Share-based Payment Arrangement [Abstract] Quantity Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Outstanding at beginning of year (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Assumed in acquisition (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Assumed in Acquisition Share-based Compensation Arrangement by Share-based Payment Award, Options, Assumed in Acquisition Options exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Options forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Options expired/canceled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Options outstanding at end of year (in shares) Options exercisable at end of year (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Weighted-Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Outstanding at beginning of year (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Assumed in acquisition (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Assumed in Acquisition, Weighted Average Exercise Price Share-based Compensation Arrangements by Share-based Payment Award, Options, Assumed in Acquisition, Weighted Average Exercise Price Options exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Options forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Options expired (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Options outstanding at end of year (in dollars per share) Options exercisable at end of year (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Fair Value Disclosures [Abstract] Fair Value, By Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping, Disclosure Item Amounts [Axis] Measurement Basis [Axis] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Estimated Fair Value Estimate of Fair Value Measurement [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Mortgage Loans Mortgage Loans [Member] Mortgage Loans [Member] Other Loans Other Loans [Member] Other Loans [Member] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Financial assets Assets, Fair Value Disclosure [Abstract] Total cash, cash equivalents, restricted cash, and restricted cash equivalents Cash and Cash Equivalents, at Carrying Value Trading securities Debt Securities, Trading, and Equity Securities, FV-NI Total investment securities available for sale Debt Securities, Available-for-sale Mortgage loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group Private equity investments Private Equity Investments Private Equity Investments Mutual funds and mutual funds held in rabbi trusts Mutual Funds and Mutual Funds Held In Rabbi Trusts Mutual Funds and Mutual Funds Held In Rabbi Trusts Loans, net Loans and Leases Receivable, Net Amount GGL/SBA loans servicing asset Servicing Asset at Fair Value, Amount Derivative assets Derivative Asset Financial Liabilities Financial Liabilities Fair Value Disclosure [Abstract] Non-interest-bearing deposits Noninterest-bearing Deposit Liabilities Non-time interest-bearing deposits Interest-bearing Deposit Liabilities Time deposits Time Deposits Total deposits Deposits Federal funds purchased and securities sold under repurchase agreements Federal Funds Purchased And Other Short Term Borrowings Federal funds purchased, repurchase agreements, and other short-term borrowings Trading liability for short positions Trading Liabilities, Fair Value Disclosure Other short-term borrowings Other Short-term Borrowings Long-term debt Long-term Debt Earnout liability Earnout Liabilities, Fair Value Disclosure Earnout Liabilities, Fair Value Disclosure Derivative liabilities Derivative Liability, Fair Value, Gross Liability Goodwill and Intangible Assets Disclosure [Abstract] Aggregate estimated amortization expense Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract] 2020 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2024 Finite-Lived Intangible Assets, Amortization Expense, Year Five Quarterly Financial Data [Abstract] Summary of Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior Notes Senior Notes [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2.289% Fixed-to-Floating Rate Senior Bank Notes due 2023 Two Point Two Eight Nine Percent Fixed-to-Floating Rate Senior Bank Notes due 2023 [Member] Two Point Two Eight Nine Percent Fixed-to-Floating Rate Senior Bank Notes due 2023 [Member] Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] SOFR Secured Overnight Financing Rate (SOFR) [Member] Secured Overnight Financing Rate (SOFR) [Member] Statistical Measurement [Axis] Statistical Measurement [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Debt, face amount Debt Instrument, Face Amount Stated percentage Debt Instrument, Interest Rate, Stated Percentage Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Notice of redemption period Debt Instrument, Notice of Redemption Period Debt Instrument, Notice of Redemption Period Redemption price, percentage Debt Instrument, Redemption Price, Percentage Mortgage loans held for sale Change In Mortgage Loans Held For Sale Included In Net Income Changes in the fair value of mortgage loans held for sale that were included in the consolidated statements of income during the reporting period. Fair value Additional Collateral, Aggregate Fair Value Unpaid principal balance Fair value option, aggregate unpaid principal balance of mortgage loans held for sale Fair value option, aggregate unpaid principal balance of mortgage loans held for sale. Fair value less aggregate unpaid principal balance Fair Value, Option, Aggregate Differences, Long-term Debt Instruments Loans and Allowance for Loan Losses [Abstract] Loans and Allowance for Loan Losses [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Total consumer Retail [Member] Other consumer loans Other Consumer Loans [Member] Other Consumer Loans [Member] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Axis] External Credit Rating by Grouping [Domain] External Credit Rating by Grouping [Domain] Interest Income Recorded Interest Income Recorded [Member] Interest Income Recorded [Member] Substandard Substandard [Member] Loss And Charged Off Loss And Charged Off [Member] Loss and Charged Off [Member] Accruing TDRs With Modifications And Renewals Completed Accruing Tdrs With Modifications And Renewals Completed [Member] Accruing TDRS With Modifications And Renewals Completed [Member] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] FCB Financial Holdings, Inc. FCB Financial Holdings, Inc. [Member] FCB Financial Holdings, Inc. [Member] Industry Sector [Axis] Industry Sector [Axis] Industry Sector [Domain] Industry Sector [Domain] Troubled Debt Restructuring That Subsequently Defaulted Troubled Debt Restructuring That Subsequently Defaulted [Member] Troubled debt restructuring that subsequently defaulted [Member] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Interest income recognized Impaired Financing Receivable, Interest Income, Accrual Method Loans and leases receivable, impaired, interest lost on nonaccrual loans Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Purchases of loans Payments to Acquire Loans Receivable Loans pledged as collateral Loans Pledged as Collateral Retail loan substandard period (in days) Retail Loan Downgraded To Substandard Delinquency status upon which a retail loan is downgraded to substandard Retail loan charge-off period (in days) Retail Loan Charge Off Delinquency status upon which a retail loan will be charged off in its entirety. Loans Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Loans Loans acquired at fair value, discount Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, Discount Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Acquired During Period, at