$KMX
CARMAX INC Stock $kmx

$kmx Overview Financials Valuation SEC Filings Company Website

2021 Q1 Form 10-K Financial Statement

#000117001021000053 Filed on April 20, 2021

Income Statement

Concept	2021 Q1	2020 Q1	2019 Q1
Revenue	$5.164B	$4.962B	$4.319B
YoY Change	4.07%	14.91%	5.74%
Cost Of Revenue	$4.523B	$4.290B	$3.719B
YoY Change	5.44%	15.34%	4.84%
Gross Profit	$641.4M	$672.9M	$599.4M
YoY Change	-4.68%	12.26%	11.67%
Gross Profit Margin	12.42%	13.56%	13.88%
Selling, General & Admin	$556.1M	$484.7M	$429.0M
YoY Change	14.72%	13.0%	4.93%
% of Gross Profit	86.7%	72.04%	71.57%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$61.70M	$57.60M	$46.60M
YoY Change	7.12%	23.61%	-0.21%
% of Gross Profit	9.62%	8.56%	7.77%
Operating Expenses	$547.0M	$484.7M	$429.0M
YoY Change	12.85%	13.0%	4.93%
Operating Profit	$94.40M	$188.1M	$170.4M
YoY Change	-49.82%	10.4%	33.22%
Interest Expense	$167.9M	$89.60M	$82.70M
YoY Change	87.39%	8.34%	1.6%
% of Operating Profit	177.86%	47.63%	48.53%
Other Income/Expense, Net
YoY Change
Pretax Income	$262.2M	$276.6M	$255.8M
YoY Change	-5.21%	8.13%	21.75%
Income Tax	$52.30M	$61.70M	$63.30M
% Of Pretax Income	19.95%	22.31%	24.75%
Net Earnings	$209.9M	$214.9M	$192.6M
YoY Change	-2.34%	11.62%	57.64%
Net Earnings / Revenue	4.06%	4.33%	4.46%
Basic Earnings Per Share		$1.32	$1.14
Diluted Earnings Per Share	$1.268M	$1.30	$1.13
COMMON SHARES
Basic Shares Outstanding	163.2M shares	162.6M shares	166.2M shares
Diluted Shares Outstanding

Balance Sheet

Concept	2021 Q1	2020 Q1	2019 Q1
SHORT-TERM ASSETS
Cash & Short-Term Investments	$132.0M	$58.00M	$47.00M
YoY Change	127.59%	23.4%	4.44%
Cash & Equivalents	$132.3M	$58.21M	$46.94M
Short-Term Investments
Other Short-Term Assets	$91.83M	$86.93M	$67.10M
YoY Change	5.64%	29.55%	-28.21%
Inventory	$3.157B	$2.846B	$2.519B
Prepaid Expenses
Receivables	$239.1M	$191.1M	$139.9M
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$4.117B	$3.664B	$3.214B
YoY Change	12.37%	13.99%	4.98%
LONG-TERM ASSETS
Property, Plant & Equipment	$3.056B	$3.069B	$2.828B
YoY Change	-0.44%	8.52%	6.04%
Goodwill	$653.0K
YoY Change
Intangibles
YoY Change
Long-Term Investments
YoY Change
Other Assets	$282.8M	$258.7M	$186.0M
YoY Change	9.3%	39.14%	17.1%
Total Long-Term Assets	$17.42B	$17.42B	$15.50B
YoY Change	0.04%	12.35%	7.48%
TOTAL ASSETS
Total Short-Term Assets	$4.117B	$3.664B	$3.214B
Total Long-Term Assets	$17.42B	$17.42B	$15.50B
Total Assets	$21.54B	$21.08B	$18.72B
YoY Change	2.18%	12.63%	7.04%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$799.3M	$737.1M	$593.2M
YoY Change	8.44%	24.27%	11.98%
Accrued Expenses	$415.5M	$331.7M	$318.2M
YoY Change	25.24%	4.25%	14.15%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$1.000M
YoY Change		-100.0%
Long-Term Debt Due	$9.927M	$9.251M	$10.18M
YoY Change	7.31%	-9.1%	-97.21%
Total Short-Term Liabilities	$1.699B	$1.535B	$1.312B
YoY Change	10.68%	17.02%	11.71%
LONG-TERM LIABILITIES
Long-Term Debt	$14.74B	$15.02B	$13.78B
YoY Change	-1.88%	9.04%	8.03%
Other Long-Term Liabilities	$434.8M	$393.9M	$272.8M
YoY Change	10.4%	44.38%	12.47%
Total Long-Term Liabilities	$434.8M	$393.9M	$272.8M
YoY Change	10.4%	44.38%	12.47%
TOTAL LIABILITIES
Total Short-Term Liabilities	$1.699B	$1.535B	$1.312B
Total Long-Term Liabilities	$434.8M	$393.9M	$272.8M
Total Liabilities	$17.18B	$17.31B	$15.36B
YoY Change	-0.79%	12.71%	8.41%
SHAREHOLDERS EQUITY
Retained Earnings	$2.888B	$2.488B	$2.104B
YoY Change	16.05%	18.26%	2.78%
Common Stock	$81.59M	$81.54M	$83.74M
YoY Change	0.06%	-2.62%	-6.83%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$4.365B	$3.769B	$3.357B
YoY Change
Total Liabilities & Shareholders Equity	$21.54B	$21.08B	$18.72B
YoY Change	2.18%	12.63%	7.04%

