USD
CY2020	cof	Interest Expense Other Borrowings InterestExpenseOtherBorrowings	44000000	USD
CY2019	cof	Interest Expense Other Borrowings InterestExpenseOtherBorrowings	71000000	USD
CY2018	cof	Interest Expense Other Borrowings InterestExpenseOtherBorrowings	82000000	USD
CY2020	us-gaap	Interest Expense InterestExpense	3120000000	USD
CY2019	us-gaap	Interest Expense InterestExpense	5173000000	USD
CY2018	us-gaap	Interest Expense InterestExpense	4301000000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	22913000000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	23340000000	USD
CY2018	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	22875000000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	10264000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	6236000000	USD
CY2018	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	5856000000	USD
CY2020	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	12649000000	USD
CY2019	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	17104000000	USD
CY2018	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	17019000000	USD
CY2020	cof	Interchange Fees Net InterchangeFeesNet	3017000000	USD
CY2019	cof	Interchange Fees Net InterchangeFeesNet	3179000000	USD
CY2020	us-gaap	Occupancy Net OccupancyNet	2118000000	USD
CY2018	cof	Interchange Fees Net InterchangeFeesNet	2823000000	USD
CY2020	cof	Service Chargesand Other Customer Related Fees ServiceChargesandOtherCustomerRelatedFees	1243000000	USD
CY2019	cof	Service Chargesand Other Customer Related Fees ServiceChargesandOtherCustomerRelatedFees	1330000000	USD
CY2018	cof	Service Chargesand Other Customer Related Fees ServiceChargesandOtherCustomerRelatedFees	1585000000	USD
CY2020	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	25000000	USD
CY2019	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	26000000	USD
CY2018	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-209000000	USD
CY2020	us-gaap	Noninterest Income Other NoninterestIncomeOther	1325000000	USD
CY2019	us-gaap	Noninterest Income Other NoninterestIncomeOther	718000000	USD
CY2018	us-gaap	Noninterest Income Other NoninterestIncomeOther	1002000000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	5610000000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	5253000000	USD
CY2018	us-gaap	Noninterest Income NoninterestIncome	5201000000	USD
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	6805000000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	6388000000	USD
CY2018	us-gaap	Labor And Related Expense LaborAndRelatedExpense	5727000000	USD
CY2019	us-gaap	Occupancy Net OccupancyNet	2098000000	USD
CY2018	us-gaap	Occupancy Net OccupancyNet	2118000000	USD
CY2020	us-gaap	Marketing Expense MarketingExpense	1610000000	USD
CY2019	us-gaap	Marketing Expense MarketingExpense	2274000000	USD
CY2018	us-gaap	Marketing Expense MarketingExpense	2174000000	USD
CY2020	us-gaap	Professional And Contract Services Expense ProfessionalAndContractServicesExpense	1312000000	USD
CY2019	us-gaap	Professional And Contract Services Expense ProfessionalAndContractServicesExpense	1237000000	USD
CY2018	us-gaap	Professional And Contract Services Expense ProfessionalAndContractServicesExpense	1145000000	USD
CY2020	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	1215000000	USD
CY2019	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	1290000000	USD
CY2018	us-gaap	Communications And Information Technology CommunicationsAndInformationTechnology	1260000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	60000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	112000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	174000000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	1936000000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	2084000000	USD
CY2018	us-gaap	Other Noninterest Expense OtherNoninterestExpense	2304000000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	15056000000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	15483000000	USD
CY2018	us-gaap	Noninterest Expense NoninterestExpense	14902000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	3203000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	6874000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	7318000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	486000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1341000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1293000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	2717000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	5533000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6025000000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-3000000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	13000000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-10000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	2714000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	5546000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	6015000000	USD
CY2020	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	20000000	USD
CY2019	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	41000000	USD
CY2018	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	40000000	USD
CY2020	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	280000000	USD
CY2019	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	282000000	USD
CY2018	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	265000000	USD
CY2020	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	39000000	USD
CY2019	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	31000000	USD
CY2018	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	0	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	2375000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	5192000000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	5710000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	5.20
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	11.07
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	11.92
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.01
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.03
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.02
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.19
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.10
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.90
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	5.19
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	11.02
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	11.84
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.01
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.03
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.02
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.18
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.05
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.82
CY2020	us-gaap	Net Income Loss NetIncomeLoss	2714000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	5546000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	6015000000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	1259000000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	650000000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-459000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	1008000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	772000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-74000000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	76000000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	70000000	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-39000000	USD
CY2020	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	0	USD
CY2019	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	26000000	USD
CY2018	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	447000000	USD
CY2020	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	3000000	USD
CY2019	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	13000000	USD
CY2018	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	-11000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2346000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1531000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-136000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	5060000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	7077000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	5879000000	USD
CY2020Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	4708000000	USD
CY2019Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	4129000000	USD
CY2020Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	35801000000	USD
CY2019Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	9278000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	40509000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents And Federal Funds Sold CashCashEquivalentsAndFederalFundsSold	13407000000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	262000000	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	342000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	97600000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	1000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	100445000000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	79213000000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	251624000000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	265809000000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	15564000000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	7208000000	USD
CY2020Q4	us-gaap	Notes Receivable Net NotesReceivableNet	236060000000	USD
CY2019Q4	us-gaap	Notes Receivable Net NotesReceivableNet	258601000000	USD
CY2020Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	596000000	USD
CY2019Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	251000000	USD
CY2020Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	2710000000	USD
CY2019Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	400000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4287000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4378000000	USD
CY2020Q4	us-gaap	Interest Receivable InterestReceivable	1471000000	USD
CY2019Q4	us-gaap	Interest Receivable InterestReceivable	1758000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2020Q4	us-gaap	Other Assets OtherAssets	21205000000	USD
CY2019Q4	us-gaap	Other Assets OtherAssets	17613000000	USD
CY2020Q4	us-gaap	Assets Assets	421602000000	USD
CY2019Q4	us-gaap	Assets Assets	390365000000	USD
CY2020Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	352000000	USD
CY2019Q4	us-gaap	Interest Payable Current And Noncurrent InterestPayableCurrentAndNoncurrent	439000000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	31142000000	USD
CY2019Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	23488000000	USD
CY2020Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	274300000000	USD
CY2019Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	239209000000	USD
CY2020Q4	us-gaap	Deposits Deposits	305442000000	USD
CY2019Q4	us-gaap	Deposits Deposits	262697000000	USD
CY2020Q4	us-gaap	Secured Debt SecuredDebt	12414000000	USD
CY2019Q4	us-gaap	Secured Debt SecuredDebt	17808000000	USD
CY2020Q4	us-gaap	Federal Funds Purchased And Securities Sold Under Agreements To Repurchase FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	668000000	USD
CY2019Q4	us-gaap	Federal Funds Purchased And Securities Sold Under Agreements To Repurchase FederalFundsPurchasedAndSecuritiesSoldUnderAgreementsToRepurchase	314000000	USD
CY2020Q4	us-gaap	Unsecured Debt UnsecuredDebt	27382000000	USD
CY2019Q4	us-gaap	Unsecured Debt UnsecuredDebt	30472000000	USD
CY2020Q4	us-gaap	Other Borrowings OtherBorrowings	75000000	USD
CY2019Q4	us-gaap	Other Borrowings OtherBorrowings	7103000000	USD
CY2020Q4	cof	Debt Excluding Secured Debt DebtExcludingSecuredDebt	28125000000	USD
CY2019Q4	cof	Debt Excluding Secured Debt DebtExcludingSecuredDebt	37889000000	USD
CY2020Q4	us-gaap	Other Liabilities OtherLiabilities	15065000000	USD
CY2019Q4	us-gaap	Other Liabilities OtherLiabilities	13521000000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	361398000000	USD
CY2019Q4	us-gaap	Liabilities Liabilities	332354000000	USD
CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2019Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	50000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	50000000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	4975000	shares
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	4975000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Outstanding PreferredStockSharesOutstanding	4975000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	4975000	shares
CY2020Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2019Q4	us-gaap	Preferred Stock Value PreferredStockValue	0	USD
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	1000000000	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	679932837	shares
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	672969391	shares
CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	458972202	shares
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	456562399	shares
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	7000000	USD
CY2019Q4	us-gaap	Common Stock Value CommonStockValue	7000000	USD
CY2020Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	33480000000	USD
CY2019Q4	us-gaap	Additional Paid In Capital AdditionalPaidInCapital	32980000000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	40088000000	USD
CY2019Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	40340000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	3494000000	USD
CY2019Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	1156000000	USD
CY2019Q4	cof	Treasury Stock Par Or Stated Value Per Share TreasuryStockParOrStatedValuePerShare	0.01
CY2020Q4	cof	Treasury Stock Par Or Stated Value Per Share TreasuryStockParOrStatedValuePerShare	0.01
CY2020Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	220960635	shares
CY2019Q4	us-gaap	Treasury Stock Common Shares TreasuryStockCommonShares	216406992	shares
CY2020Q4	us-gaap	Treasury Stock Common Value TreasuryStockCommonValue	16865000000	USD
CY2019Q4	us-gaap	Treasury Stock Common Value TreasuryStockCommonValue	16472000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	60204000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	58011000000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	421602000000	USD