Acquisition, Discount Contractual required payments Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Contractual Required Payments Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Contractual Required Payments Contractual required payments at fair value Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Contractual Required Payments, at Fair Value Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Contractual Required Payments, at Fair Value Cash flows expected not to be collected Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses Impaired financing receivable, recorded investment, nonaccrual status Impaired Financing Receivable, Recorded Investment, Nonaccrual Status Impaired Financing Receivable, Recorded Investment, Nonaccrual Status Subsequent default, number of contracts Financing Receivable, Troubled Debt Restructuring, Subsequent Default, Number of Contracts Modifications, post-modification recorded investment Financing Receivable, Troubled Debt Restructuring, Postmodification Accruing troubled debt restructuring Accruing Troubled Debt Restructuring Accruing Troubled Debt Restructuring Provision for losses on loans Provision for Loan and Lease Losses Commercial-type impaired loans Commercial-type Impaired Loans Commercial-type Impaired Loans Investments income recognized in impairment loans, excluding TDRs Impaired Financing Receivable, Interest Income, Accrual Method, Excluding Trouble Debt Restructuring Impaired Financing Receivable, Interest Income, Accrual Method, Excluding Trouble Debt Restructuring Debt Disclosure [Abstract] Long-term Debt and Short-term Borrowings Debt and Capital Leases Disclosures [Text Block] Loans Outstanding by Classification Loans Outstanding By Classification Table Text Block Loans Outstanding By Classification Schedule of Current, Accruing Past Due, and Nonaccrual Loans Financing Receivable, Nonaccrual [Table Text Block] Loan Portfolio Credit Exposure Loan Portfolio Credit Exposure [Table Text Block] Loan Portfolio Credit Exposure [Table Text Block] Schedule of Acquired Loan Portfolio Schedule of Acquired Portfolio Loans [Table Text Block] Schedule of Acquired Portfolio Loans [Table Text Block] Schedule of Changes in Accretable Difference Schedule Of Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Movement [Table Text Block] Schedule Of Certain Loans Acquired In Transfer Not Accounted For As Debt Securities Accretable Yield Movement [Table Text Block] Schedule of Allowances for Loan Losses and Recorded Investment in Loans Allowance for Credit Losses [Text Block] Schedule of Impaired Loans Impaired Financing Receivables [Table Text Block] Troubled Debt Restructurings Financing Receivable, Troubled Debt Restructuring [Table Text Block] Subsequent Event Subsequent Events [Text Block] Other Assets [Abstract] ROU assets Leases, Right-of-Use Asset Leases, Right-of-Use Asset Federal Reserve Bank and FHLB Stock Federal Reserve Bank Stock And Federal Home Loan Bank Stock Federal Reserve Bank Stock And Federal Home Loan Bank Stock Investments in low income housing, solar energy tax credit, and other CRA partnerships Tax credit partnerships Tax credit partnerships Derivative asset positions Accrued interest receivable Interest Receivable Accounts receivable Accounts Receivable, after Allowance for Credit Loss Deferred tax asset, net Deferred Income Tax Assets, Net Prepaid expenses Prepaid Expense MPS receivable Merchant Payment Services, Receivables Merchant Payment Services, Receivables Other real estate Real Estate Acquired Through Foreclosure Taxes receivable Income Taxes Receivable Trading account assets, at fair value Debt Securities, Trading Miscellaneous other assets Other Assets, Miscellaneous Total other assets Other Assets Investments [Abstract] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] U.S. Treasury securities US Treasury Securities [Member] U.S. Government agency securities US Government Agencies Short-term Debt Securities [Member] Mortgage-backed securities issued by U.S. Government agencies Mortgage Backed Securities Issued By U S Government Agencies [Member] Mortgage Backed Securities Issued By U S Government Agencies [Member] Mortgage-backed securities issued by U.S. Government sponsored enterprises Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises Collateralized Mortgage Obligations Issued By U S Government Sponsored Enterprises [Member] Collateralized Mortgage Obligations Issued by U.S. Government Sponsored Enterprises [Member] Commercial mortgage-backed securities issued by U.S. Government agencies or sponsored enterprises Commercial mortgage-backed securities issued by U.S. Government sponsored agencies [Member] Commercial mortgage-backed securities issued by U.S. Government sponsored agencies [Member] State and municipal securities US States and Political Subdivisions Debt Securities [Member] Asset-backed securities Asset-backed Securities [Member] Corporate debt and other debt securities Corporate Debt Securities [Member] Debt Securities, Available-for-sale [Line Items] Debt Securities, Available-for-sale [Line Items] Amortized Cost Debt Securities, Available-for-sale, Amortized Cost Gross Unrealized Gains Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax Fair Value Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Summary of Derivative Instruments [Abstract] Derivative [Table] Derivative [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash Flow Hedging Cash Flow Hedging [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not Designated As Hedging Instruments Not Designated as Hedging Instrument [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest rate contracts Interest Rate Contract [Member] Mortgage derivatives Mortgage Derivative [Member] Mortgage Derivative [Member] Other contracts Other Contract [Member] Visa derivative Visa Derivative [Member] Visa Derivative [Member] Financial Instruments [Domain] Interest Rate Lock Commitments Interest Rate Lock Commitments [Member] Forward commitments to sell fixed-rate mortgage loans Forward commitments to sell fixed-rate mortgage loans [Member] Forward commitments to sell fixed-rate mortgage loans [Member] Derivative [Line Items] Derivative [Line Items] Notional Amount Derivative, Notional Amount Fair Value of Derivative Assets Derivative Asset, Fair Value, Amount Not Offset Against Collateral Fair Value of Derivative Liabilities Derivative Liability, Fair Value, Amount Not Offset Against Collateral Impact of Derivatives on Balance Sheet Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block] Effect of Fair Value Hedges on Consolidated Statements of Income Effect of Fair Value Hedges on the Consolidated Statements of Income Effect of Fair Value Hedges on the Consolidated Statements of Income Condensed Financial Information Disclosure [Abstract] Condensed Financial Statements [Table] Condensed Financial Statements [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] Parent Company Parent Company [Member] Condensed Financial Statements, Captions [Line Items] Condensed Financial Statements, Captions [Line Items] Income Revenues [Abstract] Cash dividends received from subsidiaries Cash Dividends Received from Bank Subsidiaries Cash Dividends Received from Bank Subsidiaries Cash distributions received from Synovus Bank Cash Distributions Received from Bank Subsidiaries Cash Distributions Received from Bank Subsidiaries Interest income Investment Income, Interest Other income (loss) Other Income (Loss) Other Income (Loss) Total income Total Income Total Income Expenses Interest Expense [Abstract] Interest expense Interest Expense Other expenses Noninterest Expense Total expenses Total Expense Total Expense