Cashflow Statement

Concept	2021 Q1	2020 Q1	2019 Q1
OPERATING ACTIVITIES
Net Income	$209.9M	$214.9M	$192.6M
YoY Change	-2.34%	11.62%	57.64%
Depreciation, Depletion And Amortization	$61.70M	$57.60M	$46.60M
YoY Change	7.12%	23.61%	-0.21%
Cash From Operating Activities	-$200.6M	-$118.7M	$48.40M
YoY Change	69.0%	-345.25%	-56.98%
INVESTING ACTIVITIES
Capital Expenditures	-$40.50M	-$82.70M	-$61.30M
YoY Change	-51.03%	34.91%	-11.42%
Acquisitions
YoY Change
Other Investing Activities	$34.50M	-$50.10M	-$200.0K
YoY Change	-168.86%	24950.0%	-118.18%
Cash From Investing Activities	-$6.100M	-$132.8M	-$61.50M
YoY Change	-95.41%	115.93%	-9.96%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	110.3M	277.9M	39.20M
YoY Change	-60.31%	608.93%	-359.6%
NET CHANGE
Cash From Operating Activities	-200.6M	-118.7M	48.40M
Cash From Investing Activities	-6.100M	-132.8M	-61.50M
Cash From Financing Activities	110.3M	277.9M	39.20M
Net Change In Cash	-96.40M	26.40M	26.10M
YoY Change	-465.15%	1.15%	-10.31%
FREE CASH FLOW
Cash From Operating Activities	-$200.6M	-$118.7M	$48.40M
Capital Expenditures	-$40.50M	-$82.70M	-$61.30M
Free Cash Flow	-$160.1M	-$36.00M	$109.7M
YoY Change	344.72%	-132.82%	-39.63%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2021	dei	Amendment Flag AmendmentFlag	false
CY2021	dei	Document Fiscal Year Focus DocumentFiscalYearFocus	2021
CY2021	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
CY2021	dei	Entity Central Index Key EntityCentralIndexKey	0001170010
CY2021	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--02-28
CY2021Q1	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.50
CY2020Q1	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.50
CY2021Q1	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	350000000	shares
CY2020Q1	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	350000000	shares
CY2021Q1	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	163172333	shares
CY2020Q1	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	163081376	shares
CY2021Q1	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	163172333	shares
CY2020Q1	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	163081376	shares
CY2021	dei	Document Type DocumentType	10-K
CY2021	dei	Document Annual Report DocumentAnnualReport	true
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-02-28
CY2021	dei	Document Transition Report DocumentTransitionReport	false
CY2021	dei	Entity File Number EntityFileNumber	001-31420
CY2021	dei	Entity Registrant Name EntityRegistrantName	CARMAX, INC.
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	VA
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	54-1821055
CY2021	dei	Entity Address Address Line1 EntityAddressAddressLine1	12800 Tuckahoe Creek Parkway
CY2021	dei	Entity Address City Or Town EntityAddressCityOrTown	Richmond,
CY2021	dei	Entity Address State Or Province EntityAddressStateOrProvince	VA
CY2021	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	23238
CY2021	dei	City Area Code CityAreaCode	804
CY2021	dei	Local Phone Number LocalPhoneNumber	747-0422
CY2021	dei	Security12b Title Security12bTitle	Common Stock
CY2021	dei	Trading Symbol TradingSymbol	KMX
CY2021	dei	Security Exchange Name SecurityExchangeName	NYSE
CY2021	dei	Entity Well Known Seasoned Issuer EntityWellKnownSeasonedIssuer	Yes
CY2021	dei	Entity Voluntary Filers EntityVoluntaryFilers	No
CY2021	dei	Entity Current Reporting Status EntityCurrentReportingStatus	Yes
CY2021	dei	Entity Interactive Data Current EntityInteractiveDataCurrent	Yes
CY2021	dei	Entity Filer Category EntityFilerCategory	Large Accelerated Filer
CY2021	dei	Entity Small Business EntitySmallBusiness	false
CY2021	dei	Entity Emerging Growth Company EntityEmergingGrowthCompany	false
CY2021	dei	Icfr Auditor Attestation Flag IcfrAuditorAttestationFlag	true
CY2021	dei	Entity Shell Company EntityShellCompany	false
CY2020Q3	dei	Entity Public Float EntityPublicFloat	17553869713	USD
CY2021Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	163180172	shares
CY2021	us-gaap	Revenues Revenues	18950149000	USD
CY2020	us-gaap	Revenues Revenues	20319987000	USD
CY2019	us-gaap	Revenues Revenues	18173100000	USD
CY2021	us-gaap	Cost Of Revenue CostOfRevenue	16571024000	USD
CY2020	us-gaap	Cost Of Revenue CostOfRevenue	17597647000	USD
CY2019	us-gaap	Cost Of Revenue CostOfRevenue	15692509000	USD
CY2021	us-gaap	Gross Profit GrossProfit	2379125000	USD
CY2020	us-gaap	Gross Profit GrossProfit	2722340000	USD
CY2019	us-gaap	Gross Profit GrossProfit	2480591000	USD
CY2021	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	562810000	USD
CY2020	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	456030000	USD
CY2019	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	438690000	USD
CY2021	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	1898775000	USD
CY2020	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	1940067000	USD
CY2019	us-gaap	Selling General And Administrative Expense SellingGeneralAndAdministrativeExpense	1730275000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	164836000	shares
CY2021	us-gaap	Interest Expense InterestExpense	86178000	USD
CY2020	us-gaap	Interest Expense InterestExpense	83007000	USD
CY2019	us-gaap	Interest Expense InterestExpense	75792000	USD
CY2021	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	8275000	USD
CY2020	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	5690000	USD
CY2019	us-gaap	Nonoperating Income Expense NonoperatingIncomeExpense	-408000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	965257000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1160986000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	1112806000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	218338000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	272553000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	270393000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	746919000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	888433000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	842413000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	163183000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	174463000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	165133000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	166820000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	175884000	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.58
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.39
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.83
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.52
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CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.79
CY2021	us-gaap	Net Income Loss NetIncomeLoss	746919000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	888433000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	842413000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-28640000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	50824000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	1981000	USD
CY2021	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	2740000	USD
CY2020	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	-31237000	USD
CY2019	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	-11717000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	31380000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-82061000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-13698000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	778299000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	806372000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	828715000	USD
CY2021Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	132319000	USD
CY2020Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	58211000	USD
CY2021Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	496415000	USD
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CY2021Q1	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	239070000	USD
CY2020Q1	us-gaap	Accounts Receivable Net Current AccountsReceivableNetCurrent	191090000	USD
CY2021Q1	us-gaap	Inventory Net InventoryNet	3157159000	USD