CY2019Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	390365000000	USD
CY2017Q4	us-gaap	Stockholders Equity StockholdersEquity	48730000000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	5879000000	USD
CY2018	us-gaap	Dividends Common Stock DividendsCommonStock	773000000	USD
CY2018	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	265000000	USD
CY2018	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	2284000000	USD
CY2018	cof	Stock Issued During Period Value New Issuesand Restricted Stock Netof Forfeitures StockIssuedDuringPeriodValueNewIssuesandRestrictedStockNetofForfeitures	175000000	USD
CY2018	cof	Stock Issued During Period Value Stock Optionsand Warrants Exercisedand Restricted Stock Vesting StockIssuedDuringPeriodValueStockOptionsandWarrantsExercisedandRestrictedStockVesting	38000000	USD
CY2018	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	168000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	51668000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	7077000000	USD
CY2019Q4	cof	Other Comprehensive Income Loss Transfer Of Securities Held To Maturity Net Of Tax OtherComprehensiveIncomeLossTransferOfSecuritiesHeldToMaturityNetOfTax	888000000	USD
CY2019	us-gaap	Dividends Common Stock DividendsCommonStock	753000000	USD
CY2019	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	282000000	USD
CY2019	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	1481000000	USD
CY2019	cof	Stock Issued During Period Value New Issuesand Restricted Stock Netof Forfeitures StockIssuedDuringPeriodValueNewIssuesandRestrictedStockNetofForfeitures	199000000	USD
CY2019	cof	Stock Issued During Period Value Stock Optionsand Warrants Exercisedand Restricted Stock Vesting StockIssuedDuringPeriodValueStockOptionsandWarrantsExercisedandRestrictedStockVesting	17000000	USD
CY2019	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	1462000000	USD
CY2019	us-gaap	Stock Redeemed Or Called During Period Value StockRedeemedOrCalledDuringPeriodValue	1000000000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	227000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	58011000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	5060000000	USD
CY2020	us-gaap	Dividends Common Stock DividendsCommonStock	460000000	USD
CY2020	us-gaap	Dividends Preferred Stock Cash DividendsPreferredStockCash	280000000	USD
CY2020	us-gaap	Treasury Stock Value Acquired Cost Method TreasuryStockValueAcquiredCostMethod	393000000	USD
CY2020	cof	Stock Issued During Period Value New Issuesand Restricted Stock Netof Forfeitures StockIssuedDuringPeriodValueNewIssuesandRestrictedStockNetofForfeitures	241000000	USD
CY2019Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020	cof	Stock Issued During Period Value Stock Optionsand Warrants Exercisedand Restricted Stock Vesting StockIssuedDuringPeriodValueStockOptionsandWarrantsExercisedandRestrictedStockVesting	62000000	USD
CY2020	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	1330000000	USD
CY2020	us-gaap	Stock Redeemed Or Called During Period Value StockRedeemedOrCalledDuringPeriodValue	1375000000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	200000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	60204000000	USD
CY2020Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
CY2020Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.10
CY2020Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q1	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q2	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2019Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q4	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2018Q3	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.40
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	2717000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	5533000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6025000000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-3000000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	13000000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-10000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	2714000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	5546000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	6015000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	6236000000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	10264000000	USD
CY2018	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	5856000000	USD
CY2020	us-gaap	Depreciation And Amortization DepreciationAndAmortization	3501000000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	3339000000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	2396000000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-1627000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-296000000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	714000000	USD
CY2020	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	25000000	USD
CY2019	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	26000000	USD
CY2018	us-gaap	Debt And Equity Securities Gain Loss DebtAndEquitySecuritiesGainLoss	-209000000	USD
CY2020	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	6000000	USD
CY2019	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	50000000	USD
CY2018	us-gaap	Gain Loss On Sales Of Loans Net GainLossOnSalesOfLoansNet	548000000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	203000000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	239000000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	170000000	USD
CY2020	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	520000000	USD
CY2019	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	0	USD
CY2018	us-gaap	Other Noncash Income Expense OtherNoncashIncomeExpense	125000000	USD
CY2020	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	10055000000	USD
CY2019	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	9798000000	USD
CY2018	us-gaap	Payments For Origination And Purchases Of Loans Held For Sale PaymentsForOriginationAndPurchasesOfLoansHeldForSale	9039000000	USD
CY2020	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	9856000000	USD
CY2019	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	10668000000	USD
CY2018	us-gaap	Proceeds From Sale And Collection Of Loans Heldforsale ProceedsFromSaleAndCollectionOfLoansHeldforsale	8442000000	USD
CY2020	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-287000000	USD
CY2019	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	63000000	USD
CY2018	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	74000000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-979000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-662000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Assets IncreaseDecreaseInOtherOperatingAssets	-476000000	USD
CY2020	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-87000000	USD
CY2019	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-19000000	USD
CY2018	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	45000000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	1212000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	194000000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-1553000000	USD
CY2020	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	3000000	USD
CY2019	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	7000000	USD
CY2018	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	-6000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	16699000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	16639000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	12978000000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	43026000000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	12105000000	USD
CY2018	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	14022000000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	8553000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	22324000000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	7510000000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	812000000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	4780000000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	6399000000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	0	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	396000000	USD
CY2018	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	19166000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	0	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	5050000000	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	2419000000	USD
CY2020	cof	Payments For Proceeds From Sale Of Financing Receivable Held For Investment PaymentsForProceedsFromSaleOfFinancingReceivableHeldForInvestment	-4136000000	USD
CY2019	cof	Payments For Proceeds From Sale Of Financing Receivable Held For Investment PaymentsForProceedsFromSaleOfFinancingReceivableHeldForInvestment	21280000000	USD
CY2018	cof	Payments For Proceeds From Sale Of Financing Receivable Held For Investment PaymentsForProceedsFromSaleOfFinancingReceivableHeldForInvestment	-1015000000	USD
CY2020	us-gaap	Proceeds From Recoveries Of Loan Previously Charged Off ProceedsFromRecoveriesOfLoanPreviouslyChargedOff	2452000000	USD
CY2019	us-gaap	Proceeds From Recoveries Of Loan Previously Charged Off ProceedsFromRecoveriesOfLoanPreviouslyChargedOff	2557000000	USD
CY2018	us-gaap	Proceeds From Recoveries Of Loan Previously Charged Off ProceedsFromRecoveriesOfLoanPreviouslyChargedOff	2503000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	710000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	887000000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	874000000	USD
CY2020	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	7000000	USD
CY2019	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	8393000000	USD
CY2018	us-gaap	Payments To Acquire Businesses Net Of Cash Acquired PaymentsToAcquireBusinessesNetOfCashAcquired	600000000	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	822000000	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	877000000	USD
CY2018	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	802000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-14841000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-22998000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-15618000000	USD
CY2020	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	42519000000	USD
CY2019	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	12643000000	USD
CY2018	us-gaap	Increase Decrease In Deposits IncreaseDecreaseInDeposits	6077000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	1248000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	6656000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Secured Debt ProceedsFromIssuanceOfSecuredDebt	997000000	USD
CY2020	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	6885000000	USD
CY2019	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	7285000000	USD
CY2018	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	2673000000	USD
CY2020	cof	Proceedsfrom Issuanceof Unsecured Debtand Long Term Fhlb Advances Netof Issuance Cost ProceedsfromIssuanceofUnsecuredDebtandLongTermFHLBAdvancesNetofIssuanceCost	3987000000	USD
CY2019	cof	Proceedsfrom Issuanceof Unsecured Debtand Long Term Fhlb Advances Netof Issuance Cost ProceedsfromIssuanceofUnsecuredDebtandLongTermFHLBAdvancesNetofIssuanceCost	4142000000	USD
CY2018	cof	Proceedsfrom Issuanceof Unsecured Debtand Long Term Fhlb Advances Netof Issuance Cost ProceedsfromIssuanceofUnsecuredDebtandLongTermFHLBAdvancesNetofIssuanceCost	5977000000	USD
CY2020	cof	Repaymentsof Unsecured Debtand Long Term Fhlb Advances RepaymentsofUnsecuredDebtandLongTermFHLBAdvances	8156000000	USD
CY2019	cof	Repaymentsof Unsecured Debtand Long Term Fhlb Advances RepaymentsofUnsecuredDebtandLongTermFHLBAdvances	5595000000	USD
CY2018	cof	Repaymentsof Unsecured Debtand Long Term Fhlb Advances RepaymentsofUnsecuredDebtandLongTermFHLBAdvances	14163000000	USD
CY2020	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	-6674000000	USD
CY2019	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	-2104000000	USD
CY2018	us-gaap	Proceeds From Repayments Of Other Debt ProceedsFromRepaymentsOfOtherDebt	8671000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	241000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	199000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	175000000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	460000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	753000000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	773000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	1330000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	1462000000	USD
CY2018	us-gaap	Proceeds From Issuance Of Preferred Stock And Preference Stock ProceedsFromIssuanceOfPreferredStockAndPreferenceStock	0	USD
CY2020	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	280000000	USD
CY2019	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	282000000	USD
CY2018	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	265000000	USD
CY2020	cof	Payments For Redemption Of Preferred Stock PaymentsForRedemptionOfPreferredStock	1375000000	USD
CY2019	cof	Payments For Redemption Of Preferred Stock PaymentsForRedemptionOfPreferredStock	1000000000	USD
CY2018	cof	Payments For Redemption Of Preferred Stock PaymentsForRedemptionOfPreferredStock	0	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	393000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	1481000000	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	2284000000	USD
CY2020	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	62000000	USD
CY2019	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	17000000	USD
CY2018	us-gaap	Proceeds From Stock Plans ProceedsFromStockPlans	38000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	25164000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	6619000000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1777000000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	27022000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	260000000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-863000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	13749000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	13489000000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	14352000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	40771000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	13749000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	13489000000	USD