Income before income taxes and equity in undistributed income (loss) of subsidiaries Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Allocated income tax benefit Income Tax Expense (Benefit), Intraperiod Tax Allocation Income before equity in undistributed income (loss) of subsidiaries Income (Loss) Before Equity in Undistributed Net Income (Loss) of Subsidiaries Income (Loss) Before Equity in Undistributed Net Income (Loss) of Subsidiaries Equity in undistributed income (loss) of subsidiaries Equity in Undistributed Income (Loss) from Continuing Operations of Subsidiaries Equity in Undistributed Income (Loss) from Continuing Operations of Subsidiaries Net income Net Income (Loss) Attributable to Parent Less: Preferred stock dividends and redemption charge Preferred Stock Dividends and Other Adjustments Net income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Earnings Per Share [Abstract] Net Income Per Common Share Earnings Per Share [Text Block] Segment Reporting [Abstract] Number of reportable segments Number of Reportable Segments Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Scenario [Axis] Scenario [Axis] Scenario [Domain] Scenario [Domain] Pro Forma Pro Forma [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Community Banking Community Banking [Member] Community Banking [Member] Wholesale Banking Wholesale Banking [Member] Wholesale Banking [Member] Financial Management Services Financial Management Services [Member] Financial Management Services [Member] Consolidation Items [Axis] Consolidation Items [Axis] Consolidation Items [Domain] Consolidation Items [Domain] Operating Segments Operating Segments [Member] Treasury and Corporate Other Corporate, Non-Segment [Member] Segment Reporting Information [Line Items] Segment Reporting Information [Line Items] Income Statement Related Disclosures Income Statement Related Disclosures [Abstract] Net interest income Interest Income (Expense), Net Non-interest income Noninterest Income Non-interest expense Pre-provision net revenue Revenues Balance Sheet Related Disclosures Balance Sheet Related Disclosures [Abstract] Total loans net of deferred fees and costs Loans and Leases Receivable, Net of Deferred Income Total deposits Total full-time equivalent employees Entity Number of Employees Financing Receivable, Credit Quality Indicator [Table] Financing Receivable, Credit Quality Indicator [Table] Pass Pass [Member] Special Mention Special Mention [Member] Doubtful Doubtful [Member] Loss Total commercial and industrial Commercial And Industrial [Member] Commercial and Industrial [Member] Total commercial real estate Commercial Real Estate [Member] Commercial, financial, and agricultural Commercial, Financial and Agricultural [Member] Commercial, Financial and Agricultural [Member] Owner-occupied Owner-Occupied [Member] Owner-Occupied [Member] Investment properties Investment Properties [Member] Investment Properties [Member] 1-4 family properties One To Four Family Properties [Member] One To Four Family Properties [Member] Land and development Land Acquisition [Member] Land Acquisition [Member] Consumer mortgages Consumer Loan [Member] Home equity lines Home Equity Line of Credit [Member] Credit cards Credit Card Receivable [Member] Financing Receivable, Credit Quality Indicator [Line Items] Financing Receivable, Credit Quality Indicator [Line Items] Total loans Loans and Leases Receivable, Gross Performing, accrual of interest Loans and Leases Receivable, Performing, Accrual of Interest Loans and Leases Receivable, Performing, Accrual of Interest Allowance for loan and lease losses, percent of loan amount Allowance for Loan and Lease Losses, Percent of Loan Amount Allowance for Loan and Lease Losses, Percent of Loan Amount Deferred fees and costs, net Loans and Leases Receivable, Deferred Income Paydowns and payoffs SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Table] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Axis] Financial Asset, Period Past Due [Domain] Financial Asset, Period Past Due [Domain] Current Financing Receivables, Current and Less than 30 Days Past Due, and Still Accruing [Member] Financing Receivables, Current and Less than 30 Days Past Due, and Still Accruing [Member] Accruing 30-89 Days Past Due Financing Receivables, 30 to 89 Days Pat Due [Member] Financing Receivables, 30 to 89 Days Pat Due [Member] Accruing 90 Days or Greater Past Due Financing Receivables, 90 to 149 Days Pat Due [Member] Financing Receivables, 90 to 149 Days Pat Due [Member] Total Accruing Past Due Total Accruing Past Due [Member] Total Accruing Past Due [Member] Acquired Loans, ASC 310-30 Acquired Loans, ASC 310-30 [Member] Acquired Loans, ASC 310-30 [Member] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items] Loans, net of deferred fees and costs Non-accrual Financing Receivable, Nonaccrual ASC 310-30 Loans(2) Certain Loans Acquired in Transfer, Accretable Yield Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums Deferred fees and costs, net Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Preferred Stock Preferred Stock [Member] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Treasury Stock Treasury Stock [Member] AOCI AOCI Attributable to Parent [Member] Retained Earnings Retained Earnings [Member] Class of Stock [Axis] Class of Stock [Axis] Class of Stock [Domain] Class of Stock [Domain] Series C Preferred Stock Series C Preferred Stock [Member] Series D Preferred Stock Series D Preferred Stock [Member] Series E Preferred Stock Series E Preferred Stock [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Cumulative-effect adjustment from adoption of ASU 2014-09 Accounting Standards Update 2014-09 [Member] Cumulative effect adjustment from adoption of ASU 2016-01 Accounting Standards Update 2016-01 [Member] Cumulative-effect adjustment from adoption of ASU 2016-02 Accounting Standards Update 2016-02 [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Adoption of new accounting pronouncements Cumulative Effect of New Accounting Principle in Period of Adoption Reclassification from adoption of ASU 2018-02 Tax Cuts and Jobs Act, Reclassification from AOCI to Retained Earnings, Tax Effect Net income Other comprehensive income (loss), net of income taxes Other Comprehensive Income (Loss), Net of Tax Cash dividends declared on common stock Dividends, Common Stock, Cash Cash dividends paid on Preferred Stock Dividends, Preferred Stock, Cash Repurchases of common stock including costs to repurchase Stock Repurchased During Period, Value Issuance of Preferred Stock, net of issuance costs Stock Issued During Period, Value, New Issues Issuance of common stock for earnout payment Stock Issued During Period, Value, Acquisitions Common stock reissued Stock Reissued During Period, Value, Acquisitions Stock Reissued During Period, Value, Acquisitions Fair value of exchanged equity awards and warrants attributed to purchase price Fair Value of Exchanged Equity Awards and Warrants Attributed to Purchase Price Fair Value of Exchanged Equity Awards and Warrants Attributed to Purchase Price Restricted share unit vesting and taxes paid related to net share settlement Restricted Share Unit Activity Issuance of restricted share units, which are the right to receive shares upon the completion of vesting requirements, net of forfeitures. Stock options exercised Stock Issued During Period, Value, Stock Options Exercised Warrants exercised with net settlement and common stock reissued Stock Issued During Period, Value, Warrants Exercised Stock Issued During Period, Value, Warrants Exercised Share-based compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Ending balance ASSETS