CY2020Q1	us-gaap	Inventory Net InventoryNet	2846416000	USD
CY2021Q1	us-gaap	Other Assets Current OtherAssetsCurrent	91833000	USD
CY2020Q1	us-gaap	Other Assets Current OtherAssetsCurrent	86927000	USD
CY2021Q1	us-gaap	Assets Current AssetsCurrent	4116796000	USD
CY2020Q1	us-gaap	Assets Current AssetsCurrent	3663687000	USD
CY2021Q1	us-gaap	Notes Receivable Net NotesReceivableNet	13489819000	USD
CY2020Q1	us-gaap	Notes Receivable Net NotesReceivableNet	13551711000	USD
CY2021Q1	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	3055563000	USD
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CY2021Q1	us-gaap	Deferred Income Tax Assets Net DeferredIncomeTaxAssetsNet	164261000	USD
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CY2021Q1	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	431652000	USD
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CY2021Q1	us-gaap	Short Term Bank Loans And Notes Payable ShortTermBankLoansAndNotesPayable	0	USD
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CY2021Q1	us-gaap	Other Long Term Debt Noncurrent OtherLongTermDebtNoncurrent	1322415000	USD
CY2020Q1	us-gaap	Other Long Term Debt Noncurrent OtherLongTermDebtNoncurrent	1778672000	USD
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CY2020Q1	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	393873000	USD
CY2021Q1	us-gaap	Liabilities Liabilities	17176928000	USD
CY2020Q1	us-gaap	Liabilities Liabilities	17313307000	USD
CY2021Q1	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q1	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
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CY2020Q1	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	2488417000	USD
CY2021Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4364613000	USD
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CY2020Q1	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	21082182000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	746919000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	888433000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	842413000	USD
CY2021	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	242156000	USD
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CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	182247000	USD
CY2021	us-gaap	Share Based Compensation ShareBasedCompensation	121899000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	108861000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	75011000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	160703000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	185695000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	153848000	USD
CY2021	kmx	Provision For Contract Cancellation Reserves ProvisionForContractCancellationReserves	72235000	USD
CY2020	kmx	Provision For Contract Cancellation Reserves ProvisionForContractCancellationReserves	89272000	USD
CY2019	kmx	Provision For Contract Cancellation Reserves ProvisionForContractCancellationReserves	63937000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-35787000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-1102000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2300000	USD
CY2021	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	1409000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-3507000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	-2825000	USD
CY2021	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	43507000	USD
CY2020	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	51240000	USD
CY2019	us-gaap	Increase Decrease In Accounts Receivable IncreaseDecreaseInAccountsReceivable	6529000	USD
CY2021	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	323318000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	326961000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	128761000	USD
CY2021	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	50000	USD
CY2020	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	19843000	USD
CY2019	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-32890000	USD
CY2021	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	300838000	USD
CY2020	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	1308919000	USD
CY2019	us-gaap	Increase Decrease In Finance Receivables IncreaseDecreaseInFinanceReceivables	1046631000	USD
CY2021	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	12862000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	-4265000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	7230000	USD
CY2021	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	106788000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	85442000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	86360000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-65169000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-109827000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Liabilities IncreaseDecreaseInOtherOperatingLiabilities	-89709000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	667760000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-236606000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	162971000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	164536000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	331896000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	304636000	USD
CY2021	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	1846000	USD
CY2020	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	3000	USD
CY2019	us-gaap	Proceeds From Sale Of Property Plant And Equipment ProceedsFromSaleOfPropertyPlantAndEquipment	692000	USD
CY2021	us-gaap	Proceeds From Sales Of Business Affiliate And Productive Assets ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets	29911000	USD
CY2020	us-gaap	Proceeds From Sales Of Business Affiliate And Productive Assets ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets	0	USD
CY2019	us-gaap	Proceeds From Sales Of Business Affiliate And Productive Assets ProceedsFromSalesOfBusinessAffiliateAndProductiveAssets	0	USD
CY2021	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	3729000	USD
CY2020	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	59050000	USD
CY2019	us-gaap	Payments To Acquire Investments PaymentsToAcquireInvestments	6147000	USD
CY2021	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	8325000	USD
CY2020	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	1579000	USD
CY2019	us-gaap	Proceeds From Sale And Maturity Of Other Investments ProceedsFromSaleAndMaturityOfOtherInvestments	1578000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-128183000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-389364000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-308513000	USD
CY2021	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-40000	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-1089000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	1002000	USD
CY2021	kmx	Proceeds From Revolving Line Of Credit And Long Term Debt ProceedsFromRevolvingLineOfCreditAndLongTermDebt	1754300000	USD
CY2020	kmx	Proceeds From Revolving Line Of Credit And Long Term Debt ProceedsFromRevolvingLineOfCreditAndLongTermDebt	6277600000	USD
CY2019	kmx	Proceeds From Revolving Line Of Credit And Long Term Debt ProceedsFromRevolvingLineOfCreditAndLongTermDebt	4314500000	USD
CY2021	kmx	Payments On Revolving Line Of Credit And Long Term Debt PaymentsOnRevolvingLineOfCreditAndLongTermDebt	2217305000	USD
CY2020	kmx	Payments On Revolving Line Of Credit And Long Term Debt PaymentsOnRevolvingLineOfCreditAndLongTermDebt	6199793000	USD
CY2019	kmx	Payments On Revolving Line Of Credit And Long Term Debt PaymentsOnRevolvingLineOfCreditAndLongTermDebt	4155718000	USD
CY2021	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	18296000	USD
CY2020	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	20102000	USD
CY2019	us-gaap	Payments Of Debt Issuance Costs PaymentsOfDebtIssuanceCosts	17063000	USD
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	7424000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	4151000	USD
CY2019	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	894000	USD
