Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Defined benefit plan, expected future employer contributions, current fiscal year Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year Net transfers into (out of) Level 3 Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers, Net Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortized Cost Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date [Abstract] Award Timing Predetermined Award Timing Predetermined [Flag] Amortization of qualifying investments Investment Program, Proportional Amortization Method, Applied, Amortization Expense Net unrealized gains (losses) on securities available for sale OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment, Tax Entity File Number Entity File Number Credit Risk Contract Credit Risk Contract [Member] Capital Surplus Additional Paid-in Capital [Member] Schedule of Financing Receivable, Performance of Modified Loan Schedule of Financing Receivable, Performance of Modified Loan [Table Text Block] Schedule of Financing Receivable, Performance of Modified Loan Tabular List, Table Tabular List [Table Text Block] Mortgage loans - LOCOM Mortgage Loan - LOCOM [Member] Mortgage Loan - LOCOM [Member] Summary of Accounting Changes New Accounting Pronouncements, Policy [Policy Text Block] Fair Value of Assets and Liabilities Fair Value Measurement and Measurement Inputs, Recurring and Nonrecurring [Text Block] Tax credit investments Other Assets Tax Credit Investments Tax credit investments in other assets Goodwill [Line Items] Goodwill [Line Items] Measurement Basis [Axis] Measurement Basis [Axis] Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Forwards and futures purchased Forwards And Futures Purchased [Member] Forwards and Futures Purchased [Member] FICO score 620-659 Fico Score 620 To 659 [Member] Fico Score 620 To 659 Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Cash dividends paid - preferred stock Payments of Ordinary Dividends, Preferred Stock and Preference Stock Recoveries Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Recovery Schedule of Stock by Class [Table] Stock, Class of Stock [Table] Changes in fair value included in net income Fair Value, Option, Changes in Fair Value, Gain (Loss) Schedule of Indefinite-Lived Intangible Assets [Table] Intangible Asset, Indefinite-Lived [Table] Adjustment to Compensation, Amount Adjustment to Compensation Amount Pension Plan Pension Plan [Member] Loans Held For Sale, Residential Real Estate Loans Held For Sale, Residential Real Estate [Member] Loans Held for Sale, Residential Real Estate [Member] Stock-based compensation expense Share-Based Payment Arrangement, Noncash Expense Derivative asset, notional amount Derivative Asset, Notional Amount FICO score less than 620 Fico Score Less Than 620 [Member] Fico Score Less Than 620 Employee Stock Option Share-Based Payment Arrangement, Option [Member] Securities gains (losses), net Debt and Equity Securities, Realized Gain (Loss) Total taxes paid Income Taxes Paid C&I General C I [Member] General C&I [Member] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Common stock Dividends, Common Stock, Cash FHN shareholders' equity Equity, Attributable to Parent Measurement Frequency [Axis] Measurement Frequency [Axis] Debt Securities, Available-for-sale [Table] Debt Securities, Available-for-Sale [Table] Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Subtotal Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date Common stock, authorized (in shares) Common Stock, Shares Authorized Preferred stock issuance (in shares) Stock Issued During Period, Shares, New Issues Recurring Fair Value, Recurring [Member] Other assets: Other Assets Financial Instruments [Abstract] Derivative valuation adjustment Derivative Valuation Adjustment Prior Sales Of Visa Shares Derivative Valuation Adjustment Prior Sales Of Visa Class B Shares Liabilities Liabilities and Equity [Abstract] Assets Cash Flow Hedge Derivative Instrument Assets at Fair Value Cover [Abstract] Cover [Abstract] Assets And Liabilities [Domain] Assets And Liabilities [Domain] Assets And Liabilities [Domain] Fair value carrying amount Portion at Fair Value Measurement [Member] Maximum Maximum [Member] Collateral pledged Derivative Liability Collateral Right to Reclaim Collateral Amount of right to receive cash and securities collateral under master netting arrangements offset against derivative liabilities. Government agency issued MBS and CMO Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, without Single Maturity Date Term borrowings: Long-Term Debt, Unclassified [Abstract] Net income attributable to noncontrolling interest Net income attributable to noncontrolling interest Net Income (Loss) Attributable to Noncontrolling Interest Mortgage banking noninterest income Mortgage Banking Noninterest Income [Member] Mortgage banking noninterest income [Member] Fair Value of Loans [Axis] Fair Value of Loans [Axis] Fair Value of Loans [Axis] Stock options exercised and restricted stock awards (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, before Forfeiture Total fair value Debt Securities, Available-for-Sale, Unrealized Loss Position After 10 years Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year 10 Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Schedule of Book Value and Estimated Fair Value of Financial Instruments Summary Of Book Value And Estimated Fair Value Of Financial Instruments [Table Text Block] Tabular disclosure of the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments, assets, and liabilities. Such certain disclosures about the financial instruments, assets, and liabilities that includes the fair value of the required items together with their carrying amounts (as appropriate). Schedule of VIEs not Consolidated by FHN Summary of VIE Not Consolidated by FHN [Table Text Block] Schedule of information summarizing types of unconsolidated VIE, maximum loss exposure, amounts recorded on the Consolidated Balance Sheet, and associated balance sheet line items. Visa Class B Shares Visa Class B Shares [Member] Visa Class B Shares [Member] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Available-for-sale securities sold Debt Securities, Available-for-Sale, Sold at Par Value Other service charges and fees Other service charges and fees Other Service Charges And Fees Other Service Charges And Fees Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Other Assets Other Assets [Member] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Non Affiliates Non Affiliates [Member] Non Affiliates [Member] Weighted-average Term Extension (in years) Financing Receivable, Modified, Weighted Average Term Increase from Modification Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Revolving Loans Converted to Term Loans Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan Federal funds sold and securities purchased under agreements to resell Federal Funds Sold and Securities Purchased under Agreements to Resell Government agency issued MBS and CMO Debt Securities, Held-to-Maturity, Maturity, without Single Maturity Date, Fair Value Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Gain (loss), cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Schedule of Gains/(losses) on Nonrecurring Fair Value Measurements Gains Losses On Fair Value Asset And Liabilities Measured On Non Recurring Basis [Table Text Block] Schedule of gains/(losses) on fair value assets and liabilities measured on a nonrecurring basis. Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Total interest expense Interest expense Interest Expense, Operating Within 1 year Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, Year One Offsetting Liabilities [Table] Offsetting Liabilities [Table] Visa covered litigation resolution amount Measurement Input, Visa Covered Litigation Resolution Amount [Member] Measurement Input, Visa Covered Litigation Resolution Amount [Member] Derivative Instruments With Accelerated Termination Provisions Derivative Instruments With Accelerated Termination Provisions [Member] Derivative Instruments With Accelerated Termination Provisions [Member] Document Fiscal Period Focus Document Fiscal Period Focus Schedule of Differences between the Fair Value Carrying Amount of Mortgages Held-for-sale and Aggregate Unpaid Principal Amount Fair Value Option, Disclosures [Table Text Block] Award Timing Method Award Timing Method [Text Block] Total Non- Accruing Financing Receivable, Excluding Accrued Interest, Nonaccrual Award Type Award Type [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Variable Rate Basis Spread, Percentage One Variable Rate Basis Spread, Percentage One [Member] Variable Rate Basis Spread, Percentage One Mortgage Banking [Abstract] Loan commitments Commitments, Fair Value Disclosure Trading Symbol Trading Symbol Interest on term borrowings Interest Expense, Long-Term Debt Entity Address, City or Town Entity Address, City or Town Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Schedule of the Impact of Qualifying LIHTC Investments Schedule Of Variable Interest Entities [Table Text Block] Summary of the impact of qualifying LIHTC investments on the provision/(benefit) for income taxes. Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Other Other Consumer Loans Class [Member] Other Consumer Loans Class [Member] Net increase in short-term borrowings Proceeds from (Repayments of) Short-Term Debt Income Statement Location [Domain] Statement of Income Location, Balance [Domain] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Interest on short-term borrowings Interest Expense, Short-Term Borrowings Entity Emerging Growth Company Entity Emerging Growth Company Transfers between available for sale and held to maturity debt securities Transfers Between Available For Sale And Held To Maturity Debt Securities Transfers Between Available For Sale And Held To Maturity Debt Securities Collateral cash receivables Derivative Liability, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Sub Class of Financing Receivable [Domain] Sub Class of Financing Receivable [Domain] Sub Class of Financing Receivable [Domain] Gains (Losses) Derivative, Gain (Loss) on Derivative, Net Appraisals from comparable properties Valuation Technique, Appraisals From Comparable Properties [Member] Appraisals From Comparable Properties [Member] Total noninterest income Noninterest income Noninterest Income Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Total Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss Gross Unrealized Losses Debt Securities, Held-to-Maturity, Accumulated Unrecognized Loss Total other assets Total other assets Other Assets, Fair Value Disclosure Gains (losses) on financial assets measured on non-recurring basis Net Gains Loss On Financial Assets Measured On Nonrecurring Basis Net Gains Loss On Financial Assets Measured On Nonrecurring Basis Loans and Leases Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Noninterest expense Noninterest Expense [Abstract] Cash and due from banks Cash and Due from Banks Tax credits and Other tax benefits related to qualifying investments Investment Program, Proportional Amortization Method, Elected, Income Tax Credit and Other Income Tax Benefit, before Amortization Expense Legal and professional fees Legal and professional fees Legal Fees Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Write down percentage based on time in default Debt Securities, Available For Sale, Excluding Accrued Interest, Write Down Percentage Based On Time In Default Debt Securities, Available For Sale, Excluding Accrued Interest, Write Down Percentage Based On Time In Default Sales, net of gains Gain (Loss) on Sale of Financing Receivable Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] After 1 year through 5 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Weighted-average Interest Rate Reduction Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification Pledged Status [Domain] Pledged Status [Domain] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date FICO score 720-739 Fico Score 720 To 739 [Member] Fico Score 720 To 739 Income tax expense Income tax expense (benefit) Income Tax Expense (Benefit) Number of moody's forecast scenarios used for macroeconomic inputs Number Of Moody's Forecast Scenarios Used For Macroeconomic Inputs Number Of Moody's Forecast Scenarios Used For Macroeconomic Inputs Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Schedule of Derivatives Associated with Fixed Income Trading Activities Schedule of Derivative Instruments Included in Trading Activities [Table Text Block] Net unrealized gains (losses) on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, Tax Other assets Other assets Other Assets Beginning balance Ending balance Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Preferred stock, issued (in shares) Preferred Stock, Shares Issued Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Hedging Instruments and Hedged Items:  Designated as Hedging Instrument [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Hedging Relationship [Axis] Hedging Relationship [Axis] Net unrealized gains (losses) on cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Offsetting [Abstract] Offsetting [Abstract] Within 1 year Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Purchases and originations Payment for Purchase, Loan, Held-for-Sale Schedule of Gains/(Losses) on Derivatives Associated with Cash Flow Hedges Schedule Of Derivative Instruments Gain Loss Associated With Cash Flow Hedges [Table Text Block] Tabular disclosure of gains/(losses) related to interest rate derivatives associated with cash flow hedges Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Additions Goodwill, Acquired During Period Stock options exercised Proceeds from Stock Options Exercised All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Other income Noninterest Income, Other Operating Income Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Weighted average exercise price of stock options excluded from the calculation of diluted EPS (in dollars per share) Stock Options, Weighted Average Exercise Price Stock Options, Weighted Average Exercise Price Finance and Insurance Companies Finance And Insurance Companies [Member] Finance And Insurance Companies Securities available for sale at fair value