Assets [Abstract] Cash due from bank subsidiary Cash and Due from Banks Funds due from other depository institutions Cash Due From Other Depository Institutions Cash Due From Other Depository Institutions Total cash, cash equivalents, restricted cash, and restricted cash equivalents Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Investment in consolidated bank subsidiary, at equity Investment in consolidated bank subsidiaries, at equity Investment in consolidated bank subsidiaries, at equity Investment in consolidated nonbank subsidiaries, at equity Investment in consolidated nonbank subsidiaries, at equity Investment in consolidated nonbank subsidiaries, at equity Note receivable from bank subsidiary Note receivable from bank subsidiary Note receivable from bank subsidiary Other assets Total assets Assets Liabilities and Shareholders' Equity Liabilities and Equity [Abstract] Other liabilities Other Liabilities Total liabilities Liabilities Shareholders’ equity: Stockholders' Equity Attributable to Parent [Abstract] Preferred stock Preferred Stock, Value, Issued Common stock Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital Treasury stock Treasury Stock, Value Accumulated other comprehensive income (loss), net Accumulated Other Comprehensive Income (Loss), Net of Tax Retained earnings Retained Earnings (Accumulated Deficit) Total shareholders’ equity Total liabilities and shareholders' equity Liabilities and Equity Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Labor and Related Expense Labor and Related Expense [Member] Labor and Related Expense [Member] Merger-Related Expense Merger-Related Expense [Member] Merger-Related Expense [Member] Other Operating Income (Expense) Other Operating Income (Expense) [Member] Non-interest expense Noninterest Expense [Member] Noninterest Expense [Member] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items] Total share-based compensation expense included in non-interest expense Share-based Payment Arrangement, Expense Interest income Interest and Dividend Income, Operating Net interest income Provision for loan losses Income tax expense Income Tax Expense (Benefit) Preferred stock dividends and redemption charge Net income per common share, basic (in dollars per share) Earnings Per Share, Basic Net income per common share, diluted (in dollars per share) Earnings Per Share, Diluted Regulatory Capital Disclosure [Abstract] Regulatory Capital Disclosure [Abstract] Schedule of Compliance with Regulatory Capital Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Statement of Financial Position [Abstract] Cash and due from banks Interest-bearing funds with Federal Reserve Bank Interest bearing funds with Federal Reserve Bank Interest bearing funds deposited with the Federal Reserve Bank. Interest earning deposits with banks Interest-bearing Deposits in Banks and Other Financial Institutions Federal funds sold and securities purchased under resale agreements Federal Funds Sold and Securities Purchased under Agreements to Resell Investment securities available for sale, at fair value Mortgage loans held for sale, at fair value Allowance for loan losses Loans and Leases Receivable, Allowance Loans, net Cash surrender value of bank-owned life insurance Bank Owned Life Insurance Premises and equipment Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, After Accumulated Depreciation And Amortization Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, After Accumulated Depreciation And Amortization Premises and equipment Property, Plant and Equipment, Net Goodwill Goodwill Other intangible assets Other Intangible Assets, Net LIABILITIES AND SHAREHOLDERS' EQUITY Liabilities Liabilities [Abstract] Deposits: Deposits [Abstract] Non-interest-bearing deposits Interest-bearing deposits Interest-Bearing Deposit Liabilities And Time Deposits Interest-Bearing Deposit Liabilities And Time Deposits Federal funds purchased and securities sold under repurchase agreements Shareholders' Equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Preferred Stock - no par value; authorized 100,000,000 shares; issued 22,000,000 and 8,000,000 Common stock - $1.00 par value; authorized 342,857,143 shares; issued 166,800,623 and 143,300,449; outstanding 147,157,596 and 115,865,510 Treasury stock, at cost; 19,643,027 and 27,434,939 shares Accumulated other comprehensive income (loss), net Share-based Compensation, Allocation of Recognized Period Costs Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block] Schedule of Measuring Compensation Expense Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block] Schedule of Stock Options Activity Share-based Payment Arrangement, Option, Activity [Table Text Block] Schedule of Restricted Stock Units Activity Schedule of Nonvested Restricted Stock Units Activity [Table Text Block] Schedule of Grants Under All Synovus Equity Compensation Plans Schedule of Aggregate Information of Grants Under All Entity Equity Compensation Plans [Table Text Block] Schedule of Aggregate Information of Grants Under All Entity Equity Compensation Plans [Table Text Block] Regulatory Capital Regulatory Capital Requirements under Banking Regulations [Text Block] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Table] Financing Receivable, Past Due [Line Items] Financing Receivable, Past Due [Line Items] Loans outstanding Financing Receivable, before Allowance for Credit Loss Total loans Total loans, net of deferred fees and costs Business Combinations [Abstract] Schedule of Business Acquisition Schedule of Business Acquisitions, by Acquisition [Table Text Block] Business Acquisition, Pro Forma Information Business Acquisition, Pro Forma Information [Table Text Block] Schedule of Acquisition Related Costs Schedule of Business Acquisition, Acquisition Related Costs [Table Text Block] Schedule of Business Acquisition, Acquisition Related Costs [Table Text Block] Income Tax Disclosure [Abstract] Income Tax Expense (Benefit) Reconciliation Effective Income Tax Rate Reconciliation, Amount [Abstract] Income tax expense at statutory federal income tax rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount State income tax expense, net of federal income tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Adjustment related to reduction in U.S. federal statutory income tax rate Effective Income Tax Rate Reconciliation, Tax Cuts and Jobs Act, Amount Low income housing tax credits and other tax benefits Effective Income Tax Rate Reconciliation, Affordable Housing Projects Tax Credits and Other Tax Benefits Effective Income Tax Rate Reconciliation, Affordable Housing Projects Tax Credits and Other Tax Benefits Low income housing tax credit amortization Effective Income Tax Rate Reconciliation, Affordable Housing Projects Amortization Effective Income Tax Rate Reconciliation, Affordable Housing Projects Amortization Executive compensation Effective Income Tax Rate Reconciliation, Executive Compensation Effective Income Tax Rate Reconciliation, Executive Compensation FDIC premiums Effective Income Tax Rate Reconciliation, FDIC Premiums Effective Income Tax Rate Reconciliation, FDIC Premiums Bank-owned life insurance Effective Income Tax Rate Reconciliation, Nondeductible Expense, Bank Owned Life Insurance, Amount Effective Income Tax Rate Reconciliation, Nondeductible Expense, Bank Owned Life Insurance, Amount Excess tax benefit from share-based compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Amount General business tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Amount Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Total income tax expense Effective tax rate Effective Income Tax Rate