CY2021	kmx	Proceeds From Issuance Of Non Recourse Debt ProceedsFromIssuanceOfNonRecourseDebt	10805546000	USD
CY2020	kmx	Proceeds From Issuance Of Non Recourse Debt ProceedsFromIssuanceOfNonRecourseDebt	11786432000	USD
CY2019	kmx	Proceeds From Issuance Of Non Recourse Debt ProceedsFromIssuanceOfNonRecourseDebt	10892502000	USD
CY2021	kmx	Payments On Non Recourse Debt PaymentsOnNonRecourseDebt	10654011000	USD
CY2020	kmx	Payments On Non Recourse Debt PaymentsOnNonRecourseDebt	10708564000	USD
CY2019	kmx	Payments On Non Recourse Debt PaymentsOnNonRecourseDebt	10001712000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	229938000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	567747000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	904726000	USD
CY2021	us-gaap	Proceeds From Issuance Or Sale Of Equity ProceedsFromIssuanceOrSaleOfEquity	143148000	USD
CY2020	us-gaap	Proceeds From Issuance Or Sale Of Equity ProceedsFromIssuanceOrSaleOfEquity	124397000	USD
CY2019	us-gaap	Proceeds From Issuance Or Sale Of Equity ProceedsFromIssuanceOrSaleOfEquity	58130000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-424020000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	686983000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	186021000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	115557000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	61013000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Excluding Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseExcludingExchangeRateEffect	40479000	USD
CY2020Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	656390000	USD
CY2019Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	595377000	USD
CY2018Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	554898000	USD
CY2021Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	771947000	USD
CY2020Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	656390000	USD
CY2019Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	595377000	USD
CY2021Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	132319000	USD
CY2020Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	58211000	USD
CY2019Q1	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	46938000	USD
CY2021Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	496415000	USD
CY2020Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	481043000	USD
CY2019Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	440669000	USD
CY2021Q1	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	143213000	USD
CY2020Q1	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	117136000	USD
CY2019Q1	us-gaap	Restricted Cash And Cash Equivalents Noncurrent RestrictedCashAndCashEquivalentsNoncurrent	107770000	USD
CY2021Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	771947000	USD
CY2020Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	656390000	USD
CY2019Q1	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	595377000	USD
CY2018Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3316849000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	842413000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13698000	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	45870000	USD
CY2019	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	903101000	USD
CY2019	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	58131000	USD
CY2019	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-2300000	USD
CY2019Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3357028000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	888433000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-82061000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	48122000	USD
CY2020	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	561657000	USD
CY2020	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	124397000	USD
CY2020	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-5387000	USD
CY2020Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	3768875000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	746919000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	31380000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	49656000	USD
CY2021	us-gaap	Stock Repurchased And Retired During Period Value StockRepurchasedAndRetiredDuringPeriodValue	216290000	USD
CY2021	us-gaap	Stock Issued During Period Value Stock Options Exercised StockIssuedDuringPeriodValueStockOptionsExercised	143147000	USD
CY2021	us-gaap	Stock Issued During Period Value Share Based Compensation StockIssuedDuringPeriodValueShareBasedCompensation	-5768000	USD
CY2021Q1	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	4364613000	USD
CY2021	us-gaap	Nature Of Operations NatureOfOperations	Business and Background<div style="margin-bottom:12pt;text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">CarMax, Inc. (“we,” “our,” “us,” “CarMax” and “the company”), including its wholly owned subsidiaries, is the nation’s largest and most profitable retailer of used vehicles. We operate in two reportable segments: CarMax Sales Operations and CarMax Auto Finance (“CAF”). Our CarMax Sales Operations segment consists of all aspects of our auto merchandising and service operations, excluding financing provided by CAF. Our CAF segment consists solely of our own finance operation that provides financing to customers buying retail vehicles from CarMax.</span></div><div style="text-align:justify"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We deliver an unrivaled customer experience by offering a broad selection of quality used vehicles and related products and services at competitive, no-haggle prices using a customer-friendly sales process. Our omni-channel platform, which gives us the largest addressable market in the used car industry, empowers customers to buy a car on their terms – online, in-store or a seamless combination of both.</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:12pt;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%">Customers can choose to complete the car-buying experience in-person at one of our stores; or buy the car online and receive delivery through contactless curbside pickup, available nationwide, or home delivery, available to most customers.</span><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:12pt;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%">We offer customers a range of related products and services, including the appraisal and purchase of vehicles directly from consumers; the financing of retail vehicle purchases through CAF and third-party finance providers; the sale of extended protection plan (“EPP”) products, which include extended service plans (“ESPs”) and guaranteed asset protection (“GAP”); and vehicle repair service. Vehicles purchased through the appraisal process that do not meet our retail standards are sold to licensed dealers through on-site or virtual wholesale auctions.</span></div>
CY2021	kmx	Investment Maturity Period InvestmentMaturityPeriod	three months or less
CY2021Q1	us-gaap	Cash Cash Equivalents And Short Term Investments CashCashEquivalentsAndShortTermInvestments	46900000	USD
CY2021Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	496400000	USD
CY2020Q1	us-gaap	Restricted Cash And Cash Equivalents At Carrying Value RestrictedCashAndCashEquivalentsAtCarryingValue	481000000.0	USD
CY2021	kmx	Number Of Warehouses NumberOfWarehouses	3	warehouse
CY2021Q1	us-gaap	Investments And Other Noncurrent Assets InvestmentsAndOtherNoncurrentAssets	152900000	USD
CY2020Q1	us-gaap	Investments And Other Noncurrent Assets InvestmentsAndOtherNoncurrentAssets	156700000	USD
CY2021Q1	us-gaap	Accrued Employee Benefits Current AccruedEmployeeBenefitsCurrent	223100000	USD
CY2020Q1	us-gaap	Accrued Employee Benefits Current AccruedEmployeeBenefitsCurrent	142900000	USD
CY2021Q1	us-gaap	Workers Compensation Liability Current WorkersCompensationLiabilityCurrent	42900000	USD
CY2020Q1	us-gaap	Workers Compensation Liability Current WorkersCompensationLiabilityCurrent	41000000.0	USD
CY2021	us-gaap	Advertising Expense AdvertisingExpense	218600000	USD
