Entity Central Index Key Available for sale debt securities amortized cost before mortgage backed securities. Amortized cost held to maturity before mortgage backed securities. Recorded investment in TDR's that are still accruing. Finance lease liability payments due thereafter. Lessee Operating lease liability payments due thereafter. Amount of money in interest-bearing domestic and foreign accounts that entitle the depositor to withdraw funds at any time without prior notice, also known as demand deposits. Service charges on deposit accounts. Income earned from bank card and credit card services including late, over limit, and annual fees. This item excludes interest income earned on credit card balances and transactions. Includes interchange fees earned from bank card and credit card transactions. Also includes ATM and other banking fees. The noninterest income, net of associated expenses, derived from mortgage banking activities (fees and commissions), including fees earned from servicing third-party assets. Gross income from services rendered by the trust department acting in any fiduciary capacity. Also include fees and commissions from securities brokerage activities, investment advisory and management services and from sales of annuities (fixed, variable, and other). Other comprehensive income change in unrealized holding gain (loss) on securities transferred to held to maturity before tax and reclassification. Other comprehensive income change in unrealized holding gain loss on securities transferred to held to maturity tax. Other comprehensive income loss securities transfers to held to maturity net of tax. Gross amount of derivative assets offset in the statement of financial position. Gross amount of derivative liabilities offset in the statement of financial position. Provision for loan losses expensed included acquired loans. Cover [Abstract] Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Trading Symbol Trading Symbol Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Shell Company Entity Shell Company Title of 12(b) Security Security12b Title Security Exchange Name Security Exchange Name Entity Current Reporting Status Entity Current Reporting Status Entity File Number Entity File Number Entity Incorporation, State or Country Code Entity Incorporation State Country Code Entity Tax Identification Number Entity Tax Identification Number Entity Address, Address Line One Entity Address Address Line1 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Postal Zip Code Entity Address Postal Zip Code City Area Code City Area Code Local Phone Number Local Phone Number Document Quarterly Report Document Quarterly Report Document Transition Report Document Transition Report Entity Interactive Data Current Entity Interactive Data Current Loans and leases receivable gross carrying amount covered and not covered. Reflects the carrying amount of noncovered loans and leases and loans covered by loss sharing agreement with Federal Deposit Insurance Corporation that partially indemnifies bank against losses, net of unearned income and the allowance for loan losses, acquired loans. Loans and leases receivable net LHFI and net acquired loans. Statement Of Financial Position [Abstract] Assets Assets [Abstract] Cash and due from banks Cash And Due From Banks Federal funds sold and securities purchased under reverse repurchase agreements Federal Funds Sold And Securities Purchased Under Agreements To Resell Securities available for sale, at fair value (amortized cost: $1,791,852; allowance for credit losses: $0) Available For Sale Securities Debt Securities Securities held to maturity, net of allowance for credit losses of $0 (fair value: $731,441-2020; $746,202-2019) Held To Maturity Securities Loans held for sale (LHFS) Loans Receivable Held For Sale Net Not Part Of Disposal Group Loans held for investment (LHFI) Loans And Leases Receivable Net Of Deferred Income Less allowance for credit losses (ACL), LHFI Loans And Leases Receivable Allowance Net LHFI Loans And Leases Receivable Net Reported Amount Acquired loans Loans And Leases Receivable Gross Carrying Amount Covered And Not Covered Less allowance for loan losses, acquired loans Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Allowance For Loan Losses Net acquired loans Loans And Leases Receivable Net Reported Amount Acquired Net LHFI and acquired loans Loans And Leases Receivable Net L H F I And Net Acquired Loans Premises and equipment, net Property Plant And Equipment Net Mortgage servicing rights Servicing Asset At Fair Value Amount Goodwill Goodwill Identifiable intangible assets, net Intangible Assets Net Excluding Goodwill Other real estate Other Real Estate Operating lease right-of-use assets Operating Lease Right Of Use Asset Other assets Other Assets Total Assets Assets Liabilities Liabilities [Abstract] Deposits: Deposits [Abstract] Noninterest-bearing Noninterest Bearing Deposit Liabilities Interest-bearing Interest Bearing Deposit Liabilities Total deposits Deposits Federal funds purchased and securities sold under repurchase agreements Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Other borrowings Other Borrowings ACL on off-balance sheet credit exposures Off Balance Sheet Credit Loss Liability Junior subordinated debt securities Junior Subordinated Debenture Owed To Unconsolidated Subsidiary Trust Operating lease liabilities Operating Lease Liability Other liabilities Other Liabilities Total Liabilities Liabilities Shareholders' Equity Stockholders Equity [Abstract] Common stock, no par value: Authorized: 250,000,000 shares Issued and outstanding: 63,396,912 shares - 2020; 64,200,111 shares - 2019 Common Stock Value Capital surplus Additional Paid In Capital Common Stock Retained earnings Retained Earnings Accumulated Deficit Accumulated other comprehensive income (loss), net of tax Accumulated Other Comprehensive Income Loss Net Of Tax Total Shareholders' Equity Stockholders Equity Total Liabilities and Shareholders' Equity Liabilities And Stockholders Equity Securities available-for-sale, amortized cost Available For Sale Debt Securities Amortized Cost Basis Securities available-for-sale, allowance for credit Losses Debt Securities Available For Sale Allowance For Credit Loss Securities held to maturity, net of allowance for credit losses Debt Securities Held To Maturity Allowance For Credit Loss Securities held to maturity, fair value Held To Maturity Securities Fair Value Common stock, par value (in dollars per share) Common Stock No Par Value Common stock, authorized (in shares) Common Stock Shares Authorized Common stock, issued (in shares) Common Stock Shares Issued Common stock, outstanding (in shares) Common Stock Shares Outstanding Interest and fee income derived from acquired loans not otherwise specified in the existing taxonomy. The provision for loan losses on acquired loans. Expenses and fees incurred from communication, data processing, advertising, security, professional, and other service-related fees. Income Statement [Abstract] Interest Income Interest And Dividend Income Operating [Abstract] Interest and fees on LHFS & LHFI Interest And Fee Income Loans And Leases Held In Portfolio Interest and fees on acquired loans Interest And Fees On Acquired Loans Interest on securities: Interest And Dividend Income Securities By Taxable Status [Abstract] Taxable Interest Income Securities Taxable Tax exempt Interest Income Securities Tax Exempt Interest on federal funds sold and securities purchased under reverse repurchase agreements Interest Income Federal Funds Sold And Securities Purchased Under Agreements To Resell Other interest income Other Interest And Dividend Income Total Interest Income Interest And Dividend Income Operating Interest Expense Interest Expense [Abstract] Interest on deposits Interest Expense Deposits Interest on federal funds purchased and securities sold under repurchase agreements Interest Expense Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Other interest expense Interest Expense Other Total Interest Expense Interest Expense Net Interest Income Interest Income Expense Net Provision for credit losses (PCL) Provision For Loan Losses Expensed Provision for loan losses, acquired loans Provision For Loan Losses Acquired Loans Net Interest Income After PCL Interest Income Expense After Provision For Loan Loss Noninterest Income Noninterest Income [Abstract] Service charges on deposit accounts Service Charges On Deposit Accounts Bank card and other fees General Banking Other Mortgage banking, net Mortgage Banking Income Insurance commissions Insurance Commissions And Fees Wealth management Wealth Management Income Other, net Nonoperating Income Expense Total Noninterest Income Noninterest Income Noninterest Expense Noninterest Expense [Abstract] Salaries and employee benefits Labor And Related Expense Services and fees Services And Fees Net occupancy - premises Occupancy Net Equipment expense Equipment Expense Other real estate expense, net Other Revenue Expense From Real Estate Operations Credit loss expense related to off-balance sheet credit exposures Off Balance Sheet Credit Loss Liability Credit Loss Expense Reversal Other expense Other Noninterest Expense Total Noninterest Expense Noninterest Expense Income Before Income Taxes Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Income taxes Income Tax Expense Benefit Net Income Net Income Loss Earnings Per Share Earnings Per Share [Abstract] Basic Earnings Per Share Basic Diluted Earnings Per Share Diluted Other comprehensive income loss transfers from available for sale to held to maturity securities net of tax. Other comprehensive income (loss) reclassification adjustment from AOCI pension and other post retirement benefit plans for net loss due to lump sum settlements net of tax. Statement Of Income And Comprehensive Income [Abstract] Net income per consolidated statements of income Net unrealized gains (losses) on available for sale securities and transferred securities: Other Comprehensive Income Available For Sale Securities Adjustment Net Of Tax Period Increase Decrease [Abstract] Net unrealized holding gains (losses) arising during the period Other Comprehensive Income Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax Change in net unrealized holding loss on securities transferred to held to maturity Other Comprehensive Income Loss Transfers From Available For Sale To Held To Maturity Securities Net Of Tax Pension and other postretirement benefit plans: Other Comprehensive Income Defined Benefit Plans Adjustment Net Of Tax Period Increase Decrease [Abstract] Reclassification adjustments for changes realized in net income: Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans Net Of Tax [Abstract] Net change in prior service costs Other Comprehensive Income Loss Amortization Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Prior Service Cost Credit Net Of Tax Recognized net loss due to lump sum settlement Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Post Retirement Benefit Plans For Net Loss Due To Lump Sum Settlements Net Of Tax Change in net actuarial loss Other Comprehensive Income Loss Reclassification Adjustment From A O C I Pension And Other Postretirement Benefit Plans For Net Gain Loss Net Of Tax Derivatives: Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent [Abstract] Change in the accumulated gain (loss) on effective cash flow hedge derivatives Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax Reclassification adjustment for (gain) loss realized in net income Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Net Of Tax Other comprehensive income (loss), net of tax Other Comprehensive Income Loss Net Of Tax Portion Attributable To Parent Comprehensive income Comprehensive Income Net Of Tax Adjustments related to tax withholding for share based compensation shares. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Capital Surplus [Member] Additional Paid In Capital [Member] Retained Earnings [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) [Member] Accumulated Other Comprehensive Income [Member] Statement [Line Items] Statement [Line Items] Balance Balance (in shares) FASB ASU 2016-13 adoption adjustment New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification Other comprehensive income (loss), net of tax Common stock dividends paid ($0.23 per share) Dividends Common Stock Shares withheld to pay taxes, long-term incentive plan Adjustments Related To Tax Withholding For Share Based Compensation Shares withheld to pay taxes, long-term incentive plan (in shares) Adjustments Related To Tax Withholding For Share Based Compensation Shares Repurchase and retirement of common stock Stock Repurchased And Retired During Period Value Repurchase and retirement of common stock (in shares) Stock Repurchased And Retired During Period Shares Compensation expense, long-term incentive plan Adjustments To Additional Paid In Capital Sharebased Compensation Other Longterm Incentive Plans Requisite Service Period Recognition Balance Balance (in shares) Cash dividends paid on common stock (in dollars per share) Common Stock Dividends Per Share Cash Paid Provision (reversal) for loan lease and other losses. Mortgage servicing rights net. The increase (decrease) during the reporting period in member bank stock. Payments to acquire insurance book of business. Payments under financing lease obligations. Statement Of Cash Flows [Abstract] Operating Activities Net Cash Provided By Used In Operating Activities [Abstract] Adjustments to reconcile net income to net cash provided by operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Credit loss expense, net Provision Reversal For Loan Lease And Other Losses Depreciation and amortization Depreciation Amortization And Accretion Net Net amortization of securities Accretion Amortization Of Discounts And Premiums Investments Gains on sales of loans, net Gain Loss On Sale Of Loans And Leases Deferred income tax provision Deferred Income Tax Expense Benefit Proceeds from sales of loans held for sale Proceeds From Sale Of Mortgage Loans Held For Sale Purchases and originations of loans held for sale Payments For Origination Of Mortgage Loans Held For Sale Originations of mortgage servicing rights Mortgage Servicing Rights Net Earnings on bank-owned life insurance Bank Owned Life Insurance Income Net change in other assets Increase Decrease In Other Operating Assets Net change in other liabilities Increase Decrease In Other Operating Liabilities Other operating activities, net Increase Decrease In Other Operating Capital Net Net cash from operating activities Net Cash Provided By Used In Operating Activities Investing Activities Net Cash Provided By Used In Investing Activities [Abstract] Proceeds from maturities, prepayments and calls of securities held to maturity Proceeds From Maturities Prepayments And Calls Of Held To Maturity Securities Proceeds from maturities, prepayments and calls of securities available for sale Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities Purchases of securities available for sale Payments To Acquire Available For Sale Securities Debt Net proceeds from bank-owned life insurance Payments For Proceeds From Life Insurance Policies Net change in federal funds sold and securities purchased under reverse repurchase agreements Proceeds From Payments For Federal Funds Sold And Securities Purchased Under Agreements To Resell Net Net change in member bank stock Decrease Increase In Member Bank Stock Net change in loans Payments For Proceeds From Loans And Leases Purchases of premises and equipment Payments To Acquire Property Plant And Equipment Proceeds from sales of premises and equipment Proceeds From Sale Of Property Plant And Equipment Proceeds from sales of other real estate Proceeds From Sale Of Foreclosed Assets Purchases of software Payments For Software Investments in tax credit and other partnerships Payments To Acquire Other Investments Purchase of insurance book of business Payments To Acquire Insurance Book Of Business Net cash from investing activities Net Cash Provided By Used In Investing Activities Financing Activities Net Cash Provided By Used In Financing Activities [Abstract] Net change in deposits Increase Decrease In Deposits Net change in federal funds purchased and securities sold under repurchase agreements Increase Decrease In Federal Funds Purchased And Securities Sold Under Agreements To Repurchase Net Net change in short-term borrowings Proceeds From Repayments Of Short Term Debt Maturing In More Than Three Months Payments on long-term FHLB advances Payments For Federal Home Loan Bank Advances Payments under finance lease obligations Payments Under Financing Lease Obligations Common stock dividends Payments Of Dividends Common Stock Repurchase and retirement of common stock Payments For Repurchase Of Common Stock Shares withheld to pay taxes, long-term incentive plan Payments Related To Tax Withholding For Share Based Compensation Net cash from financing activities Net Cash Provided By Used In Financing Activities Net change in cash and cash equivalents Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash and cash equivalents at beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash and cash equivalents at end of period Organization Consolidation And Presentation Of Financial Statements [Abstract] Business, Basis of Financial Statement Presentation and Principles of Consolidation Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Investments Debt And Equity Securities [Abstract] Securities Available for Sale and Held to Maturity Investments In Debt And Marketable Equity Securities And Certain Trading Assets Disclosure [Text Block] Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract] Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI Loans Notes Trade And Other Receivables Disclosure [Text Block] This entire disclosure related to loans acquired in a business acquisition including those covered by indemnification agreements with the FDIC. Certain Loans Acquired In Transfer Not Accounted For As Debt Securities [Abstract] Acquired Loans Acquired Loans Including Covered Loans [Text Block] Mortgage Banking [Abstract] Mortgage Banking Transfers And Servicing Of Financial Assets [Text Block] Entire disclosure for other real estate and covered other real estate. Other Real Estate And Foreclosed Assets [Abstract] Other Real Estate Other Real Estate [Text Block] Leases [Abstract] Leases Leases Of Lessee Disclosure [Text Block] Deposits Deposit Liabilities Disclosures [Text Block] The entire disclosure for Securities Sold Under Repurchase Agreements. Securities Sold Under Repurchase Agreements [Abstract] Securities Sold Under Repurchase Agreements Securities Sold Under Repurchase Agreements [Text Block] Revenue From Contract With Customer [Abstract] Revenue from Contracts with Customers Revenue From Contract With Customer [Text Block] Compensation And Retirement Disclosure [Abstract] Defined Benefit and Other Postretirement Benefits Pension And Other Postretirement Benefits Disclosure [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Stock and Incentive Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Commitments And Contingencies Disclosure [Abstract] Contingencies Commitments And Contingencies Disclosure [Text Block] Earnings Per Share (EPS) Earnings Per Share [Text Block] Supplemental Cash Flow Information [Abstract] Statements of Cash Flows Cash Flow Supplemental Disclosures [Text Block] Stockholders Equity Note [Abstract] Shareholders' Equity Stockholders Equity Note Disclosure [Text Block] Fair Value Disclosures [Abstract] Fair Value Fair Value Disclosures [Text Block] Derivative Instruments And Hedging Activities Disclosure [Abstract] Derivative Financial Instruments Derivative Instruments And Hedging Activities Disclosure [Text Block] Segment Reporting [Abstract] Segment Information Segment Reporting Disclosure [Text Block] New Accounting Pronouncements And Changes In Accounting Principles [Abstract] Accounting Policies Recently Adopted and Pending Accounting Pronouncements New Accounting Pronouncements And Changes In Accounting Principles [Text Block] Accounting Policies [Abstract] Credit Loss, Financial Instrument Credit Loss Financial Instrument Policy [Text Block] Securities available for sale. Securities Available for Sale Securities Available For Sale Policy [Text Block] Securities Held to Maturity. Securities Held to Maturity Securities Held To Maturity Policy [Text Block] Allowance for Credit Losses, LHFI (ACL) Finance Loan And Lease Receivables Held For Investment Allowance And Nonperforming Loans Nonperforming Loans Policy Disclosure of new accounting pronouncements issued that are either adopted or yet to be adopted, including effective date of pronouncement and impact to the financial statements. Accounting Policies Recently Adopted and Pending Accounting Pronouncements Accounting Policies Recently Adopted And Pending Accounting Pronouncements Policy [Text Block] Securities Held to Maturity by Credit Rating, as Determined by Moody's Debt Securities Held To Maturity Credit Quality Indicator Table [Text Block] Amortized Cost and Estimated Fair Value of Available for Sale and Held to Maturity Securities Marketable Securities [Text Block] Securities with Gross Unrealized Losses, Segregated by Length of Impairment Schedule Of Unrealized Loss On Investments Table [Text Block] Contractual Maturities of Available for Sale and Held to Maturity Securities Investments Classified By Contractual Maturity Date Table [Text Block] Loan Portfolio Held for Investment Schedule Of Accounts Notes Loans And Financing Receivable [Text Block] Schedule of amortized cost basis of loans on nonaccrual status. Schedule of Amortized Cost Basis of Loans on Nonaccrual Status Schedule Of Amortized Cost Basis Of Loans On Nonaccrual Status Table [Text Block] Aging Analysis of Past Due and Nonaccrual LHFI by Loan Type Past Due Financing Receivables Table [Text Block] Impaired Financing Receivables Impaired Financing Receivables Table [Text Block] Impact of Modifications Classified as Troubled Debt Restructurings Troubled Debt Restructurings On Financing Receivables Table [Text Block] Tabular disclosure of Troubled Debt Restructuring Subsequently Defaulted. Troubled Debt Restructuring Subsequently Defaulted Troubled Debt Restructuring Subsequently Defaulted Table [Text Block] Tabular disclosure of troubled debt restructurings related to loans held for investments, by loan type (i.e. Accruing, Nonaccrual). Troubled Debt Restructuring Related to Loans Held for Investment by Loan Type Troubled Debt Restructuring Related To Loans Held For Investment Excluding Covered Loans By Loan Type Table [Text Block] Schedule of amortized cost basis of collateral-dependent loans. Schedule of Amortized Cost Basis of Collateral-Dependent Loans Schedule Of Amortized Cost Basis Of Collateral Dependent Loans Carrying Amount of Loans by Credit Quality Indicator Financing Receivable Credit Quality Indicators Table [Text Block] Summary of portfolio Segments loan classes, loan pools and ACL methodology and macroeconomic variables. Summary of Trustmark's Portfolio Segments, Loan Classes, Loan Pools and the ACL Methodology and Loss Drivers Summary Of Portfolio Segments Loan Classes Loan Pools And A C L Methodology And Macroeconomic Variables Table [Text Block] Change in Allowance for Loan Losses Allowance For Credit Losses On Financing Receivables Table [Text Block] Schedule of acquired loans. Schedule of Acquired Loans Schedule Of Acquired Loans Table [Text Block] Tabular disclosure of changes in the carrying value of acquired loans. Changes in the Carrying Value of Acquired Loans Schedule Of Changes In Carrying Value Of Acquired Loans Table [Text Block] Tabular disclosure of the changes in accretable yield of acquired loans. Changes in Accretable Yield of Acquired Loans Schedule Of Changes In Accretable Yield Of Acquired Loans Table [Text Block] Tabular disclosure of the components of the allowance for loan losses on acquired loans. Components of the Allowance for Loan Losses on Acquired Loans Schedule Of Components Of Allowance For Loan Losses On Acquired Loans Table [Text Block] Tabular disclosure of acquired loans by credit quality indicator. The credit quality indicator is a statistic about the credit quality of financing receivables. Examples include, but not limited to, consumer credit risk scores, credit-rating-agency ratings, an entity's internal credit risk grades, loan-to-value ratios, collateral, collection experience and other internal metrics. Acquired Loans by Loan Class and Credit Quality Indicator Carrying Amount Of Acquired Loans By Credit Quality Indicator Table [Text Block] Tabular disclosure of acquired loans that are past due but not impaired, financing receivables that are 90 days past due and still accruing, and financing receivables on nonaccrual status. Aging Analysis of Past Due and Nonaccrual Acquired Loans Aging Analysis Of Past Due And Nonaccrual Acquired Loans By Class Table [Text Block] Schedule of Activity in the Mortgage Servicing Rights Schedule Of Servicing Assets At Fair Value [Text Block] Tabular disclosure of mortgage loans sold and serviced for others. Schedule of Mortgage Loans Sold and Serviced for Others Schedule Of Mortgage Loans Sold And Serviced For Others Table [Text Block] Changes and Losses Net on Other Real Estate [Table Text Block] Changes and Gains (Losses), Net on Other Real Estate Changes And Losses Net On Other Real Estate Table [Text Block] Tabular disclosure of other real estate properties, excluding covered other real estate, by type of property. Other Real Estate, By Type of Property Other Real Estate Excluding Covered Other Real Estate By Type Of Property Table [Text Block] Tabular disclosure of other real estate properties, excluding covered other real estate, by geographic location. Other Real Estate, By Geographic Location Other Real Estate Excluding Covered Other Real Estate By Geographic Location Table [Text Block] Components of Net Lease Cost Lease Cost Table [Text Block] Schedule of cash payments included in measurement of lease liabilities. Cash Payments Included in Measurement of Lease Liabilities Schedule Of Cash Payments Included In Measurement Of Lease Liabilities Table [Text Block] Schedule of balance sheet information and weighted-average lease terms and discount rates related to leases. Balance Sheet Information and Weighted-Average Lease Terms and Discount Rates Related to Leases Schedule Of Balance Sheet Information And Weighted Average Lease Terms And Discount Rates Related To Leases Table [Text Block] Tabular disclosure of future minimum lease commitments for operating and finance lease. Future Minimum Rental Commitments Under