Reconciliation, Percent Provisional income tax expense (benefit) Tax Cuts and Jobs Act, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, provisional income tax expense Tax Cuts and Jobs Act, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Change in tax rate, income tax expense (benefit) Tax Cuts and Jobs Act of 2017, Effective Tax Rate, Change in Tax Rate, Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, Effective Tax Rate, Change in Tax Rate, Income Tax Expense (Benefit) Tax credit, research Effective Income Tax Rate Reconciliation, Tax Credit, Research, Amount Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Business Acquisition [Line Items] Pro Forma, Net interest income Business Acquisition, Pro Forma Interest Income, Net Business Acquisition, Pro Forma Interest Income, Net Actual, Non-interest income Pro Forma, Non-interest income Business Acquisition, Pro Forma Non-interest Income Business Acquisition, Pro Forma Non-interest Income Actual, Income before income taxes Pro Forma, Income before income taxes Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Business Acquisition, Pro Forma Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Actual, Net income available to common shareholders Pro Forma, Net income available to common shareholders Business Acquisition, Pro Forma Net Income (Loss) Business Combination, Acquisition Related Costs, Before Tax Business Combination, Acquisition Related Costs, Before Tax Business Combination, Acquisition Related Costs, Before Tax Fair Value Accounting Fair Value Disclosures [Text Block] Loans And Allowance For Loan Losses Loans, Net of Unearned Income [Text Block] Schedule of Loans, Net of Unearned Income [Text Block] Financial Instruments Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Changes in Fair Value Included in Consolidated Statements of Income Changes In Fair Value Included In Consolidated Statements Of Income [Text Block] Changes In Fair Value Included In Consolidated Statements Of Income [Text Block] Changes in Level 3 Fair Value Measurements Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Assets and Liabilities Measured at Fair Value on Non-Recurring Basis Fair Value Measurements, Nonrecurring [Table Text Block] Carrying and Estimated Fair Values of Financial Instruments Carried on Balance Sheet Fair Value, by Balance Sheet Grouping [Table Text Block] Derivative Instruments Derivative Instruments and Hedging Activities Disclosure [Text Block] Schedule of Segment Reporting Information, by Segment Schedule of Segment Reporting Information, by Segment [Table Text Block] Stockholders' Equity Note [Abstract] Schedule of Change in Preferred and Common Shares Issued and Common Shares Held as Treasury Shares Schedule of Stockholders Equity [Table Text Block] Schedule of Changes in Accumulated Other Comprehensive Income (Loss) Comprehensive Income (Loss) [Table Text Block] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of Net Operating Loss and Tax Credit Carryforward Schedule of Net Operating Loss and Tax Credit Carryforward [Table Text Block] Schedule of Net Operating Loss and Tax Credit Carryforward [Table Text Block] Reconciliation of Unrecognized Tax Benefits Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Amortized Cost, Within One year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Amortized Cost Amortized Cost, 1 to 5 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Amortized Cost Amortized Cost, 5 to 10 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Amortized Cost Amortized Cost, More Than 10 years Debt Securities, Available-for-sale, Allocated and Single Maturity Date, Maturity, after 10 Years, Amortized Cost Fair Value, Within One year Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, within One Year, Fair Value Fair Value, 1 to 5 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after One Through Five Years, Fair Value Fair Value, 5 to 10 Years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after Five Through Ten Years, Fair Value Fair Value, More Than 10 years Debt Securities, Available-for-sale, Maturity, Allocated and Single Maturity Date, after 10 Years, Fair Value Total Fair Value Financing Receivable, Troubled Debt Restructuring [Table] Financing Receivable, Troubled Debt Restructuring [Table] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Financing Receivable, Troubled Debt Restructurings [Domain] Loan Restructuring Modification [Domain] Below Market Interest Rate Interest Rate Below Market Reduction [Member] Other Concessions Term Extensions and or Other Concessions [Member] Term Extensions and/or Other Concessions [Member] Principal Forgiveness Principal Forgiveness [Member] Financing Receivable, Troubled Debt Restructuring [Line Items] Financing Receivable, Troubled Debt Restructuring [Line Items] Number of Contracts Financing Receivable, Modifications, Number of Contracts Total loans Write-down Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock, shares at cost (in shares) Treasury Stock, Shares Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] 2013 Omnibus Plan Two Thousand Thirteen Omnibus Plan [Member] Two Thousand Thirteen Omnibus Plan [Member] Award Type [Axis] Award Type [Axis] Award Type [Domain] Award Type [Domain] Restricted Share Units Restricted Stock Units (RSUs) [Member] Market Restricted Share Units Market Restricted Stock Units (MRSUs) [Member] Market Restricted Stock Units (MRSUs) [Member] Performance Share Units Performance Share Units (PSUs) [Member] Performance Share Units (PSUs) [Member] vesting vesting [Member] vesting [Member] performance period performance period [Member] Performance period ROAA and ROATCE ROAA and ROATCE [Member] ROAA and ROATCE [Member] Nature of Expense [Axis] Nature of Expense [Axis] Interim Period, Costs Not Allocable [Domain] Interim Period, Costs Not Allocable [Domain] Compensation Expense and Remaining to Purchase Price Compensation Expense and Remaining to Purchase Price [Member] Compensation Expense and Remaining to Purchase Price [Member] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] Merger-Related Expense, Settle in Equity Merger-Related Expense, Settle in Equity [Member] Merger-Related Expense, Settle in Equity [Member] Merger-Related Expense, Settled in Cash Merger-Related Expense, Settled in Cash [Member] Merger-Related Expense, Settled in Cash [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Shares of authorized but unissued common stock reserved for future grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized Grants for option equivalent (in shares) Grants For Option Equivalent Grants For Option Equivalent Grants of full value awards equivalents (in shares) Grants Of Full Value Awards Equivalents Grants Of Full Value Awards Equivalents Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period Options, assumed in period (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Assumed in Period Share-based Compensation Arrangement by Share-based Payment Award, Options, Assumed in Period Options exercised (in shares) Converted options and restricted share units, fair value Share-based Compensation Arrangement by Share-based Payment Award, Converted Awards, Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Converted Awards, Fair Value Other equity compensation, non-vested shares outstanding, fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Nonvested Merger exchange ratio Business Combination, Common Stock, Shares Outstanding, Merger Exchange Ratio Business Combination, Common Stock, Shares Outstanding, Merger Exchange Ratio Share-based compensation expense Tax benefit recognized from compensation expense Share-based Payment