CY2020	us-gaap	Advertising Expense AdvertisingExpense	191800000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	167000000.0	USD
CY2021	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	18950100000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	20320000000.0	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	18173100000	USD
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	1142000000.0	USD
CY2020	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	1104100000	USD
CY2019	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	972900000	USD
CY2021	us-gaap	Financing Interest Expense FinancingInterestExpense	314100000	USD
CY2020	us-gaap	Financing Interest Expense FinancingInterestExpense	358100000	USD
CY2019	us-gaap	Financing Interest Expense FinancingInterestExpense	289300000	USD
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	827900000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	746000000.0	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	683600000	USD
CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	160700000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	185700000	USD
CY2019	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	153800000	USD
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	667200000	USD
CY2020	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	560300000	USD
CY2019	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	529800000	USD
CY2021	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-2200000	USD
CY2020	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	0	USD
CY2019	us-gaap	Other Nonoperating Income Expense OtherNonoperatingIncomeExpense	-400000	USD
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	46000000.0	USD
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	42300000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	38300000	USD
CY2021	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	56200000	USD
CY2020	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	62000000.0	USD
CY2019	us-gaap	Other Cost And Expense Operating OtherCostAndExpenseOperating	52400000	USD
CY2021	us-gaap	Direct Operating Costs DirectOperatingCosts	102200000	USD
CY2020	us-gaap	Direct Operating Costs DirectOperatingCosts	104300000	USD
CY2019	us-gaap	Direct Operating Costs DirectOperatingCosts	90700000	USD
CY2021	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	562800000	USD
CY2020	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	456000000.0	USD
CY2019	kmx	Net Income Loss From Financing NetIncomeLossFromFinancing	438700000	USD
CY2021	kmx	Kmx Average Balance Of Loans Held In Porfolio Kmx_averageBalanceOfLoansHeldInPorfolio	13463300000	USD
CY2020	kmx	Kmx Average Balance Of Loans Held In Porfolio Kmx_averageBalanceOfLoansHeldInPorfolio	13105100000	USD
CY2019	kmx	Kmx Average Balance Of Loans Held In Porfolio Kmx_averageBalanceOfLoansHeldInPorfolio	12150200000	USD
CY2021Q1	us-gaap	Non Recourse Debt NonRecourseDebt	13760000000	USD
CY2020Q1	us-gaap	Non Recourse Debt NonRecourseDebt	13610000000	USD
CY2021Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13847200000	USD
CY2020Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13617800000	USD
CY2021Q1	us-gaap	Interest Receivable InterestReceivable	57400000	USD
CY2020Q1	us-gaap	Interest Receivable InterestReceivable	56200000	USD
CY2021Q1	us-gaap	Other Receivables OtherReceivables	-3700000	USD
CY2020Q1	us-gaap	Other Receivables OtherReceivables	35500000	USD
CY2021Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	411100000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	157800000	USD
CY2021Q1	us-gaap	Notes Receivable Net NotesReceivableNet	13489800000	USD
CY2020Q1	us-gaap	Notes Receivable Net NotesReceivableNet	13551700000	USD
CY2021Q1	us-gaap	Financing Receivable Originated In Current Fiscal Year FinancingReceivableOriginatedInCurrentFiscalYear	5561700000	USD
CY2021Q1	us-gaap	Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear	4112600000	USD
CY2021Q1	us-gaap	Financing Receivable Originated Two Years Before Latest Fiscal Year FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear	2337200000	USD
CY2021Q1	us-gaap	Financing Receivable Originated Three Years Before Latest Fiscal Year FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear	1226900000	USD
CY2021Q1	us-gaap	Financing Receivable Originated Four Years Before Latest Fiscal Year FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear	494900000	USD
CY2021Q1	us-gaap	Financing Receivable Originated Five Or More Years Before Latest Fiscal Year FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear	113900000	USD
CY2021Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13847200000	USD
CY2021Q1	kmx	Total Ending Managed Receivables As Percentage By Major Credit Grade TotalEndingManagedReceivablesAsPercentageByMajorCreditGrade	1.000
CY2020Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13617800000	USD
CY2020Q1	kmx	Total Ending Managed Receivables As Percentage By Major Credit Grade TotalEndingManagedReceivablesAsPercentageByMajorCreditGrade	1.000
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	157800000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	138200000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	359800000	USD
CY2019Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	138200000	USD
CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	230400000	USD
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CY2021	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	121000000.0	USD
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CY2021	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	160700000	USD
CY2020	us-gaap	Provision For Loan Lease And Other Losses ProvisionForLoanLeaseAndOtherLosses	185700000	USD
CY2021Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	411100000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	157800000	USD
CY2021Q1	us-gaap	Notes And Loans Receivable Gross Current NotesAndLoansReceivableGrossCurrent	13454700000	USD
CY2021Q1	us-gaap	Financing Receivable Recorded Investment Past Due FinancingReceivableRecordedInvestmentPastDue	392500000	USD
CY2021Q1	kmx	Past Due Receivables As Percentage Of Total Ending Managed Receivables PastDueReceivablesAsPercentageOfTotalEndingManagedReceivables	0.0283
CY2021Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13847200000	USD
CY2020Q1	us-gaap	Notes Receivable Gross NotesReceivableGross	13617800000	USD
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CY2021Q1	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	685585000	USD
CY2021Q1	us-gaap	Trading Securities TradingSecurities	24049000	USD
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CY2020Q1	us-gaap	Cash And Cash Equivalents Fair Value Disclosure CashAndCashEquivalentsFairValueDisclosure	273203000	USD
CY2020Q1	us-gaap	Trading Securities TradingSecurities	22668000	USD
CY2020Q1	us-gaap	Assets Fair Value Disclosure AssetsFairValueDisclosure	295871000	USD
CY2020Q1	kmx	Item As Percentage Of Total Assets At Fair Value ItemAsPercentageOfTotalAssetsAtFairValue	1.000
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CY2020Q1	us-gaap	Liabilities Fair Value Disclosure LiabilitiesFairValueDisclosure	23992000	USD
CY2020Q1	kmx	Item As Percentage Of Total Liabilities ItemAsPercentageOfTotalLiabilities	0.001
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-02-28
CY2021Q1	us-gaap	Senior Notes SeniorNotes	500000000	USD
CY2020Q1	us-gaap	Senior Notes SeniorNotes	500000000	USD
CY2021Q1	us-gaap	Debt Instrument Fair Value DebtInstrumentFairValue	556993000	USD
CY2020Q1	us-gaap	Debt Instrument Fair Value DebtInstrumentFairValue	546197000	USD
CY2021Q1	us-gaap	Finance Lease Right Of Use Asset Before Accumulated Amortization FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization	127142000	USD
CY2020Q1	us-gaap	Finance Lease Right Of Use Asset Before Accumulated Amortization FinanceLeaseRightOfUseAssetBeforeAccumulatedAmortization	84434000	USD
CY2021Q1	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	4469827000	USD
CY2020Q1	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	4336022000	USD
CY2021Q1	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	1414264000	USD