Finance and Operating Leases Schedule Of Future Minimum Rental Payments For Operating And Finance Leases Table [Text Block] Tabular disclosure of the components of deposit liabilities. Deposits Summary Deposits Table [Text Block] Tabular disclosure of the Securities Sold Under Repurchase Agreements. Securities Sold Under Agreements To Repurchase [Abstract] Schedule of Securities Sold Under Repurchase Agreements Schedule Of Securities Sold Under Repurchase Agreements Table [Text Block] Summary of Noninterest Income Disaggregated by Reportable Operating Segment and Revenue Stream Disaggregation Of Revenue Table [Text Block] Defined Benefit Plans And Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans And Other Postretirement Benefit Plans Disclosures [Table] Retirement Plan Type Retirement Plan Type [Axis] Retirement Plan Type Retirement Plan Type [Domain] Trustmark Capital Accumulation Plan [Member] Pension Plans Defined Benefit [Member] Supplemental Retirement Plan [Member] Other Pension Plans Postretirement Or Supplemental Plans Defined Benefit [Member] Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans And Other Postretirement Benefit Plans Table Text Block [Line Items] Net Periodic Benefit Cost Schedule Of Defined Benefit Plans Disclosures [Text Block] Summary of Stock Plan Activity Share Based Compensation Arrangement By Share Based Payment Award Options Vested And Expected To Vest Outstanding And Exercisable Table [Text Block] Compensation Expense for Awards and Units Under Stock Plan Schedule Of Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Text Block] Schedule of changes in off-balance sheet credit loss liability. Summary of Changes in ACL on Off-balance Sheet Credit Exposures Schedule Of Changes In Off Balance Sheet Credit Loss Liability Table [Text Block] Weighted-Average Shares Used to Calculate Basic and Diluted EPS Schedule Of Weighted Average Number Of Shares Table [Text Block] Weighted-Average Antidilutive Stock Awards Excluded from Determining Diluted EPS Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Cash Flows Supplementary Disclosures Schedule Of Cash Flow Supplemental Disclosures Table [Text Block] Table of Actual Regulatory Capital Amounts and Ratios Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Text Block] Net Change in Components of Accumulated Other Comprehensive Income (Loss) and the Related Tax Effects Schedule Of Amounts Recognized In Other Comprehensive Income Loss Table [Text Block] Components of Reclassifications Out of Accumulated Other Comprehensive Income (Loss) Schedule Of Accumulated Other Comprehensive Income Loss Table [Text Block] Financial Assets and Liabilities Measured at Fair Value Recurring Basis Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis Table [Text Block] Changes in Level 3 Assets Measured at Fair Value on a Recurring Basis Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Text Block] Carrying Amounts and Estimated Fair Values of Financial Instruments Fair Value By Balance Sheet Grouping [Text Block] Tabular disclosure of the fair value and contractual principal outstanding of loans held for sale accounted for under the fair value option. Fair Value and the Contractual Principal Outstanding of the LHFS Fair Value And Contractual Principal Outstanding Of Loan Held For Sale Table [Text Block] Fair Value of Derivative Instruments Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value [Text Block] Effects of Derivative Instruments on Statements of Operations Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance [Text Block] Schedule of Amount Included in Other Comprehensive Income for Derivative Instruments Designated as Hedges of Cash Flows Schedule Of Cash Flow Hedges Included In Accumulated Other Comprehensive Income Loss Table [Text Block] Tabular disclosure of derivative and other financial assets and liabilities that are subject to offsetting, including master netting arrangements. Information about Financial Instruments that are Eligible for Offset in the Consolidated Balance Sheets Schedule Of Information About Financial Instruments That Are Eligible For Offset In Consolidated Balance Sheets Table [Text Block] Schedule of Segment Information Schedule Of Segment Reporting Information By Segment [Text Block] The number of offices in Alabama, Florida, Mississippi, Tennessee and Texas. Business, basis of financial statement presentation and principles of consolidation. Business, basis of financial statement presentation and principles of consolidation. Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Table] Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Table] Subsequent Event Type Subsequent Event Type [Axis] Subsequent Event Type Subsequent Event Type [Domain] Subsequent Event [Member] Subsequent Event [Member] Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items] Business Basis Of Financial Statement Presentation And Principles Of Consolidation [Line Items] Number of offices Number Of Offices Number of individual loans modified as per CARES Act. Aggregate principal balances of loans modified as per CARES Act. Period of extension on interest part of loans modified as per CARES Act. Period of extension on full payment deferrals part of loans modified as per CARES act. Number of individual loans modified as per CARES Act Number Of Individual Loans Modified As Per C A R E S Act Aggregate principal balances of loans modified as per CARES Act Aggregate Principal Balances Of Loans Modified As Per C A R E S Act Period of extension on interest part of loans modified as per CARES Act Period Of Extension On Interest Part Of Loans Modified As Per C A R E S Act Period of extension on full payment deferrals part of loans modified as per CARES Act Period Of Extension On Full Payment Deferrals Part Of Loans Modified As Per C A R E S Act Expected credit loss. 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. Information by available for sale and held to maturity securities. Schedule Of Available For Sale And Held To Maturity Securities [Table] Schedule Of Available For Sale And Held To Maturity Securities [Table] Adjustments for New Accounting Pronouncements Adjustments For New Accounting Pronouncements [Axis] Type of Adoption Type Of Adoption [Member] ASU 2016-13 [Member] Accounting Standards Update201613 [Member] Debt Security Category Information By Category Of Debt Security [Axis] Other than Temporary Impairment, Credit Losses Recognized in Earnings, Categories of Investments Other Than Temporary Impairment Credit Losses Recognized In Earnings Categories Of Investments [Domain] Securities Available for Sale [Member] Availableforsale Securities [Member] Securities Held to Maturity [Member] Heldtomaturity Securities [Member] Financial Asset, Period Past Due Financing Receivables Period Past Due [Axis] Financial Asset, Period Past Due Financing Receivables Period Past Due [Domain] 30 Days or More Past Due [Member] Financing Receivables30 To59 Days Past Due [Member] Schedule of Available For Sale and Held to Maturity Securities [Line Items] Schedule Of Available For Sale And Held To Maturity Securities [Line Items] Expected credit loss Expected Credit Loss Cumulative effect adjustment through retained earnings Cumulative Effect On Retained Earnings Net Of Tax1 Accrued interest receivable Interest Receivable Expected credit loss, current. Current expected credit loss Expected Credit Loss Current Potential credit loss exposure. Securities held to maturity Potential credit loss exposure Potential Credit Loss Exposure Reserve for credit loss Provision For Loan And Lease Losses Debt securities Held-to-maturity nonaccrual. Held-to-maturity, past due Debt Securities Held To Maturity Past Due Held-to-maturity nonnaccrual Debt Securities Held To Maturity Nonaccrual1 Credit Rating, Moody's Credit Rating Moodys [Axis] External Credit Rating, Moody's External Credit Rating Moodys [Member] Aaa [Member] Moodys Aaa Rating [Member] Moody's, Aa1 to Aa3 rating. Aaa1 to Aa3 [Member] Moody S Aa1 To Aa3 Rating [Member] Moodys Not Rated Rating. Not Rated [Member] Moodys Not Rated Rating [Member] Securities Held to Maturity Amortized Cost Financial Instrument Financial Instrument [Axis] Financial Instruments Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] U.S. Government Agency Obligations [Member] U S Government Agencies Debt Securities [Member] Obligations of States and Political Subdivisions [Member] U S States And Political Subdivisions [Member] Securities collateralized by residential real estate mortgage considered as pass-through securities guaranteed by GNMA. Residential Mortgage Pass-Through Securities Guaranteed by GNMA [Member] Residential Mortgage Pass Through Securities Guaranteed By G N M A [Member] Securities collateralized by residential real estate mortgage considered as pass-through securities issued by FNMA and FHLMC. Residential Mortgage Pass-Through Securities Issued by FNMA and FHLMC [Member] Residential Mortgage Pass Through Securities Issued By F N M A And F H L M C [Member] Other securities collateralized by residential real estate mortgage considered as pass-through securities issued or guaranteed by FNMA, FHLMC or GNMA. Other Residential Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member] Other Residential Mortgage Backed Securities Issued Or Guaranteed By F N M A F H L M C Or G N M A [Member] Commercial Mortgage-Backed Securities Issued or Guaranteed by FNMA, FHLMC or GNMA [Member] Commercial Mortgage Backed Securities [Member] Securities Available for Sale, Amortized Cost Securities Available for Sale, Gross Unrealized Gains Available For Sale Debt Securities Accumulated Gross Unrealized Gain Before Tax Securities Available for Sale, Gross Unrealized (Losses) Available For Sale Debt Securities Accumulated Gross Unrealized Loss Before Tax Securities Available for Sale, Estimated Fair Value Securities Held to Maturity, Amortized Cost Securities Held to Maturity, Gross Unrealized Gains Held To Maturity Securities Accumulated Unrecognized Holding Gain Securities Held to Maturity, Gross Unrealized (Losses) Held To Maturity Securities Accumulated Unrecognized Holding Loss Securities Held to Maturity, Estimated Fair Value This item represents the amount of securities categorized as available-for-sale being transferred to the held-to-maturity securities category. Amount before tax and reclassification adjustments of unrealized holding gain (loss) on available-for-sale securities at date of transfer. Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities at date of transfer. Unamortized, unrealized gain (loss) at the end of an accounting period on available for sale securities transferred to held to maturity securities . Reclassification of Securities available for sale to securities held to maturity Reclassification Of Available For Sale To Held To Maturity Securities Net unrealized holding loss on AFS Securities at date of transfer Other Comprehensive Income Loss Unrealized Holding Gain Loss On Securities Arising During Period Before Tax At Date Of Transfer Net unrealized holding losses on AFS Securities, net of tax at date of transfer Other Comprehensive Income Loss Unrealized Holding Gain Loss On Securities Arising During Period Net Of Tax At Date Of Transfer Net unamortized, unrealized loss on transfer of securities Accumulated Other Comprehensive Income Loss Transferred Securities Adjustment Net unamortized, unrealized loss on transfer of securities, net of tax Accumulated Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax This item represents the aggregate fair value of investments categorized as available-for-sale and held-to-maturity securities that have been in a continuous unrealized loss position for less than twelve months. This item represents the aggregate fair value of investments categorized as available-for-sale and held-to-maturity securities that have been in a continuous unrealized loss position for twelve months or longer. This item represents the aggregate fair value of investments in an unrealized loss position which are categorized as available-for-sale and held-to-maturity securities. This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized as available-for-sale and held-to-maturity securities. This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months for those securities which are categorized as available-for-sale and held-to-maturity securities. This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for twelve months or longer for those securities which are categorized as available-for-sale and held-to-maturity securities. Estimated Fair Value, Less than 12 Months Estimated Fair Value Less Than12 Months Estimated Fair Value, 12 Months or More Estimated Fair Value12 Months Or More Estimated Fair Value, Total Total Estimated Fair Value Gross Unrealized (Losses), Less than 12 Months Gross Unrealized Losses Less Than12 Months Gross Unrealized (Losses), 12 Months or More Gross Unrealized Losses12 Months Or More Gross Unrealized (Losses), Total Total Gross Unrealized Losses Other-than-temporary impairments Impairment Of Investments Securities pledged to collateralize agreements The carrying value as of the balance sheet date of securities pledged and securities that an institution sells and agrees to repurchase (the identical or substantially the same securities) as a seller-borrower at a specified date for a specified price, also known as a repurchase agreement, or repo. Pledged securities to the discount window providing additional contingency funding to collateralize agreements. Pledged to collateralize public deposits and securities sold under repurchase agreements and for other purposes as permitted by law Pledged Collateralize Deposits And Securities Sold Under Repurchase Agreements Pledged securities providing additional contingency funding Pledged Securities Providing Additional Contingency Funding Fair value of held to maturity securities before mortgage back securities. Fair value of available for sale securities before mortgage back securities. Securities Available for Sale, Amortized Cost [Abstract] Available For Sale Securities Fair Value To Amortized Cost Basis [Abstract] Due in one year or less Available For Sale Securities Debt Maturities Within One Year Amortized Cost Due after one year through five years Available For Sale Securities Debt Maturities After One Through Five Years Amortized Cost Due after five years through ten years Available For Sale Securities Debt Maturities After Five Through Ten Years Amortized Cost Due after ten years Available For Sale Securities Debt Maturities After Ten Years Amortized Cost Total amortized cost, before mortgage-backed securities Available For Sale Debt Securities Amortized Cost Before Mortgage Backed Securities Mortgage-backed securities Available For Sale Securities Debt Maturities Without Single Maturity Date Amortized Cost Securities Available for Sale, Estimated Fair Value [Abstract] Available For Sale Securities Debt Maturities Fair Value [Abstract] Due in one year or less Available For Sale Securities Debt Maturities Within One Year Fair Value Due after one year through five years Available For Sale Securities Debt Maturities After One Through Five Years Fair Value Due after five years through ten years Available For Sale Securities Debt Maturities After Five Through Ten Years Fair Value Due after ten years Available For Sale Securities Debt Maturities After Ten Years Fair Value Total fair value, before mortgage-backed securities Fair Value Of Available For Sale Securities Before Mortgage Back Securities Mortgage-backed securities Available For Sale Securities Debt Maturities Without Single Maturity Date Fair Value Total Securities Held to Maturity, Amortized Cost [Abstract] Held To Maturity Securities Debt Maturities Net Carrying Amount [Abstract] Due in one year or less Held To Maturity Securities Debt Maturities Within One Year Net Carrying Amount Due after one year through five years Held To Maturity Securities Debt Maturities After One Through Five Years Net Carrying Amount Due after five years through ten years Held To Maturity Securities Debt Maturities After Five Through Ten Years Net Carrying Amount Due after ten years Held To Maturity Securities Debt Maturities After Ten Years Net Carrying Amount Total amortized cost, before mortgage-backed securities Amortized Cost Held To Maturity Before Mortgage Backed Securities Mortgage-backed securities Held To Maturity Securities Debt Maturities Without Single Maturity Date Net Carrying Amount Securities Held to Maturity, Estimated Fair Value [Abstract] Held To Maturity Securities Debt Maturities Fair Value [Abstract] Due in one year or less Held To Maturity Securities Debt Maturities Within One Year Fair Value Due after one year through five years Held To Maturity Securities Debt Maturities After One Through Five Years Fair Value Due after five years through ten years Held To Maturity Securities Debt Maturities After Five Through Ten Years Fair Value Due after ten years Held To Maturity Securities Debt Maturities After Ten Years Fair Value Total fair value, before mortgage-backed securities Fair Value Of Held To Maturity Securities Before Mortgage Back Securities Mortgage-backed securities Held To Maturity Securities Debt Maturities Without Single Maturity Date Fair Value Total Schedule Of Financing Receivable Allowance For Credit Losses [Table] Schedule Of Financing Receivable Allowance For Credit Losses [Table] Financing Receivable Portfolio Segment Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment Financing Receivable Portfolio Segment [Domain] Class of financing receivables related to nonfarm, nonresidential properties financing receivables. Secured by Nonfarm, Nonresidential Properties [Member] Nonresidential Properties Financing Receivables [Member] Commercial and Industrial Loans [Member] Commercial Portfolio Segment [Member] Consumer Loans [Member] Consumer Portfolio Segment [Member] Class of financing receivables related to state and other political subdivision loan financing receivables. State and Other Political Subdivision Loans [Member] State And Other Political Subdivision Loans Financing Receivable [Member] Other commercial loans financing receivable. Other Commercial Loans [Member] Other Commercial Loans Financing Receivable [Member] Real Estate, Type of Property Mortgage Loans On Real Estate Description Type Of Property [Axis] Real Estate Mortgage Loans On Real Estate Name Property Type [Domain] Class of financing receivables related to real estate construction, land development and other land operations financing receivables. Construction, Land Development and Other Land [Member] Construction Land Development And Other Financing Receivable [Member] Class of financing receivables related to residential financing receivables for mortgages. Secured by 1-4 Family Residential Properties [Member] Residential Financing Receivable [Member] Other residential financing receivable. Other Secured by 1-4 Family Residential Properties [Member] Other Residential Financing Receivable [Member] Class of financing receivables that are not otherwise categorized and are secured by real estate. Other Real Estate Secured [Member] Other Real Estate Secured Financing Receivable [Member] Other construction. Other Construction [Member] Other Construction [Member] Collateral Collateral [Axis] Collateral Collateral [Domain] Loans Secured by Real Estate [Member] Real Estate [Member] Other Loans Secured by Real Estate. Other Loans Secured by Real Estate [Member] Other Loans Secured By Real Estate [Member] Other Loans Secured by Real Estate [Member] Financing Receivable Allowance For Credit Losses [Line Items] Financing Receivable Allowance For Credit Losses [Line Items] Loan Portfolio [Abstract] Receivables [Abstract] Total LHFI Schedule Of Impaired Financing Receivable [Table] Schedule Of Impaired Financing Receivable [Table] Commercial Credits [Member] Non-Business Purpose Credits [Member] Financing Receivable Impaired [Line Items] Financing Receivable Impaired [Line Items] Accrued interest receivable Loans And Leases Receivable Impaired Nonperforming Accrual Of Interest The maximum concentration for any loan concentration as a percentage of total loans held for investment. Number of key market regions the entity operates that are included in the qualitative reserve allocation review process. Maximum concentration of loan as a percentage of total LHFI Concentration Risk Credit Risk Financial Instrument Maximum Exposure Percentage Key market regions Key Market Regions In Qualitative Reserve Allocation Term of loan is contractually past due to be classified as a past due loan. Term of past due for loan to classify as nonaccrual. Number of days to pass to be classified as past due LHFI Term Of Loan Is Contractually Past Due To Classify As Past Due Loan Number of days past due for loan to be classified as nonaccrual Term Of Past Due For Loan To Classify As Nonaccrual Financing receivable recorded investment nonaccrual with no ACL. Other construction financing receivable. Other Construction [Member] Other Construction Financing Receivable [Member] Financing Receivable, Recorded Investment, Aging [Abstract] Financing Receivable Recorded Investment Aging [Abstract] Nonaccrual With No ACL Financing Receivable Recorded Investment Nonaccrual With No A C L Total Nonaccrual Financing Receivable Recorded Investment Nonaccrual Status Loans Past Due 90 Days or More Still Accruing Financing Receivable Recorded Investment90 Days Past Due And Still Accruing Past Due 30 to 59 Days [Member] Past Due 60 to 89 Days [Member] Financing Receivables60 To89 Days Past Due [Member] Past Due 90 Days or More [Member] Financing Receivables Equal To Greater Than90 Days Past Due [Member] Class of financing receivables that are not otherwise categorized and not related to real estate. Other Loans [Member] Other Loans Financing Receivable [Member] Total Past Due Financing Receivable Recorded Investment Past Due Nonaccrual Current Loans Financing Receivable Recorded Investment Current The minimum loan amount for a nonaccrual LHFI to be specifically reviewed for impairment and deemed impaired. Minimum loan amount for loan to be specifically reviewed for impairment and deemed impaired Minimum Loan Amount For Loan To Be Specifically Reviewed For Impairment And Deemed Impaired Loan and Lease Receivables, Impaired [Abstract] Loan And Lease Receivables Impaired [Abstract] Total LHFI Unpaid Principal Balance Impaired Financing Receivable Unpaid Principal Balance Total LHFI With No Related Allowance Recorded Impaired Financing Receivable With No Related Allowance Recorded Investment Total LHFI With an Allowance Recorded Impaired Financing Receivable With Related Allowance Recorded Investment Total LHFI Recorded Investment Impaired Financing Receivable Recorded Investment Related Allowance Impaired Financing Receivable Related Allowance Average Recorded Investment Impaired Financing Receivable Average Recorded Investment Classified as troubled debt restructuring LHFI. Loans Held for Investment classified as Troubled debt restructurings (TDRs) which is primarily comprised of credits with interest only payments. Unused commitments on troubled debt restructurings. LHFI classified as TDRs Classified As Troubled Debt Restructuring L H F I LHFI classified as TDRs from credits with interest only payments Troubled Debt Restructurings Comprised Of Credits With Interest Only Payments Unused commitments on TDRs Unused Commitments On Troubled Debt Restructurings Amount of allowance for credit losses related to financing receivable that has undergone troubled debt restructuring. Reduction to the allowance for credit losses related to financing receivables, excluding covered loans, that have undergone troubled debt restructuring and deemed uncollectible. Financing receivable, related allowance Financing Receivable Post Modification Recorded Investment Related Allowance Financing receivable, related charge-offs Financing Receivable Post Modification Recorded Investment Related Write Offs Schedule Of Financing Receivable Troubled Debt Restructurings [Table] Schedule Of Financing Receivable Troubled Debt Restructurings [Table] Loan Restructuring Modification Loan Restructuring Modification [Axis] Loan Restructuring Modification Loan Restructuring Modification [Domain] Classes of financing receivables and portfolio segments related to troubled debt restructurings in which a modification was made within the last 12 months and for which there was no payment default in the current reporting period. Troubled Debt Restructurings [Member] Troubled Debt Restructurings [Member] Financing Receivable Modifications [Line Items] Financing Receivable Modifications [Line Items] Number of Contracts Financing Receivable Modifications Number Of Contracts2 Pre-Modification Outstanding Recorded Investment Financing Receivable Modifications Pre Modification Recorded Investment2 Post-Modification Outstanding Recorded Investment Financing Receivable Modifications Post Modification Recorded Investment2 Number of Contracts Financing Receivable Modifications Subsequent Default Number Of Contracts1 Recorded Investment Financing Receivable Modifications Subsequent Default Recorded Investment1 Classes of financing receivables and portfolio segments related to troubled debt restructurings in which a modification was made within the last 12 months and for which there was a payment default in the current reporting period. Troubled Debt Restructurings [Member] Troubled Debt Restructurings That Subsequently Defaulted [Member] Accruing Financing Receivable Recorded Investment Accruing Total Financing Receivable Modifications Recorded Investment Financing receivable collateral dependent loans. MachineryAndEquipment [Member] Machinery And Equipment [Member] Inventory and receivables. Inventory and Receivables [Member] Inventory And Receivables [Member] Vehicles [Member] Vehicles [Member] Miscellaneous. Miscellaneous [Member] Miscellaneous [Member] Collateral-Dependent Loans Financing Receivable Collateral Dependent Loans This line item represents the number of key quality ratios on which entity's loan portfolio credit quality indicators focused. The minimum of days past due used as a baseline for the evaluation of collateral documentation under the entity's loan policy. Schedule Of Financing Receivable Recorded Investment Credit Quality Indicator [Table] Schedule Of Financing Receivable Recorded Investment Credit Quality Indicator [Table] Statistical Measurement Range [Axis] Statistical Measurement Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type Mortgage Loans On Real Estate Loan Type [Axis] SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Loan Type Mortgage Loans On Real Estate Loan Type [Domain] Allowance for credit losses. Allowance for Credit Losses, ACL [Member] Allowance For Credit Losses A C L [Member] Financing Receivable Recorded Investment [Line Items] Financing Receivable Recorded Investment [Line Items] Number of days used as baseline in evaluating collateral documentation exceptions for loan policy Term Of Past Due Used In Evaluating Collateral Exceptions Number of key quality ratios Number Of Key Quality Ratios Minimum exposure for commercial accruing substandard loans to be reviewed on an individual basis. Minimum exposure for commercial accruing substandard loans to be reviewed on an individual basis Minimum Exposure For Commercial Accruing Substandard Loans To Be Reviewed On Individual Basis This line item represents the period to conduct asset review by the entity. Financing Receivable [Abstract] Financing Receivable [Abstract] Financing Receivable [Abstract] Period to conduct asset review Period To Conduct Asset Review Credit amount used in baseline evaluation. Credit amount used as baseline in evaluating loan policy Credit Amount Used In Baseline Evaluation Type of Borrower Class Of Financing Receivable Type Of Borrower [Axis] Class of Financing Receivable, Type of Borrower Class Of Financing Receivable Type Of Borrower [Domain] Commercial LHFI [Member] Commercial Borrower [Member] Internal Credit Assessment Internal Credit Assessment [Axis] Internal Credit Assessment Internal Credit Assessment [Domain] Pass - RR 1 through RR 6 [Member] Pass [Member] Special Mention - RR 7 [Member] Special Mention [Member] Substandard - RR [Member] Substandard [Member] Doubtful - RR 9 [Member] Doubtful [Member] Consumer LHFI [Member] Consumer Borrower [Member] Financing receivables current due. Current [Member] Financing Receivables Current Due [Member] Financing receivables that are more than 30 days past due but fewer than 90 days past due. Past Due 30-89 Days [Member] Financing Receivables30 To89 Days Past Due [Member] Nonaccrual. Nonaccrual [Member] Nonaccrual [Member] Term Loans by Origination Year, 2020 Financing Receivable Originated In Current Fiscal Year Term Loans by Origination Year, 2019 Financing Receivable Originated In Fiscal Year Before Latest Fiscal Year Term Loans by Origination Year, 2018 Financing Receivable Originated Two Years Before Latest Fiscal Year Term Loans by Origination Year, 2017 Financing Receivable Originated Three Years Before Latest Fiscal Year Term Loans by Origination Year, 2016 Financing Receivable Originated Four Years Before Latest Fiscal Year Term Loans by Origination Year, Prior to 2016 Financing Receivable Originated Five Or More Years Before Latest Fiscal Year Financing Receivable, Revolving Loans Financing Receivable Revolving Financing Receivable, before Allowance for Credit Loss Notes Receivable Gross Pass Categories 1-6 [Member] Special Mention Category 7 [Member] Substandard Category 8 [Member] Doubtful Category 9 [Member] Financing receivable commercial Recorded Investment in financing receivables categorized as consumer loans including those current, past due and nonaccrual status. Current Financing Receivable, Recorded Investment, Past Due Subtotal Consumer Loans Financing Receivable Recorded Investment Loans held for sale eligible for repurchase that are equal to or greater than 90 days past due. The amount of the outstanding principal of a loan may be repurchased under GNMA Optional repurchase Program for loans in a pool that become delinquent. LHFS past due 90 days or more Covered Serviced Financing Receivable Recorded Investment Equal To Greater Than90 Days Past Due Percentage of outstanding principal to be repurchased under GNMA optional repurchase program Optional Repurchase Program Principal Percentage May Be Repurchased Quantitative portion of allowance for credit losses for loan pools estimation methodology. Loans Secured by Real Estate [Member] Commercial Real Estate Portfolio Segment [Member] Class of Financing Receivable Financing Receivable Recorded Investment By Class Of Financing Receivable [Axis] Class of Financing Receivable Financing Receivable Recorded Investment Class Of Financing Receivable [Domain] Construction, Land Development and Other Land [Member] Construction Loans [Member] Secured by nonfarm, nonresidential properties. Secured by Nonfarm, Nonresidential Properties [Member] Secured By Nonfarm Nonresidential Properties [Member] Class of financing receivables related to commercial and industrial financing receivables Commercial and Industrial Loans [Member] Commercial And Industrial Loans [Member] Consumer loans. Consumer Loans [Member] Consumer Loans [Member] State and Other Political Subdivision Loans. State and Other Political Subdivision Loans [Member] State And Other Political Subdivision Loans [Member] Other commercial loans. Other Commercial Loans [Member] Other Commercial Loans [Member] Family Residential Construction. 1 -4 Family Residential Construction [Member] Family Residential Construction [Member] Lots and Development. Lots and Development [Member] Lots And Development [Member] Unimproved Land. Unimproved Land [Member] Unimproved Land [Member] Consumer 1-4 Family - 1st Liens [Member] Consumer Family First Liens [Member] Nonowner Occupied Hotel/Motel. Nonowner-Occupied - Hotel/Motel [Member] Nonowner Occupied Hotel Motel [Member] Nonowner Occupied Office. Nonowner-Occupied - Office [Member] Nonowner Occupied Office [Member] Non-Owner Occupied- Retail. Nonowner-Occupied- Retail [Member] Non Owner Occupied Retail [Member] Nonowner Occupied Senior Living Nursing Homes. Nonowner-Occupied- Senior Living/ Nursing Homes [Member] Nonowner Occupied Senior Living Nursing Homes [Member] Nonowner-occupied - All Other. Nonowner-occupied - All Other [Member] Nonowner Occupied All Other [Member] Nonresidential Nonowner- Occupied - Apartments. Nonresidential Nonowner- Occupied - Apartments [Member] Nonresidential Nonowner Occupied Apartments [Member] Nonresidential Owner- Occupied. Nonresidential Owner- Occupied [Member] Nonresidential Owner Occupied [Member] Other Construction Loan Pool. Other Construction [Member] Other Construction Loan Pool [Member] Trustmark Mortgage. Trustmark Mortgage [Member] Trustmark Mortgage [Member] Commercial and Industrial - Non-Working Capital. Commercial and Industrial - Non-Working Capital [Member] Commercial And Industrial Non Working Capital [Member] Commercial and Industrial - Working Capital. Commercial and Industrial - Working Capital [Member] Commercial And Industrial Working Capital [Member] Credit Cards. Credit Cards [Member] Credit Cards [Member] Overdrafts. Overdrafts [Member] Overdrafts [Member] All Other Consumer. All Other Consumer [Member] All Other Consumer [Member] Obligations of State and Political Subdivisions. Obligations of State and Political Subdivisions [Member] Obligations Of State And Political Subdivisions [Member] Class of financing receivables that are not otherwise categorized and not related to real estate. Other Loans [Member] Other Loans [Member] Methodology Quantitative Portion Of Allowance For Credit Losses For Loan Pools Estimation Methodology Allowance for credit loss macroeconomic variables. Loss Drivers Allowance For Credit Loss Macroeconomic Variables Allowance for Loan Losses, LHFI. Allowance for Loan Losses, LHFI [Member] Allowance For Loan Losses L H F I [Member] Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract] Financing Receivable Allowance For Credit Loss Additional Information [Abstract] Individually Evaluated for Credit Loss Financing Receivable Allowance For Credit Losses Individually Evaluated For Impairment1 Collectively Evaluated for Credit Loss Financing Receivable Allowance For Credit Losses Collectively Evaluated For Impairment Total New accounting pronouncement or change in accounting principle effect of adoption quantification, loans held for investments. New accounting pronouncement or change in accounting principle, effect of adoption, quantification, allowance for loan losses acquired loans transfer. New accounting pronouncement or change in accounting principle, effect of adoption, quantification, adjustment of allowance for credit losses acquired loans. Financing receivable allowance for credit losses write offs recoveries net. Financing Receivable, Allowance for Credit Losses [Roll Forward] Financing Receivable Allowance For Credit Losses Roll Forward Balance at beginning of period FASB ASU 2016-13 Adoption Adjustment LHFI New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification Loans Held For Investments Allowance for loan losses, acquired loans transfer New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification Allowance For Loan Losses Acquired Loans Transfer Acquired loans ACL adjustment New Accounting Pronouncement Or Change In Accounting Principle Effect Of Adoption Quantification Adjustment Of Allowance For Credit Losses Acquired Loans Loans charged-off Financing Receivable Allowance For Credit Losses Write Offs Recoveries Financing Receivable Allowance For Credit Losses Recovery Net (charge-offs) recoveries Financing Receivable Allowance For Credit Losses Write Offs Recoveries Net PCL Balance at end of period The carrying value of acquired loans during the period. Credit Loss Status Credit Loss Status [Axis] Credit Loss Status Credit Loss Status [Domain] Purchased Credit Deteriorated (PCD) Loans [Member] Financial Asset Acquired With Credit Deterioration [Member] Acquired loans Acquired Loans Carrying Value Loans Allowance for loan losses, acquired loans Financing Receivable, Allowance for Credit Losses [Line Items] Net acquired loans Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Carrying Amount Net Certain loans acquired in transfer not accounted for as debt securities transferred to loans held for investment. Net payments received during the period on purchased loans. Monetary Duration Credit. Represents changes in interest cash flows for loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that was acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable, due to the impact of modifications incorporated into the quarterly assessment of expected future cash flows and/or changes in interest rates on variable rate loans. The increases or decreases in the aggregate excess of a loan's other changes over the investor's initial investment in the loan. This relates to loans not accounted for as debt securities, with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable. Carrying value of acquired loans [Abstract] 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. Information by acquired financing receivable. Schedule Of Acquired Financing Receivable Recorded Investment Credit Quality Indicator [Table] Schedule Of Acquired Financing Receivable Recorded Investment Credit Quality Indicator [Table] Acquired Impaired [Member] Unlikely To Be Collected Financing Receivable [Member] Financial Instrument Performance Status Financial Instrument Performance Status [Axis] Financial Instrument Performance Status Financial Instrument Performance Status [Domain] Acquired Not ASC 310-30 [Member] Performing Financing Receivable [Member] Schedule Of Acquired Financing Receivable Recorded Investment Credit Quality Indicator [Line Items] Schedule Of Acquired Financing Receivable Recorded Investment Credit Quality Indicator [Line Items] Carrying value of acquired loans [Abstract] Carrying Value Of Acquired Loans [Abstract] Carrying value, net, beginning FASB ASU 2016-13 adoption adjustment Transfers Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Transferred To Loans Held For Investment Accretion to interest income Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Accretion Payments received, net Change In Carrying Amount Of Loans Payments Received Net Other Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Changes In Expected Cash Flows That Do Not Affect Nonaccretable Difference Change in allowance for loan losses, acquired loans Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Change In Credit Losses Carrying value, net, ending Certain loans acquired in transfer not accounted for as debt securities accretable yield adoption of accounting standard adjustments. Change in accretable difference on acquired loans [Abstract] Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Movement Schedule Roll Forward Accretable yield at beginning of period Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield FASB ASU 2016-13 adoption adjustment Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Adoption Of Accounting Standard Adjustments Disposals, net Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Disposals Of Loans Reclassification from nonaccretable difference Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Reclassifications To From Nonaccretable Difference Accretable yield at end of period Certain loans acquired in transfer not accounted for as debt securities allowance for loan losses adoption of accounting standard adjustments. Allowance for loan and lease losses recoveries and write-off, net. Allowance for Loan and Lease Losses [Roll Forward] Allowance For Loan And Lease Losses Roll Forward Balance at beginning of period FASB ASU 2016-13 adoption adjustment Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Allowance For Loan Losses Adoption Of Accounting Standard Adjustments Net (charge-offs) recoveries Allowance For Loan And Lease Losses Recoveries And Write Offs Net Balance at end of period