CY2020	cof	Transfer Of To Portfolio Financing Receivables To From Held For Sale TransferOfToPortfolioFinancingReceivablesToFromHeldForSale	2192000000	USD
CY2019	cof	Transfer Of To Portfolio Financing Receivables To From Held For Sale TransferOfToPortfolioFinancingReceivablesToFromHeldForSale	1589000000	USD
CY2018	cof	Transfer Of To Portfolio Financing Receivables To From Held For Sale TransferOfToPortfolioFinancingReceivablesToFromHeldForSale	855000000	USD
CY2020	us-gaap	Debt Securities Held To Maturity Transfer Amount DebtSecuritiesHeldToMaturityTransferAmount	0	USD
CY2019	us-gaap	Debt Securities Held To Maturity Transfer Amount DebtSecuritiesHeldToMaturityTransferAmount	33187000000	USD
CY2018	us-gaap	Debt Securities Held To Maturity Transfer Amount DebtSecuritiesHeldToMaturityTransferAmount	0	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	3580000000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	4790000000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	3933000000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	988000000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	626000000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	407000000	USD
CY2020	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	segment
CY2020	us-gaap	Use Of Estimates UseOfEstimates	The preparation of the consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and in the related disclosures. These estimates are based on information available as of the date of the consolidated financial statements. While management makes its best judgments, actual amounts or results could differ from these estimates.<span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%"> </span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Certain prior period amounts have been reclassified to conform to the current period presentation.</span>
CY2020	us-gaap	Financing Receivable Allowance For Credit Losses Policy For Uncollectible Amounts FinancingReceivableAllowanceForCreditLossesPolicyForUncollectibleAmounts	<div style="margin-bottom:9pt;margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Allowance for Credit Losses - Available for Sale Investment Securities</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We maintain an allowance for credit losses (“allowance”) that represents management’s current estimate of expected credit losses over the contractual terms of our investment securities classified as available for sale. When an investment security available for sale is impaired due to credit factors, we recognize a provision for credit losses in our consolidated statements of income and an allowance for credit losses on our consolidated balance sheets. Credit losses recognized in the allowance for credit losses are limited to the amount by which the investment security’s amortized cost basis exceeds its fair value. Investment securities in unrealized gain positions do not have an allowance for credit losses as the investment security could be sold at its fair value to prevent realization of credit losses. We exclude accrued interest from the fair value and amortized cost basis of an investment security for purposes of measuring impairment. Charge-offs of uncollectible amounts of investment securities are deducted from the allowance for credit losses.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For certain of our securities available for sale, we have determined that there is no risk of impairment due to credit factors. These investment securities include high quality debt instruments that are issued and guaranteed by the United States government and its agencies or are issued through certain government-sponsored enterprises. Management performs periodic assessments to reevaluate this conclusion by considering any changes in historical losses, current conditions, and reasonable and supportable forecasts.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We evaluate impairment on a quarterly basis at the individual security level and determine whether any portion of the decline in fair value is due to a credit loss. We make this determination through the use of quantitative and qualitative analyses. Our qualitative analysis includes factors such as the extent to which fair value is less than amortized cost, any changes in the security’s credit rating, past defaults or delayed payments, and adverse conditions impacting the security or issuer. A credit loss exists to the extent that management does not expect to recover the amortized cost basis.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For investment securities which require further assessment, we perform a quantitative analysis using a discounted cash flow methodology and compare the present value of expected future cash flows from the security available for sale to the security’s amortized cost basis. Projected future cash flows reflect management’s best estimate and are based on our understanding of past events, current conditions, reasonable and supportable forecasts, and are discounted by the security’s effective interest rate adjusted for prepayments. The allowance for credit losses for investment securities reflects the difference by which the amortized cost basis exceeds the present value of future cash flows and is limited to the amount by which the security’s amortized cost exceeds its fair value. See “Note 2—Investment Securities” for additional information.</span></div><div style="margin-bottom:9pt;margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Allowance for Credit Losses - Loans Held for Investment</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We maintain an allowance for credit losses (“allowance”) that represents management’s current estimate of expected credit losses over the contractual terms of our loans held for investment. We measure the allowance on a quarterly basis through consideration of past events, including historical experience, current conditions and reasonable and supportable forecasts.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We measure current expected credit losses over the contractual terms of our loans. The contractual terms are adjusted for expected prepayments but are not extended for renewals or extensions, except when an extension or renewal arises from a borrower option that is not unconditionally cancellable or through a TDR that is reasonably expected to occur.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We aggregate loans sharing similar risk characteristics into pools for purposes of measuring expected credit losses. Pools are reassessed periodically to confirm that all loans within each pool continue to share similar risk characteristics. Expected credit losses for loans that do not share similar risk characteristics with other financial assets are measured individually.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Expected recoveries of amounts previously charged off or expected to be charged off are recognized within the allowance, with a corresponding reduction to our provision for credit losses. At times expected recoveries may result in a negative allowance. We limit the allowance to amounts previously charged off and expected to be charged off. Charge-offs of uncollectible amounts result in a reduction to the allowance and recoveries of previously charged off amounts result in an increase to the allowance.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">When developing an estimate of expected credit losses, we use both quantitative and qualitative methods in considering all available information relevant to assessing collectability. This may include internal information, external information, or a combination of both relating to past events, current conditions, and reasonable and supportable forecasts. Significant judgment is applied to the development and duration of reasonable and supportable forecasts used in our estimation of lifetime losses. We estimate expected credit losses over the duration of those forecasts and then revert, on a rational and systematic basis, to historical losses at each relevant loss component of the estimate. Expected losses for contractual terms extending beyond the reasonable and supportable forecast and reversion periods are based on those historical losses.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Management will consider and may qualitatively adjust for conditions, changes and trends in loan portfolios that may not be captured in modeled results. These adjustments are referred to as qualitative factors and represent management’s judgment of the imprecision and risks inherent in the processes and assumptions used in establishing the allowance for credit losses. Management’s judgment may involve an assessment of current and forward-looking conditions including but not limited to changes in lending policies and procedures, nature and volume of the portfolio, external factors, and uncertainty as it relates to economic, model or forecast risks, where not already captured in the modeled results.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Expected credit losses for collateral-dependent loans are based on the fair value of the underlying collateral. When we intend to liquidate the collateral, the fair value of the collateral is adjusted for expected costs to sell. A loan is deemed to be a collateral-dependent loan when (i) we determine foreclosure or repossession of the underlying collateral is probable, or (ii) foreclosure or repossession is not probable, but the borrower is experiencing financial difficulty and we expect repayment to be provided substantially through the operation or sale of the collateral. The allowance for a collateral-dependent loan reflects the difference between the loan’s amortized cost basis and the fair value (less selling costs, where applicable) of the loan's underlying collateral.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Our credit card and consumer banking loan portfolios consist of smaller-balance, homogeneous loans. The consumer banking loan portfolio is divided into two primary portfolio segments: auto loans and retail banking loans. The credit card and consumer banking loan portfolios are further divided by our business units into groups based on common risk characteristics, such as origination year, contract type, interest rate, borrower credit score and geography. The commercial banking loan portfolio is primarily composed of larger-balance, non-homogeneous loans. These loans are subject to reviews that result in internal risk ratings. In assessing the risk rating of a particular commercial banking loan, among the factors we consider are the financial condition of the borrower, geography, collateral performance, historical loss experience and industry-specific information that management believes is relevant in determining and measuring expected credit losses. Subjective assessment and interpretation are involved. Emphasizing one factor over another or considering additional factors could impact the risk rating assigned to that commercial banking loan.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For consumer banking and commercial banking loans, the contractual period typically does not include renewals or extensions because the renewals and extensions are generally not at the borrower’s exclusive option to exercise. Management has determined that the undrawn credit exposure that is associated with our credit card loans is unconditionally cancellable. For this reason, expected credit losses are measured based on the drawn balance at each quarterly measurement date, but not on the undrawn exposure. Because credit card loans do not have a defined contractual life, management estimates both the volume and application of payments to determine a contractual life of the drawn balance at the measurement date over which expected credit losses are developed for credit card loans.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">With the exception of credit card loans, we have made a policy election to not measure an allowance on accrued interest for loans held for investment because we reverse uncollectible accrued interest in a timely manner. See the “Delinquent and Nonperforming Loans” and “Charge-Offs - Loans” sections of this Note for information on what we consider timely. For credit card loans, we do not make this election, as we reserve for uncollectible accrued interest relating to credit card loans in the allowance.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance related to credit card and consumer banking loans assessed on a pooled basis is based on a modeled calculation, which is supplemented by management judgment as described above. Because of the homogeneous nature of our consumer loan portfolios, the allowance is based on the aggregated portfolio segment evaluations. The allowance is established through a process that begins with estimates of historical losses in each pool based upon various statistical analyses, with adjustments for current conditions and reasonable and supportable forecasts of conditions, which includes expected economic conditions. Loss forecast models are utilized to estimate expected credit losses and consider several portfolio indicators including, but not limited to, expected economic conditions, historical loss experience, account seasoning, the value of collateral underlying secured loans, estimated foreclosures or defaults based on observable trends, delinquencies, bankruptcy filings, unemployment, borrower credit scores and general business trends. Management believes these factors are relevant in estimating expected credit losses and also considers an evaluation of overall portfolio credit quality based on indicators such as changes in our credit evaluation, underwriting and collection management policies, the effect of other external factors such as competition and legal and regulatory requirements, general economic conditions and business trends, and uncertainties in forecasting and modeling techniques used in estimating our allowance.