CY2020Q1	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	1266920000	USD
CY2021Q1	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	3055563000	USD
CY2020Q1	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	3069102000	USD
CY2021	us-gaap	Depreciation Depreciation	195300000	USD
CY2020	us-gaap	Depreciation Depreciation	190600000	USD
CY2019	us-gaap	Depreciation Depreciation	169800000	USD
CY2020Q1	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	117900000	USD
CY2019Q1	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	102800000	USD
CY2021	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	65600000	USD
CY2020	us-gaap	Valuation Allowances And Reserves Deductions ValuationAllowancesAndReservesDeductions	74200000	USD
CY2021	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	72200000	USD
CY2020	us-gaap	Valuation Allowances And Reserves Charged To Cost And Expense ValuationAllowancesAndReservesChargedToCostAndExpense	89300000	USD
CY2021Q1	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	124500000	USD
CY2020Q1	us-gaap	Valuation Allowances And Reserves Balance ValuationAllowancesAndReservesBalance	117900000	USD
CY2021Q1	kmx	Cancellation Reserves Current Portion CancellationReservesCurrentPortion	58700000	USD
CY2020Q1	kmx	Cancellation Reserves Current Portion CancellationReservesCurrentPortion	63500000	USD
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	209447000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	225858000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	218497000	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	44678000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	47797000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	49596000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	254125000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	273655000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	268093000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-27971000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	146000	USD
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CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-1248000	USD
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CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-35787000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-1102000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	2300000	USD
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CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	272553000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	270393000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
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CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
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CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.034
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CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.006
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.005
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CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.226
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CY2020Q1	kmx	Deferred Tax Assets Leasing Arrangements DeferredTaxAssetsLeasingArrangements	119558000	USD
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CY2021Q1	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	901000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	917000	USD
CY2021Q1	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	382203000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	309878000	USD
CY2021Q1	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	21302000	USD
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CY2020Q1	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	67589000	USD
CY2021Q1	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	110006000	USD
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CY2020Q1	us-gaap	Deferred Tax Liabilities Deferred Expense Capitalized Inventory Costs DeferredTaxLiabilitiesDeferredExpenseCapitalizedInventoryCosts	18493000	USD
CY2021Q1	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	217942000	USD
CY2020Q1	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	220036000	USD
CY2021Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	164261000	USD
CY2020Q1	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	89842000	USD
CY2020Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	30865000	USD
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CY2018Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	28685000	USD
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CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	3493000	USD
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CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	4468000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	2913000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	266000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	3634000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	4170000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	2498000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	4000	USD
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CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	44000	USD
CY2021	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	1218000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	3829000	USD
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CY2021Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	28997000	USD
CY2020Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	30865000	USD
CY2019Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	30270000	USD
CY2021Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	29000000.0	USD
CY2021Q1	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	7600000	USD
CY2020Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	30900000	USD
CY2020Q1	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	9200000	USD
CY2019Q1	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	30300000	USD
CY2019Q1	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	10700000	USD
CY2021Q1	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	4700000	USD
CY2020Q1	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	4000000.0	USD
CY2019Q1	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	3200000	USD
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CY2020Q1	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	168835000	USD
CY2021Q1	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	307992000	USD
CY2020Q1	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	310939000	USD
CY2021Q1	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	-98219000	USD
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CY2020Q1	us-gaap	Defined Benefit Plan Amounts Recognized In Balance Sheet DefinedBenefitPlanAmountsRecognizedInBalanceSheet	-142104000	USD
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CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-1107000	USD
CY2019	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	-207000	USD
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CY2019	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Loss Net Gain Loss Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax	4560000	USD
CY2021Q1	kmx	Financing Obligation Payments Due Next Fiscal Year FinancingObligationPaymentsDueNextFiscalYear	53129000	USD
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CY2021Q1	kmx	Financing Obligations Payments Due Year Three FinancingObligationsPaymentsDueYearThree	56075000	USD
CY2021Q1	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	209773000	USD
CY2020Q1	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	168835000	USD
CY2021Q1	kmx	Financing Obligations FinancingObligations	533578000	USD
CY2020Q1	kmx	Financing Obligations FinancingObligations	536739000	USD
CY2021Q1	us-gaap	Non Recourse Debt NonRecourseDebt	13764808000	USD
CY2020Q1	us-gaap	Non Recourse Debt NonRecourseDebt	13613272000	USD
CY2021Q1	us-gaap	Debt Longterm And Shortterm Combined Amount DebtLongtermAndShorttermCombinedAmount	15098386000	USD
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CY2020Q1	us-gaap	Long Term Debt And Capital Lease Obligations Current LongTermDebtAndCapitalLeaseObligationsCurrent	433456000	USD
CY2021Q1	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	25888000	USD
CY2020Q1	us-gaap	Unamortized Debt Issuance Expense UnamortizedDebtIssuanceExpense	25240000	USD
CY2021Q1	us-gaap	Long Term Debt LongTermDebt	14619919000	USD
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CY2021Q1	kmx	Financing Obligations Payments Due Year Four FinancingObligationsPaymentsDueYearFour	54747000	USD
CY2021	us-gaap	Interest Paid Capitalized InterestPaidCapitalized	3300000	USD
CY2021Q1	kmx	Financing Obligations Payments Due Year Five FinancingObligationsPaymentsDueYearFive	57943000	USD
CY2021Q1	kmx	Financing Obligations Payments Due After Year Five FinancingObligationsPaymentsDueAfterYearFive	845920000	USD
CY2021Q1	kmx	Financing Obligations Payments Due FinancingObligationsPaymentsDue	1121594000	USD
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CY2021Q1	kmx	Financing Obligations FinancingObligations	533578000	USD
CY2021Q1	us-gaap	Non Recourse Debt NonRecourseDebt	13760000000	USD
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CY2021	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	124211000	USD
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	110757000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	76684000	USD
CY2021Q1	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	59600000	USD
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	5.33
CY2021	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Period For Recognition1 EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1	P1Y10M24D
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.000
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.000
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Dividend Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate	0.000
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum	0.361
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum	0.561
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum	0.268
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum	0.326
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMinimum	0.261
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRateMaximum	0.341
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Weighted Average Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate	0.382
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Weighted Average Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate	0.292
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Weighted Average Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsWeightedAverageVolatilityRate	0.291
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum	0.001
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum	0.007
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum	0.015
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum	0.024
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Minimum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum	0.017
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate Maximum ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum	0.030
CY2021	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y7M6D
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y7M6D
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P4Y7M6D
CY2021	us-gaap	Net Income Loss NetIncomeLoss	746919000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	888433000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	842413000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	163183000	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	164836000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	174463000	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	165133000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	166820000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	175884000	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.58
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	5.39
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	4.83
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.52
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	4.79
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1131764	shares
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	1355679	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	4009566	shares
CY2018Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-54312000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-10162000	USD
CY2019	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	3536000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-13698000	USD
CY2019Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-68010000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	-86885000	USD
CY2020	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-4824000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	-82061000	USD
CY2020Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-150071000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Before Reclassifications Net Of Tax OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax	13113000	USD
CY2021	us-gaap	Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax	-18267000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax OtherComprehensiveIncomeLossNetOfTax	31380000	USD
CY2021Q1	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-118691000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	33913000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-68861000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Net Unamortized Gain Loss Arising During Period Before Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax	-4560000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	8184000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-16607000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-1101000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	25729000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-52254000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-3459000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-3837000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-1874000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax	-1949000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-926000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-444000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax	-471000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-2911000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1430000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	-1478000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	-28640000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	50824000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent	1981000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-17122000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-47083000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	-9103000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-4506000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-12452000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax	-2400000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-12616000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-34631000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax	-6703000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-20841000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	-4614000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Before Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax	6809000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	-5485000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	-1220000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax	1795000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	-15356000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	-3394000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Reclassification Adjustment From Aoci On Derivatives Net Of Tax OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax	5014000	USD
CY2021	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	2740000	USD
CY2020	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	-31237000	USD
CY2019	us-gaap	Other Comprehensive Income Derivatives Qualifying As Hedges Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeDerivativesQualifyingAsHedgesNetOfTaxPortionAttributableToParent	-11717000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	31380000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-82061000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-13698000	USD
CY2021Q1	kmx	Accumulated Other Comprehensive Income Loss Deferred Taxes AccumulatedOtherComprehensiveIncomeLossDeferredTaxes	38700000	USD
CY2020Q1	kmx	Accumulated Other Comprehensive Income Loss Deferred Taxes AccumulatedOtherComprehensiveIncomeLossDeferredTaxes	48800000	USD
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	57325000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	57656000	USD
CY2021	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	8362000	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	5769000	USD
CY2021	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	10724000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	7678000	USD
CY2021	kmx	Finance Lease Cost FinanceLeaseCost	19086000	USD
CY2020	kmx	Finance Lease Cost FinanceLeaseCost	13447000	USD
CY2021	us-gaap	Lease Cost LeaseCost	76411000	USD
CY2020	us-gaap	Lease Cost LeaseCost	71103000	USD
CY2021Q1	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	431652000	USD
CY2020Q1	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	449094000	USD
CY2021Q1	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	109665000	USD
CY2020Q1	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	75320000	USD
CY2021Q1	kmx	Totalleaseassets Totalleaseassets	541317000	USD
CY2020Q1	kmx	Totalleaseassets Totalleaseassets	524414000	USD
CY2021Q1	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	30953000	USD
CY2020Q1	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	30980000	USD
CY2021Q1	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	9422000	USD
CY2020Q1	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	5066000	USD
CY2021Q1	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	423618000	USD
CY2020Q1	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	440671000	USD
CY2021Q1	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	120094000	USD
CY2020Q1	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	79327000	USD
CY2021Q1	kmx	Totalleaseliabilities Totalleaseliabilities	584087000	USD
CY2020Q1	kmx	Totalleaseliabilities Totalleaseliabilities	556044000	USD
CY2021Q1	kmx	Finance Lease Accumulated Depreciation FinanceLeaseAccumulatedDepreciation	17500000	USD
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-02-28
CY2020Q1	kmx	Finance Lease Accumulated Depreciation FinanceLeaseAccumulatedDepreciation	9100000	USD
CY2021Q1	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P19Y4M13D
CY2020Q1	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P19Y11M23D
CY2021Q1	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P13Y6M21D
CY2020Q1	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P13Y6M18D
CY2021Q1	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0536	Rate
CY2020Q1	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0540	Rate
CY2021Q1	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.1509	Rate
CY2020Q1	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.1032	Rate
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	56762000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	57145000	USD
CY2021	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	8517000	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	4027000	USD
CY2021	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	7424000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	4151000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	14010000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	27136000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	45857000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	53111000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	53378000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	21974000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	51167000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	23776000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	50293000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	26599000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	49197000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	23310000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	43359000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	23881000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	529331000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	190869000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	776725000	USD
CY2021Q1	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	310409000	USD
CY2021Q1	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	322154000	USD
CY2021Q1	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	180893000	USD
CY2021Q1	us-gaap	Operating Lease Liability OperatingLeaseLiability	454571000	USD
CY2021Q1	us-gaap	Finance Lease Liability FinanceLeaseLiability	129516000	USD
CY2021Q1	kmx	Lessee Lease Not Yet Commenced Amount LesseeLeaseNotYetCommencedAmount	36900000	USD
CY2021	us-gaap	Interest Paid InterestPaid	86437000	USD
CY2020	us-gaap	Interest Paid InterestPaid	85607000	USD
CY2019	us-gaap	Interest Paid InterestPaid	74204000	USD
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	247748000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	286008000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	220669000	USD
CY2021	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	-25595000	USD
CY2020	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	3840000	USD
CY2019	us-gaap	Capital Expenditures Incurred But Not Yet Paid CapitalExpendituresIncurredButNotYetPaid	-3066000	USD
CY2021	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	4726000	USD
CY2020	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	48942000	USD
CY2019	us-gaap	Capital Lease Obligations Incurred CapitalLeaseObligationsIncurred	35848000	USD
CY2021Q1	us-gaap	Former Gain Contingency Recognized In Current Period FormerGainContingencyRecognizedInCurrentPeriod	40300000	USD
CY2021Q1	us-gaap	Standard Product Warranty Accrual StandardProductWarrantyAccrual	15200000	USD
CY2020Q1	us-gaap	Standard Product Warranty Accrual StandardProductWarrantyAccrual	10500000	USD
CY2021Q1	us-gaap	Purchase Obligation PurchaseObligation	141200000	USD
CY2021Q1	us-gaap	Purchase Obligation Due In Next Twelve Months PurchaseObligationDueInNextTwelveMonths	68000000.0	USD

Files In Submission

Name	View Source	Status
0001170010-21-000053-index-headers.html	Edgar Link	pending
0001170010-21-000053-index.html	Edgar Link	pending
0001170010-21-000053.txt	Edgar Link	pending
0001170010-21-000053-xbrl.zip	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
kmx-20210228.htm	Edgar Link	pending
kmx-20210228.xsd	Edgar Link	pending
kmx-20210228_cal.xml	Edgar Link	unprocessable
kmx-20210228_def.xml	Edgar Link	unprocessable
kmx-20210228_g1.jpg	Edgar Link	pending
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kmx-20210228_htm.xml	Edgar Link	completed
kmx-20210228_lab.xml	Edgar Link	unprocessable
kmx-20210228_pre.xml	Edgar Link	unprocessable
kmxfy21exhibit211.htm	Edgar Link	pending
kmxfy21exhibit231.htm	Edgar Link	pending
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$KMX
CARMAX INC Stock $kmx

2021 Q1 Form 10-K Financial Statement

#000117001021000053 Filed on April 20, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$KMX CARMAX INC Stock $kmx

2021 Q1 Form 10-K Financial Statement

#000117001021000053 Filed on April 20, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$KMX
CARMAX INC Stock $kmx