$FNB
FNB CORP/PA/ Stock $fnb

$fnb Overview Financials Valuation SEC Filings Company Website

2021 Q4 Form 10-K Financial Statement

#000003780822000005 Filed on February 24, 2022

Income Statement

Concept	2021 Q4	2021	2020 Q4
Revenue		$1.005B	$270.0M
YoY Change		-11.06%	-11.76%
Cost Of Revenue
YoY Change
Gross Profit
YoY Change
Gross Profit Margin
Selling, General & Admin
YoY Change
% of Gross Profit
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$10.00M	$46.00M
YoY Change		6.98%
% of Gross Profit
Operating Expenses
YoY Change
Operating Profit
YoY Change
Interest Expense		$98.00M	$36.00M
YoY Change		-52.88%	-55.0%
% of Operating Profit
Other Income/Expense, Net
YoY Change
Pretax Income	$123.0M	$503.0M	$85.00M
YoY Change	44.71%	46.65%	-26.72%
Income Tax	$24.00M	$98.00M	$14.00M
% Of Pretax Income	19.51%	19.48%	16.47%
Net Earnings	$99.00M	$405.0M	$72.00M
YoY Change	37.5%	41.61%	-24.21%
Net Earnings / Revenue		40.3%	26.67%
Basic Earnings Per Share		$1.24	$0.22
Diluted Earnings Per Share	$310.2K	$1.23	$0.22
COMMON SHARES
Basic Shares Outstanding	318.9M shares	319.8M shares	322.6M shares
Diluted Shares Outstanding		323.5M shares

Balance Sheet

Concept	2021 Q4	2021	2020 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments
YoY Change
Cash & Equivalents	$3.493B		$1.383B
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	$485.0M	$485.0M	$332.0M
YoY Change	46.08%	5.66%	-0.3%
Goodwill	$2.262B		$2.262B
YoY Change	0.0%		0.0%
Intangibles	$42.00M		$54.00M
YoY Change	-22.22%		-19.4%
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	$39.51B	$39.51B	$37.35B
YoY Change	5.78%	5.78%	7.91%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable
YoY Change
Accrued Expenses	$149.0M	$149.0M	$134.0M
YoY Change	11.19%	11.19%	4.69%
Deferred Revenue
YoY Change
Short-Term Debt	$1.536B	$376.0M	$1.804B
YoY Change	-14.86%	-6.7%	-43.91%
Long-Term Debt Due	$130.0M	$130.0M	$121.0M
YoY Change	7.44%	7.44%	12.04%
Total Short-Term Liabilities	$279.0M	$279.0M	$255.0M
YoY Change	9.41%	9.41%	8.05%
LONG-TERM LIABILITIES
Long-Term Debt	$682.0M	$682.0M	$695.0M
YoY Change	-1.87%	-1.87%	71.6%
Other Long-Term Liabilities	$270.0M	$270.0M	$240.0M
YoY Change	12.5%	12.5%	-8.4%
Total Long-Term Liabilities	$952.0M	$952.0M	$935.0M
YoY Change	1.82%	1.82%	40.18%
TOTAL LIABILITIES
Total Short-Term Liabilities	$279.0M	$279.0M	$255.0M
Total Long-Term Liabilities	$952.0M	$952.0M	$935.0M
Total Liabilities	$34.36B	$34.36B	$32.40B
YoY Change	6.08%	6.08%	8.96%
SHAREHOLDERS EQUITY
Retained Earnings	$1.110B		$869.0M
YoY Change	27.73%		8.9%
Common Stock	$4.112B		$4.090B
YoY Change	0.54%		0.49%
Preferred Stock
YoY Change
Treasury Stock (at cost)	$117.0M		$68.00M
YoY Change	72.06%		151.85%
Treasury Stock Shares	10.53M shares		6.428M shares
Shareholders Equity	$5.150B	$5.150B	$4.959B
YoY Change
Total Liabilities & Shareholders Equity	$39.51B	$39.51B	$37.35B
YoY Change	5.78%	5.78%	7.91%

Cashflow Statement

Concept	2021 Q4	2021	2020 Q4
OPERATING ACTIVITIES
Net Income	$99.00M	$405.0M	$72.00M
YoY Change	37.5%	41.61%	-24.21%
Depreciation, Depletion And Amortization	$10.00M	$46.00M
YoY Change		6.98%
Cash From Operating Activities	$146.0M	$530.0M	$194.0M
YoY Change	-24.74%	369.03%	59.02%
INVESTING ACTIVITIES
Capital Expenditures	-$15.00M	$58.00M	-$8.000M
YoY Change	87.5%	41.46%	-46.67%
Acquisitions
YoY Change
Other Investing Activities	-$762.0M	$0.00	$460.0M
YoY Change	-265.65%		-233.33%
Cash From Investing Activities	-$777.0M	-$153.0M	$452.0M
YoY Change	-271.9%	-91.6%	-225.56%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$43.00M
YoY Change		13.16%
Debt Paid & Issued, Net		$438.0M
YoY Change		-23.69%
Cash From Financing Activities	14.00M	$1.733B	-163.0M
YoY Change	-108.59%	-30.49%	-171.49%
NET CHANGE
Cash From Operating Activities	146.0M	$530.0M	194.0M
Cash From Investing Activities	-777.0M	-$153.0M	452.0M
Cash From Financing Activities	14.00M	$1.733B	-163.0M
Net Change In Cash	-617.0M	$2.110B	483.0M
YoY Change	-227.74%	169.13%	-4930.0%
FREE CASH FLOW
Cash From Operating Activities	$146.0M	$530.0M	$194.0M
Capital Expenditures	-$15.00M	$58.00M	-$8.000M
Free Cash Flow	$161.0M	$472.0M	$202.0M
YoY Change	-20.3%	555.56%	47.45%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
CY2021	us-gaap	Goodwill Period Increase Decrease GoodwillPeriodIncreaseDecrease	0	USD
CY2021	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	PA
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 Registrant Name EntityRegistrantName	FNB CORP/PA/
CY2021	dei	Entity Central Index Key EntityCentralIndexKey	0000037808
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset Statement Of Financial Position Extensible List OperatingLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherAssets
CY2021Q4	us-gaap	Operating Lease Liability Statement Of Financial Position Extensible List OperatingLeaseLiabilityStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherLiabilities
CY2021Q4	us-gaap	Finance Lease Right Of Use Asset Statement Of Financial Position Extensible List FinanceLeaseRightOfUseAssetStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2021-01-31#PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization
CY2021Q4	us-gaap	Finance Lease Liability Statement Of Financial Position Extensible List FinanceLeaseLiabilityStatementOfFinancialPositionExtensibleList	http://fasb.org/us-gaap/2021-01-31#OtherLiabilities
CY2008	fnb	Defined Benefit Plan Assumptions Consecutive Period Of Highest Average Compensation DefinedBenefitPlanAssumptionsConsecutivePeriodOfHighestAverageCompensation	P5Y
CY2008	fnb	Defined Benefit Plan Assumptions Consecutive Term Of Employment DefinedBenefitPlanAssumptionsConsecutiveTermOfEmployment	P10Y
CY2021	dei	Document Type DocumentType	10-K
CY2021	dei	Document Annual Report DocumentAnnualReport	true
CY2021	dei	Document Period End Date DocumentPeriodEndDate	2021-12-31
CY2021	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--12-31
CY2021	dei	Document Transition Report DocumentTransitionReport	false
CY2021	dei	Entity File Number EntityFileNumber	001-31940
CY2021	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	25-1255406
CY2021	dei	Entity Address Address Line1 EntityAddressAddressLine1	One North Shore Center,
CY2021	dei	Entity Address Address Line2 EntityAddressAddressLine2	12 Federal Street,
CY2021	dei	Entity Address City Or Town EntityAddressCityOrTown	Pittsburgh,
CY2021	dei	Entity Address State Or Province EntityAddressStateOrProvince	PA
CY2021	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	15212
CY2021	dei	City Area Code CityAreaCode	800
CY2021	dei	Local Phone Number LocalPhoneNumber	555-5455
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
CY2021Q2	dei	Entity Public Float EntityPublicFloat	3814544208	USD
CY2022Q1	dei	Entity Common Stock Shares Outstanding EntityCommonStockSharesOutstanding	353095351	shares
CY2021Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	337000000	USD
CY2020Q4	us-gaap	Cash And Due From Banks CashAndDueFromBanks	369000000	USD
CY2021Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	3156000000	USD
CY2020Q4	us-gaap	Interest Bearing Deposits In Banks InterestBearingDepositsInBanks	1014000000	USD
CY2021Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	3493000000	USD
CY2020Q4	us-gaap	Cash And Cash Equivalents At Carrying Value CashAndCashEquivalentsAtCarryingValue	1383000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3416000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3380000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3426000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3463000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3506000000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2973000000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	3463000000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	2868000000	USD
CY2021Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	269000000	USD
CY2020Q4	us-gaap	Loans Held For Sale Fair Value Disclosure LoansHeldForSaleFairValueDisclosure	144000000	USD
CY2021Q4	fnb	Financing Receivable Held For Sale Net Not Part Of Disposal Group Excluding Accrued Interest FinancingReceivableHeldForSaleNetNotPartOfDisposalGroupExcludingAccruedInterest	295000000	USD
CY2020Q4	fnb	Financing Receivable Held For Sale Net Not Part Of Disposal Group Excluding Accrued Interest FinancingReceivableHeldForSaleNetNotPartOfDisposalGroupExcludingAccruedInterest	154000000	USD
CY2021Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	36000000	USD
CY2020Q4	us-gaap	Financing Receivable Deferred Income FinancingReceivableDeferredIncome	77000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	24968000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	25459000000	USD
CY2021Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	344000000	USD
CY2020Q4	us-gaap	Financing Receivable Allowance For Credit Loss Excluding Accrued Interest FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest	363000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	24624000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest After Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestAfterAllowanceForCreditLoss	25096000000	USD
CY2021Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	345000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	332000000	USD
CY2021Q4	us-gaap	Goodwill Goodwill	2262000000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	2262000000	USD
CY2021Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	42000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	54000000	USD
CY2021Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	546000000	USD
CY2020Q4	us-gaap	Bank Owned Life Insurance BankOwnedLifeInsurance	549000000	USD
CY2021Q4	us-gaap	Other Assets OtherAssets	1017000000	USD
CY2020Q4	us-gaap	Other Assets OtherAssets	1193000000	USD
CY2021Q4	us-gaap	Assets Assets	39513000000	USD
CY2020Q4	us-gaap	Assets Assets	37354000000	USD
CY2021Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10789000000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	9042000000	USD
CY2021Q4	us-gaap	Deposits Money Market Deposits And Negotiable Order Of Withdrawal Now DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW	14409000000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits And Negotiable Order Of Withdrawal Now DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW	13157000000	USD
CY2021Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3669000000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3261000000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	2859000000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	3662000000	USD
CY2021Q4	us-gaap	Deposits Deposits	31726000000	USD
CY2020Q4	us-gaap	Deposits Deposits	29122000000	USD
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	1536000000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	1804000000	USD
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	682000000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	1095000000	USD
CY2021Q4	us-gaap	Other Liabilities OtherLiabilities	419000000	USD
CY2020Q4	us-gaap	Other Liabilities OtherLiabilities	374000000	USD
CY2021Q4	us-gaap	Liabilities Liabilities	34363000000	USD
CY2020Q4	us-gaap	Liabilities Liabilities	32395000000	USD
CY2020Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2021Q4	us-gaap	Preferred Stock Par Or Stated Value Per Share PreferredStockParOrStatedValuePerShare	0.01
CY2021Q4	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	1000
CY2020Q4	us-gaap	Preferred Stock Liquidation Preference PreferredStockLiquidationPreference	1000
CY2021Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	20000000	shares
CY2021Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	110877	shares
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	110877	shares
CY2021Q4	us-gaap	Preferred Stock Value PreferredStockValue	107000000	USD
CY2020Q4	us-gaap	Preferred Stock Value PreferredStockValue	107000000	USD
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2021Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.01
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2021Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	500000000	shares
CY2021Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	329464669	shares
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	328057368	shares
CY2021Q4	us-gaap	Common Stock Value CommonStockValue	3000000	USD
CY2020Q4	us-gaap	Common Stock Value CommonStockValue	3000000	USD
CY2021Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	4109000000	USD
CY2020Q4	us-gaap	Additional Paid In Capital Common Stock AdditionalPaidInCapitalCommonStock	4087000000	USD
CY2021Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	1110000000	USD
CY2020Q4	us-gaap	Retained Earnings Accumulated Deficit RetainedEarningsAccumulatedDeficit	869000000	USD
CY2021Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-62000000	USD
CY2020Q4	us-gaap	Accumulated Other Comprehensive Income Loss Net Of Tax AccumulatedOtherComprehensiveIncomeLossNetOfTax	-39000000	USD
CY2021Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	10531177	shares
CY2020Q4	us-gaap	Treasury Stock Shares TreasuryStockShares	6427839	shares
CY2021Q4	us-gaap	Treasury Stock Value TreasuryStockValue	117000000	USD
CY2020Q4	us-gaap	Treasury Stock Value TreasuryStockValue	68000000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	5150000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	4959000000	USD
CY2021Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	39513000000	USD
CY2020Q4	us-gaap	Liabilities And Stockholders Equity LiabilitiesAndStockholdersEquity	37354000000	USD
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	886000000	USD
CY2020	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	990000000	USD
CY2019	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	1085000000	USD
CY2021	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	86000000	USD
CY2020	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	106000000	USD
CY2019	us-gaap	Interest Income Securities Taxable InterestIncomeSecuritiesTaxable	126000000	USD
CY2021	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	29000000	USD
CY2020	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	32000000	USD
CY2019	us-gaap	Interest Income Securities Tax Exempt InterestIncomeSecuritiesTaxExempt	32000000	USD
CY2021	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	4000000	USD
CY2020	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	2000000	USD
CY2019	us-gaap	Other Interest And Dividend Income OtherInterestAndDividendIncome	4000000	USD
CY2021	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1005000000	USD
CY2020	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1130000000	USD
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	1000000	USD
CY2019	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1247000000	USD
CY2021	us-gaap	Interest Expense Deposits InterestExpenseDeposits	47000000	USD
CY2020	us-gaap	Interest Expense Deposits InterestExpenseDeposits	133000000	USD
CY2019	us-gaap	Interest Expense Deposits InterestExpenseDeposits	217000000	USD
CY2021	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	27000000	USD
CY2020	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	38000000	USD
CY2019	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	80000000	USD
CY2021	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	24000000	USD
CY2020	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	37000000	USD
CY2019	us-gaap	Interest Expense Long Term Debt InterestExpenseLongTermDebt	33000000	USD
CY2021	us-gaap	Interest Expense InterestExpense	98000000	USD
CY2020	us-gaap	Interest Expense InterestExpense	208000000	USD
CY2019	us-gaap	Interest Expense InterestExpense	330000000	USD
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	907000000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	922000000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	917000000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	123000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	44000000	USD
CY2021	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	906000000	USD
CY2020	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	799000000	USD
CY2019	us-gaap	Interest Income Expense After Provision For Loan Loss InterestIncomeExpenseAfterProvisionForLoanLoss	873000000	USD
CY2021	fnb	Service Charges ServiceCharges	122000000	USD
CY2020	fnb	Service Charges ServiceCharges	108000000	USD
CY2019	fnb	Service Charges ServiceCharges	124000000	USD
CY2021	fnb	Trust Services TrustServices	37000000	USD
CY2020	fnb	Trust Services TrustServices	31000000	USD
CY2019	fnb	Trust Services TrustServices	28000000	USD
CY2021	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	25000000	USD
CY2020	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	24000000	USD
CY2019	us-gaap	Insurance Commissions And Fees InsuranceCommissionsAndFees	20000000	USD
CY2021	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	22000000	USD
CY2020	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	17000000	USD
CY2019	us-gaap	Investment Banking Advisory Brokerage And Underwriting Fees And Commissions InvestmentBankingAdvisoryBrokerageAndUnderwritingFeesAndCommissions	17000000	USD
CY2021	fnb	Capital Markets Income CapitalMarketsIncome	37000000	USD
CY2020	fnb	Capital Markets Income CapitalMarketsIncome	39000000	USD
CY2019	fnb	Capital Markets Income CapitalMarketsIncome	33000000	USD
CY2021	fnb	Mortgage Bank Operating Income MortgageBankOperatingIncome	37000000	USD
CY2020	fnb	Mortgage Bank Operating Income MortgageBankOperatingIncome	50000000	USD
CY2019	fnb	Mortgage Bank Operating Income MortgageBankOperatingIncome	32000000	USD
CY2021	fnb	Dividendson Nonmarketable Equity Securities DividendsonNonmarketableEquitySecurities	9000000	USD
CY2020	fnb	Dividendson Nonmarketable Equity Securities DividendsonNonmarketableEquitySecurities	14000000	USD
CY2019	fnb	Dividendson Nonmarketable Equity Securities DividendsonNonmarketableEquitySecurities	19000000	USD
CY2021	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	15000000	USD
CY2020	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	14000000	USD
CY2019	us-gaap	Bank Owned Life Insurance Income BankOwnedLifeInsuranceIncome	12000000	USD
CY2021	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-17000000	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	0	USD
CY2021	us-gaap	Noninterest Income Other NoninterestIncomeOther	26000000	USD
CY2020	us-gaap	Noninterest Income Other NoninterestIncomeOther	14000000	USD
CY2019	us-gaap	Noninterest Income Other NoninterestIncomeOther	9000000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	330000000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	294000000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	294000000	USD
CY2021	us-gaap	Labor And Related Expense LaborAndRelatedExpense	418000000	USD
CY2020	us-gaap	Labor And Related Expense LaborAndRelatedExpense	406000000	USD
CY2019	us-gaap	Labor And Related Expense LaborAndRelatedExpense	375000000	USD
CY2021	us-gaap	Occupancy Net OccupancyNet	58000000	USD
CY2020	us-gaap	Occupancy Net OccupancyNet	71000000	USD
CY2019	us-gaap	Occupancy Net OccupancyNet	59000000	USD
CY2021	us-gaap	Equipment Expense EquipmentExpense	70000000	USD
CY2020	us-gaap	Equipment Expense EquipmentExpense	66000000	USD
CY2019	us-gaap	Equipment Expense EquipmentExpense	62000000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	13000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	14000000	USD
CY2021	us-gaap	Professional Fees ProfessionalFees	71000000	USD
CY2020	us-gaap	Professional Fees ProfessionalFees	69000000	USD
CY2019	us-gaap	Professional Fees ProfessionalFees	64000000	USD
CY2021	us-gaap	Marketing Expense MarketingExpense	14000000	USD
CY2020	us-gaap	Marketing Expense MarketingExpense	13000000	USD
CY2019	us-gaap	Marketing Expense MarketingExpense	13000000	USD
CY2021	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	18000000	USD
CY2020	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	20000000	USD
CY2019	us-gaap	Federal Deposit Insurance Corporation Premium Expense FederalDepositInsuranceCorporationPremiumExpense	23000000	USD
CY2021	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	13000000	USD
CY2020	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	14000000	USD
CY2019	us-gaap	Taxes Excluding Income And Excise Taxes TaxesExcludingIncomeAndExciseTaxes	12000000	USD
CY2021	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	2000000	USD
CY2020	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2019	us-gaap	Business Combination Acquisition Related Costs BusinessCombinationAcquisitionRelatedCosts	0	USD
CY2021	us-gaap	Other Noninterest Expense OtherNoninterestExpense	57000000	USD
CY2020	us-gaap	Other Noninterest Expense OtherNoninterestExpense	78000000	USD
CY2019	us-gaap	Other Noninterest Expense OtherNoninterestExpense	74000000	USD
CY2021	us-gaap	Noninterest Expense NoninterestExpense	733000000	USD
CY2020	us-gaap	Noninterest Expense NoninterestExpense	750000000	USD
CY2019	us-gaap	Noninterest Expense NoninterestExpense	696000000	USD
CY2021	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	503000000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	343000000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	471000000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	98000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	57000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	84000000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	405000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	286000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	387000000	USD
CY2021	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2020	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2019	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	397000000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	397000000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	278000000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	278000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	379000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	379000000	USD
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.24
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.86
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.17
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.23
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.85
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.16
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	4000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	3000000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	405000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	286000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	387000000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	-16000000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	15000000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax	16000000	USD
CY2021	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	-57000000	USD
CY2020	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	54000000	USD
CY2019	us-gaap	Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax	57000000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	1000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-11000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationTax	-5000000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	4000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-40000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Before Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossBeforeReclassificationAfterTax	-17000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationTax	0	USD
CY2021	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	-14000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	-18000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Cash Flow Hedge Gain Loss Reclassification After Tax OtherComprehensiveIncomeLossCashFlowHedgeGainLossReclassificationAfterTax	2000000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-5000000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	2000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax	-1000000	USD
CY2021	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	16000000	USD
CY2020	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	-6000000	USD
CY2019	us-gaap	Other Comprehensive Income Defined Benefit Plans Net Unamortized Gain Loss Arising During Period Net Of Tax OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax	3000000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-23000000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	26000000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	41000000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	382000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	312000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	428000000	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	4608000000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	428000000	USD
CY2019	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	72.52
CY2019	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2019	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.48
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	157000000	USD
CY2019	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	0	USD
CY2019	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	12000000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	4883000000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	312000000	USD
CY2020	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	72.52
CY2020	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2020	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.48
CY2020	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	157000000	USD
CY2020	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	1000000	USD
CY2020	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	38000000	USD
CY2020	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	16000000	USD
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	4959000000	USD
CY2021	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	382000000	USD
CY2021	us-gaap	Preferred Stock Dividends Per Share Cash Paid PreferredStockDividendsPerShareCashPaid	72.52
CY2021	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2021	us-gaap	Common Stock Dividends Per Share Cash Paid CommonStockDividendsPerShareCashPaid	0.48
CY2021	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	156000000	USD
CY2021	us-gaap	Stock Issued During Period Value New Issues StockIssuedDuringPeriodValueNewIssues	-3000000	USD
CY2021	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	43000000	USD
CY2021	us-gaap	Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	19000000	USD
CY2021Q4	us-gaap	Stockholders Equity StockholdersEquity	5150000000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	405000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	286000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	387000000	USD
CY2021	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	10000000	USD
CY2020	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	-3000000	USD
CY2019	us-gaap	Depreciation Amortization And Accretion Net DepreciationAmortizationAndAccretionNet	45000000	USD
CY2021	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	1000000	USD
CY2020	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	123000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	44000000	USD
CY2021	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	15000000	USD
CY2020	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	-18000000	USD
CY2019	us-gaap	Deferred Income Taxes And Tax Credits DeferredIncomeTaxesAndTaxCredits	33000000	USD
CY2021	us-gaap	Payments To Purchase Loans Held For Sale PaymentsToPurchaseLoansHeldForSale	2034000000	USD
CY2020	us-gaap	Payments To Purchase Loans Held For Sale PaymentsToPurchaseLoansHeldForSale	1886000000	USD
CY2019	us-gaap	Payments To Purchase Loans Held For Sale PaymentsToPurchaseLoansHeldForSale	1481000000	USD
CY2021	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	1946000000	USD
CY2020	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	1830000000	USD
CY2019	us-gaap	Proceeds From Sale Of Loans Held For Sale ProceedsFromSaleOfLoansHeldForSale	1495000000	USD
CY2021	fnb	Gain Loss On Sale Of Financing Receivables GainLossOnSaleOfFinancingReceivables	53000000	USD
CY2020	fnb	Gain Loss On Sale Of Financing Receivables GainLossOnSaleOfFinancingReceivables	47000000	USD
CY2019	fnb	Gain Loss On Sale Of Financing Receivables GainLossOnSaleOfFinancingReceivables	25000000	USD
CY2021	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-14000000	USD
CY2020	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	-19000000	USD
CY2019	us-gaap	Increase Decrease In Accrued Interest Receivable Net IncreaseDecreaseInAccruedInterestReceivableNet	8000000	USD
CY2021	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-3000000	USD
CY2020	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	-8000000	USD
CY2019	us-gaap	Increase Decrease In Interest Payable Net IncreaseDecreaseInInterestPayableNet	1000000	USD
CY2021	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	-3000000	USD
CY2020	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	6000000	USD
CY2019	us-gaap	Life Insurance Corporate Or Bank Owned Change In Value LifeInsuranceCorporateOrBankOwnedChangeInValue	7000000	USD
CY2021	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-226000000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	177000000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	225000000	USD
CY2021	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	530000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	113000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	259000000	USD
CY2021	fnb	Payments For Proceeds From Financing Receivables PaymentsForProceedsFromFinancingReceivables	-558000000	USD
CY2020	fnb	Payments For Proceeds From Financing Receivables PaymentsForProceedsFromFinancingReceivables	2604000000	USD
CY2019	fnb	Payments For Proceeds From Financing Receivables PaymentsForProceedsFromFinancingReceivables	1427000000	USD
CY2021	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	1683000000	USD
CY2020	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	2360000000	USD
CY2019	us-gaap	Payments To Acquire Available For Sale Securities Debt PaymentsToAcquireAvailableForSaleSecuritiesDebt	655000000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	1634000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	2244000000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	770000000	USD
CY2021	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	1448000000	USD
CY2020	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	301000000	USD
CY2019	us-gaap	Payments To Acquire Held To Maturity Securities PaymentsToAcquireHeldToMaturitySecurities	494000000	USD
CY2021	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	844000000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	703000000	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfHeldToMaturitySecurities	468000000	USD
CY2021	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	58000000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	41000000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	46000000	USD
CY2021	fnb	Proceedsfrom Loans Sold Not Originatedfor Sale ProceedsfromLoansSoldNotOriginatedforSale	0	USD
CY2020	fnb	Proceedsfrom Loans Sold Not Originatedfor Sale ProceedsfromLoansSoldNotOriginatedforSale	537000000	USD
CY2019	fnb	Proceedsfrom Loans Sold Not Originatedfor Sale ProceedsfromLoansSoldNotOriginatedforSale	262000000	USD
CY2021	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
CY2020	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	0	USD
CY2019	us-gaap	Payments For Proceeds From Other Investing Activities PaymentsForProceedsFromOtherInvestingActivities	9000000	USD
CY2021	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-153000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1822000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-1131000000	USD
CY2021	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	3406000000	USD
CY2020	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	5402000000	USD
CY2019	us-gaap	Increase Decrease In Demand Deposits IncreaseDecreaseInDemandDeposits	1873000000	USD
CY2021	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-802000000	USD
CY2020	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-1065000000	USD
CY2019	us-gaap	Increase Decrease In Time Deposits IncreaseDecreaseInTimeDeposits	-539000000	USD
CY2021	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-267000000	USD
CY2020	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-1412000000	USD
CY2019	us-gaap	Proceeds From Repayments Of Short Term Debt ProceedsFromRepaymentsOfShortTermDebt	-913000000	USD
CY2021	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	25000000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	328000000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	954000000	USD
CY2021	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	438000000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	574000000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	239000000	USD
CY2021	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	43000000	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	38000000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2021	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	8000000	USD
CY2020	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	8000000	USD
CY2019	us-gaap	Payments Of Dividends Preferred Stock And Preference Stock PaymentsOfDividendsPreferredStockAndPreferenceStock	8000000	USD
CY2021	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	156000000	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	157000000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	157000000	USD
CY2021	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	16000000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	17000000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	12000000	USD
CY2021	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	1733000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	2493000000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	983000000	USD
CY2021	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	2110000000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	784000000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	111000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1383000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	599000000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	488000000	USD
CY2021Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	3493000000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	1383000000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	599000000	USD
CY2021	us-gaap	Nature Of Operations NatureOfOperations	<div><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:700;line-height:120%">NATURE OF OPERATIONS</span></div><div style="margin-top:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">F.N.B. Corporation, headquartered in Pittsburgh, Pennsylvania, is a diversified financial services company operating in seven states and the District of Columbia. Our market coverage spans several major metropolitan areas including: Pittsburgh, Pennsylvania; Baltimore, Maryland; Cleveland, Ohio; Washington, D.C.; and Charlotte, Raleigh, Durham and the Piedmont Triad (Winston-Salem, Greensboro and High Point) in North Carolina. As of December 31, 2021, we had 334 banking offices throughout Pennsylvania, Ohio, Maryland, West Virginia, North Carolina, South Carolina, Washington D.C. and Virginia.</span></div><div style="margin-top:12pt"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:10pt;font-weight:400;line-height:120%">We provide a full range of commercial banking, consumer banking, and wealth management solutions through our subsidiary network which is led by our largest affiliate, FNBPA, founded in 1864. Commercial banking solutions include corporate banking, small business banking, investment real estate financing, government banking, business credit, capital markets and lease financing. Consumer banking provides a full line of consumer banking products and services including deposit products, mortgage lending, consumer lending and a complete suite of mobile and online banking services. Wealth management services include asset management, private banking and insurance.</span></div>
CY2021Q4	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	7	state
CY2021Q4	us-gaap	Number Of Stores NumberOfStores	334	bank
CY2021	us-gaap	Use Of Estimates UseOfEstimates	Use of EstimatesOur accounting and reporting policies conform with GAAP. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect the amounts reported in the Consolidated Financial Statements and accompanying Notes to Consolidated Financial Statements. Actual results could materially differ from those estimates. Material estimates that are particularly susceptible to significant changes include the ACL, accounting for loans acquired in a business combination prior to January 1, 2020, fair value of financial instruments, goodwill and other intangible assets, income taxes and DTAs and litigation reserves.
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	105000000	USD
CY2020Q1	fnb	Financing Receivable Purchasedwith Credit Deterioration Amountat Purchase Price Included With Allowance For Credit Losses Adjustment FinancingReceivablePurchasedwithCreditDeteriorationAmountatPurchasePriceIncludedWithAllowanceForCreditLossesAdjustment	50300000	USD
CY2019Q4	fnb	Impaired Financing Receivable Allowances For Commercial Loans ImpairedFinancingReceivableAllowancesForCommercialLoans	1000000	USD
CY2021	fnb	Core Deposits Intangibles Amortization Period CoreDepositsIntangiblesAmortizationPeriod	P10Y
CY2021Q4	fnb	Income Tax Examination Likelihood Of Unfavorable Settlement Percentage IncomeTaxExaminationLikelihoodOfUnfavorableSettlementPercentage	0.50
CY2020Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesAvailableForSaleAmortizedCostAllowanceForCreditLossExcludingAccruedInterest	0	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3416000000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	36000000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	26000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3426000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Amortized Cost Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesAvailableForSaleAmortizedCostExcludingAccruedInterestBeforeAllowanceForCreditLoss	3380000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax	84000000	USD
CY2020Q4	us-gaap	Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax	1000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3463000000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	3463000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	62000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	19000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3506000000	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	2868000000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Gain HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain	105000000	USD
CY2020Q4	us-gaap	Held To Maturity Securities Accumulated Unrecognized Holding Loss HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss	0	USD
CY2020Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	2973000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost	45000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Within One Year Fair Value AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue	45000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount	1000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Within One Year Fair Value HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue	1000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost	374000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After One Through Five Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	371000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount	21000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue	22000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost	96000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	97000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount	142000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue	144000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Amortized Cost AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost	73000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities After Ten Years Fair Value AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue	73000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount	855000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities After Ten Years Fair Value HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue	891000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date Amortized Cost Basis AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	588000000	USD
CY2021Q4	us-gaap	Available For Sale Securities Debt Maturities Single Maturity Date AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate	586000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Amortized Cost Basis HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis	1019000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Debt Maturities Single Maturity Date Fair Value HeldToMaturitySecuritiesDebtMaturitiesSingleMaturityDateFairValue	1058000000	USD
CY2021Q4	us-gaap	Available For Sale Debt Securities Amortized Cost Basis AvailableForSaleDebtSecuritiesAmortizedCostBasis	3416000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Excluding Accrued Interest DebtSecuritiesAvailableForSaleExcludingAccruedInterest	3426000000	USD
CY2021Q4	us-gaap	Debt Securities Held To Maturity Excluding Accrued Interest Before Allowance For Credit Loss DebtSecuritiesHeldToMaturityExcludingAccruedInterestBeforeAllowanceForCreditLoss	3463000000	USD
CY2021Q4	us-gaap	Held To Maturity Securities Fair Value HeldToMaturitySecuritiesFairValue	3506000000	USD
CY2021Q4	fnb	Securities With Carrying Value Pledged To Secure Public Deposits Trust Deposits And For Other Purposes SecuritiesWithCarryingValuePledgedToSecurePublicDepositsTrustDepositsAndForOtherPurposes	5660000000	USD
CY2020Q4	fnb	Securities With Carrying Value Pledged To Secure Public Deposits Trust Deposits And For Other Purposes SecuritiesWithCarryingValuePledgedToSecurePublicDepositsTrustDepositsAndForOtherPurposes	5384000000	USD
CY2021Q4	us-gaap	Securities Held As Collateral At Fair Value SecuritiesHeldAsCollateralAtFairValue	392000000	USD
CY2020Q4	us-gaap	Securities Held As Collateral At Fair Value SecuritiesHeldAsCollateralAtFairValue	402000000	USD
CY2021Q4	fnb	Percentage Of Securities Held As Collateral At Fair Value PercentageOfSecuritiesHeldAsCollateralAtFairValue	0.879
CY2020Q4	fnb	Percentage Of Securities Held As Collateral At Fair Value PercentageOfSecuritiesHeldAsCollateralAtFairValue	0.914
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	60	security
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	1679000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	23000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	14	security
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	102000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	3000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	74	security
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	1781000000	USD
CY2021Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	26000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsNumberOfPositions	7	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12Months	168000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than12 Months Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss	1000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Number Of Positions DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerNumberOfPositions	17	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLonger	71000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Continuous Unrealized Loss Position12 Months Or Longer Accumulated Loss DebtSecuritiesAvailableForSaleContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss	0	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Number Of Positions DebtSecuritiesAvailableForSaleUnrealizedLossPositionNumberOfPositions	24	security
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position DebtSecuritiesAvailableForSaleUnrealizedLossPosition	239000000	USD
CY2020Q4	us-gaap	Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss DebtSecuritiesAvailableForSaleUnrealizedLossPositionAccumulatedLoss	1000000	USD
CY2021Q4	us-gaap	Municipal Debt Securities At Carrying Value MunicipalDebtSecuritiesAtCarryingValue	1000000000	USD
CY2021Q4	fnb	Municipal Bonds Percent With Formal Credit Enhancement Insurance MunicipalBondsPercentWithFormalCreditEnhancementInsurance	0.61
CY2021Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	50000.00	USD
CY2020Q4	us-gaap	Debt Securities Held To Maturity Allowance For Credit Loss Excluding Accrued Interest DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest	40000.00	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	122000000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Stock FederalHomeLoanBankStock	154000000	USD
CY2021Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	123000000	USD
CY2020Q4	us-gaap	Federal Reserve Bank Stock FederalReserveBankStock	124000000	USD
CY2021Q4	us-gaap	Other Investments OtherInvestments	245000000	USD
CY2020Q4	us-gaap	Other Investments OtherInvestments	278000000	USD
CY2021Q4	fnb	Other Nonmarketable Equity Securities Impairment OtherNonmarketableEquitySecuritiesImpairment	0	USD
CY2020Q4	fnb	Other Nonmarketable Equity Securities Impairment OtherNonmarketableEquitySecuritiesImpairment	0	USD
CY2021Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	48900000	USD
CY2020Q4	us-gaap	Financing Receivable Accrued Interest Before Allowance For Credit Loss FinancingReceivableAccruedInterestBeforeAllowanceForCreditLoss	62900000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	24968000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	25459000000	USD
CY2020Q1	fnb	Financing Receivable Purchasedwith Credit Deterioration Amountat Purchase Price Included With Allowance For Credit Losses Adjustment FinancingReceivablePurchasedwithCreditDeteriorationAmountatPurchasePriceIncludedWithAllowanceForCreditLossesAdjustment	50300000	USD
CY2020Q1	us-gaap	Financing Receivable Purchased With Credit Deterioration Discount Premium FinancingReceivablePurchasedWithCreditDeteriorationDiscountPremium	110000000	USD
CY2021Q4	fnb	Financing Receivable Discount Premium Remaining FinancingReceivableDiscountPremiumRemaining	30000000	USD
CY2020Q4	fnb	Financing Receivable Discount Premium Remaining FinancingReceivableDiscountPremiumRemaining	50900000	USD
CY2021Q4	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	7	state
CY2020Q4	fnb	Financing Receivables Related Parties FinancingReceivablesRelatedParties	7000000	USD
CY2021	fnb	Financing Receivables Related Parties Additions FinancingReceivablesRelatedPartiesAdditions	2000000	USD
CY2021	fnb	Financing Receivables Related Parties Proceeds FinancingReceivablesRelatedPartiesProceeds	3000000	USD
CY2021Q4	fnb	Financing Receivables Related Parties FinancingReceivablesRelatedParties	6000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	6587000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	4518000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	3256000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	1952000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	1579000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	4130000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	2946000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	24968000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year One Originated Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearOneOriginatedCurrentFiscalYear	7565000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Two Originated Fiscal Year Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearTwoOriginatedFiscalYearBeforeCurrentFiscalYear	4429000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Three Originated Two Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearThreeOriginatedTwoYearsBeforeCurrentFiscalYear	2837000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Four Originated Three Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFourOriginatedThreeYearsBeforeCurrentFiscalYear	2281000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Year Five Originated Four Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestYearFiveOriginatedFourYearsBeforeCurrentFiscalYear	1800000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Originated More Than Five Years Before Current Fiscal Year FinancingReceivableExcludingAccruedInterestOriginatedMoreThanFiveYearsBeforeCurrentFiscalYear	3917000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Revolving FinancingReceivableExcludingAccruedInterestRevolving	2630000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	25459000000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	6000000	USD
CY2021Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	88000000	USD
CY2021Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	24968000000	USD
CY2021Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	24000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment90 Days Past Due And Still Accruing FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing	16000000	USD
CY2020Q4	us-gaap	Financing Receivable Recorded Investment Nonaccrual Status FinancingReceivableRecordedInvestmentNonaccrualStatus	170000000	USD
CY2020Q4	us-gaap	Financing Receivable Excluding Accrued Interest Before Allowance For Credit Loss FinancingReceivableExcludingAccruedInterestBeforeAllowanceForCreditLoss	25459000000	USD
CY2020Q4	us-gaap	Financing Receivable Nonaccrual No Allowance FinancingReceivableNonaccrualNoAllowance	52000000	USD
CY2021Q4	fnb	Financing Receivable Short Term Modification Due To Unusual Or Infrequent Event FinancingReceivableShortTermModificationDueToUnusualOrInfrequentEvent	21000000	USD
CY2020Q4	fnb	Financing Receivable Short Term Modification Due To Unusual Or Infrequent Event FinancingReceivableShortTermModificationDueToUnusualOrInfrequentEvent	397000000	USD
CY2020Q2	fnb	Financing Receivable Short Term Modification Due To Unusual Or Infrequent Event FinancingReceivableShortTermModificationDueToUnusualOrInfrequentEvent	2400000000	USD
CY2021Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	92000000	USD
CY2020Q4	us-gaap	Financing Receivable Modifications Recorded Investment FinancingReceivableModificationsRecordedInvestment	91000000	USD
CY2021	fnb	Restructured Loans Receivable Returned To Performing Status RestructuredLoansReceivableReturnedToPerformingStatus	7400000	USD
CY2021Q4	fnb	Financing Receivable Pooled Allowance Restructured FinancingReceivablePooledAllowanceRestructured	3900000	USD
CY2020Q4	fnb	Financing Receivable Pooled Allowance Restructured FinancingReceivablePooledAllowanceRestructured	4100000	USD
CY2021	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	139	contract
CY2021	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	30000000	USD
CY2021	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	28000000	USD
CY2020	us-gaap	Financing Receivable Modifications Number Of Contracts2 FinancingReceivableModificationsNumberOfContracts2	187	contract
CY2020	us-gaap	Financing Receivable Modifications Pre Modification Recorded Investment2 FinancingReceivableModificationsPreModificationRecordedInvestment2	29000000	USD
CY2020	us-gaap	Financing Receivable Modifications Post Modification Recorded Investment2 FinancingReceivableModificationsPostModificationRecordedInvestment2	17000000	USD
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	3	contract
CY2021	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	0	USD
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Number Of Contracts1 FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1	30	contract
CY2020	us-gaap	Financing Receivable Modifications Subsequent Default Recorded Investment1 FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1	3000000	USD
CY2020Q1	us-gaap	Financing Receivable Allowance For Credit Losses Period Increase Decrease FinancingReceivableAllowanceForCreditLossesPeriodIncreaseDecrease	105000000	USD
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Growth Housing Price Index ForecastedMacroeconomicVariablesPercentageOfGrowthHousingPriceIndex	0.063
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Growth Commercial Real Estate Price Index ForecastedMacroeconomicVariablesPercentageOfGrowthCommercialRealEstatePriceIndex	0.130
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Growth Sp Volatility In Next Fiscal Year ForecastedMacroeconomicVariablesPercentageOfGrowthSPVolatilityInNextFiscalYear	0.152
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Decline Sp Volatility In Next Second Year ForecastedMacroeconomicVariablesPercentageOfDeclineSPVolatilityInNextSecondYear	0.019
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Growth Gross Domestic Product ForecastedMacroeconomicVariablesPercentageOfGrowthGrossDomesticProduct	0.04
CY2021Q4	fnb	Forecasted Macroeconomic Variables Percentage Of Unemployment ForecastedMacroeconomicVariablesPercentageOfUnemployment	0.06
CY2018Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	180000000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Write Offs FinancingReceivableAllowanceForCreditLossesWriteOffs	42000000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Losses Recovery FinancingReceivableAllowanceForCreditLossesRecovery	14000000	USD
CY2019	us-gaap	Financing Receivable Allowance For Credit Loss Writeoff After Recovery FinancingReceivableAllowanceForCreditLossWriteoffAfterRecovery	28000000	USD
CY2019	us-gaap	Provision For Loan Losses Expensed ProvisionForLoanLossesExpensed	44000000	USD
CY2019Q4	us-gaap	Financing Receivable Allowance For Credit Losses FinancingReceivableAllowanceForCreditLosses	196000000	USD
CY2021Q4	us-gaap	Land Land	59000000	USD
CY2020Q4	us-gaap	Land Land	57000000	USD
CY2021Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	229000000	USD
CY2020Q4	us-gaap	Buildings And Improvements Gross BuildingsAndImprovementsGross	231000000	USD
CY2021Q4	us-gaap	Machinery And Equipment Gross MachineryAndEquipmentGross	344000000	USD
CY2020Q4	us-gaap	Machinery And Equipment Gross MachineryAndEquipmentGross	311000000	USD
CY2021Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	12000000	USD
CY2020Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	0	USD
CY2021Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Before Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization	644000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Before Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetBeforeAccumulatedDepreciationAndAmortization	599000000	USD
CY2021Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization	299000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAccumulatedDepreciationAndAmortization	267000000	USD
CY2021Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	345000000	USD
CY2020Q4	us-gaap	Property Plant And Equipment And Finance Lease Right Of Use Asset After Accumulated Depreciation And Amortization PropertyPlantAndEquipmentAndFinanceLeaseRightOfUseAssetAfterAccumulatedDepreciationAndAmortization	332000000	USD
CY2021	us-gaap	Depreciation Depreciation	46000000	USD
CY2020	us-gaap	Depreciation Depreciation	43000000	USD
CY2019	us-gaap	Depreciation Depreciation	42000000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	2262000000	USD
CY2020	us-gaap	Goodwill Period Increase Decrease GoodwillPeriodIncreaseDecrease	0	USD
CY2020Q4	us-gaap	Goodwill Goodwill	2262000000	USD
CY2021Q4	us-gaap	Goodwill Goodwill	2262000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	215000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	173000000	USD
CY2021Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	42000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	215000000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	161000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Excluding Goodwill IntangibleAssetsNetExcludingGoodwill	54000000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	13000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	14000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	10000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	10000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	8000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	7000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	5000000	USD
CY2021Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	40000000	USD
CY2021Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	139700000	USD
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	148600000	USD
CY2021Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	11900000	USD
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	12000000	USD
CY2021Q4	fnb	Lessee Operating Lease Lease Not Yet Commenced Right Of Use Asset LesseeOperatingLeaseLeaseNotYetCommencedRightOfUseAsset	69200000	USD
CY2021Q4	fnb	Lessee Operating Lease Lease Not Yet Commenced Liability LesseeOperatingLeaseLeaseNotYetCommencedLiability	90600000	USD
CY2021	us-gaap	Operating Lease Cost OperatingLeaseCost	29000000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	27000000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	27000000	USD
CY2021	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1000000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1000000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	1000000	USD
CY2021	us-gaap	Variable Lease Cost VariableLeaseCost	3000000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	3000000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	4000000	USD
CY2021	us-gaap	Lease Cost LeaseCost	33000000	USD
CY2020	us-gaap	Lease Cost LeaseCost	31000000	USD
CY2019	us-gaap	Lease Cost LeaseCost	32000000	USD
CY2021	us-gaap	Operating Lease Payments OperatingLeasePayments	27000000	USD
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	26000000	USD
CY2021	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	0	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	0	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	23000000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	20000000	USD
CY2021	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	12000000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Finance Lease Liability RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability	0	USD
CY2021Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P9Y9M29D
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P9Y5M12D
CY2021Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P23Y1M2D
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P0Y
CY2021Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.024
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.026
CY2021Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.019
CY2020Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	26000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	0	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid Year One OperatingAndFinanceLeaseLiabilityToBePaidYearOne	26000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	22000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	0	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid Year Two OperatingAndFinanceLeaseLiabilityToBePaidYearTwo	22000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	20000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	0	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid Year Three OperatingAndFinanceLeaseLiabilityToBePaidYearThree	20000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	15000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	0	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid Year Four OperatingAndFinanceLeaseLiabilityToBePaidYearFour	15000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	12000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	0	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid Year Five OperatingAndFinanceLeaseLiabilityToBePaidYearFive	12000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	75000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	15000000	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid After Year Five OperatingAndFinanceLeaseLiabilityToBePaidAfterYearFive	90000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	170000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	15000000	USD
CY2021Q4	fnb	Operating And Finance Lease Liability To Be Paid OperatingAndFinanceLeaseLiabilityToBePaid	185000000	USD
CY2021Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	21000000	USD
CY2021Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	3000000	USD
CY2021Q4	fnb	Operating And Finance Lease Liability Undiscounted Excess Amount OperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount	24000000	USD
CY2021Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	149000000	USD
CY2021Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	12000000	USD
CY2021Q4	fnb	Operating And Finance Lease Liability OperatingAndFinanceLeaseLiability	161000000	USD
CY2021Q4	fnb	Proportional Amortization Method Qualified Affordable Housing Project Investments Other Assets ProportionalAmortizationMethodQualifiedAffordableHousingProjectInvestmentsOtherAssets	86000000	USD
CY2020Q4	fnb	Proportional Amortization Method Qualified Affordable Housing Project Investments Other Assets ProportionalAmortizationMethodQualifiedAffordableHousingProjectInvestmentsOtherAssets	71000000	USD
CY2021Q4	fnb	Equity Method Qualified Affordable Housing Project Investments Other Assets EquityMethodQualifiedAffordableHousingProjectInvestmentsOtherAssets	1000000	USD
CY2020Q4	fnb	Equity Method Qualified Affordable Housing Project Investments Other Assets EquityMethodQualifiedAffordableHousingProjectInvestmentsOtherAssets	3000000	USD
CY2021Q4	fnb	Qualified Affordable Housing Project Investments Other Assets QualifiedAffordableHousingProjectInvestmentsOtherAssets	87000000	USD
CY2020Q4	fnb	Qualified Affordable Housing Project Investments Other Assets QualifiedAffordableHousingProjectInvestmentsOtherAssets	74000000	USD
CY2021Q4	fnb	Qualified Affordable Housing Project Investments Unfunded Commitments QualifiedAffordableHousingProjectInvestmentsUnfundedCommitments	34000000	USD
CY2020Q4	fnb	Qualified Affordable Housing Project Investments Unfunded Commitments QualifiedAffordableHousingProjectInvestmentsUnfundedCommitments	45000000	USD
CY2021	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1000000	USD
CY2020	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1000000	USD
CY2019	us-gaap	Amortization Method Qualified Affordable Housing Project Investments Amortization AmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	1000000	USD
CY2021	fnb	Proportional Amortization Method Qualified Affordable Housing Project Investments Amortization ProportionalAmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	13000000	USD
CY2020	fnb	Proportional Amortization Method Qualified Affordable Housing Project Investments Amortization ProportionalAmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	11000000	USD
CY2019	fnb	Proportional Amortization Method Qualified Affordable Housing Project Investments Amortization ProportionalAmortizationMethodQualifiedAffordableHousingProjectInvestmentsAmortization	8000000	USD
CY2021	fnb	Amortization Method Qualified Affordable Housing Project Investments Low Income Housing Tax Credit AmortizationMethodQualifiedAffordableHousingProjectInvestmentsLowIncomeHousingTaxCredit	-15000000	USD
CY2020	fnb	Amortization Method Qualified Affordable Housing Project Investments Low Income Housing Tax Credit AmortizationMethodQualifiedAffordableHousingProjectInvestmentsLowIncomeHousingTaxCredit	-12000000	USD
CY2019	fnb	Amortization Method Qualified Affordable Housing Project Investments Low Income Housing Tax Credit AmortizationMethodQualifiedAffordableHousingProjectInvestmentsLowIncomeHousingTaxCredit	-9000000	USD
CY2021	fnb	Amortization Method Qualified Affordable Housing Project Investments Other Tax Benefits Relatedto Tax Credit Investments AmortizationMethodQualifiedAffordableHousingProjectInvestmentsOtherTaxBenefitsRelatedtoTaxCreditInvestments	-2000000	USD
CY2020	fnb	Amortization Method Qualified Affordable Housing Project Investments Other Tax Benefits Relatedto Tax Credit Investments AmortizationMethodQualifiedAffordableHousingProjectInvestmentsOtherTaxBenefitsRelatedtoTaxCreditInvestments	-2000000	USD
CY2019	fnb	Amortization Method Qualified Affordable Housing Project Investments Other Tax Benefits Relatedto Tax Credit Investments AmortizationMethodQualifiedAffordableHousingProjectInvestmentsOtherTaxBenefitsRelatedtoTaxCreditInvestments	-2000000	USD
CY2021	fnb	Amortization Method Qualified Affordable Housing Project Investments Provision For Income Tax AmortizationMethodQualifiedAffordableHousingProjectInvestmentsProvisionForIncomeTax	-4000000	USD
CY2020	fnb	Amortization Method Qualified Affordable Housing Project Investments Provision For Income Tax AmortizationMethodQualifiedAffordableHousingProjectInvestmentsProvisionForIncomeTax	-3000000	USD
CY2019	fnb	Amortization Method Qualified Affordable Housing Project Investments Provision For Income Tax AmortizationMethodQualifiedAffordableHousingProjectInvestmentsProvisionForIncomeTax	-3000000	USD
CY2021Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	10789000000	USD
CY2020Q4	us-gaap	Noninterest Bearing Deposit Liabilities NoninterestBearingDepositLiabilities	9042000000	USD
CY2021Q4	us-gaap	Deposits Money Market Deposits And Negotiable Order Of Withdrawal Now DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW	14409000000	USD
CY2020Q4	us-gaap	Deposits Money Market Deposits And Negotiable Order Of Withdrawal Now DepositsMoneyMarketDepositsAndNegotiableOrderOfWithdrawalNOW	13157000000	USD
CY2021Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3669000000	USD
CY2020Q4	us-gaap	Deposits Savings Deposits DepositsSavingsDeposits	3261000000	USD
CY2021Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	1540000000	USD
CY2020Q4	us-gaap	Time Deposits Less Than100000 TimeDepositsLessThan100000	1895000000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	2859000000	USD
CY2021Q4	fnb	Time Deposits100000 Through250000 TimeDeposits100000Through250000	866000000	USD
CY2020Q4	fnb	Time Deposits100000 Through250000 TimeDeposits100000Through250000	1173000000	USD
CY2021Q4	fnb	Time Deposits250000 Or More TimeDeposits250000OrMore	453000000	USD
CY2020Q4	fnb	Time Deposits250000 Or More TimeDeposits250000OrMore	594000000	USD
CY2021Q4	us-gaap	Time Deposits TimeDeposits	2859000000	USD
CY2020Q4	us-gaap	Time Deposits TimeDeposits	3662000000	USD
CY2021Q4	us-gaap	Deposits Deposits	31726000000	USD
CY2020Q4	us-gaap	Deposits Deposits	29122000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year One TimeDepositMaturitiesYearOne	2047000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Two TimeDepositMaturitiesYearTwo	440000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Three TimeDepositMaturitiesYearThree	160000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Four TimeDepositMaturitiesYearFour	103000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities Year Five TimeDepositMaturitiesYearFive	91000000	USD
CY2021Q4	us-gaap	Time Deposit Maturities After Year Five TimeDepositMaturitiesAfterYearFive	18000000	USD
CY2021Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	376000000	USD
CY2020Q4	us-gaap	Securities Sold Under Agreements To Repurchase SecuritiesSoldUnderAgreementsToRepurchase	403000000	USD
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	1030000000	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Maturities Summary Due Within One Year Of Balance Sheet Date FederalHomeLoanBankAdvancesMaturitiesSummaryDueWithinOneYearOfBalanceSheetDate	1280000000	USD
CY2021Q4	fnb	Subordinated Notes Short Term SubordinatedNotesShortTerm	130000000	USD
CY2020Q4	fnb	Subordinated Notes Short Term SubordinatedNotesShortTerm	121000000	USD
CY2021Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	1536000000	USD
CY2020Q4	us-gaap	Short Term Borrowings ShortTermBorrowings	1804000000	USD
CY2021Q4	fnb	Shortterm Advances Overnight Maturities ShorttermAdvancesOvernightMaturities	0	USD
CY2020Q4	fnb	Shortterm Advances Overnight Maturities ShorttermAdvancesOvernightMaturities	0	USD
CY2021Q4	fnb	Shortterm Advances ShorttermAdvances	1000000000	USD
CY2021Q4	fnb	Shortterm Advances Percentage Bearing Fixed Interest Rate ShorttermAdvancesPercentageBearingFixedInterestRate	1.000
CY2020Q4	fnb	Shortterm Advances ShorttermAdvances	1300000000	USD
CY2020Q4	fnb	Shortterm Advances Percentage Bearing Fixed Interest Rate ShorttermAdvancesPercentageBearingFixedInterestRate	1.000
CY2021	fnb	Short Term Debt Weighted Average Interest Rate During Period ShortTermDebtWeightedAverageInterestRateDuringPeriod	0.0161
CY2020	fnb	Short Term Debt Weighted Average Interest Rate During Period ShortTermDebtWeightedAverageInterestRateDuringPeriod	0.0153
CY2019	fnb	Short Term Debt Weighted Average Interest Rate During Period ShortTermDebtWeightedAverageInterestRateDuringPeriod	0.0224
CY2021Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0161
CY2020Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0157
CY2019Q4	us-gaap	Short Term Debt Weighted Average Interest Rate ShortTermDebtWeightedAverageInterestRate	0.0176
CY2021Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	0	USD
CY2020Q4	us-gaap	Federal Home Loan Bank Advances Long Term FederalHomeLoanBankAdvancesLongTerm	400000000	USD
CY2021Q4	us-gaap	Senior Notes SeniorNotes	299000000	USD
CY2020Q4	us-gaap	Senior Notes SeniorNotes	299000000	USD
CY2021Q4	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	68000000	USD
CY2020Q4	us-gaap	Subordinated Long Term Debt SubordinatedLongTermDebt	81000000	USD
CY2021Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	67000000	USD
CY2020Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	66000000	USD
CY2021Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	248000000	USD
CY2020Q4	us-gaap	Other Long Term Debt OtherLongTermDebt	249000000	USD
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	682000000	USD
CY2020Q4	us-gaap	Long Term Debt LongTermDebt	1095000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Next Twelve Months LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths	18000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Two LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	336000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Three LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	3000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Four LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour	104000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal In Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	6000000	USD
CY2021Q4	us-gaap	Long Term Debt Maturities Repayments Of Principal After Year Five LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	215000000	USD
CY2021Q4	us-gaap	Long Term Debt LongTermDebt	682000000	USD
CY2021Q4	us-gaap	Longterm Debt Weighted Average Interest Rate LongtermDebtWeightedAverageInterestRate	0.0312
CY2020Q4	us-gaap	Longterm Debt Weighted Average Interest Rate LongtermDebtWeightedAverageInterestRate	0.0323
CY2019Q4	us-gaap	Longterm Debt Weighted Average Interest Rate LongtermDebtWeightedAverageInterestRate	0.0333
CY2021Q4	fnb	Number Of Unconsolidated Subsidiary Trusts NumberOfUnconsolidatedSubsidiaryTrusts	3	trust
CY2021Q4	fnb	Percentage Of Each Trust Common Equity Owned PercentageOfEachTrustCommonEquityOwned	1
CY2021Q4	us-gaap	Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust JuniorSubordinatedDebentureOwedToUnconsolidatedSubsidiaryTrust	67000000	USD
CY2021Q4	us-gaap	Debt Instrument Face Amount DebtInstrumentFaceAmount	558000000	USD
CY2021	us-gaap	Proceeds From Debt Net Of Issuance Costs ProceedsFromDebtNetOfIssuanceCosts	560000000	USD
CY2021Q4	us-gaap	Long Term Debt Fair Value LongTermDebtFairValue	547000000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	3000000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	20000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	3000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	37000000	USD
CY2021Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	182000000	USD
CY2021Q4	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	25000000	USD
CY2020Q4	us-gaap	Derivative Asset Not Subject To Master Netting Arrangement DerivativeAssetNotSubjectToMasterNettingArrangement	373000000	USD
CY2020Q4	us-gaap	Derivative Liability Not Subject To Master Netting Arrangement DerivativeLiabilityNotSubjectToMasterNettingArrangement	3000000	USD
CY2021Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	14526000000	USD
CY2021Q4	us-gaap	Derivative Assets DerivativeAssets	185000000	USD
CY2021Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	45000000	USD
CY2020Q4	us-gaap	Derivative Notional Amount DerivativeNotionalAmount	12480000000	USD
CY2020Q4	us-gaap	Derivative Assets DerivativeAssets	376000000	USD
CY2020Q4	us-gaap	Derivative Liabilities DerivativeLiabilities	40000000	USD
CY2021	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	886000000	USD
CY2021	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	27000000	USD
CY2020	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	990000000	USD
CY2020	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	38000000	USD
CY2019	us-gaap	Interest And Fee Income Loans And Leases InterestAndFeeIncomeLoansAndLeases	1085000000	USD
CY2019	us-gaap	Interest Expense Short Term Borrowings InterestExpenseShortTermBorrowings	80000000	USD
CY2021Q4	us-gaap	Additional Collateral Aggregate Fair Value AdditionalCollateralAggregateFairValue	200000	USD
CY2020Q4	us-gaap	Additional Collateral Aggregate Fair Value AdditionalCollateralAggregateFairValue	300000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	3000000	USD
CY2021Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	0	USD
CY2021Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	3000000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	0	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	20000000	USD
CY2021Q4	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	0	USD
CY2021Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	20000000	USD
CY2021Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountNotOffsetAgainstCollateral	3000000	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Securities DerivativeCollateralObligationToReturnSecurities	0	USD
CY2020Q4	us-gaap	Derivative Collateral Obligation To Return Cash DerivativeCollateralObligationToReturnCash	3000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral DerivativeFairValueOfDerivativeAssetAmountOffsetAgainstCollateral	0	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Not Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountNotOffsetAgainstCollateral	37000000	USD
CY2020Q4	us-gaap	Derivative Collateral Right To Reclaim Securities DerivativeCollateralRightToReclaimSecurities	0	USD
CY2020Q4	us-gaap	Derivative Collateral Right To Reclaim Cash DerivativeCollateralRightToReclaimCash	37000000	USD
CY2020Q4	us-gaap	Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral DerivativeFairValueOfDerivativeLiabilityAmountOffsetAgainstCollateral	0	USD
CY2021Q4	fnb	Percentage Of Commitments To Extend Credit Dependent On Financial Condition PercentageOfCommitmentsToExtendCreditDependentOnFinancialCondition	0.724
CY2021Q4	fnb	Allowance For Credit Losses On Loan Commitments AllowanceForCreditLossesOnLoanCommitments	19200000	USD
CY2020Q4	fnb	Allowance For Credit Losses On Loan Commitments AllowanceForCreditLossesOnLoanCommitments	13700000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	4125588	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber	4680786	shares
CY2021Q4	us-gaap	Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	9000000	USD
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	56000000	USD
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Outstanding Weighted Average Remaining Contractual Terms ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsOutstandingWeightedAverageRemainingContractualTerms	P1Y4M17D
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	196086	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.61
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	246084	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.14
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	458354	shares
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	7.99
CY2021	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	28168	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	7.38
CY2020	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	33945	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	5.74
CY2019	us-gaap	Stock Issued During Period Shares Stock Options Exercised StockIssuedDuringPeriodSharesStockOptionsExercised	183566	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice	7.86
CY2021	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	591	shares
CY2021	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	6.44
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	16053	shares
CY2020	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	7.38
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod	28704	shares
CY2019	us-gaap	Share Based Compensation Arrangements By Share Based Payment Award Options Forfeitures In Period Weighted Average Exercise Price ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice	7.65
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	167327	shares
CY2021Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.83
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	196086	shares
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.61
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber	246084	shares
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	8.14
CY2021Q4	us-gaap	Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range Number Of Outstanding Options ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions	167327	shares
CY2021Q4	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Intrinsic Value1 SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	600000	USD
CY2021Q4	fnb	Number Of Supplemental Non Qualified Retirement Plans NumberOfSupplementalNonQualifiedRetirementPlans	2	retirementPlan
CY2021Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	172000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	187000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	187000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	175000000	USD
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	4000000	USD
CY2020	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	6000000	USD
CY2021	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	8000000	USD
CY2020	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	-17000000	USD
CY2021	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	11000000	USD
CY2020	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	11000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	172000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	187000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	189000000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	173000000	USD
CY2021	us-gaap	Defined Benefit Plan Actual Return On Plan Assets DefinedBenefitPlanActualReturnOnPlanAssets	22000000	USD
CY2020	us-gaap	Defined Benefit Plan Actual Return On Plan Assets DefinedBenefitPlanActualReturnOnPlanAssets	20000000	USD
CY2021	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	1000000	USD
CY2020	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	7000000	USD
CY2021	us-gaap	Defined Benefit Plan Plan Assets Benefits Paid DefinedBenefitPlanPlanAssetsBenefitsPaid	11000000	USD
CY2020	us-gaap	Defined Benefit Plan Plan Assets Benefits Paid DefinedBenefitPlanPlanAssetsBenefitsPaid	11000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	201000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	189000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	29000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Funded Status Of Plan DefinedBenefitPlanFundedStatusOfPlan	2000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0272
CY2020Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.0231
CY2021Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Rate Of Compensation Increase DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease	0.0350
CY2020Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Rate Of Compensation Increase DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease	0.0350
CY2021	fnb	Defined Benefit Plan Assumptions Used In Calculation Percentage Of Non Callable Corporate Bonds DefinedBenefitPlanAssumptionsUsedInCalculationPercentageOfNonCallableCorporateBonds	0.10
CY2021	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	4000000	USD
CY2020	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	6000000	USD
CY2019	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	7000000	USD
CY2021	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	12000000	USD
CY2020	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	13000000	USD
CY2019	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	11000000	USD
CY2021	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-3000000	USD
CY2020	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-3000000	USD
CY2019	us-gaap	Defined Benefit Plan Amortization Of Gains Losses DefinedBenefitPlanAmortizationOfGainsLosses	-2000000	USD
CY2021	us-gaap	Pension Expense PensionExpense	-5000000	USD
CY2020	us-gaap	Pension Expense PensionExpense	-4000000	USD
CY2019	us-gaap	Pension Expense PensionExpense	-2000000	USD
CY2021	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Actuarial Net Gains Losses DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeActuarialNetGainsLosses	-18000000	USD
CY2020	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Actuarial Net Gains Losses DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeActuarialNetGainsLosses	10000000	USD
CY2019	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Actuarial Net Gains Losses DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeActuarialNetGainsLosses	1000000	USD
CY2021	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Amortization Of Actuarial Loss DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAmortizationOfActuarialLoss	-3000000	USD
CY2020	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Amortization Of Actuarial Loss DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAmortizationOfActuarialLoss	-3000000	USD
CY2019	fnb	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Amortization Of Actuarial Loss DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAmortizationOfActuarialLoss	-2000000	USD
CY2021	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Loss Net Gain Loss Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax	21000000	USD
CY2020	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Loss Net Gain Loss Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax	-7000000	USD
CY2019	us-gaap	Defined Benefit Plan Amounts Recognized In Other Comprehensive Income Loss Net Gain Loss Before Tax DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax	1000000	USD
CY2021	fnb	Defined Benefit Plan Amounts Recognized In Net Periodic Pension Cost And Other Comprehensive Income DefinedBenefitPlanAmountsRecognizedInNetPeriodicPensionCostAndOtherComprehensiveIncome	-26000000	USD
CY2020	fnb	Defined Benefit Plan Amounts Recognized In Net Periodic Pension Cost And Other Comprehensive Income DefinedBenefitPlanAmountsRecognizedInNetPeriodicPensionCostAndOtherComprehensiveIncome	3000000	USD
CY2019	fnb	Defined Benefit Plan Amounts Recognized In Net Periodic Pension Cost And Other Comprehensive Income DefinedBenefitPlanAmountsRecognizedInNetPeriodicPensionCostAndOtherComprehensiveIncome	-3000000	USD
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0231
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0317
CY2019	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate	0.0416
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Rate Of Compensation Increase DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease	0.0350
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Rate Of Compensation Increase DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease	0.0350
CY2019	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Rate Of Compensation Increase DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease	0.0350
CY2021	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0675
CY2020	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0725
CY2019	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0725
CY2021Q1	us-gaap	Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets	0.0675
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Employer Contributions Next Fiscal Year DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear	1000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	10000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	11000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	10000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	10000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	11000000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	51000000	USD
CY2021	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent Of Match DefinedContributionPlanEmployerMatchingContributionPercentOfMatch	1
CY2021	us-gaap	Defined Contribution Plan Employer Matching Contribution Percent DefinedContributionPlanEmployerMatchingContributionPercent	0.06
CY2021	fnb	Defined Contribution Plan Employer Discretionary Contribution Percentage DefinedContributionPlanEmployerDiscretionaryContributionPercentage	0.03
CY2021	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	19000000	USD
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	17000000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	15000000	USD
CY2020	fnb	Defined Benefit Plan Dividend Received On Common Stock DefinedBenefitPlanDividendReceivedOnCommonStock	200000	USD
CY2021	fnb	Defined Benefit Plan Dividend Received On Common Stock DefinedBenefitPlanDividendReceivedOnCommonStock	200000	USD
CY2021Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	201000000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	189000000	USD
CY2021	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	79000000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	71000000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	47000000	USD
CY2021	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	4000000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	5000000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	4000000	USD
CY2021	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	83000000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	76000000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	51000000	USD
CY2021	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	12000000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-20000000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	30000000	USD
CY2021	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	3000000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1000000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	3000000	USD
CY2021	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	15000000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-19000000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	33000000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	98000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	57000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	84000000	USD
CY2021	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2020	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	0.016
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.011
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2021	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.011
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.017
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.028
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Exempt Income EffectiveIncomeTaxRateReconciliationTaxExemptIncome	0.022
CY2021	fnb	Effective Income Tax Rate Reconciliation Cash Surrender Value Of Life Insurance EffectiveIncomeTaxRateReconciliationCashSurrenderValueOfLifeInsurance	-0.005
CY2020	fnb	Effective Income Tax Rate Reconciliation Cash Surrender Value Of Life Insurance EffectiveIncomeTaxRateReconciliationCashSurrenderValueOfLifeInsurance	-0.008
CY2019	fnb	Effective Income Tax Rate Reconciliation Cash Surrender Value Of Life Insurance EffectiveIncomeTaxRateReconciliationCashSurrenderValueOfLifeInsurance	-0.005
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.032
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.063
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.042
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.022
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.025
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.014
CY2021	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.007
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.015
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	0.011
CY2021	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.196
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.167
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.177
CY2021	us-gaap	Investment Tax Credit InvestmentTaxCredit	0	USD
CY2020	us-gaap	Investment Tax Credit InvestmentTaxCredit	8300000	USD
CY2019	us-gaap	Investment Tax Credit InvestmentTaxCredit	7900000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	76000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Provision For Loan Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsProvisionForLoanLosses	80000000	USD
CY2021Q4	fnb	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Discount On Acquired Loans DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDiscountOnAcquiredLoans	8000000	USD
CY2020Q4	fnb	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Discount On Acquired Loans DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsDiscountOnAcquiredLoans	16000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	37000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	38000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	14000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	12000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	1000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Impairment Losses DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsImpairmentLosses	1000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	2000000	USD
CY2021Q4	fnb	Deferred Tax Assets Tax Deferred Expense Lease Liability DeferredTaxAssetsTaxDeferredExpenseLeaseLiability	36000000	USD
CY2020Q4	fnb	Deferred Tax Assets Tax Deferred Expense Lease Liability DeferredTaxAssetsTaxDeferredExpenseLeaseLiability	30000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	4000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Unrealized Losses On Availablefor Sale Securities Gross DeferredTaxAssetsUnrealizedLossesOnAvailableforSaleSecuritiesGross	0	USD
CY2021Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	13000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	14000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	189000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	193000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	34000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	33000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	155000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	160000000	USD
CY2021Q4	fnb	Deferred Tax Liabilities Loan Fees DeferredTaxLiabilitiesLoanFees	6000000	USD
CY2020Q4	fnb	Deferred Tax Liabilities Loan Fees DeferredTaxLiabilitiesLoanFees	6000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	11000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	12000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	1000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Prepaid Expenses DeferredTaxLiabilitiesPrepaidExpenses	1000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	11000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssetsIntangibleAssets	13000000	USD
CY2021Q4	fnb	Deferred Tax Liabilities Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxLiabilitiesTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	4000000	USD
CY2020Q4	fnb	Deferred Tax Liabilities Tax Deferred Expense Compensation And Benefits Employee Benefits DeferredTaxLiabilitiesTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits	0	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	33000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Leasing Arrangements DeferredTaxLiabilitiesLeasingArrangements	32000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	10000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Mortgage Servicing Rights DeferredTaxLiabilitiesMortgageServicingRights	8000000	USD
CY2021Q4	fnb	Deferred Tax Liabilities Lease Rightof Use Asset DeferredTaxLiabilitiesLeaseRightofUseAsset	34000000	USD
CY2020Q4	fnb	Deferred Tax Liabilities Lease Rightof Use Asset DeferredTaxLiabilitiesLeaseRightofUseAsset	28000000	USD
CY2021Q4	fnb	Deferred Tax Liabilities Unrealized Gains On Securities DeferredTaxLiabilitiesUnrealizedGainsOnSecurities	0	USD
CY2020Q4	fnb	Deferred Tax Liabilities Unrealized Gains On Securities DeferredTaxLiabilitiesUnrealizedGainsOnSecurities	7000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2000000	USD
CY2021Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	112000000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	109000000	USD
CY2021Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	43000000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Liabilities Net DeferredTaxAssetsLiabilitiesNet	51000000	USD
CY2021Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	33700000	USD
CY2021Q4	us-gaap	Tax Credit Carryforward Amount TaxCreditCarryforwardAmount	3300000	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	2700000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	2000000	USD
CY2021Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	2500000	USD
CY2021Q4	fnb	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations Next12 Months UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitationsNext12Months	100000	USD
CY2021	us-gaap	Oci Before Reclassifications Net Of Tax Attributable To Parent OciBeforeReclassificationsNetOfTaxAttributableToParent	-37000000	USD
CY2021	us-gaap	Reclassification From Aoci Current Period Net Of Tax Attributable To Parent ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent	-14000000	USD
CY2021	us-gaap	Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	-23000000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	405000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	286000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	387000000	USD
CY2021	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2020	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2019	us-gaap	Dividends Preferred Stock DividendsPreferredStock	8000000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	397000000	USD
CY2021	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	397000000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	278000000	USD
CY2020	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	278000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Basic NetIncomeLossAvailableToCommonStockholdersBasic	379000000	USD
CY2019	us-gaap	Net Income Loss Available To Common Stockholders Diluted NetIncomeLossAvailableToCommonStockholdersDiluted	379000000	USD
CY2021	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	319791100	shares
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	323368639	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	324938720	shares
CY2021	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	3690388	shares
CY2020	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	2119325	shares
CY2019	us-gaap	Weighted Average Number Diluted Shares Outstanding Adjustment WeightedAverageNumberDilutedSharesOutstandingAdjustment	1122418	shares
CY2021	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	323481488	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	325487964	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	326061138	shares
CY2021	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.24
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.86
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.17
CY2021	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.23
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.85
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.16
CY2021	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	22375	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0	shares
CY2021Q4	us-gaap	Capital Capital	3531000000	USD
CY2021Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1218
CY2021Q4	us-gaap	Capital Required To Be Well Capitalized CapitalRequiredToBeWellCapitalized	2899000000	USD
CY2021Q4	us-gaap	Capital Required To Be Well Capitalized To Risk Weighted Assets CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.1000
CY2021Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	3044000000	USD
CY2021Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.1050
CY2021Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	2984000000	USD
CY2021Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1029
CY2021Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized TierOneRiskBasedCapitalRequiredToBeWellCapitalized	1739000000	USD
CY2021Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.0600
CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	2464000000	USD
CY2021Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0850
CY2021Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	2877000000	USD
CY2021Q4	fnb	Common Equity Tier One Risk Based Capital To Risk Weighted Assets CommonEquityTierOneRiskBasedCapitalToRiskWeightedAssets	0.0992
CY2021Q4	fnb	Common Equity Tier One Risk Based Capital Required For Capital Adequacy CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacy	2029000000	USD
CY2021Q4	fnb	Common Equity Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0700
CY2021Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	2984000000	USD
CY2021Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0799
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	1493000000	USD
CY2021Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2021Q4	us-gaap	Risk Weighted Assets RiskWeightedAssets	28991000000	USD
CY2020Q4	us-gaap	Capital Capital	3324000000	USD
CY2020Q4	us-gaap	Capital To Risk Weighted Assets CapitalToRiskWeightedAssets	0.1233
CY2020Q4	us-gaap	Capital Required To Be Well Capitalized CapitalRequiredToBeWellCapitalized	2695000000	USD
CY2020Q4	us-gaap	Capital Required To Be Well Capitalized To Risk Weighted Assets CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.1000
CY2020Q4	us-gaap	Capital Required For Capital Adequacy CapitalRequiredForCapitalAdequacy	2830000000	USD
CY2020Q4	us-gaap	Capital Required For Capital Adequacy To Risk Weighted Assets CapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.1050
CY2020Q4	us-gaap	Tier One Risk Based Capital TierOneRiskBasedCapital	2759000000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital To Risk Weighted Assets TierOneRiskBasedCapitalToRiskWeightedAssets	0.1024
CY2020Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized TierOneRiskBasedCapitalRequiredToBeWellCapitalized	1617000000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets	0.0600
CY2020Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy TierOneRiskBasedCapitalRequiredForCapitalAdequacy	2291000000	USD
CY2020Q4	us-gaap	Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0850
CY2020Q4	us-gaap	Common Equity Tier One Capital CommonEquityTierOneCapital	2652000000	USD
CY2020Q4	fnb	Common Equity Tier One Risk Based Capital To Risk Weighted Assets CommonEquityTierOneRiskBasedCapitalToRiskWeightedAssets	0.0984
CY2020Q4	us-gaap	Tier One Leverage Capital To Average Assets TierOneLeverageCapitalToAverageAssets	0.0783
CY2020Q4	fnb	Common Equity Tier One Risk Based Capital Required For Capital Adequacy CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacy	1886000000	USD
CY2020Q4	fnb	Common Equity Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets CommonEquityTierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets	0.0700
CY2020Q4	us-gaap	Tier One Leverage Capital TierOneLeverageCapital	2759000000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy TierOneLeverageCapitalRequiredForCapitalAdequacy	1410000000	USD
CY2020Q4	us-gaap	Tier One Leverage Capital Required For Capital Adequacy To Average Assets TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets	0.0400
CY2020Q4	us-gaap	Risk Weighted Assets RiskWeightedAssets	26948000000	USD
CY2021Q4	us-gaap	Statutory Accounting Practices Statutory Amount Available For Dividend Payments Without Regulatory Approval StatutoryAccountingPracticesStatutoryAmountAvailableForDividendPaymentsWithoutRegulatoryApproval	462100000	USD
CY2021Q4	fnb	Loans To Affiliate Amount Maximum LoansToAffiliateAmountMaximum	717200000	USD
CY2021	us-gaap	Interest Paid Net InterestPaidNet	101000000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	216000000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	329000000	USD
CY2021	us-gaap	Income Taxes Paid IncomeTaxesPaid	74000000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	57000000	USD
CY2021	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1005000000	USD
CY2021	us-gaap	Interest Expense InterestExpense	98000000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	40000000	USD
CY2021	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	4000000	USD
CY2020	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	3000000	USD
CY2019	us-gaap	Transfer Of Other Real Estate TransferOfOtherRealEstate	15000000	USD
CY2021	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	0	USD
CY2020	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	537000000	USD
CY2019	us-gaap	Transfer Of Portfolio Loans And Leases To Held For Sale1 TransferOfPortfolioLoansAndLeasesToHeldForSale1	389000000	USD
CY2021	fnb	Transfer Of Loans To Portfolio Loans From Held For Sale TransferOfLoansToPortfolioLoansFromHeldForSale	0	USD
CY2020	fnb	Transfer Of Loans To Portfolio Loans From Held For Sale TransferOfLoansToPortfolioLoansFromHeldForSale	0	USD
CY2019	fnb	Transfer Of Loans To Portfolio Loans From Held For Sale TransferOfLoansToPortfolioLoansFromHeldForSale	110000000	USD
CY2020Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	0	USD
CY2019Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	0	USD
CY2021Q4	us-gaap	Restricted Cash And Cash Equivalents RestrictedCashAndCashEquivalents	0	USD
CY2021	us-gaap	Number Of Reportable Segments NumberOfReportableSegments	3	segment
CY2021	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	907000000	USD
CY2021	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	1000000	USD
CY2021	us-gaap	Noninterest Income NoninterestIncome	330000000	USD
CY2021	fnb	Non Interest Expense Excluding Amortization Of Intangibles NonInterestExpenseExcludingAmortizationOfIntangibles	721000000	USD
CY2021	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	12000000	USD
CY2021	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	98000000	USD
CY2021	us-gaap	Net Income Loss NetIncomeLoss	405000000	USD
CY2021Q4	us-gaap	Assets Assets	39513000000	USD
CY2021Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	2304000000	USD
CY2020	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1130000000	USD
CY2020	us-gaap	Interest Expense InterestExpense	208000000	USD
CY2020	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	922000000	USD
CY2020	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	123000000	USD
CY2020	us-gaap	Noninterest Income NoninterestIncome	294000000	USD
CY2020	fnb	Non Interest Expense Excluding Amortization Of Intangibles NonInterestExpenseExcludingAmortizationOfIntangibles	737000000	USD
CY2020	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	13000000	USD
CY2020Q4	us-gaap	Assets Assets	37354000000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	57000000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	286000000	USD
CY2020Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	2316000000	USD
CY2019	us-gaap	Interest And Dividend Income Operating InterestAndDividendIncomeOperating	1247000000	USD
CY2019	us-gaap	Interest Expense InterestExpense	330000000	USD
CY2019	us-gaap	Interest Income Expense Net InterestIncomeExpenseNet	917000000	USD
CY2019	us-gaap	Provision For Loan And Lease Losses ProvisionForLoanAndLeaseLosses	44000000	USD
CY2019	us-gaap	Noninterest Income NoninterestIncome	294000000	USD
CY2019	fnb	Non Interest Expense Excluding Amortization Of Intangibles NonInterestExpenseExcludingAmortizationOfIntangibles	682000000	USD
CY2019	us-gaap	Amortization Of Intangible Assets AmortizationOfIntangibleAssets	14000000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	84000000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	387000000	USD
CY2019Q4	us-gaap	Assets Assets	34615000000	USD
CY2019Q4	us-gaap	Intangible Assets Net Including Goodwill IntangibleAssetsNetIncludingGoodwill	2329000000	USD
CY2021Q4	fnb	Percentage Of Securities Using Market Based Information PercentageOfSecuritiesUsingMarketBasedInformation	1.000
CY2020	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	USD
CY2021	us-gaap	Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Transfers Out Of Level3 FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetTransfersOutOfLevel3	0	USD
CY2021	fnb	Short Term Borrowings Fair Value For Amounts That Maturity In Period ShortTermBorrowingsFairValueForAmountsThatMaturityInPeriod	P90D
CY2021	dei	Auditor Name AuditorName	Ernst and Young LLP
CY2021	dei	Auditor Location AuditorLocation	Pittsburgh, PA
CY2021	dei	Auditor Firm AuditorFirmId	42

Files In Submission

Name	View Source	Status
0000037808-22-000005-index-headers.html	Edgar Link	pending
0000037808-22-000005-index.html	Edgar Link	pending
0000037808-22-000005.txt	Edgar Link	pending
0000037808-22-000005-xbrl.zip	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
fnb-10xk2021xex21xq4.htm	Edgar Link	pending
fnb-10xk2021xex23xq4.htm	Edgar Link	pending
fnb-10xk2021xex311xq4.htm	Edgar Link	pending
fnb-10xk2021xex312xq4.htm	Edgar Link	pending
fnb-10xk2021xex321xq4.htm	Edgar Link	pending
fnb-10xk2021xex322xq4.htm	Edgar Link	pending
fnb-20211231.htm	Edgar Link	pending
fnb-20211231.xsd	Edgar Link	pending
fnb-20211231_cal.xml	Edgar Link	unprocessable
fnb-20211231_def.xml	Edgar Link	unprocessable
fnb-20211231_g1.jpg	Edgar Link	pending
fnb-20211231_htm.xml	Edgar Link	completed
fnb-20211231_lab.xml	Edgar Link	unprocessable
fnb-20211231_pre.xml	Edgar Link	unprocessable
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
R127.htm	Edgar Link	pending
R128.htm	Edgar Link	pending
R129.htm	Edgar Link	pending
R13.htm	Edgar Link	pending
R130.htm	Edgar Link	pending
R131.htm	Edgar Link	pending
R132.htm	Edgar Link	pending
R133.htm	Edgar Link	pending
R134.htm	Edgar Link	pending
R135.htm	Edgar Link	pending
R136.htm	Edgar Link	pending
R137.htm	Edgar Link	pending
R138.htm	Edgar Link	pending
R139.htm	Edgar Link	pending
R14.htm	Edgar Link	pending
R140.htm	Edgar Link	pending
R141.htm	Edgar Link	pending
R142.htm	Edgar Link	pending
R143.htm	Edgar Link	pending
R144.htm	Edgar Link	pending
R145.htm	Edgar Link	pending
R146.htm	Edgar Link	pending
R147.htm	Edgar Link	pending
R148.htm	Edgar Link	pending
R149.htm	Edgar Link	pending
R15.htm	Edgar Link	pending
R150.htm	Edgar Link	pending
R151.htm	Edgar Link	pending
R152.htm	Edgar Link	pending
R153.htm	Edgar Link	pending
R154.htm	Edgar Link	pending
R155.htm	Edgar Link	pending
R156.htm	Edgar Link	pending
R157.htm	Edgar Link	pending
R158.htm	Edgar Link	pending
R159.htm	Edgar Link	pending
R16.htm	Edgar Link	pending
R160.htm	Edgar Link	pending
R161.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

$FNB
FNB CORP/PA/ Stock $fnb

2021 Q4 Form 10-K Financial Statement

#000003780822000005 Filed on February 24, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FNB FNB CORP/PA/ Stock $fnb

2021 Q4 Form 10-K Financial Statement

#000003780822000005 Filed on February 24, 2022

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$FNB
FNB CORP/PA/ Stock $fnb