Fair Value Securities available-for-sale Total securities available for sale Debt Securities, Available-for-Sale, Excluding Accrued Interest Common stock issued for: Shares Granted or Issued, Share-Based Payment Arrangement [Abstract] Sales Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Sales Amortization of unrecognized: Amortization [Abstract] Schedule of Derivative Assets and Collateral Received Schedule Of Derivative Assets And Collateral Received1 [Table Text Block] Schedule Of Derivative Assets And Collateral Received1 Subsequent Event Subsequent Event [Member] Allowance for credit losses Financing Receivable And Off-Balance Sheet Credit Loss Liability, Allowance For Credit Loss, Excluding Accrued Interest Financing Receivable And Off-Balance Sheet Credit Loss Liability, Allowance For Credit Loss, Excluding Accrued Interest Net interest income Interest Income (Expense), Operating Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Derivative liability, measurement input Derivative Liability, Measurement Input USDA & SBA loans - LOCOM Government Guaranteed Loans (SBA and USDA) [Member] Government Guaranteed Loans (SBA and USDA) [Member] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Gross amounts of recognized liabilities Derivative liabilities Derivative Liability, Subject to Master Netting Arrangement, before Offset Equity Components [Axis] Equity Components [Axis] 2023 2022 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Fair Value, Concentration of Risk, Disclosure Items [Domain] Fair Value, Concentration of Risk, Disclosure Items [Domain] Forwards and futures sold Forwards And Futures Sold [Member] Forwards and Futures Sold [Member] Variable Interest Entities Variable Interest Entity Disclosure [Text Block] Entity Address, State or Province Entity Address, State or Province Leased asset impairments Operating Lease, Impairment Loss Financial Asset, Period Past Due [Domain] Financial Asset, Aging [Domain] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Antidilutive Security, Excluded EPS Calculation [Table] Net Carrying Amount Servicing Asset Individual: Individual [Axis] Property, plant, and equipment and finance lease right-of-use asset Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Cash dividends paid Payments of Ordinary Dividends, Common Stock Credit card workout program term extension, maximum period Credit Card Workout Program Term Extension, Maximum Period Credit Card Workout Program Term Extension, Maximum Period Entities [Table] Entities [Table] Gross Carrying Amount Servicing Asset at Amortized Cost Maximum Loss Exposure Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount Government agency issued MBS and CMO Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Amortized Cost Principal Forgiven/Payment Deferred Principal Forgiveness [Member] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Entity Interactive Data Current Entity Interactive Data Current Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Interest on investment securities Interest Income, Debt Securities, Available-for-Sale, Operating Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Modified [Line Items] Home Equity Line of Credit HELOC Home Equity Line of Credit [Member] Up to 30 Days Maturity Less than 30 Days [Member] Maturity Less Than 30 Days [Member] Securities collateral (not recognized on FHN’s Balance Sheets) Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, Collateral, Obligation to Return Security Not Offset Total Accruing Financing Receivable, Excluding Accrued Interest, Accruing Financing Receivable, Excluding Accrued Interest, Accruing Total noninterest expense Noninterest expense Noninterest Expense Customer Interest Rate Contracts Hedging  Customer Interest Rate Contracts Hedging [Member] Customer Interest Rate Contracts Hedging [Member] Fair Value Of Loans [Domain] Fair Value Of Loans [Domain] Fair Value of Loans [Domain] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Allowance for Credit Losses Allowance for Credit Losses [Text Block] Interest on deposits Interest Expense, Deposits Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Noninterest income Noninterest income: Noninterest Income [Abstract] Gain (loss) due to fair value adjustments and other Loans Held-for-sale, Adjustment for Gain (Loss), Fair Value Disclosure Loans Held-for-sale, Adjustment for Gain (Loss), Fair Value Disclosure Entity Central Index Key Entity Central Index Key PEO Name PEO Name Total revenues Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Schedule of Financing Receivable Credit Quality Indicators Financing Receivable Credit Quality Indicators [Table Text Block] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Noninterest-bearing deposits Noninterest-Bearing Deposit Liabilities Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Nonqualified Plan Nonqualified Plan [Member] Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Expected loss forecasts, supportable forecast period, minimum Expected Loss Forecasts, Supportable Forecast Period, Minimum Expected Loss Forecasts, Supportable Forecast Period, Minimum Class of Stock [Domain] Class of Stock [Domain] Variable Rate Basis Spread, Percentage Two Variable Rate Basis Spread, Percentage Two [Member] Variable Rate Basis Spread, Percentage Two Derivatives, other Derivatives Other [Member] Derivatives, Other [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] OREO Real Estate Acquired Through Foreclosure Balance Sheet Location [Axis] Statement of Financial Position Location, Balance [Axis] Loans and leases Financing Receivable, before Allowance for Credit Loss Retirement Benefits, Description [Abstract] Retirement Benefits, Description [Abstract] Qualified Plan Qualified Plan [Member] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Entity Address, Address Line One Entity Address, Address Line One Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Investments [Domain] Investments [Domain] Depreciation and amortization of premises and equipment Depreciation Premises And Equipment The amount of expense charged against earnings in the period to allocate the cost, net of salvage value, of premises and equipment over their remaining estimated productive lives. Revolving Loans Financing Receivable, Excluding Accrued Interest, Revolving, Converted to Term Loan, Writeoff Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Reserve for remaining unfunded commitments: Off-Balance-Sheet, Credit Loss, Liability [Roll Forward] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Derivatives Derivative Instruments and Hedging Activities Disclosure [Text Block] Preferred Stock Preferred Stock [Text Block] Schedule of Stock by Class Schedule of Stock by Class [Table Text Block] Fair Value as of Grant Date Award Grant Date Fair Value Held for sale Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] 2022 2021 Financing Receivable, Excluding Accrued Interest, Year Five, Originated, Four Years before Current Fiscal Year Variability in cash flows related to debt instruments (primarily loans) Held-To-Maturity Trust Preferred Loans Principal Balance Held-to-maturity trust preferred loans. Personnel expense Personnel