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance related to commercial banking loans assessed on a pooled basis is based on our historical loss experience for loans with similar risk characteristics and consideration of the current credit quality of the portfolio, which is supplemented by management judgment as described above. These are adjusted for current conditions, and reasonable and supportable forecasts of conditions likely to cause future losses which vary from historical levels. We apply internal risk ratings to commercial banking loans, which we use to assess credit quality and derive a total loss estimate based on an estimated probability of default (“default rate”) and loss given default (“loss severity”). Management may also apply judgment to adjust the loss factors derived, taking into consideration both quantitative and qualitative factors, including general economic conditions, industry-specific and geographic trends, portfolio concentrations, trends in internal credit quality indicators, and current and past underwriting standards that have occurred but are not yet reflected in the historical data underlying our loss estimates.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The allowance related to smaller-balance homogeneous credit card and consumer banking loans whose terms have been modified in a TDR is calculated on a pool basis using historical loss experience, adjusted for current conditions and reasonable and supportable forecasts of conditions likely to cause future losses which vary from historical levels for the respective class of assets. The allowance related to consumer banking loans that are assessed at a loan-level is determined based on key considerations that include the borrower’s overall financial condition, resources and payment history, prospects for support from financially responsible guarantors, and when applicable, the estimated realizable value of any collateral. The allowance related to commercial banking loans that are assessed at a loan-level is generally determined in accordance with our policy for estimating expected credit losses for collateral-dependent loans as described above.</span></div><div style="margin-bottom:9pt;margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Off-balance sheet credit exposures</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">In addition to the allowance, we also measure expected credit losses related to unfunded lending commitments that are not unconditionally cancellable in our Commercial Banking business. This reserve is measured using the same measurement objectives as the allowance for loans held for investment and is recorded within other liabilities on our consolidated balance sheets. These commitments are segregated by risk according to our internal risk rating scale, which we use to assess credit quality and derive an expected credit loss estimate. We assess these risk classifications, taking into consideration both quantitative and qualitative factors, including historical loss experience, adjusted for current conditions and reasonable and supportable forecasts of conditions likely to cause future losses which vary from historical levels, and utilization assumptions to estimate the reserve for unfunded lending commitments. Expected credit losses are not measured on unfunded lending commitments that are unconditionally cancellable, including all of our unfunded credit card and consumer banking lending commitments and certain of our unfunded commercial banking lending commitments.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Determining the appropriateness of the allowance and the reserve for unfunded lending commitments is complex and requires judgment by management about the effect of matters that are inherently uncertain. Subsequent evaluations of the loan portfolio, in light of the factors then prevailing, may result in significant changes in the reserve for unfunded lending commitments in future periods. See “Note 4—Allowance for Credit Losses and Reserve for Unfunded Lending Commitments” for additional information.</span></div><div style="margin-bottom:9pt;margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Significant Accounting Policies Prior to our Adoption of the CECL Standard</span></div><div style="margin-bottom:9pt;margin-top:9pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">Loans Held for Investment - Estimate of Incurred Loan and Lease Losses</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">In periods prior to 2020, the allowance represented management’s current estimate of incurred loan and lease losses inherent in our loans held for investment portfolio as of each balance sheet date. The provision for credit losses reflected credit losses we believed had been incurred and would eventually be recognized over time through charge-offs.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Management performed a quarterly analysis of our loan portfolio to determine if impairment had occurred and to assess the adequacy of the allowance based on historical and current trends as well as other factors affecting credit losses. We applied documented systematic methodologies to separately calculate the allowance for our credit card, consumer banking and commercial banking loan portfolios. Our allowance for loan and lease losses consisted of three components that were allocated to cover the estimated probable losses in each loan portfolio based on the results of our detailed review and loan impairment assessment process: (i) a component for loans collectively evaluated for impairment; (ii) an asset-specific component for individually impaired loans; and (iii) a component related to PCI loans that experienced significant decreases in expected cash flows subsequent to acquisition. Each of our allowance components was supplemented by an amount that represented management’s qualitative judgment of the imprecision and risks inherent in the processes and assumptions used in establishing the allowance.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">The component of the allowance related to credit card and consumer banking loans that we collectively evaluated for impairment was based on a statistical calculation. The component of the allowance for commercial banking loans that we collectively evaluated for impairment was based on our historical loss experience for loans with similar risk characteristics and consideration of the current credit quality of the portfolio. The asset-specific component of the allowance includes smaller-balance homogeneous credit card and consumer banking loans whose terms have been modified in a TDR and larger-balance nonperforming, non-homogeneous commercial banking loans. We generally measured the asset-specific component of the allowance based on the difference between the recorded investment of individually impaired loans and the present value of expected future cash flows. In addition to the allowance, we also estimated probable losses related to contractually binding unfunded lending commitments.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-style:italic;font-weight:400;line-height:120%">Loans Acquired - Credit Impaired</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">For PCI loans, we aggregated loans acquired in the same fiscal quarter into one or more pools if the loans have common risk characteristics. A pool is then accounted for as a single asset, with a single composite interest rate and an aggregate fair value and expected cash flows. </span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Subsequent to acquisition, decreases in expected cash flows resulting from credit deterioration subsequent to acquisition generally resulted in an impairment charge recognized in our provision for credit losses and an increase in the allowance for loan and lease losses. Significant increases in the cash flows expected to be collected would first reduce any previously recorded allowance for loan and lease losses. See “Note 3—Loans” for additional information.</span></div><div style="margin-bottom:9pt;margin-top:9pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We recorded charge-offs on PCI loans only if actual losses exceed estimated credit losses incorporated into the fair value recorded at acquisition. Further, PCI loans are not classified as delinquent or nonperforming.</span></div>
CY2020	cof	Loan Commitmentand Origination Feesand Discountsor Premiums Amortization Period LoanCommitmentandOriginationFeesandDiscountsorPremiumsAmortizationPeriod	P12M
CY2020	cof	Threshold Period Past Duefor Delinquency Statusof Financing Receivables ThresholdPeriodPastDueforDelinquencyStatusofFinancingReceivables	P30D
CY2020Q4	cof	Cof Customer Loyalty Program Liability Cof_CustomerLoyaltyProgramLiability	5400000000	USD
CY2019Q4	cof	Cof Customer Loyalty Program Liability Cof_CustomerLoyaltyProgramLiability	4700000000	USD
CY2020	us-gaap	Debt Securities Available For Sale Change In Present Value Interest Income DebtSecuritiesAvailableForSaleChangeInPresentValueInterestIncome	230000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	97569000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Allowance For Credit Loss DebtSecuritiesAvailableForSaleAllowanceForCreditLoss	1000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	97569000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	2997000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	120000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	100445000000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	77984000000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	1561000000	USD
CY2019Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	332000000	USD
CY2019Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	79213000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	9095000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	64000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	2059000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	55000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	11154000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	119000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	15882000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	120000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	12252000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	212000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	28134000000	USD
CY2019Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	332000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	320	security
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Fair Value AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsFairValue	632000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveFairValue	14150000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenFairValue	7096000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Fair Value AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenFairValue	78567000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Securities AvailableForSaleSecuritiesDebtSecurities	100445000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Next Rolling Twelve Months Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesNextRollingTwelveMonthsAmortizedCostBasis	628000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Two Through Five Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearTwoThroughFiveAmortizedCostBasis	14091000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling Year Six Through Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingYearSixThroughTenAmortizedCostBasis	6860000000	USD
CY2020Q4	us-gaap	Available For Sale Securities Debt Maturities Rolling After Year Ten Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesRollingAfterYearTenAmortizedCostBasis	75990000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Maturity Rolling Within One Year Weighted Average Yield DebtSecuritiesAvailableForSaleMaturityRollingWithinOneYearWeightedAverageYield	0.0143
CY2020	us-gaap	Number Of Reporting Units NumberOfReportingUnits	4	segment
CY2020Q4	us-gaap	Debt Securities Available For Sale Maturity Rolling After One Through Five Years Weighted Average Yield DebtSecuritiesAvailableForSaleMaturityRollingAfterOneThroughFiveYearsWeightedAverageYield	0.0074
CY2020Q4	us-gaap	Debt Securities Available For Sale Maturity Rolling After Five Through Ten Years Weighted Average Yield DebtSecuritiesAvailableForSaleMaturityRollingAfterFiveThroughTenYearsWeightedAverageYield	0.0176
CY2020Q4	us-gaap	Debt Securities Available For Sale Maturity Rolling After10 Years Weighted Average Yield DebtSecuritiesAvailableForSaleMaturityRollingAfter10YearsWeightedAverageYield	0.0220
CY2020Q4	cof	Debt Securities Available For Sale Weighted Average Yield DebtSecuritiesAvailableForSaleWeightedAverageYield	0.0196
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	25000000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	44000000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Gain DebtSecuritiesAvailableForSaleRealizedGain	13000000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedLossExcludingOtherThanTemporaryImpairment	0	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedLossExcludingOtherThanTemporaryImpairment	18000000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedLossExcludingOtherThanTemporaryImpairment	21000000	USD
CY2020	us-gaap	Debt Securities Available For Sale Realized Gain Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedGainLossExcludingOtherThanTemporaryImpairment	25000000	USD
CY2019	us-gaap	Debt Securities Available For Sale Realized Gain Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedGainLossExcludingOtherThanTemporaryImpairment	26000000	USD
CY2018	us-gaap	Debt Securities Available For Sale Realized Gain Loss Excluding Other Than Temporary Impairment DebtSecuritiesAvailableForSaleRealizedGainLossExcludingOtherThanTemporaryImpairment	-8000000	USD
CY2020	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	812000000	USD
CY2019	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	4780000000	USD
CY2018	us-gaap	Proceeds From Sale Of Available For Sale Securities Debt ProceedsFromSaleOfAvailableForSaleSecuritiesDebt	6399000000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	1000000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	1000000	USD
CY2020Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	1200000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	245060000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	6564000000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	251624000000	USD
CY2020Q4	cof	Financing Receivable Percent Current FinancingReceivablePercentCurrent	0.974
CY2020Q4	us-gaap	Financing Receivable Percent Past Due1 FinancingReceivablePercentPastDue1	0.026
CY2020Q4	cof	Financing Receivable Percentageof Total Loan FinancingReceivablePercentageofTotalLoan	1.000
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Current FinancingReceivableRecordedInvestmentCurrent	255736000000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	9947000000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	265809000000	USD
CY2019Q4	cof	Financing Receivable Percent Current FinancingReceivablePercentCurrent	0.962
CY2019Q4	us-gaap	Financing Receivable Percent Past Due1 FinancingReceivablePercentPastDue1	0.037
CY2019Q4	cof	Financing Receivable Percentageof Total Loan FinancingReceivablePercentageofTotalLoan	1.000
CY2020Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	1100000000	USD
CY2019Q4	us-gaap	Unamortized Loan Commitment And Origination Fees And Unamortized Discounts Or Premiums UnamortizedLoanCommitmentAndOriginationFeesAndUnamortizedDiscountsOrPremiums	1100000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	1302000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	995000000	USD
CY2020Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	449000000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	2407000000	USD
CY2019Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	983000000	USD
CY2020Q4	cof	Financing Receivable Percent90 Days Past Dueand Still Accruing FinancingReceivablePercent90DaysPastDueandStillAccruing	0.005
CY2020Q4	us-gaap	Financing Receivable Nonaccrual Percent Past Due1 FinancingReceivableNonaccrualPercentPastDue1	0.004
CY2020Q4	cof	Financing Receivable Nonaccrual No Allowance Percent Past Due FinancingReceivableNonaccrualNoAllowancePercentPastDue	0.002
CY2019Q4	cof	Financing Receivable Percent90 Days Past Dueand Still Accruing FinancingReceivablePercent90DaysPastDueandStillAccruing	0.009
CY2019Q4	us-gaap	Financing Receivable Nonaccrual Percent Past Due1 FinancingReceivableNonaccrualPercentPastDue1	0.004
CY2020	us-gaap	Financing Receivable Nonaccrual Interest Income FinancingReceivableNonaccrualInterestIncome	39000000	USD
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	2100000000	USD
CY2019Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	1700000000	USD
CY2020Q4	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	173000000	USD
CY2019Q4	us-gaap	Loans And Leases Receivable Impaired Commitment To Lend LoansAndLeasesReceivableImpairedCommitmentToLend	178000000	USD
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	1489000000	USD
CY2019	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	998000000	USD
CY2018	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	1053000000	USD
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	96905	contract
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	414000000	USD
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	122156	contract
CY2019	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	306000000	USD
CY2018	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	129120	contract
CY2018	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	437000000	USD
CY2020Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	2700000000	USD
CY2019Q4	us-gaap	Loans Receivable Held For Sale Net Not Part Of Disposal Group LoansReceivableHeldForSaleNetNotPartOfDisposalGroup	400000000	USD
CY2019Q4	us-gaap	Variable Interest Entity Entity Maximum Loss Exposure Amount VariableInterestEntityEntityMaximumLossExposureAmount	5413000000	USD
CY2020	cof	Uncollectible Portionof Billed Finance Chargesand Fees UncollectiblePortionofBilledFinanceChargesandFees	1100000000	USD
CY2019	cof	Uncollectible Portionof Billed Finance Chargesand Fees UncollectiblePortionofBilledFinanceChargesandFees	1400000000	USD
CY2018	cof	Uncollectible Portionof Billed Finance Chargesand Fees UncollectiblePortionofBilledFinanceChargesandFees	1300000000	USD
CY2020Q4	us-gaap	Variable Interest Entity Entity Maximum Loss Exposure Amount VariableInterestEntityEntityMaximumLossExposureAmount	5343000000	USD
CY2020	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	556000000	USD
CY2019	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	554000000	USD
CY2020	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	607000000	USD
CY2019	us-gaap	Affordable Housing Tax Credits And Other Tax Benefits Amount AffordableHousingTaxCreditsAndOtherTaxBenefitsAmount	610000000	USD
CY2020Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	4500000000	USD
CY2019Q4	us-gaap	Amortization Method Qualified Affordable Housing Project Investments AmortizationMethodQualifiedAffordableHousingProjectInvestments	4400000000	USD
CY2019Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	1500000000	USD
CY2020Q4	us-gaap	Qualified Affordable Housing Project Investments Commitment QualifiedAffordableHousingProjectInvestmentsCommitment	1500000000	USD
CY2020Q4	us-gaap	Goodwill Gross GoodwillGross	14653000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2020Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	396000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	306000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	90000000	USD
CY2020	us-gaap	Finite Lived Intangible Assets Remaining Amortization Period1 FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1	P7Y1M6D
CY2020Q4	cof	Intangible Assets Gross Including Goodwill IntangibleAssetsGrossIncludingGoodwill	15049000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	306000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	14743000000	USD
CY2020Q4	cof	Mortgage Servicing Assetat Amortized Cost Gross MortgageServicingAssetatAmortizedCostGross	542000000	USD
CY2020Q4	cof	Servicing Assetat Amortized Cost Accumulated Amortization ServicingAssetatAmortizedCostAccumulatedAmortization	175000000	USD
CY2020Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	367000000	USD
CY2019Q4	us-gaap	Goodwill Gross GoodwillGross	14653000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2019Q4	us-gaap	Intangible Assets Gross Excluding Goodwill IntangibleAssetsGrossExcludingGoodwill	2178000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	2004000000	USD
CY2019Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	174000000	USD
CY2019	us-gaap	Finite Lived Intangible Assets Remaining Amortization Period1 FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1	P5Y7M6D
CY2019Q4	cof	Intangible Assets Gross Including Goodwill IntangibleAssetsGrossIncludingGoodwill	16831000000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	2004000000	USD
CY2019Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	14827000000	USD
CY2019Q4	cof	Mortgage Servicing Assetat Amortized Cost Gross MortgageServicingAssetatAmortizedCostGross	555000000	USD
CY2019Q4	cof	Servicing Assetat Amortized Cost Accumulated Amortization ServicingAssetatAmortizedCostAccumulatedAmortization	255000000	USD
CY2019Q4	us-gaap	Servicing Asset At Amortized Value ServicingAssetAtAmortizedValue	300000000	USD
CY2020	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	69000000	USD
CY2019	us-gaap	Servicing Asset At Amortized Value Amortization1 ServicingAssetAtAmortizedValueAmortization1	70000000	USD
CY2019	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2020	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2018	us-gaap	Impairment Of Intangible Assets Indefinitelived Excluding Goodwill ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill	0	USD
CY2017Q4	us-gaap	Goodwill Goodwill	14533000000	USD
CY2018	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	33000000	USD
CY2018	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	17000000	USD
CY2018	us-gaap	Goodwill Other Increase Decrease GoodwillOtherIncreaseDecrease	-5000000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	14544000000	USD
CY2019	us-gaap	Goodwill Acquired During Period GoodwillAcquiredDuringPeriod	107000000	USD
CY2019	us-gaap	Goodwill Written Off Related To Sale Of Business Unit GoodwillWrittenOffRelatedToSaleOfBusinessUnit	1000000	USD
CY2019	us-gaap	Goodwill Other Increase Decrease GoodwillOtherIncreaseDecrease	3000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	14653000000	USD
CY2018	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	174000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	112000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	60000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Rolling Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextRollingTwelveMonths	20000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Two FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearTwo	16000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Three FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearThree	13000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Four FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFour	10000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling Year Five FiniteLivedIntangibleAssetsAmortizationExpenseRollingYearFive	9000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Rolling After Year Five FiniteLivedIntangibleAssetsAmortizationExpenseRollingAfterYearFive	14000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	82000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	8993000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	9188000000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	4706000000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	4810000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4287000000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	4378000000	USD
CY2020	us-gaap	Depreciation Nonproduction DepreciationNonproduction	809000000	USD
CY2019	us-gaap	Depreciation Nonproduction DepreciationNonproduction	741000000	USD
CY2018	us-gaap	Depreciation Nonproduction DepreciationNonproduction	728000000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1316000000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	1433000000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1688000000	USD
CY2019Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1756000000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y8M12D
CY2019Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P8Y10M24D
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.031
CY2019Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.033
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	315000000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	316000000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	43000000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	39000000	USD
CY2020	us-gaap	Operating Lease Expense OperatingLeaseExpense	358000000	USD
CY2019	us-gaap	Operating Lease Expense OperatingLeaseExpense	355000000	USD
CY2020	us-gaap	Sublease Income SubleaseIncome	26000000	USD
CY2019	us-gaap	Sublease Income SubleaseIncome	26000000	USD
CY2020	us-gaap	Lease Cost LeaseCost	332000000	USD
CY2019	us-gaap	Lease Cost LeaseCost	329000000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	325000000	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	328000000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	180000000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	112000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	296000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	272000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	250000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	216000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	180000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	721000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	1935000000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	247000000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	1688000000	USD
CY2020Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	69000000	USD
CY2019Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	96000000	USD
CY2020Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	75000000	USD
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P4Y4M24D
CY2019Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	103000000	USD
CY2019Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P5Y10M24D
CY2020	cof	Finance Lease Cost FinanceLeaseCost	24000000	USD
CY2019	cof	Finance Lease Cost FinanceLeaseCost	27000000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	31142000000	USD
CY2019Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	23488000000	USD
CY2020Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	274300000000	USD
CY2019Q4	us-gaap	Interest Bearing Deposit Liabilities InterestBearingDepositLiabilities	239209000000	USD
CY2020Q4	us-gaap	Deposits Deposits	305442000000	USD
CY2019Q4	us-gaap	Deposits Deposits	262697000000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	668000000	USD
CY2019Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	7314000000	USD
CY2020Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	39871000000	USD
CY2019Q4	us-gaap	Long Term Debt And Capital Lease Obligations LongTermDebtAndCapitalLeaseObligations	48383000000	USD
CY2020Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	40539000000	USD
CY2019Q4	us-gaap	Debt And Capital Lease Obligations DebtAndCapitalLeaseObligations	55697000000	USD
CY2020Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	4200000000	USD
CY2019Q4	us-gaap	Time Deposits At Or Above Fdic Insurance Limit TimeDepositsAtOrAboveFDICInsuranceLimit	6500000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates Next Twelve Months TimeDepositMaturitiesWithContractualMaturityDatesNextTwelveMonths	21381000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates Year Two TimeDepositMaturitiesWithContractualMaturityDatesYearTwo	6447000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates Year Three TimeDepositMaturitiesWithContractualMaturityDatesYearThree	2212000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates Year Four TimeDepositMaturitiesWithContractualMaturityDatesYearFour	2196000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates Year Five TimeDepositMaturitiesWithContractualMaturityDatesYearFive	385000000	USD
CY2020Q4	cof	Time Deposit Maturities With Contractual Maturity Dates After Year Five TimeDepositMaturitiesWithContractualMaturityDatesAfterYearFive	126000000	USD
CY2020Q4	cof	Time Deposits With Contractual Maturity Dates TimeDepositsWithContractualMaturityDates	32747000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Dates Debt Longtermand Shortterm Combined Amount Maturities Next Twelve Months TimeDepositsMaturitiesWithContractualMaturityDatesDebtLongtermandShorttermCombinedAmountMaturitiesNextTwelveMonths	28278000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Long Term Debt Maturities Year Two TimeDepositsMaturitiesWithContractualMaturityDatesandLongTermDebtMaturitiesYearTwo	14590000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Long Term Debt Maturities Year Three TimeDepositsMaturitiesWithContractualMaturityDatesandLongTermDebtMaturitiesYearThree	9349000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Long Term Debt Maturities Year Four TimeDepositsMaturitiesWithContractualMaturityDatesandLongTermDebtMaturitiesYearFour	8431000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Long Term Debt Maturities Year Five TimeDepositsMaturitiesWithContractualMaturityDatesandLongTermDebtMaturitiesYearFive	4165000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Long Term Debt Maturities After Year Five TimeDepositsMaturitiesWithContractualMaturityDatesandLongTermDebtMaturitiesAfterYearFive	8473000000	USD
CY2020Q4	cof	Time Deposits Maturities With Contractual Maturity Datesand Debt Longtermand Shortterm Combined Amount TimeDepositsMaturitiesWithContractualMaturityDatesandDebtLongtermandShorttermCombinedAmount	73286000000	USD
CY2020Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	232327000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	3415000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	1518000000	USD
CY2019Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	255546000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	1729000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	1197000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	1148000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	739000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	633000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	523000000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	2267000000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	779000000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	1096000000	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	674000000	USD
CY2020Q4	cof	Derivative Credit Risk Valuation Adjustment Derivative Assets Liabilities DerivativeCreditRiskValuationAdjustmentDerivativeAssetsLiabilities	31000000	USD
CY2019Q4	cof	Derivative Credit Risk Valuation Adjustment Derivative Assets Liabilities DerivativeCreditRiskValuationAdjustmentDerivativeAssetsLiabilities	12000000	USD
CY2020Q4	us-gaap	Hedged Asset Discontinued Fair Value Hedge Cumulative Increase Decrease HedgedAssetDiscontinuedFairValueHedgeCumulativeIncreaseDecrease	200000000	USD
CY2019Q4	cof	Amortized Costof Closed Prepayment Assets AmortizedCostofClosedPrepaymentAssets	5900000000	USD
CY2019Q4	cof	Amortized Cost Of Closed Prepayable Assets Designated In Fair Value Hedges AmortizedCostOfClosedPrepayableAssetsDesignatedInFairValueHedges	3100000000	USD
CY2019Q4	cof	Hedged Lola Assets Cumulative Basis Adjustment HedgedLOLAAssetsCumulativeBasisAdjustment	75000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	3415000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	383000000	USD
CY2020Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	765000000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	2267000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Of Collateral DerivativeAssetFairValueOfCollateral	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	2267000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Asset Including Not Subject To Master Netting Arrangement DerivativeAssetFairValueGrossAssetIncludingNotSubjectToMasterNettingArrangement	1729000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Liability DerivativeAssetFairValueGrossLiability	347000000	USD
CY2019Q4	us-gaap	Derivative Asset Collateral Obligation To Return Cash Offset DerivativeAssetCollateralObligationToReturnCashOffset	286000000	USD
CY2019Q4	us-gaap	Derivative Assets DerivativeAssets	1096000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Of Collateral DerivativeAssetFairValueOfCollateral	0	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	1096000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	1518000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	383000000	USD
CY2020Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	356000000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	779000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Of Collateral DerivativeLiabilityFairValueOfCollateral	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	779000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Gross SecuritiesSoldUnderAgreementsToRepurchaseGross	668000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Asset SecuritiesSoldUnderAgreementsToRepurchaseAsset	0	USD
CY2020Q4	cof	Repurchase Agreement Collateral Right To Reclaim Cash Offset RepurchaseAgreementCollateralRightToReclaimCashOffset	0	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	668000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Collateral Right To Reclaim Securities SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities	668000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Amount Offset Against Collateral SecuritiesSoldUnderAgreementsToRepurchaseAmountOffsetAgainstCollateral	0	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Liability Including Not Subject To Master Netting Arrangement DerivativeLiabilityFairValueGrossLiabilityIncludingNotSubjectToMasterNettingArrangement	1197000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Asset DerivativeLiabilityFairValueGrossAsset	347000000	USD
CY2019Q4	us-gaap	Derivative Liability Collateral Right To Reclaim Cash Offset DerivativeLiabilityCollateralRightToReclaimCashOffset	176000000	USD
CY2019Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	674000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Of Collateral DerivativeLiabilityFairValueOfCollateral	0	USD
CY2019Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	674000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase Gross SecuritiesSoldUnderAgreementsToRepurchaseGross	314000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase Asset SecuritiesSoldUnderAgreementsToRepurchaseAsset	0	USD
CY2019Q4	cof	Repurchase Agreement Collateral Right To Reclaim Cash Offset RepurchaseAgreementCollateralRightToReclaimCashOffset	0	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	314000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase Collateral Right To Reclaim Securities SecuritiesSoldUnderAgreementsToRepurchaseCollateralRightToReclaimSecurities	314000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase Amount Offset Against Collateral SecuritiesSoldUnderAgreementsToRepurchaseAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	862000000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	347000000	USD
CY2019Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	1000000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	1000000	USD
CY2020Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	1500000000	USD
CY2019Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	954000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase Fair Value Of Collateral SecuritiesSoldUnderAgreementsToRepurchaseFairValueOfCollateral	682000000	USD
CY2019Q4	us-gaap	Securities Sold Under Agreements To Repurchase Fair Value Of Collateral SecuritiesSoldUnderAgreementsToRepurchaseFairValueOfCollateral	320000000	USD
CY2020	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	1877000000	USD
CY2020	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	24074000000	USD
CY2020	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	82000000	USD
CY2020	us-gaap	Interest Expense Deposits InterestExpenseDeposits	2165000000	USD
CY2020	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	232000000	USD
CY2020	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	679000000	USD
CY2020	us-gaap	Noninterest Income Other NoninterestIncomeOther	1325000000	USD
CY2019	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	2411000000	USD
CY2019	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	25862000000	USD
CY2019	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	240000000	USD
CY2019	us-gaap	Interest Expense Deposits InterestExpenseDeposits	3420000000	USD
CY2019	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	523000000	USD
CY2019	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	1159000000	USD
CY2019	us-gaap	Noninterest Income Other NoninterestIncomeOther	718000000	USD
CY2018	us-gaap	Interest And Dividend Income Securities InterestAndDividendIncomeSecurities	2211000000	USD
CY2018	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	24728000000	USD
CY2018	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	237000000	USD
CY2018	us-gaap	Interest Expense Deposits InterestExpenseDeposits	2598000000	USD
CY2018	cof	Interest Expense Secured Debt InterestExpenseSecuredDebt	496000000	USD
CY2018	cof	Interest Expense Unsecured Debt InterestExpenseUnsecuredDebt	1125000000	USD
CY2018	us-gaap	Noninterest Income Other NoninterestIncomeOther	1002000000	USD
CY2020	cof	Amortizationofbasisadjustment Amortizationofbasisadjustment	12000000	USD
CY2019	cof	Amortizationofbasisadjustment Amortizationofbasisadjustment	171000000	USD
CY2018	cof	Amortizationofbasisadjustment Amortizationofbasisadjustment	75000000	USD
CY2020	us-gaap	Cash Flow Hedge Gain Loss To Be Reclassified Within Twelve Months CashFlowHedgeGainLossToBeReclassifiedWithinTwelveMonths	652000000	USD
CY2020	us-gaap	Maximum Length Of Time Hedged In Cash Flow Hedge1 MaximumLengthOfTimeHedgedInCashFlowHedge1	P6Y
CY2020Q4	us-gaap	Preferred Stock Including Additional Paid In Capital Net Of Discount PreferredStockIncludingAdditionalPaidInCapitalNetOfDiscount	4847000000	USD
CY2019Q4	us-gaap	Preferred Stock Including Additional Paid In Capital Net Of Discount PreferredStockIncludingAdditionalPaidInCapitalNetOfDiscount	4853000000	USD
CY2019Q4	cof	Other Comprehensive Income Loss Transfer Of Securities Held To Maturity Net Of Tax OtherComprehensiveIncomeLossTransferOfSecuritiesHeldToMaturityNetOfTax	888000000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	1659000000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	400000000	USD
CY2020	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	1259000000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	855000000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	205000000	USD
CY2019	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	650000000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentBeforeTaxPortionAttributableToParent	-605000000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesTaxPortionAttributableToParent	-146000000	USD
CY2018	us-gaap	Other Comprehensive Income Availableforsale Securities Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeAvailableforsaleSecuritiesAdjustmentNetOfTaxPortionAttributableToParent	-459000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	1329000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	321000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	1008000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	1016000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	244000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	772000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification And Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAndTax	-98000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-24000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-74000000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	56000000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	-20000000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	76000000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	54000000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	-16000000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	70000000	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-39000000	USD
CY2020	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentBeforeTaxPortionAttributableToParent	0	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentBeforeTaxPortionAttributableToParent	9000000	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Translation Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTranslationAdjustmentTaxPortionAttributableToParent	48000000	USD
CY2020	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentTaxPortionAttributableToParent	0	USD
CY2020	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	0	USD
CY2019	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentBeforeTaxPortionAttributableToParent	36000000	USD
CY2019	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentTaxPortionAttributableToParent	10000000	USD
CY2019	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	26000000	USD
CY2018	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentBeforeTaxPortionAttributableToParent	588000000	USD
CY2018	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentTaxPortionAttributableToParent	141000000	USD
CY2018	cof	Other Comprehensive Income Loss Securities Transferred To Held To Maturity Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossSecuritiesTransferredToHeldToMaturityAdjustmentNetOfTaxPortionAttributableToParent	447000000	USD
CY2020	cof	Other Comprehensive Income Loss Before Tax Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxAttributableToParent	4000000	USD
CY2020	cof	Other Comprehensive Income Loss Other Tax Attributable To Parent OtherComprehensiveIncomeLossOtherTaxAttributableToParent	1000000	USD
CY2020	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	3000000	USD
CY2018	cof	Other Comprehensive Income Loss Other Tax Attributable To Parent OtherComprehensiveIncomeLossOtherTaxAttributableToParent	-4000000	USD
CY2019	cof	Other Comprehensive Income Loss Before Tax Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxAttributableToParent	17000000	USD
CY2019	cof	Other Comprehensive Income Loss Other Tax Attributable To Parent OtherComprehensiveIncomeLossOtherTaxAttributableToParent	4000000	USD
CY2019	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	13000000	USD
CY2018	cof	Other Comprehensive Income Loss Before Tax Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxAttributableToParent	-15000000	USD
CY2018	cof	Other Comprehensive Income Other Net Of Tax Attributable To Parent OtherComprehensiveIncomeOtherNetOfTaxAttributableToParent	-11000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	3048000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	702000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	2346000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	1978000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	447000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	1531000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Before Tax Portion Attributable To Parent OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	-121000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	15000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-136000000	USD
CY2020Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	40736000000	USD
CY2020Q4	cof	Common Equity Tier One Capitalto Risk Weighted Assets CommonEquityTierOneCapitaltoRiskWeightedAssets	0.137
CY2020Q4	cof	Tier One Common Capital Requiredfor Capital Adequacyto Risk Weighted Assets TierOneCommonCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.045
CY2019Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	38162000000	USD
CY2019Q4	cof	Common Equity Tier One Capitalto Risk Weighted Assets CommonEquityTierOneCapitaltoRiskWeightedAssets	0.122
CY2019Q4	cof	Tier One Common Capital Requiredfor Capital Adequacyto Risk Weighted Assets TierOneCommonCapitalRequiredforCapitalAdequacytoRiskWeightedAssets	0.045
CY2020Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	45583000000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.153
CY2020Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.060
CY2020Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.060
CY2019Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	43015000000	USD
CY2019Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.137
CY2019Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.060
CY2019Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.060
CY2020Q4	us-gaap	Capital Capital	52788000000	USD
CY2019Q4	cof	Tieronecapitalunder Basel Ii Istandardizedapproach TieronecapitalunderBaselIIIstandardizedapproach	43015000000	USD
CY2019Q4	us-gaap	Supplementary Leverage Ratio SupplementaryLeverageRatio	0.099
CY2020Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.177
CY2020Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.080
CY2020Q4	us-gaap	Capital Required To Be Well Capitalized To Risk Weighted Assets CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.100
CY2019Q4	us-gaap	Capital Capital	50348000000	USD
CY2019Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.161
CY2019Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.080
CY2019Q4	us-gaap	Capital Required To Be Well Capitalized To Risk Weighted Assets CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.100
CY2020Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	45583000000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.112
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.040
CY2019Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	43015000000	USD
CY2019Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.117
CY2019Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.040
CY2020Q4	cof	Tieronecapitalunder Basel Ii Istandardizedapproach TieronecapitalunderBaselIIIstandardizedapproach	45583000000	USD
CY2020Q4	us-gaap	Supplementary Leverage Ratio SupplementaryLeverageRatio	0.107
CY2020Q4	cof	Minimum Capital Adequacyfor Supplementary Leverage Ratio MinimumCapitalAdequacyforSupplementaryLeverageRatio	0.030
CY2019Q4	cof	Minimum Capital Adequacyfor Supplementary Leverage Ratio MinimumCapitalAdequacyforSupplementaryLeverageRatio	0.030
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	2717000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	5533000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6025000000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-3000000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	13000000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-10000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	2714000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	5546000000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	6015000000	USD
CY2020	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	20000000	USD
CY2019	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	41000000	USD
CY2018	cof	Participating Securities Distributedand Undistributed Earnings Lossexcluding Preferred Stock Dividends Basic ParticipatingSecuritiesDistributedandUndistributedEarningsLossexcludingPreferredStockDividendsBasic	40000000	USD
CY2020	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	280000000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	239000000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	170000000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	50000000	USD
CY2019	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	282000000	USD
CY2018	us-gaap	Preferred Stock Dividends Income Statement Impact PreferredStockDividendsIncomeStatementImpact	265000000	USD
CY2020	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	39000000	USD
CY2019	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	31000000	USD
CY2018	cof	Issuance Cost For Preferred Stock Redeemed IssuanceCostForPreferredStockRedeemed	0	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	2375000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	5192000000	USD
CY2018	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	5710000000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	457800000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	467600000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	479900000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	600000	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1300000	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	1600000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Contingently Issuable Shares IncrementalCommonSharesAttributableToContingentlyIssuableShares	500000	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Contingently Issuable Shares IncrementalCommonSharesAttributableToContingentlyIssuableShares	1000000.0	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Contingently Issuable Shares IncrementalCommonSharesAttributableToContingentlyIssuableShares	1100000	shares
CY2020	us-gaap	Incremental Common Shares Attributable To Call Options And Warrants IncrementalCommonSharesAttributableToCallOptionsAndWarrants	0.0	shares
CY2019	us-gaap	Incremental Common Shares Attributable To Call Options And Warrants IncrementalCommonSharesAttributableToCallOptionsAndWarrants	0.0	shares
CY2018	us-gaap	Incremental Common Shares Attributable To Call Options And Warrants IncrementalCommonSharesAttributableToCallOptionsAndWarrants	500000	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1100000	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	2300000	shares
CY2018	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	3200000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	458900000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	469900000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	483100000	shares
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	5.20
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	11.07
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	11.92
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.01
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.03
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	-0.02
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	43000000	USD
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.19
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.10
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	11.90
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	5.19
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	11.02
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	11.84
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.01
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.03
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	-0.02
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.18
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.05
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	11.82
CY2020Q4	cof	Numberof Active Stock Plans NumberofActiveStockPlans	1	plan
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	55000000	shares
CY2020Q4	us-gaap	Common Stock Capital Shares Reserved For Future Issuance CommonStockCapitalSharesReservedForFutureIssuance	7000000	shares
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	203000000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	34000000	USD
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	350000000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	316000000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	291000000	USD
CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	8000000	USD
CY2019	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	10000000	USD
CY2018	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	12000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	4000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	18000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax	-17000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	280000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	260000000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	1676000000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	1207000000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	210000000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	370000000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	301000000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	234000000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	67000000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	129000000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	135000000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	2113000000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	1637000000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	579000000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-1357000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	702000000	USD
CY2019	cof	Us Gaap Other Comprehensive Income Loss Tax Including Ht Mportfolio Transfer UsGaap_OtherComprehensiveIncomeLossTaxIncludingHTMportfolioTransfer	727000000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	15000000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.035
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.031
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.032
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.032
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.016
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.022
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.114
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.052
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.040
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.017
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.008
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Foreign Income Tax Rate Differential EffectiveIncomeTaxRateReconciliationForeignIncomeTaxRateDifferential	-0.007
CY2020	cof	Effective Income Tax Rate Reconciliation Irs Method Changes Percent EffectiveIncomeTaxRateReconciliationIRSMethodChangesPercent	0.000
CY2019	cof	Effective Income Tax Rate Reconciliation Irs Method Changes Percent EffectiveIncomeTaxRateReconciliationIRSMethodChangesPercent	0.000
CY2018	cof	Effective Income Tax Rate Reconciliation Irs Method Changes Percent EffectiveIncomeTaxRateReconciliationIRSMethodChangesPercent	-0.039
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.023
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	-0.003
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Deferred Tax Assets Valuation Allowance EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance	0.003
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.017
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.001
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.004
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.152
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.195
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.177
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	3649000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	1729000000	USD
CY2020Q4	cof	Deferred Tax Assets Rewards Programs DeferredTaxAssetsRewardsPrograms	711000000	USD
CY2019Q4	cof	Deferred Tax Assets Rewards Programs DeferredTaxAssetsRewardsPrograms	579000000	USD
CY2020Q4	cof	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	396000000	USD
CY2019Q4	cof	Deferred Tax Assets Lease Liabilities DeferredTaxAssetsLeaseLiabilities	407000000	USD
CY2020Q4	cof	Deferred Tax Assets Operating Loss Carryforwardsand Tax Credit Carryforward DeferredTaxAssetsOperatingLossCarryforwardsandTaxCreditCarryforward	314000000	USD
CY2019Q4	cof	Deferred Tax Assets Operating Loss Carryforwardsand Tax Credit Carryforward DeferredTaxAssetsOperatingLossCarryforwardsandTaxCreditCarryforward	284000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	306000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Compensation DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeCompensation	301000000	USD
CY2020Q4	cof	Deferred Tax Assets Partnership Investments DeferredTaxAssetsPartnershipInvestments	237000000	USD
CY2019Q4	cof	Deferred Tax Assets Partnership Investments DeferredTaxAssetsPartnershipInvestments	202000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	117000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Deferred Income DeferredTaxAssetsDeferredIncome	95000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	116000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Goodwill And Intangible Assets DeferredTaxAssetsGoodwillAndIntangibleAssets	161000000	USD
CY2020Q4	cof	Deferred Tax Assets Securityand Loan Valuations DeferredTaxAssetsSecurityandLoanValuations	42000000	USD
CY2019Q4	cof	Deferred Tax Assets Securityand Loan Valuations DeferredTaxAssetsSecurityandLoanValuations	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	143000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	142000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	6031000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	3900000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	296000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	223000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	5735000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	3677000000	USD
CY2020Q4	cof	Deferred Tax Liabilities Securityand Loan Valuations DeferredTaxLiabilitiesSecurityandLoanValuations	805000000	USD
CY2019Q4	cof	Deferred Tax Liabilities Securityand Loan Valuations DeferredTaxLiabilitiesSecurityandLoanValuations	234000000	USD
CY2020Q4	cof	Deferred Tax Liabilities Original Issue Discount DeferredTaxLiabilitiesOriginalIssueDiscount	481000000	USD
CY2019Q4	cof	Deferred Tax Liabilities Original Issue Discount DeferredTaxLiabilitiesOriginalIssueDiscount	600000000	USD
CY2020Q4	cof	Deferred Tax Liabilities Derivative Instruments DeferredTaxLiabilitiesDerivativeInstruments	387000000	USD
CY2019Q4	cof	Deferred Tax Liabilities Derivative Instruments DeferredTaxLiabilitiesDerivativeInstruments	93000000	USD
CY2020Q4	cof	Deferred Tax Liabilities Rightof Use Assets DeferredTaxLiabilitiesRightofUseAssets	342000000	USD
CY2019Q4	cof	Deferred Tax Liabilities Rightof Use Assets DeferredTaxLiabilitiesRightofUseAssets	393000000	USD
CY2020Q4	cof	Deferred Taxliabilities Partnership Investments DeferredTaxliabilitiesPartnershipInvestments	142000000	USD
CY2019Q4	cof	Deferred Taxliabilities Partnership Investments DeferredTaxliabilitiesPartnershipInvestments	147000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	73000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	55000000	USD
CY2020Q4	cof	Deferredtaxliabilitiesloanfeesandexpenses Deferredtaxliabilitiesloanfeesandexpenses	36000000	USD
CY2019Q4	cof	Deferredtaxliabilitiesloanfeesandexpenses Deferredtaxliabilitiesloanfeesandexpenses	100000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	0	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	189000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	143000000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	146000000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	2409000000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	1957000000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3737000000	USD
CY2020	cof	Noninterest Income Excluding Revenuefrom Contractwith Customer NoninterestIncomeExcludingRevenuefromContractwithCustomer	1873000000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	5610000000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3820000000	USD
CY2019	cof	Noninterest Income Excluding Revenuefrom Contractwith Customer NoninterestIncomeExcludingRevenuefromContractwithCustomer	1433000000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	5253000000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	3431000000	USD
CY2018	cof	Noninterest Income Excluding Revenuefrom Contractwith Customer NoninterestIncomeExcludingRevenuefromContractwithCustomer	1770000000	USD
CY2018	us-gaap	Noninterest Income NoninterestIncome	5201000000	USD
CY2020Q4	cof	Letterof Credit Issued Contractual Amountand Unused Commitmentto Extend Credit LetterofCreditIssuedContractualAmountandUnusedCommitmenttoExtendCredit	386732000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	3326000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	1720000000	USD
CY2020	us-gaap	Valuation Allowance Deferred Tax Asset Change In Amount ValuationAllowanceDeferredTaxAssetChangeInAmount	73000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	296000000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	223000000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	16000000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	4000000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	6000000	USD
CY2020Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	1600000000	USD
CY2020Q4	us-gaap	Deferred Tax Liability Not Recognized Amount Of Unrecognized Deferred Tax Liability Bad Debt Reserve For Tax Purposes Of Qualified Lender DeferredTaxLiabilityNotRecognizedAmountOfUnrecognizedDeferredTaxLiabilityBadDebtReserveForTaxPurposesOfQualifiedLender	69000000	USD
CY2020Q4	us-gaap	Bad Debt Reserve For Tax Purposes Of Qualified Lender BadDebtReserveForTaxPurposesOfQualifiedLender	287000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	1148000000	USD
CY2020Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	1148000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	739000000	USD
CY2020Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	739000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	633000000	USD
CY2019Q4	us-gaap	Derivative Asset Fair Value Gross Liability And Obligation To Return Cash Offset DerivativeAssetFairValueGrossLiabilityAndObligationToReturnCashOffset	633000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	523000000	USD
CY2019Q4	us-gaap	Derivative Liability Fair Value Gross Asset And Right To Reclaim Cash Offset DerivativeLiabilityFairValueGrossAssetAndRightToReclaimCashOffset	523000000	USD
CY2020Q4	cof	Derivative Credit Risk Valuation Adjustment Derivative Assets Liabilities DerivativeCreditRiskValuationAdjustmentDerivativeAssetsLiabilities	31000000	USD
CY2019Q4	cof	Derivative Credit Risk Valuation Adjustment Derivative Assets Liabilities DerivativeCreditRiskValuationAdjustmentDerivativeAssetsLiabilities	12000000	USD
CY2020Q1	cof	Fair Value Rmbs Cumulative Effectsfromthe Adoptionofthe Cecl Standard FairValueRMBSCumulativeEffectsfromtheAdoptionoftheCECLStandard	4000000	USD
CY2020	us-gaap	Number Of Operating Segments NumberOfOperatingSegments	3	segment
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	22913000000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	5610000000	USD
CY2020	us-gaap	Revenues Revenues	28523000000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	10264000000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	15056000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	3203000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	486000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	2717000000	USD
CY2020Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	251624000000	USD
CY2020Q4	us-gaap	Deposits Deposits	305442000000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	23340000000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	5253000000	USD
CY2019	us-gaap	Revenues Revenues	28593000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	6236000000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	15483000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	6874000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1341000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	5533000000	USD
CY2019Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	265809000000	USD
CY2019Q4	us-gaap	Deposits Deposits	262697000000	USD
CY2018	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	22875000000	USD
CY2018	us-gaap	Noninterest Income NoninterestIncome	5201000000	USD
CY2018	us-gaap	Revenues Revenues	28076000000	USD
CY2018	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	5856000000	USD
CY2018	us-gaap	Noninterest Expense NoninterestExpense	14902000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	7318000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1293000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	6025000000	USD
CY2018Q4	us-gaap	Notes Receivable Gross NotesReceivableGross	245899000000	USD
CY2018Q4	us-gaap	Deposits Deposits	249764000000	USD
CY2020	cof	Uncollectible Portionof Billed Finance Chargesand Fees UncollectiblePortionofBilledFinanceChargesandFees	1100000000	USD
CY2019Q4	cof	Letterof Credit Issued Contractual Amountand Unused Commitmentto Extend Credit LetterofCreditIssuedContractualAmountandUnusedCommitmenttoExtendCredit	401474000000	USD
CY2020Q4	cof	Off Balance Sheet Lending Commitment Carrying Value OffBalanceSheetLendingCommitmentCarryingValue	176000000	USD
CY2019Q4	cof	Off Balance Sheet Lending Commitment Carrying Value OffBalanceSheetLendingCommitmentCarryingValue	137000000	USD
CY2020Q4	us-gaap	Loss Contingency Estimate Of Possible Loss LossContingencyEstimateOfPossibleLoss	200000000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-222000000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	620000000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-266000000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-45000000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	115000000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-4000000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-29000000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-21000000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-1627000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-296000000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	714000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	486000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1341000000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	1293000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	293000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	215000000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	382000000	USD

Files In Submission

Name	View Source	Status
0000927628-21-000094-index-headers.html	Edgar Link	pending
0000927628-21-000094-index.html	Edgar Link	pending
0000927628-21-000094.txt	Edgar Link	pending
0000927628-21-000094-xbrl.zip	Edgar Link	pending
cof-12312020x10kxex10225.htm	Edgar Link	pending
cof-12312020x10kxex10226.htm	Edgar Link	pending
cof-12312020x10kxex10227.htm	Edgar Link	pending
cof-12312020x10kxex21.htm	Edgar Link	pending
cof-12312020x10kxex23.htm	Edgar Link	pending
cof-12312020x10kxex311.htm	Edgar Link	pending
cof-12312020x10kxex312.htm	Edgar Link	pending
cof-12312020x10kxex321.htm	Edgar Link	pending
cof-12312020x10kxex322.htm	Edgar Link	pending
cof-12312020x10kxex43.htm	Edgar Link	pending
cof-20201231.htm	Edgar Link	pending
cof-20201231.xsd	Edgar Link	pending
cof-20201231_cal.xml	Edgar Link	unprocessable
cof-20201231_def.xml	Edgar Link	unprocessable
cof-20201231_g1.jpg	Edgar Link	pending
cof-20201231_htm.xml	Edgar Link	completed
cof-20201231_lab.xml	Edgar Link	unprocessable
cof-20201231_pre.xml	Edgar Link	unprocessable
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
R1.htm	Edgar Link	pending
R10.htm	Edgar Link	pending
R100.htm	Edgar Link	pending
R101.htm	Edgar Link	pending
R102.htm	Edgar Link	pending
R103.htm	Edgar Link	pending
R104.htm	Edgar Link	pending
R105.htm	Edgar Link	pending
R106.htm	Edgar Link	pending
R107.htm	Edgar Link	pending
R108.htm	Edgar Link	pending
R109.htm	Edgar Link	pending
R11.htm	Edgar Link	pending
R110.htm	Edgar Link	pending
R111.htm	Edgar Link	pending
R112.htm	Edgar Link	pending
R113.htm	Edgar Link	pending
R114.htm	Edgar Link	pending
R115.htm	Edgar Link	pending
R116.htm	Edgar Link	pending
R117.htm	Edgar Link	pending
R118.htm	Edgar Link	pending
R119.htm	Edgar Link	pending
R12.htm	Edgar Link	pending
R120.htm	Edgar Link	pending
R121.htm	Edgar Link	pending
R122.htm	Edgar Link	pending
R123.htm	Edgar Link	pending
R124.htm	Edgar Link	pending
R125.htm	Edgar Link	pending
R126.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R17.htm	Edgar Link	pending
R18.htm	Edgar Link	pending
R19.htm	Edgar Link	pending
R2.htm	Edgar Link	pending
R20.htm	Edgar Link	pending
R21.htm	Edgar Link	pending
R22.htm	Edgar Link	pending
R23.htm	Edgar Link	pending
R24.htm	Edgar Link	pending
R25.htm	Edgar Link	pending
R26.htm	Edgar Link	pending
R27.htm	Edgar Link	pending
R28.htm	Edgar Link	pending
R29.htm	Edgar Link	pending
R3.htm	Edgar Link	pending
R30.htm	Edgar Link	pending
R31.htm	Edgar Link	pending
R32.htm	Edgar Link	pending
R33.htm	Edgar Link	pending
R34.htm	Edgar Link	pending
R35.htm	Edgar Link	pending
R36.htm	Edgar Link	pending
R37.htm	Edgar Link	pending
R38.htm	Edgar Link	pending
R39.htm	Edgar Link	pending
R4.htm	Edgar Link	pending
R40.htm	Edgar Link	pending
R41.htm	Edgar Link	pending
R42.htm	Edgar Link	pending
R43.htm	Edgar Link	pending
R44.htm	Edgar Link	pending
R45.htm	Edgar Link	pending
R46.htm	Edgar Link	pending
R47.htm	Edgar Link	pending
R48.htm	Edgar Link	pending
R49.htm	Edgar Link	pending
R5.htm	Edgar Link	pending
R50.htm	Edgar Link	pending
R51.htm	Edgar Link	pending
R52.htm	Edgar Link	pending
R53.htm	Edgar Link	pending
R54.htm	Edgar Link	pending
R55.htm	Edgar Link	pending
R56.htm	Edgar Link	pending
R57.htm	Edgar Link	pending
R58.htm	Edgar Link	pending
R59.htm	Edgar Link	pending
R6.htm	Edgar Link	pending
R60.htm	Edgar Link	pending
R61.htm	Edgar Link	pending
R62.htm	Edgar Link	pending
R63.htm	Edgar Link	pending
R64.htm	Edgar Link	pending
R65.htm	Edgar Link	pending
R66.htm	Edgar Link	pending
R67.htm	Edgar Link	pending
R68.htm	Edgar Link	pending
R69.htm	Edgar Link	pending
R7.htm	Edgar Link	pending
R70.htm	Edgar Link	pending
R71.htm	Edgar Link	pending
R72.htm	Edgar Link	pending
R73.htm	Edgar Link	pending
R74.htm	Edgar Link	pending
R75.htm	Edgar Link	pending
R76.htm	Edgar Link	pending
R77.htm	Edgar Link	pending
R78.htm	Edgar Link	pending
R79.htm	Edgar Link	pending
R8.htm	Edgar Link	pending
R80.htm	Edgar Link	pending
R81.htm	Edgar Link	pending
R82.htm	Edgar Link	pending
R83.htm	Edgar Link	pending
R84.htm	Edgar Link	pending
R85.htm	Edgar Link	pending
R86.htm	Edgar Link	pending
R87.htm	Edgar Link	pending
R88.htm	Edgar Link	pending
R89.htm	Edgar Link	pending
R9.htm	Edgar Link	pending
R90.htm	Edgar Link	pending
R91.htm	Edgar Link	pending
R92.htm	Edgar Link	pending
R93.htm	Edgar Link	pending
R94.htm	Edgar Link	pending
R95.htm	Edgar Link	pending
R96.htm	Edgar Link	pending
R97.htm	Edgar Link	pending
R98.htm	Edgar Link	pending
R99.htm	Edgar Link	pending
report.css	Edgar Link	pending
Show.js	Edgar Link	pending

Create your account

Find Stocks Worth Researching

Deeply Understand Businesses

Value Businesses Intelligently

$COF
CAPITAL ONE FINANCIAL CORP Stock $cof

2019 Q4 Form 10-K Financial Statement

#000092762821000094 Filed on February 25, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COF CAPITAL ONE FINANCIAL CORP Stock $cof

2019 Q4 Form 10-K Financial Statement

#000092762821000094 Filed on February 25, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$COF
CAPITAL ONE FINANCIAL CORP Stock $cof