Pass [Member] Commercial Loan [Member] Commercial Loan [Member] Acquired Loans, Commercial Loans [Abstract] Loans And Leases Receivable Disclosure [Abstract] Acquired loans Acquired Loans, Aging [Abstract] Acquired loans that are current. Recorded Investment in financing receivables that are past due at the balance sheet date. Acquired loans that are on nonaccrual status as of the balance sheet date. Acquired loans carrying value consumer. Acquired Loans, Aging [Abstract] Acquired Loans Aging Consumer Loans [Abstract] Current Acquired Loans Recorded Investment Current Acquired Loans, Past Due Acquired Loans Carrying Value Past Due Nonaccrual Acquired Loans Nonaccrual Status Subtotal Acquired Loans Carrying Value Consumer Total Acquired Loans Acquired Loans, Aging [Abstract] Acquired Loans, Aging [Abstract] Acquired Loans Aging [Abstract] Acquired Loans Mortgage servicing rights [Abstract] Servicing Asset [Abstract] Balance at beginning of period Origination of servicing assets Servicing Asset At Fair Value Additions Change in fair value [Abstract] Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Or Changes In Assumptions [Abstract] Due to market changes Asset At Fair Value Changes In Fair Value Resulting From Changes In Assumptions Due to run-off Servicing Asset At Fair Value Changes In Fair Value Resulting From Changes In Valuation Inputs Balance at end of period The estimated speed of prepayments of principal on financial assets which may be one of the factors applied in estimating the fair value of servicing assets and servicing liabilities not shown as a percentage, measured in CPR (conditional prepayment rate). Schedule of changes in the reserve for mortgage loan [Abstract] Schedule of changes in the reserve for mortgage loan [Abstract] Schedule Of Changes In The Reserve For Mortgage Loan Servicing Putback Expense [Abstract] Assumed average prepayment speed Assumed Average Prepayment Speed Average discount rate (in hundredths) Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Discount Rate Residential mortgage loans sold Mortgage Loans On Real Estate Cost Of Mortgages Sold Gains on sales of residential mortgage loans Gain Loss On Sale Of Mortgage Loans Amount of loans that underlying mortgage loans sold and serviced for others on balance sheet date. Mortgage Loans On Real Estate Schedule [Table] Mortgage Loans On Real Estate Schedule [Table] Federal National Mortgage Association [Member] Federal National Mortgage Association Certificates And Obligations F N M A [Member] Government National Mortgage Association [Member] Government National Mortgage Association Certificates And Obligations G N M A [Member] Federal Home Loan Mortgage Corporation [Member] Federal Home Loan Mortgage Corporation Certificates And Obligations F H L M C [Member] Other [Member] Mortgage Backed Securities Other [Member] Mortgage Loans On Real Estate [Line Items] Mortgage Loans On Real Estate [Line Items] Total mortgage loans sold and serviced for others Mortgage Loan Sold And Serviced For Others The period of time the company is required to provide a response to putback requests. Period of putback response Period Of Putback Response Reserve for mortgage loan servicing putback expenses Mortgage Loans On Real Estate Writedown Or Reserve Amount1 Write downs on other real estate due to revaluations. Reconciliation Of Carrying Amount Of Real Estate Investments Roll Forward Balance at beginning of period Other Real Estate And Foreclosed Assets Additions Real Estate Other Additions Disposals Real Estate Other Deductions Write-downs Write Downs On Real Estate Excluding Covered Real Estate Balance at end of period Gains (losses), net on the sale of other real estate included in other real estate expense Gains Losses On Sales Of Other Real Estate 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. Other non covered real estate. Other Non Covered Real Estate [Table] Other Non Covered Real Estate [Table] Class of property related to construction, land development and other land. Construction, Land Development And Other Land Properties [Member] Construction Land Development And Other Land Properties [Member] Class of property related to 1-4 family residential properties. 1 - 4 Family Residential Properties [Member] Family Residential14 Properties [Member] Class of property related to nonfarm nonresidential properties. Nonfarm, Nonresidential Properties [Member] Nonfarm Nonresidential Properties [Member] Other real estate, excluding covered other real estate [Line Items] Other Non Covered Real Estate [Line Items] Total other real estate 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. Reflects other real estate, excluding covered other real estate, by geographic location. Other Real Estate Excluding Covered Other Real Estate By Geographic Location [Table] Other Real Estate Excluding Covered Other Real Estate By Geographic Location [Table] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] Alabama [Member] ALABAMA Florida [Member] FLORIDA Mississippi [Member] MISSISSIPPI Tennessee [Member] TENNESSEE Texas [Member] TEXAS Other real estate, excluding covered other real estate [Line Items] Other Real Estate Excluding Covered Other Real Estate By Geographic Location [Line Items] Foreclosed residential real estate properties recorded as a result of obtaining physical possession of property Real Estate Acquired Through Foreclosure Consumer mortgage loans and that formal foreclosure proceedings are in process Foreclosed Assets Finance lease. Finance leases Finance Lease [Abstract] Amortization of right-of-use assets Finance Lease Right Of Use Asset Amortization Interest on lease liabilities Finance Lease Interest Expense Operating lease cost Operating Lease Cost Short-term lease cost Short Term Lease Cost Variable lease cost Variable Lease Cost Sublease income Sublease Income Net lease cost Lease Cost Operating Lease Cost. Operating cash flows included in operating activities Finance Lease Interest Payment On Liability Financing cash flows included in payments under finance lease obligations Finance Lease Principal Payments Operating leases Operating Lease Cost [Abstract] Operating cash flows (fixed payments) included in other operating activities, net Operating Lease Payments Operating cash flows (liability reduction) included in other operating activities, net Variable Lease Payment Weighted-average remaining lease term. Weighted average discount rate abstract. Finance lease right-of-use assets, net of accumulated depreciation Finance Lease Right Of Use Asset Finance lease liabilities Finance Lease Liability Weighted-average lease term Weighted Average Remaining Lease Term [Abstract] Finance leases Finance Lease Weighted Average Remaining Lease Term1 Operating leases Operating Lease Weighted Average Remaining Lease Term1 Weighted-average discount rate Weighted Average Discount Rate [Abstract] Finance leases Finance Lease Weighted Average Discount Rate Percent Operating leases Operating Lease Weighted Average Discount Rate Percent Finance leases, 2020 (excluding the three months ended March 31, 2020) Finance Lease Liability Payments Remainder Of Fiscal Year Finance leases, 2021 Finance Lease Liability Payments Due Year Two Finance leases, 2022 Finance Lease Liability Payments Due Year Three Finance leases, 2023 Finance Lease Liability Payments Due Year Four Finance leases, 2024 Finance Lease Liability Payments Due Year Five Thereafter Finance Lease Liability Payments Due Thereafter Finance leases, total minimum lease payments Finance Lease Liability Payments Due Finance leases, imputed interest Finance Lease Liability Undiscounted Excess Amount Operating leases, 2020 (excluding the three months ended March 31, 2020) Lessee Operating Lease Liability Payments Remainder Of Fiscal Year Operating leases, 2021 Lessee Operating Lease Liability Payments Due Year Two Operating leases, 2022 Lessee Operating Lease Liability Payments Due Year Three Operating leases, 2023 Lessee Operating Lease Liability Payments Due Year Four Operating leases, 2024 Lessee Operating Lease Liability Payments Due Year Five Thereafter Lessee Operating Lease Liability Payments Due Thereafter Operating leases, total minimum lease payments Lessee Operating Lease Liability Payments Due Operating leases, imputed interest Lessee Operating Lease Liability Undiscounted Excess Amount Noninterest-bearing demand Interest-bearing demand Interest Bearing Demand Deposit Savings Deposits Savings Deposits Time Time Deposits Debt Disclosure [Abstract] Securities sold under repurchase agreements, secured by securities carrying amount Securities Sold Under Agreements To Repurchase Amount Offset Against Collateral Securities Financing Transaction [Table] Securities Financing Transaction [Table] Securities Financing Transaction [Line Items] Securities Financing Transaction [Line Items] Securities sold under repurchase agreements by collateral pledged Securities Sold Under Agreements To Repurchase Amount Offset Against Collateral [Abstract] Total securities sold under repurchase agreements Securities Sold Under Agreements To Repurchase Other real estate sales, net gain (loss) Gains Losses On Sales Of Investment Real Estate Revenue from contract with customer. Revenue from contract with customer. Revenue From Contract With Customer [Table] Revenue From Contract With Customer [Table] Topic 606 [Member] Accounting Standards Update201409 [Member] Not Topic 606 [Member] Calculated Under Revenue Guidance In Effect Before Topic606 [Member] Segments Statement Business Segments [Axis] Segments Segment [Domain] General banking. General Banking Segment [Member] General Banking [Member] Segment provides customized solutions for customers by integrating financial services with traditional banking products and services such as money management, full-service brokerage, financial planning, personal and institutional trust and retirement services. Wealth Management Segment [Member] Wealth Management [Member] Insurance. Insurance Segment [Member] Insurance [Member] Revenue From Contract With Customer [Line Items] Revenue From Contract With Customer [Line Items] Schedule Of Defined Benefit Plans Disclosures [Table] Schedule Of Defined Benefit Plans Disclosures [Table] Retirement Plan Name Retirement Plan Name [Axis] Retirement Plan Name Retirement Plan Name [Domain] Trustmark corporation pension plan for certain employees of acquired financial institutions. Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions [Member] Trustmark Corporation Pension Plan For Certain Employees Of Acquired Financial Institutions [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Net periodic benefit cost [Abstract] Defined Benefit Plan Net Periodic Benefit Cost [Abstract] Service cost Defined Benefit Plan Service Cost Interest cost Defined Benefit Plan Interest Cost Amortization of prior service cost Defined Benefit Plan Amortization Of Prior Service Cost Credit Expected return on plan assets Defined Benefit Plan Expected Return On Plan Assets Recognized net loss due to lump sum settlements Defined Benefit Plan Recognized Net Gain Loss Due To Settlements1 Recognized net actuarial loss Defined Benefit Plan Actuarial Gain Loss Net periodic benefit cost Defined Benefit Plan Net Periodic Benefit Cost For a defined benefit plan, the previous minimum required employer contribution for the period, prior to government enactment. The Continuing Plan [Member] Scenario Statement Scenario [Axis] Scenario Scenario Unspecified [Domain] Scenario Forecast [Member] Scenario Forecast [Member] Trustmark's minimum required contribution to the Trustmark Corporation Pension Plan for Certain Employees of Acquired Financial Institutions Defined Benefit Plan Previous Minimum Employer Contribution Level of performance goal measured by return on average tangible equity (ROATE) for a share based compensation plan. Level of performance goal measured by total shareholder return (TSR) for a share based compensation plan. Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Award Type Award Type [Axis] Award Type Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain] Performance Based Award [Member] Performance Shares [Member] Restricted Stock Units (RSUs) [Member] Restricted Stock Units R S U [Member] Share based compensation based on time. Time-Vested Awards [Member] Time Vested Award [Member] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Vesting period Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1 Return on average tangible equity, performance measure Return On Average Tangible Equity Level Performance Measures Total shareholder return, performance measure T S R Performance Measure Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] Stock and incentive compensation plan. Stock and Incentive Compensation Plan [Member] Stock And Incentive Compensation Plan [Member] Performance Based Awards and Units [Member] Time-Vested Awards and Units [Member] Shares [Roll Forward] Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Roll Forward Nonvested shares, beginning of period (in shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number Granted (in shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Released from restriction (in shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Forfeited (in shares) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period Nonvested shares, end of period (in shares) Compensation expense stock and incentive plans. Performance awards and units. Performance Awards and Units [Member] Performance Awards And Units [Member] Time-vested awards and units. Time-Vested Awards and Units [Member] Time Vested Awards And Units [Member] Compensation expense [Abstract] Compensation Expense Stock And Incentive Plans [Abstract] Recognized compensation expense Allocated Share Based Compensation Expense Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingency Nature Loss Contingencies By Nature Of Contingency [Axis] Loss Contingency, Nature Loss Contingency Nature [Domain] Standby Letters of Credit [Member] Standby Letters Of Credit [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Unused commitments to extend credit Unused Commitments To Extend Credit The maximum maturity (in years) of outstanding letters of credit issued by company. Potential exposure to credit loss in the event of nonperformance Loss Contingency Estimate Of Possible Loss Letters of credit, maturity term - maximum Letters Of Credit Maximum Maturity Collateral held, fair value Securities Held As Collateral At Fair Value Off-balance sheet credit loss liability adoption of accounting standard adjustment. Balance at beginning of period FASB ASU 2016-13 adoption adjustment Off Balance Sheet Credit Loss Liability Adoption Of Accounting Standard Adjustment Balance at end of period Basic shares Weighted Average Number Of Shares Outstanding Basic Dilutive shares Weighted Average Number Diluted Shares Outstanding Adjustment Diluted shares Weighted Average Number Of Diluted Shares Outstanding Weighted-average antidilutive stock awards (in shares) Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Supplemental Cash Flow Elements [Abstract] Statement of cash flows specific transaction amounts [Abstract] Interest expense paid on deposits and borrowings Interest Paid Net Noncash transfers from loans to other real estate Mortgage Loans On Real Estate Foreclosures Securities purchased not settled Securities Purchased Under Agreements To Resell Increase Finance right-of-use assets resulting from lease liabilities Right Of Use Asset Obtained In Exchange For Finance Lease Liability Operating right-of-use assets resulting from lease liabilities Right Of Use Asset Obtained In Exchange For Operating Lease Liability Capital conservation buffer rate. Stockholders equity. Stockholders equity. Stockholders Equity [Table] Stockholders Equity [Table] Share Repurchase Program Share Repurchase Program [Axis] Share Repurchase Program Share Repurchase Program [Domain] Stock repurchase program 1. Stock Repurchase Program 1 [Member] Stock Repurchase Program One [Member] Stock repurchase program 2. Stock Repurchase Program 2 [Member] Stock Repurchase Program Two [Member] Stock repurchase program three. Stock Repurchase Program 3 [Member] Stock Repurchase Program Three [Member] Stockholders Equity [Line items] Stockholders Equity [Line Items] Capital conservation buffer rate Capital Conservation Buffer Rate Common Equity Tier One Risk Based Capital [Abstract] Common Equity Tier 1 Risk Based Capital as defined in the regulations. Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Table] Schedule Of Compliance With Regulatory Capital Requirements Under Banking Regulations [Table] Legal Entity Legal Entity [Axis] Entity Entity [Domain] Trustmark Corporation (Trustmark) is a multi-bank holding company headquartered in Jackson, Mississippi. Through its subsidiaries, Trustmark operates as a financial services organization providing banking and financial solutions to corporate institutions and individual customers through over 150 offices in Florida, Mississippi, Tennessee and Texas. Trustmark Corporation [Member] Trustmark Corporation [Member] Wholly owned subsidiary of Trustmark Corporation. Trustmark National Bank [Member] Trustmark National Bank [Member] Capital Units by Class Capital Units By Class [Axis] Capital Unit, Class Capital Unit Class [Domain] The amount of common equity tier 1 capital required as related to risk weighted assets regarding requirements for capital adequacy purposes under the regulatory framework for prompt corrective action. Common Equity Tier 1 Capital (to Risk Weighted Assets) [Member] Common Equity Tier1 Capital To Risk Weighted Assets [Member] The amount of tier 1 capital required as related to risk weighted assets regarding requirements for capital adequacy purposes under the regulatory framework for prompt corrective action. Tier 1 Capital (to Risk Weighted Assets) [Member] Tier1 Capital To Risk Weighted Assets [Member] Capital to risk weighted assets. Total Capital (to Risk Weighted Assets) [Member] Capital To Risk Weighted Assets [Member] The amount of tier 1 leverage capital required as related to average assets regarding requirements for capital adequacy purposes under the regulatory framework for prompt corrective action. Tier 1 Leverage (to Average Assets) [Member] Tier1 Leverage To Average Assets [Member] Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items] Common Equity Tier One Risk Based Capital [Abstract] Common Equity Tier One Risk Based Capital [Abstract] Actual Regulatory Capital Amount Common Equity Tier One Risk Based Capital Tier 1 Capital (to Risk Weighted Assets) [Abstract] Tier One Risk Based Capital [Abstract] Actual Regulatory Capital Amount Tier One Risk Based Capital Total Capital (to Risk Weighted Assets) [Abstract] Capital [Abstract] Actual Regulatory Capital Amount Capital Tier 1 Leverage (to Average Assets) [Abstract] Tier One Leverage Capital [Abstract] Actual Regulatory Capital Amount Tier One Leverage Capital Common Equity Tier 1 capital divided by risk weighted assets as defined by regulations. Actual Regulatory Capital Ratio Common Equity Tier One Risk Based Capital To Risk Weighted Assets Actual Regulatory Capital Ratio Tier One Risk Based Capital To Risk Weighted Assets Actual Regulatory Capital Ratio Capital To Risk Weighted Assets Actual Regulatory Capital Ratio Tier One Leverage Capital To Average Assets The minimum Common Equity Tier One Capital Ratio (Common Equity Tier one capital divided by risk-weighted assets) required for capital adequacy purposes under the regulatory framework for prompt corrective action. Minimum Regulatory Capital Required Ratio Common Equity Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Minimum Regulatory Capital Required Ratio Tier One Risk Based Capital Required For Capital Adequacy To Risk Weighted Assets Minimum Regulatory Capital Required Ratio Capital Required For Capital Adequacy To Risk Weighted Assets Minimum Regulatory Capital Required Ratio Tier One Leverage Capital Required For Capital Adequacy To Average Assets The Common Equity Tier 1 capital ratio (Common Equity Tier 1 capital divided by risk weighted assets) required to be categorized as "well capitalized" under the regulatory framework for prompt corrective action. Minimum Regulatory Provision to be Well-Capitalized Ratio Common Equity Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Minimum Regulatory Provision to be Well-Capitalized Ratio Tier One Risk Based Capital Required To Be Well Capitalized To Risk Weighted Assets Minimum Regulatory Provision to be Well-Capitalized Ratio Capital Required To Be Well Capitalized To Risk Weighted Assets Minimum Regulatory Provision to be Well-Capitalized Ratio Tier One Leverage Capital Required To Be Well Capitalized To Average Assets Amount of stock authorized for repurchase Common Stock Value Outstanding Repurchase shares of common stock Stock Repurchased During Period Shares Repurchase shares of common stock, value Stock Repurchased During Period Value Accumulated Other Comprehensive Income Loss [Table] Accumulated Other Comprehensive Income Loss [Table] Securities Available for Sale and Transferred Securities [Member] Accumulated Net Investment Gain Loss Including Portion Attributable To Noncontrolling Interest [Member] Net Change in Prior Service Costs [Member] Accumulated Defined Benefit Plans Adjustment Net Prior Service Including Portion Attributable To Noncontrolling Interest [Member] Recognized Net Loss Due to Lump Sum Settlements [Member] Accumulated Defined Benefit Plans Adjustment Net Transition Including Portion Attributable To Noncontrolling Interest [Member] Change in Net Actuarial Loss [Member] Accumulated Defined Benefit Plans Adjustment Net Gain Loss Including Portion Attributable To Noncontrolling Interest [Member] Pension and Other Postretirement Benefit Plans [Member] Accumulated Defined Benefit Plans Adjustment Including Portion Attributable To Noncontrolling Interest [Member] Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest Accumulated Net Gain Loss From Cash Flow Hedges Including Portion Attributable To Noncontrolling Interest [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income Loss [Line Items] Other comprehensive income (loss), before reclassifications, before tax amount Other Comprehensive Income Loss Before Reclassifications Before Tax Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, before tax amount Other Comprehensive Income Change In Unrealized Holding Gain Loss On Securities Transferred To Held To Maturity Before Tax And Reclassification Reclassification from accumulated other comprehensive income, current period, before tax amount Reclassification From Accumulated Other Comprehensive Income Current Period Before Tax Other comprehensive income (loss), before tax amount Other Comprehensive Income Loss Before Tax Other comprehensive income (loss), before reclassifications, tax (expense) benefit Other Comprehensive Income Loss Before Reclassifications Tax Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit Reclassification From Aoci Current Period Tax Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, tax (expense) benefit Other Comprehensive Income Change In Unrealized Holding Gain Loss On Securities Transferred To Held To Maturity Tax Other comprehensive income (loss), tax (expense) benefit Other Comprehensive Income Loss Tax Other comprehensive income (loss), before reclassifications, net of tax amount Other Comprehensive Income Loss Before Reclassifications Net Of Tax Reclassification from accumulated other comprehensive income, current period, net of tax amount Reclassification From Accumulated Other Comprehensive Income Current Period Net Of Tax Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, net of tax amount Other Comprehensive Income Loss Securities Transfers To Held To Maturity Net Of Tax Other comprehensive income (loss), net of tax amount Other Comprehensive Income Loss Net Of Tax Reclassification of certain income tax effects related to federal statutory federal income tax rate under the Tax Cuts and Jobs Act 2017. Securities Available for Sale and Transferred Securities [Member] Accumulated Net Unrealized Investment Gain Loss [Member] Defined Benefit Pension Items [Member] Accumulated Defined Benefit Plans Adjustment [Member] Cash Flow Hedge Derivatives [Member] Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges [Member] Accumulated Other Comprehensive Loss [Member] Amounts reclassified from accumulated other comprehensive income (loss) Reclassification of certain income tax effects related to the changein the federal statutory income tax rate under the Tax Reform Act Reclassification Of Certain Income Tax Effects Related To Federal Statutory Federal Income Tax Rate Under Tax Cuts And Jobs Act Of2017 Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Level 2 [Member] Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Level 1 [Member] Fair Value Inputs Level1 [Member] Level 2 [Member] Fair Value Inputs Level2 [Member] Level 3 [Member] Fair Value Inputs Level3 [Member] Measurement Frequency Fair Value By Measurement Frequency [Axis] Measurement Frequency Fair Value Measurement Frequency [Domain] Recurring Basis [Member] Fair Value Measurements Recurring [Member] U.S. Government Agency Obligations [Member] Mortgage-Backed Securities [Member] Mortgage Backed Securities [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Securities available for sale Loans held for sale Other assets - derivatives Derivative Assets Other liabilities - derivatives Derivative Liabilities This element represents unrealized gains (losses) included in net income, excluding any impact of amortization of deferred acquisition costs, value of business acquired, deferred sales inducements and deferred front-end loads and changes in future contract benefits, related to financial instruments carried at fair value and classified within Level 3 that the entity still held as of the balance sheet date. Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Table] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Table] Asset Class Fair Value By Asset Class [Axis] Asset Class Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain] Mortgage Servicing rights measured at fair value. MSR [Member] Mortgage Servicing Rights [Member] Other Assets - Derivatives [Member] Derivative Financial Instruments Assets [Member] Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items] Beginning Balance Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Value Total net (loss) gain included in Mortgage banking, net Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Gain Loss Included In Earnings1 Additions Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Purchases Sales Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales Ending Balance The amount of total gains (losses) for the period included in earnings that are attributable to the change in unrealized gains or losses still held, end of period Changes In Unrealized Gains Losses Within Level3 Financial Instruments Carried At Fair Value And Still Held Financing receivable where repayment is expected to be provided substantially through the sale of the collateral. Allowance for credit losses on financing receivable where repayment is expected to be provided substantially through the sale of the collateral. Outstanding balances in collateral dependent related to allowance for credit losses Collateral Dependent Financing Receivable Collateral dependent related to allowance for credit losses Collateral Dependent Financing Receivable Allowance For Credit Losses Outstanding balances in impaired loans Financing Receivable Individually Evaluated For Impairment Impaired loans, related allowance The (re)measured fair value amount, as of the balance sheet date, of all assets obtained in full or partial satisfaction of a debt arrangement through foreclosure proceedings or defeasance; includes real and personal property; equity interests in corporations, partnerships, and joint ventures; and beneficial interests in trusts. The overvalued amount that is written down to reduce the carrying value of an asset, that was valued at initial recognition of foreclosure, to the fair value. Foreclosed assets remeasured after initial recognition Foreclosed Assets Remeasured After Initial Recognition Fair Value Write-downs of allowance for foreclosed assets after initial recognition Write Down Of Allowance After Initial Recognition Of Foreclosure Carrying Value [Member] Fair Value By Measurement Basis [Axis] Fair Value Disclosure Item Amounts [Default] Portion At Fair Value Fair Value Disclosure [Member] Fair Value Measurement Fair Value Disclosure Item Amounts [Domain] Carrying Value [Member] Carrying Reported Amount Fair Value Disclosure [Member] Estimate Fair Value [Member] Estimate Of Fair Value Fair Value Disclosure [Member] Cash and short-term investments Cash And Cash Equivalents Fair Value Disclosure Net LHFI Deposits Refers to interest and fees derived on loans held for sale. Loans available for repurchase. Noninterest gain (loss) Mortgage banking, net for changes in fair value of LHFS Fair Value Option Changes In Fair Value Gain Loss1 Interest earned on LHFS included in Interest and fees on LHFS and LHFI Interest And Fees On L H F S And L H F I GNMA optional repurchase loans Loans Available For Repurchase Fair value and the contractual principal outstanding of the LHFS [Abstract] This item represents the difference between the aggregate fair value and the unpaid principal. Fair value and the contractual principal outstanding of the LHFS [Abstract] Fair Value And The Contractual Principal Outstanding Of The L H F S [Abstract] Fair value of LHFS Loans Held For Sale Fair Value Disclosure LHFS contractual principal outstanding Principal Amount Outstanding On Loans Held For Sale Or Securitization Fair value less unpaid principal Fair Value Less Unpaid Principal Net The reference rate for the variable rate of the interest rate derivative, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR. Schedule Of Fair Value Off Balance Sheet Risks [Table] Schedule Of Fair Value Off Balance Sheet Risks [Table] Hedging Designation Hedging Designation [Axis] Hedging Designation Hedging Designation [Domain] Designated as Hedging Instrument [Member] Designated As Hedging Instrument [Member] Interest Rate Swap [Member] Interest Rate Swap [Member] Variable Rate Variable Rate [Axis] Variable Rate Variable Rate [Domain] Three-month LIBOR [Member] London Interbank Offered Rate L I B O R [Member] Long-term Debt, Type Longterm Debt Type [Axis] Long-term Debt, Type Longterm Debt Type [Domain] Junior Subordinated Debentures [Member] Junior Subordinated Debt [Member] Derivatives not Designated as Hedging Instruments [Member] Nondesignated [Member] Derivative Instrument Derivative Instrument Risk [Axis] Derivative Contract Derivative Contract Type [Domain] Mortgage servicing Rights Hedge Mortgage Servicing Rights Hedge [Member] Mortgage Servicing Rights Hedge [Member] Forward Contracts [Member] Forward Contracts [Member] Interest Rate Lock Commitments [Member] Interest Rate Lock Commitments [Member] Guarantor Obligations, Nature Guarantee Obligations By Nature [Axis] Guarantor Obligations, Nature Guarantee Obligations Nature [Domain] Risk Participation Agreements in which Trustmark participates as the beneficiary. Beneficiary [Member] Beneficiary [Member] Guarantor [Member] Financial Guarantee [Member] Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Fair Value Off Balance Sheet Risks Disclosure Information [Line Items] Total notional amount Derivative Notional Amount Period for which cash flow hedges will be used to hedge quarterly interest payments Derivative Remaining Maturity1 Derivative inception date Derivative Inception Dates Derivative maturity date Derivative Maturity Dates Description of variable rate basis for derivative Derivative Description Of Variable Rate Basis1 Swap fixed interest rate to be paid Derivative Fixed Interest Rate Ineffectiveness related to interest rate swap designated as a cash flow hedge Gain Loss On Cash Flow Hedge Ineffectiveness Net Accumulated net, after tax gain included in accumulated other comprehensive (loss) Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax Amount of net positive or negative ineffectiveness from comparing the total hedge cost to the changes in fair value of Mortgage Servicing Rights derivative assets attributable to interest rate changes. Net (negative) positive ineffectiveness on MSR fair value Net Positive Or Negative Ineffectiveness On M S R Fair Value Amount of positive (negative) valuation adjustment on the fair value of derivative instruments, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition. Off-balance sheet obligations Fair Value Disclosure Offbalance Sheet Risks Face Amount Liability Valuation adjustment Valuation Adjustment Termination value of derivatives in a net liability position, which includes accrued interest but excludes any adjustment for nonperformance risk, related to a provision from agreements with each of its derivative counterparties stating that the entity will be considered on default on its derivative obligations if the entity defaulted on payment of indebtedness, including default where repayment of the indebtedness has not been accelerated by the lender. Termination value of derivatives Termination Value Of Derivatives Collateral Posted Collateral Already Posted Aggregate Fair Value The number of risk participation agreements the entity has entered into. Number of risk participation agreements Number Of Risk Participation Agreements Aggregate notional amount of credit risk participation agreements Derivative Asset Notional Amount Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] An option traded on a regulated exchange where the terms of each option are standardized by the exchange. The contract is standardized so that underlying asset, quantity, expiration date and strike price are known in advance. Over-the-counter options are not traded on exchanges and allow for the customization of the terms of the option contract. Exchange Traded Purchased Options [Member] Exchange Traded Purchased Options [Member] An option traded over-the-counter, as opposed to a listed stock option. The OTC option has a direct link between buyer and seller, has no secondary market, and has no standardization of striking prices and expiration dates. OTC Written Options (Rate Locks) [Member] O T C Written Options [Member] Option traded on a regulated exchange where the terms of each option are standardized by the exchange. The contract is standardized so that underlying asset, quantity, expiration date and strike price are known in advance. Exchange Traded Written Options [Member] Exchange Traded Written Options [Member] Future Contracts [Member] Future [Member] Credit Risk Participation Agreement [Member] Credit Default Swap [Member] Balance Sheet Location Balance Sheet Location [Axis] Balance Sheet Location Balance Sheet Location [Domain] Other Assets [Member] Other Assets [Member] Other Liabilities [Member] Other Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives Fair Value [Line Items] Fair value of derivative asset Derivative Fair Value Of Derivative Asset Fair value of derivative liability Derivative Fair Value Of Derivative Liability The amount of net gain (loss) recognized as noninterest income in mortgage banking, net on derivative instruments not designated as hedging instruments. The amount of net gain (loss) recognized as noninterest income in bank card and other fees on derivative instruments not designated as hedging instruments. Derivatives in Hedging Relationships [Member] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Accumulated other comprehensive income (loss) and other interest expense. Accumulated Other Comprehensive Income (Loss) and Other Interest Expense [Member] Accumulated Other Comprehensive Income Loss And Other Interest Expense [Member] The noninterest income, net of associated expenses, derived from mortgage banking activities (fees and commissions), including fees earned from servicing third-party assets. Mortgage Banking, Net [Member] Mortgage Banking Net [Member] Income earned from bank card and credit card services including late, over limit, and annual fees. This item excludes interest income earned on credit card balances and transactions. Includes interchange fees earned from bank card and credit card transactions. Also includes ATM and other banking fees. Bank Card and Other Fees [Member] Bankcard And Other Fees [Member] Amount of gain (loss) reclassified from accumulated other comprehensive income (loss) and recognized in other interest expense Derivative Instruments Gain Loss Reclassified From Accumulated O C I Into Income Effective Portion Net Amount of gain (loss) recognized in mortgage banking, net Derivative Instruments Gain Loss Classified Into Income Net Amount of gain (loss) recognized in bank card and other fees Derivative Instruments Gain Loss Classified Into Bank Card Income Net Amount of gain (loss) recognized in other comprehensive income (loss), net of tax Offsetting Assets [Table] Offsetting Assets [Table] Offsetting Assets [Line Items] Offsetting Assets [Line Items] Offsetting Derivative Assets Offsetting Derivative Assets [Abstract] Gross Amounts of Recognized Assets, Offsetting of Derivative Assets Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Assets Derivative Assets Gross Amounts Offset Net Amounts of Assets presented in the Statement of Financial Position, Offsetting of Derivative Assets Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets Derivative Collateral Obligation To Return Securities Cash Collateral Received, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Assets Derivative Asset Collateral Obligation To Return Cash Offset Net Amount, Offsetting of Derivative Assets Derivative Fair Value Of Derivative Asset Amount Offset Against Collateral Offsetting Derivative Liabilities Offsetting Derivative Liabilities [Abstract] Gross Amounts of Recognized Liabilities, Offsetting of Derivative Liabilities Gross Amounts Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities Derivative Liabilities Gross Amounts Offset Net Amounts of Liabilities presented in the Statement of Financial Position, Offsetting of Derivative Liabilities Financial Instruments, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities Derivative Collateral Right To Reclaim Securities Cash Collateral Posted, Gross Amounts Not Offset in the Statement of Financial Position, Offsetting of Derivative Liabilities Derivative Collateral Right To Reclaim Cash Net Amount, Offsetting of Derivative Liabilities Derivative Fair Value Of Derivative Liability Amount Offset Against Collateral Number of segments in which the business operates Number Of Reportable Segments Schedule Of Segment Reporting Information By Segment [Table] Schedule Of Segment Reporting Information By Segment [Table] General Banking [Member] Wealth Management [Member] Insurance [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Net interest income Provision for credit losses Provision For Loan Losses Expensed Included Acquired Loans Noninterest income Noninterest expense Selected Financial Information Segment Reporting Information Additional Information [Abstract] Total assets Financing receivable allowance for credit losses adoption of accounting standard adjustment. New Accounting Pronouncements Or Change In Accounting Principle [Table] New Accounting Pronouncements Or Change In Accounting Principle [Table] New Accounting Pronouncements Or Change In Accounting Principle [Line Items] New Accounting Pronouncements Or Change In Accounting Principle [Line Items] Decrease to loans held for investment, allowance for credit loss Financing Receivable Allowance For Credit Losses Adoption Of Accounting Standard Adjustment Increase to allowance for credit loss on off-balance sheet credit exposures One-time cumulative effect adjustment through retained earnings, before tax Cumulative Effect On Retained Earnings Before Tax1 One-time cumulative effect adjustment through retained earnings, net of tax