expense Labor and Related Expense Total adjustments Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity Effect of dilutive restricted stock, performance equity awards and options (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Assets Interest Rate Derivative Assets, at Fair Value Document Quarterly Report Document Quarterly Report Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months Current, accruing Financing Receivable, Excluding Accrued Interest, Not Past Due, Accruing Financing Receivable, Excluding Accrued Interest, Not Past Due, Accruing Commercial, Consumer & Wealth Commercial, Consumer & Wealth Segment [Member] Commercial, Consumer & Wealth Segment Schedule of Unobservable Inputs Utilized in Determining the Fair Value of Level 3 Recurring and Non-Recurring Measurements Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Counterparty Name [Domain] Counterparty Name [Domain] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Investment Type [Axis] Investment Type [Axis] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Non-PEO NEO Non-PEO NEO [Member] Interest on trading liabilities Interest Expense, Trading Liabilities Total trading revenues Trading Gain (Loss) Annual Dividend Rate Annual dividend rate Preferred Stock, Dividend Rate, Percentage Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Derivative liability, notional amount Derivative Liability, Notional Amount Other Other Intangible Assets [Member] Overnight and Continuous Maturity Overnight [Member] Gross Unrealized Gains Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax All Award Types Award Type [Domain] Gains (losses), cash flow hedges Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Noncontrolling interest Equity, Attributable to Noncontrolling Interest Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Estimate of Fair Value Measurement Estimate of Fair Value Measurement [Member] Offsetting Assets [Table] Offsetting Assets [Table] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Past due, accruing Financing Receivable, Excluding 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Offset Liabilities Derivative Instruments in Hedges, Liabilities, at Fair Value Foreclosure losses Measurement Input, Foreclosure Losses [Member] Measurement Input, Foreclosure Losses [Member] Accumulated other comprehensive loss, net Accumulated Other Comprehensive Income (Loss), Net of Tax Short-term financial assets: Short Term Financial Assets [Abstract] Other U.S. government agencies Other US Government Agencies [Member] Other US Government Agencies [Member] Financial Instruments [Domain] Types of Financial Instruments [Domain] Financial Instruments [Domain] Net unrealized gains (losses) on securities available for sale OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax After 10 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 10 Auction appraisals marketability adjustment Measurement Input, Auction Values Adjustment [Member] Measurement Input, Auction Values Adjustment Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Proprietary trust preferred issuances Proprietary Trust Preferred Issuances [Member] Proprietary Trust Preferred Issuances [Member] Gain (loss) reclassified from AOCI into interest income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum Minimum [Member] Net interest income after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Accrued interest Financing Receivable, Accrued Interest, before Allowance for Credit Loss Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Company Selected Measure Name Company Selected Measure Name Fair Value Measurement [Domain] Fair Value Measurement [Domain] Sub Class of Financing Receivable [Domain] Sub Class of Financing Receivable1 [Domain] [Domain] for Sub Class of Financing Receivable [Axis] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] After 10 years Debt Securities, Held-to-Maturity, Amortized Cost, after Allowance for Credit Loss, Maturity, Allocated and Single Maturity Date, after Year 10 Net income available to common shareholders Net Income (Loss) Available to Common Stockholders, Diluted Collateral Held [Domain] Collateral Held [Domain] Total short-term financial liabilities Short Term Financial Liabilities Short-term financial liabilities include federal funds purchased, securities sold under agreements to repurchase, and other short-term borrowings. The carrying amount is a reasonable estimate of fair value because of the relatively short time between the origination of the instrument and its expected realization. Other short-term borrowings includes a liability associated with transfers of mortgage servicing rights that did not qualify for sale accounting. This liability is accounted for at elected fair value, which is measured consistent with the related MSR. Card and digital banking fees Card and digital banking fees Card And Digital Banking Fees Card And Digital Banking Fees Goodwill [Roll Forward] Goodwill [Roll Forward] Contingencies and Other Disclosures Commitments and Contingencies Disclosure [Text Block] Net gains/(losses), loans held for sale - SBAs and USDA Net Gains Or Losses Loans Held For Sale Net gains or losses recognized in earnings on loans held for sale measured at fair value on a nonrecurring basis. Diluted average common shares (in shares) Weighted average common shares outstanding - diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Equity, mutual funds, and other Equity Mutual Funds And Other [Member] Equity Mutual Funds And Other [Member] Junior subordinated debentures Junior Subordinated Notes Entity Small Business Entity Small Business Beginning balance (in shares) Ending balance (in shares) Shares Outstanding (in shares) Preferred Stock, Shares Outstanding Schedule of Gains/(Losses) on Derivatives Associated with Interest Rate Risk Management Activities Schedule Of Derivative Instruments Gain Loss Associated With Interest Rate Risk Management Activities [Table Text Block] Tabular disclosure of gains/(losses) related to interest rate derivatives associated with interest rate risk management activities. Document Transition Report Document Transition Report After 1 year through 5 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date Gross Carrying Amount Other Finite-Lived Intangible Assets, Gross Bond equivalent yield Measurement Input, Bond Equivalent Yield [Member] Measurement Input, Bond Equivalent Yield [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Schedule of Investments [Table] Schedule of Investments [Table] Net amount Derivative Asset, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Total equity Beginning balance Ending balance Equity, Including Portion Attributable to Noncontrolling Interest Loans held for sale—first mortgages First Mortgage [Member] Commercial and industrial Commercial Financial And Industrial Portfolio Segment, Excluding Loans To Mortgage Companies [Member] Commercial Financial And Industrial Portfolio Segment, Excluding Loans To Mortgage Companies Loans held for sale—SBAs and USDA Small Business Administration And USDA [Member] Small Business Administration And USDA [Member] Document Type Document Type Level 3 Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value Debt Securities, Available-for-Sale, Unrealized Loss Position [Abstract] Earnings Per Share Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Loss Contingencies [Table] Loss Contingencies [Table] Common stock: Common Stock [Abstract] Common Stock [Abstract] Advertising and public relations Marketing and Advertising Expense Product and Service [Axis] Product and Service [Axis] Revenue from contract with customer Revenue from Contract with Customer, Excluding Assessed Tax Gross proceeds from settlements and sales Proceeds from Sale, Loan, Held-for-Sale Real estate investment trust-preferred Real Estate Investment Trust-Preferred Real estate investment trust-preferred. Statistical Measurement [Axis] Statistical Measurement [Axis] Credit Score, FICO [Domain] Credit Score, FICO [Domain] 2025 2024 Financing Receivable, Excluding Accrued Interest, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff Interest and fees on loans and leases Interest and fees on loans and leases Interest and Fee Income, Loan and Lease, Held-in-Portfolio Low income housing partnerships Low Income Housing Partnerships [Member] Low Income Housing Partnerships [Member] Schedule of Derivative Associated with Cash Flow Hedges Derivative Associated With Cash Flow Hedges [Table Text Block] Tabular disclosure of cash flow hedges related to interest rate derivatives, including, but not limited to, the fair value of the derivatives, statement of financial position location, and statement of financial performance location of these instruments. Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount PD Grade 1 -12 Commercial Loan P D Grade First Through Twelfth [Member] Commercial Loan P D Grade First Through Twelfth Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] FHLB-Cincinnati Stock FHLB Cincinnati Stock [Member] FHLB-Cincinnati Stock [Member] Net income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Mortgage banking income Mortgage banking income Fees and Commissions, Mortgage Banking and Servicing Entity Information [Line Items] Entity Information [Line Items] Combination Extended Maturity and Interest Rate Reduction [Member] Total other liabilities Other Liabilities, Fair Value Disclosure Loans Financing Receivable, Excluding Accrued Interest, Modified, after 12 Months Level 1 Level 1 Fair Value, Inputs, Level 1 [Member] Redemption price (in dollars per share) Preferred Stock, Redemption Price Per Share Diluted earnings per common share (in dollars per share) Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Deposit insurance expense Federal Deposit Insurance Corporation Premium Expense Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] After 5 years through 10 years Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 Amortized Cost Financing Receivable, Excluding Accrued Interest, Modified in Period, Amount Preferred stock Dividends, Preferred Stock, Cash First Horizon Bank First Horizon Bank [Member] First Horizon Bank [Member] Core deposit intangibles Core Deposits [Member] Variable Interest Entity, Not Primary Beneficiary Variable Interest Entity, Not Primary Beneficiary [Member] Term Extension Extended Maturity [Member] Schedule of Nonrecurring Fair Value Measurements Fair Value Asset And Liabilities Measured On Recurring And Non Recurring Basis [Table Text Block] Fair Value, Assets And Liabilities Measured on Recurring and Nonrecurring Basis [Table Text Block] Common stock repurchased Common stock repurchased under share repurchase program Stock Repurchased and Retired During Period, Value Standby and other commitments Standby And Other Commitments Standby commitments may be provided to customers in order to guarantee payment between a customer and a third party - generally to facilitate trade. Fair values are based on fees charged to enter into similar agreements. Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] PD Grades 13 Commercial Loan P D Grade Thirteen [Member] Commercial Loan PD Grade Thirteen [Member] Total net gains (losses) included in net income Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Commercial loan grades Commercial Loan Grades Commercial Loan Grades Forward contracts written Forward Contracts Written [Member] Forward Contracts Written Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items] Credit Card and Other Credit Card And Other [Member] Credit Card and Other [Member] Loans and leases Loans and leases Loans and leases Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss Dividends declared - noncontrolling interest of subsidiary preferred stock Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Net amounts of liabilities presented in the Balance Sheets Securities sold under agreements to repurchase Securities Sold under Agreements to Repurchase Gains (losses) on derivative instruments Gain (Loss) on Derivative Instruments, Net, Pretax Preferred stock conversion, fractional preferred shares per preferred stock Preferred Stock Conversion, Fractional Preferred Shares Per Preferred Stock Preferred Stock Conversion, Fractional Preferred Shares Per Preferred Stock Schedule of Investments within the Available for Sale Portfolio that had Unrealized Losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block] Expiration Date Trading Arrangement Expiration Date Schedule of Changes In Fair Value of Assets and Liabilities which Fair Value Option Included in Current Period Earnings Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table Text Block] Equity Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Unrealized net losses for equity investments with readily determinable fair value Equity Securities, FV-NI, Unrealized Gain (Loss) FICO score 700-719 Fico Score 700 To 719 [Member] Fico Score 700 To 719 Premises and equipment Property, Plant and Equipment, Net Accumulated Amortization Accumulated Amortization Of Mortgage Servicing Rights (MSRs) Accumulated Amortization Of Mortgage Servicing Rights (MSRs) Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Current Reporting Status Entity Current Reporting Status Time until resolution Measurement Input, Time Until Resolution [Member] Measurement Input, Time Until Resolution [Member] Schedule of FHN's Investment Securities Schedule Of Available For Sale Securities And Held To Maturity [Table Text Block] This item represents the entire disclosure related to reconciling the amortized cost basis and aggregate fair value of the entity's available-for-sale and held-to-maturity investment securities. Receivables [Abstract] Receivables [Abstract] Derivative [Line Items] Derivative [Line Items] Offsetting securities purchased under agreements to resell Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Cash Not Offset Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Collateral Held [Axis] Collateral Held [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Within 1 year Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One Corporate Corporate Segment [Member] Financial Instrument [Axis] Financial Instrument [Axis] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] 12 months or longer Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Net  derivative liabilities Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Current Fiscal Year End Date Current Fiscal Year End Date Sub Class of Financing Receivable [Axis] Sub Class of Financing Receivable1 [Axis] Sub Class of Financing Receivable [Axis] Loans Held For Sale By Type [Domain] Loans Held For Sale By Type [Domain] Loans Held For Sale By Type [Domain] Less than 12 months Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Total deposits Deposits OREO measurement input Other Real Estate Owned, Measurement Input Schedule of Residential Mortgage Loans Held for Sale Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Securities held to maturity (fair value of $1,056 and $1,073, respectively) Amortized Cost Securities held to maturity Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss Net amounts of liabilities presented in the Balance Sheets Derivative liabilities, fair value Derivative Liability Other expense Other expense Other Noninterest Expense Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Interest Rate Contract Interest rate derivative contracts Derivatives, interest rate contracts Interest Rate Contract [Member] Derivative assets not subject to master netting agreements (prior year less than) Derivative Asset, Not Subject to Master Netting Arrangement Amount of Principal Forgiven/Payment Deferred Financing Receivable, Excluding Accrued Interest, Modified, Increase (Decrease) from Modification Total unrealized losses Debt Securities, Available-for-Sale, Unrealized Loss Position, Accumulated Loss Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Equity, mutual funds, and other Equity Securities, FV-NI, Current Statements of Comprehensive Income/(loss) Other than Temporary Impairment Losses, Investments, Portion in Other Comprehensive Loss, Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract] Commercial Real Estate Commercial Real Estate (1) [Member] Commercial Real Estate (1) Awards excluded from the calculation of diluted EPS (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Series H preferred stock issuance Proceeds from Issuance of Preferred Stock and Preference Stock Collateral Pledged Collateral Pledged [Member] Interest-bearing deposits Interest-Bearing Deposit Liabilities Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Schedule of Loans and Leases by Portfolio Segment Schedule Of Loans By Portfolio Segment [Table Text Block] Schedule of loans by portfolio segment. Measure: Measure [Axis] Valuation Approach and Technique [Axis] Valuation Approach and Technique [Axis] Probability of resolution scenarios Measurement Input, Probability Of Resolution Scenarios [Member] Measurement Input, Probability Of Resolution Scenarios [Member] Deferred compensation mutual funds Deferred Compensation Assets [Member] Deferred Compensation Assets [Member] Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Disposal Group Classification [Domain] Disposal Group Classification [Domain] Other tax credit investments Other Tax Credit Investments [Member] Consumer Consumer Portfolio Segment [Member] Schedule of Reclassifications from AOCI Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Adjustment for value changes since appraisal Measurement Input, Adjustment For Value Changes Since Appraisal [Member] Measurement Input, Adjustment For Value Changes Since Appraisal [Member] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Entity Tax Identification Number Entity Tax Identification Number Discounted cash flow Valuation Technique, Discounted Cash Flow [Member] 2023 2022 Financing Receivable, Excluding Accrued Interest, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff Government agency issued MBS and CMO Debt Securities, Available-for-Sale, Maturity, without Single Maturity Date, Fair Value Income tax expense of items included in other comprehensive income: Supplemental Income Statement Elements [Abstract] Common stock, issued (in shares) Common Stock, Shares, Issued Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Allowance for loan and lease losses: Allowance for Loan and Lease Losses [Roll Forward] General Purchase Plan General Purchase Plan [Member] General Purchase Plan Government agency issued MBS Mortgage-Backed Security, Issued by US Government-Sponsored Enterprise [Member] Loans held for sale Loans Held For Sale [Member] Loans Held for Sale [Member] Offsetting securities sold under agreements to repurchase Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, Collateral, Obligation to Return Cash Not Offset Schedule of Goodwill by Reportable Segment Schedule of Goodwill [Table Text Block] Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Secured borrowings Borrowings Secured By Residential Real Estate Borrowings Secured By Residential Real Estate Loss Contingencies [Line Items] Loss Contingencies [Line Items] Series E Series E Preferred Stock [Member] Security Exchange Name Security Exchange Name Net amounts of assets presented in the Balance Sheets Securities purchased under agreements to resell Securities Purchased under Agreements to Resell Interest and fees on loans held for sale Interest and Fee Income, Loan and Lease, Held-for-Sale Government agency issued MBS Collateralized Mortgage-Backed Securities [Member] Assets And Liabilities, Uconsolodiated VIE, By Balance Sheet Location [Axis] Assets And Liabilities, Uconsolodiated VIE, By Balance Sheet Location [Axis] Assets And Liabilities, Uconsolodiated VIE, By Balance Sheet Location [Axis] Preferred stock dividends Dividends, Preferred Stock Other Equity Awards Other Equity Awards [Member] Other Equity Awards [Member] Asset Class [Domain] Asset Class [Domain] Total net gains (losses) included in net income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Mortgage Banking Hedges Mortgage Banking Hedges [Member] Mortgage Banking Hedges Stock-based compensation expense Shares Granted, Value, Share-Based Payment Arrangement, after Forfeiture Schedule of VIEs Consolidated by FHN Summary of VIE Consolidated by FHN [Table Text Block] Quantitative information related to VIEs consolidated by the parent company. Statement [Line Items] Statement [Line Items] Securities/ government guaranteed loans collateral Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, Collateral, Right to Reclaim Security Not Offset Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Subsequent Event [Line Items] Subsequent Event [Line Items] Common Stock Common Stock [Member] Preferred stock: Proceeds from Issuance of Preferred Stock, Preference Stock, and Warrants [Abstract] Trading liabilities Trading liabilities Trading Liabilities Other short-term borrowings Other Short-Term Borrowings Net increase in cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Gross amounts offset in the Balance Sheets Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, Liability Offset Prepayment speeds - First mortgage Measurement Input, Prepayment Rate [Member] Federal funds purchased Federal Funds Purchased Statistical Measurement [Domain] Statistical Measurement [Domain] Amortized Cost Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss Asset Class [Axis] Asset Class [Axis] Valuation Approach and Technique [Domain] Valuation Approach and Technique [Domain] Interest rate contracts Interest Rate Swap [Member] Nonaccrual, no allowance Financing Receivable, Excluding Accrued Interest, Nonaccrual, No Allowance Pledged Status [Axis] Pledged Status [Axis] Maximum loss exposure, current investments Current Investments Carrying amount of investments in low income housing partnerships which is recognized within Other Assets. Amount represents a portion of parent company's maximum loss exposure related to these unconsolidated VIE. Gross Unrealized Losses Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Basic earnings per common share (in dollars per share) Basic earnings per common share (in dollars per share) Earnings Per Share, Basic FICO score 660-699 Fico Score 660 To 699 [Member] Fico Score 660 To 699 Notes payable—New Market Tax Credit investments Notes Payable, New Market Tax Credit Investment Notes Payable, New Market Tax Credit Investment Gross amounts of recognized assets Security Purchased under Agreement to Resell, Subject to Master Netting Arrangement, before Offset Other comprehensive income (loss) Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Schedule of Segment Financial Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Short-term borrowings Short-Term Debt Gross Unrealized Gains Debt Securities, Held-to-Maturity, Accumulated Unrecognized Gain Measurement Input Type [Domain] Measurement Input Type [Domain] Fixed income Fixed income Fixed income The major component of revenue in this line item is generated from the purchase and sale of securities as both principal and agent, and from other fee sources including loan sales, portfolio advisory, and derivative sales. Government agency issued CMO Collateralized Mortgage Obligations [Member] Net unrealized gains (losses) included in net income Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Charge-offs Total Charge-offs Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff Consumer Real Estate Consumer Real Estate Portfolio Segment [Member] Consumer Real Estate Portfolio Segment [Member] Other U.S. government agencies US Government Corporations and Agencies Securities [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Net amount Security Purchased under Agreement to Resell, Including Not Subject to Master Netting Arrangement, after Offset and Deduction Excise tax on common stock repurchased Share Repurchase Program, Excise Tax Rabbi Trusts used for Deferred Compensation Plans Variable Interest Entity, Primary Beneficiary [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Accounts and Financing Receivables [Table] Trading securities Total trading securities Debt Securities, Trading, and Equity Securities, FV-NI Interest income Interest Income (Expense), Operating [Abstract] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Series C Depository Shares Series C Depository Shares [Member] Series C Depository Shares Hedging Designation [Domain] Hedging Designation [Domain] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Loans held for sale (including $167 and $151 at fair value, respectively) Balance at beginning of period Balance at end of period Loans held for sale: Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance Total liabilities and equity Liabilities and Equity Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Pension and Post-retirement Plans Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Schedule of Mortgage Servicing Rights Servicing Asset at Amortized Cost [Table Text Block] Commercial loan modifications to borrowers experiencing financial difficulty Commercial Loan Modifications To Borrowers Experiencing Financial Difficulty [Member] Commercial Loan Modifications To Borrowers Experiencing Financial Difficulty Total trading liabilities Trading Liabilities, Fair Value Disclosure Expenditures for long-lived assets Segment, Expenditure, Addition to Long-Lived Assets Gross amounts offset in the Balance Sheets Security Sold under Agreement to Repurchase, Subject to Master Netting Arrangement, Asset Offset Forward contracts Forward Contracts [Member] Net periodic benefit cost Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component Preferred Class B Preferred Class B [Member] 2026 2025 Financing Receivable, Excluding Accrued Interest, Year One, Originated, Current Fiscal Year Pay vs Performance Disclosure [Line Items] Loans and leases, fair value Loans, Net Of Unearned Income, Fair Value Disclosure Loans, Net Of Unearned Income, Fair Value Mortgage loans Mortgage Receivable [Member] 90+ Days Past Due Financial Asset, Equal to or Greater than 90 Days Past Due [Member] Schedule of Securities Purchased under Agreements to Resell and Collateral Pledged by Counterparties Securities Purchased Under Agreements To Resell And Collateral Pledged By Counterparties [Table Text Block] Securities Purchased Under Agreements To Resell And Collateral Pledged By Counterparties [Table Text Block] Liabilities: Liabilities [Abstract] Preferred stock, liquidation preference per share (in dollars per share) Preferred Stock, Liquidation Preference Per Share Past due, non-accruing Financing Receivable, Excluding Accrued Interest, Past Due, Non-Accruing Financing Receivable, Excluding Accrued Interest, Past Due, Non-Accruing Derivative liabilities related to sale Derivative Liabilities Related To Sale Derivative liabilities related to sale of a portion of Visa class B shares. SBA interest-only strips Interest-Only-Strip [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Average assets Segment Reporting Average Assets Amount of average assets attributed to the reportable segment. Schedule of Variable Interest Entities [Table] Variable Interest Entity [Table] 2024 2023 Financing Receivable, Excluding Accrued Interest, Year Three, Originated, Two Years before Current Fiscal Year Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Pre-provision net revenue Pre-Provision Net Revenue Pre-Provision Net Revenue Pension plan contribution Defined Benefit Plan, Plan Assets, Contributions by Employer Prior to 2022 Prior to 2021 Financing Receivable, Excluding Accrued Interest, Originated, More than Five Years before Current Fiscal Year, Writeoff Retirement Plan Tax Status [Axis] Retirement Plan Tax Status [Axis] Comprehensive income attributable to controlling interest Comprehensive Income (Loss), Net of Tax, Attributable to Parent Measurement Input Type [Axis] Measurement Input Type [Axis] Name Measure Name Within 1 year Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, Year One Net decrease in deposits Increase (Decrease) in Deposits Proceeds from maturities of securities available for sale Proceeds from Maturities, Prepayments and Calls of Debt Securities, Available-for-Sale Sales Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Sales Retirement Plan Tax Status [Domain] Retirement Plan Tax Status [Domain] Class of Stock [Line Items] Class of Stock [Line Items] Schedule of Securities Sold under Agreements to Repurchase and Collateral Pledged by Company Securities Sold Under Agreements To Repurchase And Collateral Pledged By Company [Table Text Block] Securities Sold Under Agreements To Repurchase And Collateral Pledged By Company [Table Text Block] Special assessment fee expense Special Assessment Fee (Credit) Special Assessment Fee (Credit) Legal Entity [Axis] Legal Entity [Axis] Total assets Total assets Assets Contractual Amount Portion at Other than Fair Value Measurement [Member] Operating Activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Receivable Type [Axis] Receivable Type [Axis] Funds transfer pricing Funds Transfer Pricing Funds Transfer Pricing Securities held to maturity: Debt Securities, Held-to-Maturity, Amortized Cost, before Allowance for Credit Loss [Abstract] FRB Stock FRB Stock [Member] FRB Stock [Member] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Derivative liabilities available for offset Derivative Asset, Subject to Master Netting Arrangement, Deduction of Financial Instrument Not Offset Credit Score, FICO [Axis] Credit Score, FICO [Axis] Securities held to maturity, fair value Fair Value Fair Value Securities held to maturity Debt Securities, Held-to-Maturity, Fair Value Total short-term financial assets Short Term Financial Assets Short-term financial assets include federal funds sold, securities purchased under agreements to resell, and interest bearing deposits with other financial institutions. Common stock - cash dividends declared per share (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-Sale [Line Items] Level 2 Level 2 Fair Value, Inputs, Level 2 [Member] After 5 years through 10 years Debt Securities, Held-to-Maturity, Fair Value, Maturity, Allocated and Single Maturity Date, after Year 5 Through 10 30-89 Days Past Due Financing Receivables 30 to 89 Days Past Due [Member] Financing receivables that are more than 29 days past due but fewer than 90 days past due. Loans held for sale: Proceeds from Sale, Loan, Held-for-Sale [Abstract] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Asset Pledged as Collateral Asset Pledged as Collateral [Member] Mortgage loans (elected fair value) Residential Mortgage [Member] Short-term financial liabilities: Short Term Financial Liabilities [Abstract] Plan Name [Axis] Plan Name [Axis] PEO PEO [Member] Proceeds from issuance of term borrowings Proceeds from Issuance of Secured Debt Schedule of Amortized Cost and Fair Value by Contractual Maturity Investments Classified by Contractual Maturity Date [Table Text Block] SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE Securities Sold under Agreements to Repurchase [Abstract] Liabilities Cash Flow Hedge Derivative Instrument Liabilities at Fair Value Low income housing tax credits Low Income Housing Tax Credits Member [Member] Low Income Housing Tax Credits [Member] Cash and cash equivalents at beginning of period Cash and cash equivalents at end of period Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Net amounts of assets presented in the Balance Sheets Derivative Asset 12 months or longer Debt Securities, Available-for-Sale, Continuous Unrealized Loss Position, 12 Months or Longer Non Recurring Fair Value, Nonrecurring [Member] Other intangible assets Net Carrying Value Intangible Assets, Net (Excluding Goodwill) Provision for remaining unfunded commitments Off-Balance-Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal) Product and Service [Domain] Product and Service [Domain] Securities available for sale: Debt Securities, Available-for-Sale [Abstract] Net income Net income Total reclassification from AOCI Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] SBAs Small Business Administrations [Member] Small Business Administrations [Member] Total liabilities Liabilities, Fair Value Disclosure Notional Derivative, Notional Amount Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Series H Series H Preferred Stock [Member] Revolving Loans Financing Receivable, Excluding Accrued Interest, Revolving OREO Other Real Estate City Area Code City Area Code Schedule of the Allowance for Loan Losses by Portfolio Segment Financing Receivable, Allowance for Credit Loss [Table Text Block] Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Loans held-for-sale, measurement input Loan, Held-for-Sale, Measurement Input Underwriting, portfolio advisory, and other noninterest income Underwriting, Portfolio Advisory, and Other Noninterest Income [Member] Underwriting, Portfolio Advisory, and Other Noninterest Income [Member] Depositary Shares, each representing a 1/4,000th interest in a share of Non-Cumulative Perpetual Preferred Stock, Series F Depository Shares, Each Representing A 1/4,000th Interest In A Share Of Non-cumulative Perpetual Preferred Stock, Series F [Member] Depository Shares, Each Representing A 1/4,000th Interest In A Share Of Non-cumulative Perpetual Preferred Stock, Series F Investing Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Option contracts written Interest Rate Lock [Member] Interest Rate Lock Actuarial (gain) loss Defined Benefit Plan, Amortization of Gain (Loss) Cash Flow Hedge Cash Flow Hedging [Member] Other liabilities Other liabilities Other Liabilities Goodwill Goodwill, beginning balance Goodwill, ending balance Goodwill Fixed asset impairments Tangible Asset Impairment Charges Subtotal Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value Equipment Equipment [Member] Mortgage Banking Activity Transfers and Servicing of Financial Assets [Text Block] Net decrease in interest-bearing deposits with banks Proceeds from (Payments for) in Interest-Bearing Deposits in Banks Supplemental Disclosures Supplemental Cash Flow Information [Abstract] Beginning balance Ending balance Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Other Performance Measure, Amount Other Performance Measure, Amount Determination of Fair Value Fair Value Measurement, Policy [Policy Text Block] Constant prepayment rate Measurement Input, Constant Prepayment Rate [Member] Securities (gains) losses, net Equity Securities, FV-NI, Gain (Loss) Derivative Instrument [Axis] Derivative Instrument [Axis] Commercial real estate Commercial Real Estate CRE Commercial Real Estate Portfolio Segment [Member] Capital surplus Additional Paid in Capital, Common Stock Entity [Domain] Entity [Domain] LMC Financing Receivable, Excluding Accrued Interest, Non-Revolving Financing Receivable, Excluding Accrued Interest, Non-Revolving Net cash (used in) provided by investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Schedule of Accruing and Non-Accruing Loans by Class Past Due And Current Financing Receivables [Table Text Block] Tabular disclosure of financing receivables that are past due but not impaired, financing receivables that are 90 days past due and still accruing, current loans, and financing receivables on nonaccrual status. 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Revenue recognized in the period for (1) performance (incentive) fees based on the investment results achieved for management of certain institutional accounts and hedge funds, (2) schedule-based fees earned for management of mutual funds and closed-end funds, based either on average daily net assets or on a combination of the average daily net assets and gross income, and (3) other investment management and advisory fees. 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