Arrangement, Expense, Tax Benefit Unrecognized compensation cost Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Unrecognized compensation cost, period of recognition (years) Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition Stock option grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Options outstanding, intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Options outstanding, weighted average remaining contractual term (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options exercisable, intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Options exercisable, weighted average remaining contractual term (years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Options exercised, intrinsic value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value Number of simulations Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Number of Simulations Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Number of Simulations Vesting range based on return on average assets (ROAA) Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Vested and Expected to Vest, Range Based on Shareholder Return Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Vested and Expected to Vest, Range Based on Shareholder Return Performance period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Share-based Compensation Arrangement by Share-based Payment Award, Award Performance Period Options, vested and expected to vest, range based on return on average assets Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Vested and Expected to Vest, Range Based on Return on Average Assets (ROAA) Share-based Compensation Arrangement by Share-based Payment Award, Other than Options, Vested and Expected to Vest, Range Based on Return on Average Assets (ROAA) Non-option awards vested, total fair value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Risk-free interest rate Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate Expected stock price volatility Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate Dividend yield Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate Simulation period Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term Shareholders' Equity and Other Comprehensive Income Stockholders' Equity Note Disclosure [Text Block] Income Tax Contingency [Table] Income Tax Contingency [Table] Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Federal and State Domestic Tax Authority and State and Local Jurisdiction [Member] Domestic Tax Authority and State and Local Jurisdiction [Member] Expiration Period [Axis] Expiration Period [Axis] Expiration Period [Axis] Expiration Period [Domain] Expiration Period [Domain] [Domain] for Expiration Period [Axis] Period through 2036 Period through 2036 [Member] Period through 2036 [Member] Period through 2029 Period through 2029 [Member] Period through 2029 [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Tax Cuts and Jobs Act of 2017, income tax benefit Tax Cuts and Jobs Act, Income Tax Expense (Benefit) Valuation allowance Deferred Tax Assets, Valuation Allowance Deferred tax assets expected to be realized Deferred Tax Assets, Amount Expected to be Realized Deferred Tax Assets, Amount Expected to be Realized Deferred tax assets, not subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration Deferred tax assets, subject to expiration Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration Tax credit carryforward, amount Tax Credit Carryforward, Amount Unrecognized tax benefits, income tax penalties and interest accrued Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Unrecognized tax benefits that would impact effective tax rate Unrecognized Tax Benefits that Would Impact Effective Tax Rate Unrecognized tax benefits, income tax penalties and interest accrued that would impact effective tax rate Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued that Would Impact Effective Tax Rate Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued that Would Impact Effective Tax Rate Approximate range of uncertain income tax positions expected to be settled or resolved during the next 12 months, minimum Increase in Unrecognized Tax Benefits is Reasonably Possible Property, Plant and Equipment [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Land Land [Member] Buildings and improvements Building and Building Improvements [Member] Leasehold improvements Leasehold Improvements [Member] Furniture and equipment Furniture and Fixtures [Member] Construction in progress Construction in Progress [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Total premises and equipment Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, Before Accumulated Depreciation And Amortization Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, Before Accumulated Depreciation And Amortization Total premises and equipment Property, Plant and Equipment, Gross Less: Accumulated depreciation and amortization Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, Accumulated Depreciation And Amortization Property, Plant, And Equipment And Finance Lease Right-Of-Use Asset, Accumulated Depreciation And Amortization Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Net premises and equipment Net premises and equipment Schedule of Other Assets Schedule of Other Assets [Table Text Block] Income Statement [Abstract] Loans, including fees Interest and Fee Income, Loans and Leases Held-in-portfolio Investment securities available for sale Interest Income, Debt Securities, Available-for-sale, Operating Mortgage loans held for sale Interest and Fee Income, Loans Held-for-sale, Mortgages Federal Reserve Bank balances Interest on Federal Reserve Bank balances Interest income earned on balances deposited with the Federal Reserve Bank. Other earning assets Interest Income, Deposits with Financial Institutions Total interest income Interest expense: Deposits Interest Expense, Deposits Federal funds purchased, securities sold under repurchase agreements, and other short-term borrowings Interest Expense, Short-term Borrowings Long-term debt Interest Expense, Long-term Debt Total interest expense Net interest income after provision for loan losses Interest Income (Expense), after Provision for Loan Loss Non-interest income: Noninterest Income [Abstract] Service charges on deposit accounts Fees and Commissions, Depositor Accounts1 Fees and Commissions, Depositor Accounts1 Fiduciary and asset management fees Fees and Commissions, Fiduciary and Trust Fees and Commissions, Fiduciary and Trust Card fees Fees and Commissions, Credit and Debit Card Fees and Commissions, Credit and Debit Card Brokerage revenue Brokerage Commissions Revenue Mortgage banking income Noninterest Income, Mortgage Banking Noninterest Income, Mortgage Banking Capital markets income Swap Fee Income Swap Fee Income Income from bank-owned life insurance Bank Owned Life Insurance Income Cabela's Transaction Fee Fees and Commissions, Mortgage Banking and Servicing Investment securities losses, net Debt and Equity Securities, Gain (Loss) Other non-interest income Noninterest Income, Other Total non-interest income Non-interest expense: Noninterest Expense [Abstract] Salaries and other personnel expense Labor and Related Expense Net occupancy and equipment expense Occupancy, Net Third-party processing and other services Information Technology and Data Processing Professional fees Professional Fees FDIC insurance and other regulatory fees F D I C Insurance And Other Regulatory Fees The premium paid to the Federal Deposit Insurance Corporation for deposit insurance plus other regulatory fees including examination fees and Federal Reserve service fees, all of which are included in noninterest expense. Advertising expense Advertising Expense Merger-related expense Business Combination, Acquisition Related Costs Loss on early extinguishment of debt, net Gain (Loss) on Extinguishment of Debt Other operating expenses Other Noninterest Expense Total non-interest expense Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Weighted average common shares outstanding, basic (in shares) Weighted Average Number of Shares Outstanding, Basic Weighted average common shares outstanding, diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Loss Contingencies [Table] Loss Contingencies [Table] Loss Contingencies by Nature of Contingency [Axis] Loss Contingency Nature [Axis] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Guarantee Obligations [Member] Guarantee Obligations [Member] Letters of credit Standby and Commercial Letters of Credit [Member] Standby and Commercial Letters of Credit [Member] Commitments to fund commercial and industrial loans Commitments to Fund Commercial and Industrial Loans [Member] Commitments to Fund Commercial and Industrial Loans [Member] Commitments to fund commercial real estate, construction, and land development loans Commitments to Fund Commercial Real Estate, Construction, and Land Development Loans [Member] Commitments to Fund Commercial Real Estate, Construction, and Land Development Loans [Member] Commitments under home equity lines of credit Commitments under Home Equity Lines of Credit [Member] Commitments under Home Equity Lines of Credit [Member] Unused credit card lines Unused Credit Card Lines [Member] Unused Credit Card Lines [Member] Other loan commitments Other Loan Commitments [Member] Other Loan Commitments [Member] Loss Contingencies [Line Items] Loss Contingencies [Line Items] Total letters of credit and unfunded lending commitments Loss Contingency, Estimate of Possible Loss Carrying amount included in other assets Affordable Housing Program Obligation Amount of future funding commitments included in carrying amount Affordable Housing Program Obligation, Future Funding Included in Carrying Amount Affordable Housing Program Obligation, Future Funding Included in Carrying Amount Short-term construction loans and letter of credit commitments Affordable Housing Program Obligation, Short-term Construction Loans and Letter of Credit Commitments Affordable Housing Program Obligation, Short-term Construction Loans and Letter of Credit Commitments Funded portion of short-term loans and letters of credit Affordable Housing Program Obligation, Funded Portion of Short-term Loans and Letters of Credit Affordable Housing Program Obligation, Funded Portion of Short-term Loans and Letters of Credit Contractual amount net of risk participations Contractual Amount Net of Risk Participations Contractual Amount Net of Risk Participations Guarantor obligations, monetary amount Guarantor Obligations, Liquidation Proceeds, Monetary Amount Guarantor obligations, advanced payment to merchant Guarantor Obligations, Advanced Payment to Merchant Guarantor Obligations, Advanced Payment to Merchant Schedule of Premises and Equipment Property, Plant and Equipment [Table Text Block] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Measurement Frequency [Domain] Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Recurring [Member] Other mortgage-backed securities Mortgage Backed Securities, Other [Member] Other investments Other Investments [Member] U.S. Government agency securities US Government Agencies Debt Securities [Member] Mutual funds Mutual Fund [Member] Trading securities Mortgage loans held for sale Mortgages Held-for-sale, Fair Value Disclosure Equity Securities, FV-NI Equity Securities, FV-NI Trading liability for short positions Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) Condensed Financial Information of Parent Company Only Disclosure [Text Block] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Federal Domestic Tax Authority [Member] State State and Local Jurisdiction [Member] Type of Tax Credits Carryforward [Axis] Type of Tax Credits Carryforward [Axis] Type of Tax Credits Carryforward [Axis] Type of Tax Credits Carryforward [Domain] Type of Tax Credits Carryforward [Domain] [Domain] for Type of Tax Credits Carryforward [Axis] Net Operating Loss Net Operating Loss Tax Credits Carryforward [Member] Net Operating Loss Tax Credits Carryforward [Member] Other Credits Other Tax Credits Carryforward [Member] Other Credits [Member] Carryforwards Expiration [Axis] Carryforwards Expiration [Axis] Carryforwards Expiration [Axis] Carryforwards Expiration [Domain] Carryforwards Expiration [Domain] Carryforwards Expiration [Domain] 2023-2028 Tax Carryforwards Expiration, Period One [Member] Tax Carryforwards Expiration, Period One [Member] 2029-2033 Tax Carryforwards Expiration, Period Two [Member] Tax Carryforwards Expiration, Period Two [Member] 2034-2036 Tax Carryforwards Expiration, Period Three [Member] Tax Carryforwards Expiration, Period Three [Member] 2020-2024 Tax Carryforwards Expiration, Period Four [Member] Tax Carryforwards Expiration, Period Four [Member] 2025-2029 Tax Carryforwards Expiration, Period Five [Member] Tax Carryforwards Expiration, Period Five [Member] Operating Loss Carryforwards [Line Items] Operating Loss Carryforwards [Line Items] Deferred Tax Asset Balance, Gross Deferred Tax Assets, Gross Valuation Allowance Total deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Pre-Tax Earnings Necessary to Realize Deferred Tax Assets, Pre-Tax Earnings Necessary to Realize Deferred Tax Assets, Pre-Tax Earnings Necessary to Realize Segment Reporting Segment Reporting Disclosure [Text Block] Finance leases Finance Lease, Liability Capital lease obligations Capital Lease Obligations Depreciation and amortization expense Depreciation, Depletion and Amortization Premises and equipment transferred to/(from) other assets, net Premises And Equipment Transferred To Other Assets Held For Sale Premises and equipment transferred to other assets held for sale Interest-bearing Deposit Liabilities [Abstract] Interest-bearing demand deposits Interest-bearing Domestic Deposit, Demand Money market accounts Deposits, Money Market Deposits Savings accounts Deposits, Savings Deposits Time deposits Time Deposits, Excluding Brokered Deposits Time Deposits, Excluding Brokered Deposits Brokered deposits Interest-bearing Domestic Deposit, Brokered Total interest-bearing deposits Aggregate amount of time deposits of $250,000 or more Time Deposits, $250,000 or More Time Deposits, $250,000 or More Time Deposits, by Maturity [Abstract] Time Deposits, Fiscal Year Maturity [Abstract] Maturing within one year Time Deposit Maturities, Next Twelve Months Between 1 - 2 years Time Deposits, Maturing in Year One and Two Time Deposits, Maturing in Year One and Two 2 - 3 years Time Deposits, Maturing in Years Two and Three Time Deposits, Maturing in Years Two and Three 3 - 4 years Time Deposits, Maturing in Years Three and Four Time Deposits, Maturing in Years Three and Four 4 - 5 years Time Deposits, Maturing in Years Four and Five Time Deposits, Maturing in Years Four and Five Thereafter Time Deposits, Maturing in After Five Years Time Deposits, Maturing in After Five Years Total Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Weighted average common shares outstanding Potentially dilutive shares from outstanding equity-based awards, warrants, and earnout payments Potentially Dilutive Shares from Assumed Exercise of Securities or Other Contracts to Purchase Common Stock Potentially Dilutive Shares from Assumed Exercise of Securities or Other Contracts to Purchase Common Stock Weighted average diluted common shares Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Measurements, Nonrecurring Fair Value, Nonrecurring [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] Impaired loans Impaired Financing Receivable, Recorded Investment Loans held for sale Other assets held for sale Other Assets, Fair Value Disclosure Stock Options Share-based Payment Arrangement, Option [Member] Stock price (Synovus' closing stock price on December 31, 2018) (in dollars per share) Share Price Weighted average fair value of converted stock options (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Fair Value of Converted Stock Options Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Weighted Average Fair Value of Converted Stock Options Term to expiration Accounting Policies [Abstract] Principles of Consolidation and Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Business Combinations Business Combinations Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Short-term Investment Investment, Policy [Policy Text Block] Investment Securities Available for Sale Marketable Securities, Policy [Policy Text Block] Mortgage Loans Held for Sale and Mortgage Banking Income Mortgage Banking Activity [Policy Text Block] Loans Held for Investments and Interest Income Loans and Interest Income [Policy Text Block] Loans and Interest Income [Policy Text Block] Purchased loans Purchased Loans Policy [Policy Text Block] Purchased Loans Policy [Policy Text Block] Allowance for Loan Losses Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Transfers of Financial Assets Transfers and Servicing of Financial Assets, Policy [Policy Text Block] Cash Surrender Value of Bank-Owned Life Insurance Cash Surrender Value of Bank-Owned Life Insurance Policy [Policy Text Block] Cash Surrender Value of Bank-Owned Life Insurance Policy [Policy Text Block] Premises and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Goodwill and Other Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Segment Disclosure Segment Reporting, Policy [Policy Text Block] Other Assets Other Assets [Policy Text Block] Other Assets [Policy Text Block] Derivative Instruments Derivatives, Policy [Policy Text Block] Non-interest Income Non-interest Income Policy [Policy Text Block] Non-interest Income Policy [Policy Text Block] Advertising Expenses Advertising Cost [Policy Text Block] Income Taxes Income Tax, Policy [Policy Text Block] Share-based Compensation Share-based Payment Arrangement [Policy Text Block] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] Share Repurchases Share Repurchase Program Policy [Policy Text Block] Share Repurchase Program Policy [Policy Text Block] Fair Value Measurements and Disclosures Fair Value of Financial Instruments, Policy [Policy Text Block] Long-term Debt Debt, Policy [Policy Text Block] Contingent Liabilities and Legal Costs Commitments and Contingencies, Policy [Policy Text Block] Recently Adopted and Issued Accounting Standards Updates New Accounting Pronouncements, Policy [Policy Text Block] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Triggering Event [Axis] Triggering Event [Axis] Triggering Event [Axis] Triggering Event [Domain] Triggering Event [Domain] [Domain] for Triggering Event [Axis] When fully phased-in on January 1, 2019 When fully phased-in on January 1, 2019 [Member] When fully phased-in on January 1, 2019 [Member] Synovus Bank Reporting Unit Synovus Bank [Member] Synovus Bank [Member] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Capital conservation buffer Capital Conservation Buffer Capital Conservation Buffer CET1 capital Common equity tier 1 capital (transitional) [Abstract] Common equity tier 1 capital (transitional) [Abstract] CET1 capital, Actual Common Equity Tier One Common Equity Tier One CET1 capital, For Capital Adequacy Purposes Common Equity Tier One Required for Capital Adequacy Common Equity Tier One Required for Capital Adequacy CET1 capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Common Equity Tier One Required to be Well Capitalized Common Equity Tier One Required to be Well Capitalized Tier 1 risk-based capital Tier One Leverage Capital [Abstract] Tier I risk-based capital, Actual Tier One Risk Based Capital Tier I risk-based capital, For Capital Adequacy Purposes Tier One Risk Based Capital Required for Capital Adequacy Tier I risk-based capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Tier One Risk Based Capital Required to be Well Capitalized Total risk-based capital Tier One Risk Based Capital [Abstract] Total risk-based capital, Actual Capital Total risk-based capital, For Capital Adequacy Purposes Capital Required for Capital Adequacy Total risk-based capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Capital Required to be Well Capitalized CET1 capital ratio Common equity tier I capital ratio (transitional) [Abstract] Common equity tier I capital ratio (transitional) [Abstract] CET1 capital ratio, Actual Common Equity Tier One to Risk Weighted Assets Common Equity Tier One to Risk Weighted Assets CET1 capital ratio, For Capital Adequacy Purposes Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets Common Equity Tier One Capital Required for Capital Adequacy to Risk Weighted Assets CET1 capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions Common Equity Tier One Capital Required to be Well Capitalized to Risk Weighted Assets Common Equity Tier One Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 risk-based capital ratio Capital [Abstract] Tier I risk-based capital ratio, Actual Tier One Risk Based Capital to Risk Weighted Assets Tier I risk-based capital ratio, For Capital Adequacy Purposes Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier I risk-based capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Total risk-based capital ratio Risk Based Ratios [Abstract] Total risk-based capital ratio, Actual Capital to Risk Weighted Assets Total risk-based capital ratio, For Capital Adequacy Purposes Capital Required for Capital Adequacy to Risk Weighted Assets Total risk-based capital ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions Capital Required to be Well Capitalized to Risk Weighted Assets Leverage ratio Leverage Ratios [Abstract] Leverage ratio, Actual Tier One Leverage Capital to Average Assets Leverage ratio, For Capital Adequacy Purposes Tier One Leverage Capital Required for Capital Adequacy to Average Assets Leverage ratio, To Be Well Capitalized Under Prompt Corrective Action Provisions Tier One Leverage Capital Required to be Well Capitalized to Average Assets Investment Securities Available for Sale Debt Securities, Available-for-sale [Table Text Block] Employer matching contribution, percent Defined Contribution Plan, Employer Matching Contribution, Percent of Match 401(k) percent of match Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Annual contribution Defined Contribution Plan, Cost Stock purchase plan, percent of match Defined Contribution Plan, Stock Purchase Plan, Percent of Mmatch Defined Contribution Plan, Stock Purchase Plan, Percent of Mmatch Stock purchase plans compensation expense Deferred Compensation Arrangement with Individual, Compensation Expense Income Taxes Income Tax Disclosure [Text Block] Statement of Comprehensive Income [Abstract] Net income, Before-tax Amount Net income, Income Tax Before-tax Amount Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax [Abstract] Net unrealized gains (losses) arising during the period Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Reclassification adjustment for realized (gains) losses included in net income Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax