XML 101 R87.htm IDEA: XBRL DOCUMENT
v3.25.4

ALLOWANCE FOR CREDIT LOSSES ON LOANS AND LEASES - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended |
--- | --- | ---
Dec. 31, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Percentage of increase, housing price index | 4.30% | 7.40% |  |
Percentage of increase, commercial real estate price index | (0.50%) | 3.90% |  |
Percentage of increase (decline), S&P volatility in next fiscal year | (2.20%) | 34.90% |  |
Percentage of increase (decline), S&P volatility in next second year | (7.90%) | 2.50% |  |
Allowance for credit loss | $ 439.0 | $ 423.0 |  |
Provision for credit losses | 86.0 | 79.8 | $ 72.0 |
Financing receivable, charge-off | 84.7 | 81.8 |  |
Allowance for credit losses on loans and leases |  |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |  |
Allowance for credit loss | $ 439.5 | 422.8 | 405.6 | $ 401.7
Financing receivable, allowance for credit loss, period increase |  | $ 16.7 |  |
Financing receivable, allowance for credit loss, period increase, percentage |  | 4.00% |  |
Financing receivable, allowance for credit loss, ratio | 1.26% | 1.25% |  |
Provision for credit losses | $ 87.2 | $ 79.9 | 71.6 |
Financing receivable, allowance for credit loss, net charge-offs | 70.5 | 62.7 | 67.7 |
Financing receivable, charge-off | $ 84.7 | $ 81.8 | $ 81.1 |

X
- Definition Financing Receivable, Allowance for Credit Loss, Ratio + References No definition available. + Details
Name: | fnb_FinancingReceivableAllowanceforCreditLossRatio
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Period Increase (Decrease), Percentage + References No definition available. + Details
Name: | fnb_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossPeriodIncreaseDecreasePercentage
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Forecasted Macroeconomic Variables, Percentage of Growth (Decline), Commercial Real Estate Price Index + References No definition available. + Details
Name: | fnb_ForecastedMacroeconomicVariablesPercentageOfGrowthDeclineCommercialRealEstatePriceIndex
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Forecasted Macroeconomic Variables, Percentage of Growth (Decline), Housing Price Index + References No definition available. + Details
Name: | fnb_ForecastedMacroeconomicVariablesPercentageOfGrowthDeclineHousingPriceIndex
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Forecasted Macroeconomic Variables, Percentage of Growth (Decline), S&P Volatility In Next Fiscal Year + References No definition available. + Details
Name: | fnb_ForecastedMacroeconomicVariablesPercentageOfGrowthDeclineSPVolatilityInNextFiscalYear
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Forecasted Macroeconomic Variables, Percentage of Growth (Decline), S&P Volatility In Next Second Year + References No definition available. + Details
Name: | fnb_ForecastedMacroeconomicVariablesPercentageOfGrowthDeclineSPVolatilityInNextSecondYear
Namespace Prefix: | fnb_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph c -Publisher SEC + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of increase (decrease) in allowance for credit loss on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of decrease (increase) in allowance for credit loss on financing receivable from writeoff (recovery). Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoffAfterRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-22 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=fnb_AllowanceForCreditLossesOnLoansAndLeasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |