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] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Useful Life (in years) Property, Plant and Equipment, Useful Life Total premises and equipment Property, Plant and Equipment, Gross Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Premises and equipment, net Property, Plant and Equipment, Net Other Assets [Abstract] Cash surrender value of bank-owned life insurance Cash Surrender Value of Life Insurance 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 Accrued interest receivable Interest Receivable Investments in low income housing tax credit partnerships Tax credit partnerships Tax credit partnerships Taxes receivable(1) Income Taxes Receivable Accounts receivable Accounts Receivable, Net Prepaid expenses Prepaid Expense Private equity investments Private Equity Investments Private Equity Investments Derivative asset positions Derivative Asset Other properties held for sale Disposal Group, Including Discontinued Operation, Other Assets SBA/GGL servicing assets, net Servicing Asset Miscellaneous other assets Other Assets, Miscellaneous Total other assets Other Assets Alternative minimum tax credits Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax Schedule of Premises and Equipment Property, Plant and Equipment [Table Text Block] Schedule of Future Minimum Rental Payments for Operating Leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Income Tax Disclosure [Abstract] 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 2018 Period through 2018 [Member] Period through 2018 [Member] Period through 2035 Period through 2035 [Member] Period through 2035 [Member] Period through 2027 Period through 2027 [Member] Period through 2027 [Member] Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Tax Cuts and Jobs Act of 2017, income tax expense Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense (Benefit) Decrease in valuation allowance Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Tax Cuts and Jobs Act of 2017, income tax expense Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit) Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Change in Tax Rate, Provisional Income Tax Expense (Benefit) Deferred tax assets expected to be realized Deferred Tax Assets, Amount Expected to be Realized Deferred Tax Assets, Amount Expected to be Realized Valuation allowance Deferred Tax Assets, Valuation Allowance 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 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] Fair Value Hedging Fair Value Hedging [Member] Derivative Instrument Risk [Axis] Derivative Instrument [Axis] Derivative Contract Type [Domain] Derivative Contract [Domain] Interest Rate Swap Interest Rate Swap [Member] Servicing Assets at Fair Value by Types of Financial instrument [Axis] Financial Instrument [Axis] Types of Financial Instruments [Domain] Financial Instruments [Domain] Fixed Rate Residential Mortgage Fixed Rate Residential Mortgage [Member] Derivative [Line Items] Derivative [Line Items] Derivative, fair value Derivative, Fair Value, Net Unamortized deferred net loss balance from previously terminated cash flow hedges Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Remaining deferred (gain) loss balance on all previously terminated fair value hedges Deferred (Gain) Loss on Discontinuation of Fair Value Hedge Notional amount of interest rate swap contracts Derivative, Notional Amount Increase (decrease) derivative, notional amount Increase (Decrease) Derivative, Notional Amount Increase (Decrease) Derivative, Notional Amount Commitments to fund fixed-rate mortgage loans Commitments to Fund Fixed Rate Mortgage Loans Commitments to Fund Fixed Rate Mortgage Loans Unrealized gain on fair value of fixed-rate mortgage loans to customers Increase (Decrease) in Fair Value of Interest Rate Fair Value Hedging Instruments Sale of outstanding commitments Commitments To Sell Mortgage Loans Commitments to sell mortgage loans as of the balance sheet date. Gain (loss) on fair value commitments to sell mortgage loans Gain (Loss) on Fair Value Commitments To Sell Mortgage Loans Gain (Loss) on Fair Value Commitments To Sell Mortgage Loans Derivative, Collateral, Right to Reclaim Cash Derivative, Collateral, Right to Reclaim Cash Variation margin, amount reducing derivative asset Variation margin, amount reducing derivative asset Variation margin, amount reducing derivative asset Deferred gains of hedges reclassified into earnings Deferred Gains (Loss) on Discontinuation of Cash Flow Hedge Reclassified to Earnings Deferred Gains (Loss) on Discontinuation of Cash Flow Hedge Reclassified to Earnings Deferred gains of hedges reclassified into loss on extinguishment of debt Deferred Gains (Loss) on Discontinuation of Cash Flow Hedge Reclassified to Gain (Loss) on Extinguishment of Debt Deferred Gains (Loss) on Discontinuation of Cash Flow Hedge Reclassified to Gain (Loss) on Extinguishment of Debt Quarterly Financial Data [Abstract] Interest income Interest and Dividend Income, Operating Net interest income Interest Income (Expense), Net Provision for loan losses Provision for Loan and Lease Losses Income before income taxes Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net income available common shareholders Net Income (Loss) Available to Common Stockholders, Basic 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 Share-based Compensation [Abstract] Stock option grants (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Shares 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 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 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 Document And Entity Information [Abstract] Document and Entity Information [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 Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Trading Symbol Trading Symbol Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Voluntary Filers Entity Voluntary Filers Entity Current Reporting Status Entity Current Reporting Status Entity Public Float Entity Public Float Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Goodwill [Table] Schedule of Goodwill [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Trust Services Reporting Unit Trust Services [Member] Trust Services [Member] Synovus Bank Reporting Unit Synovus Bank [Member] Synovus Bank [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Goodwill Goodwill Accumulated impairment losses Goodwill, Impairment Loss Measurement period adjustments Goodwill, Period Increase (Decrease) Goodwill Fair Value Disclosures [Abstract] 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] Fair Value Inputs, Assets, Quantitative Information Fair Value Inputs, Assets, Quantitative Information [Table Text Block] Carrying and Estimated Fair Values of Financial Instruments Carried on Balance Sheet Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of Quarterly Financial Information Quarterly Financial Information [Table Text Block] Accounting Policies [Abstract] Basis Of Presentation [Table] Basis Of Presentation [Table] Basis Of Presentation [Table] Schedule of Investment Income, Reported Amounts, by Category [Axis] Investment Type [Axis] Investment Income, Categories [Domain] Investments [Domain] Cash And Cash Equivalents Cash and Cash Equivalents [Member] Loans Rating [Axis] Loans Rating [Axis] Loans Rating [Axis] Loans Rating [Domain] Loans Rating [Domain] [Domain] for Loans Rating [Axis] DRR Methodology DRR Methodology [Member] DRR Methodology [Member] Title of Individual [Axis] Title of Individual [Axis] Relationship to Entity [Domain] Relationship to Entity [Domain] Non-employee Director Non-employee Director [Member] Non-employee Director [Member] Non-employee Non-employee [Member] Non-employee [Member] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-02 Accounting Standards Update 2016-02 [Member] Accounting Standards Update 2016-09 Accounting Standards Update 2016-09 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Retained Earnings Retained Earnings [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] Basis Of Presentation [Line Items] Basis Of Presentation [Line Items] Basis Of Presentation [Line Items] Total deposits Cash And Due From Banks Restricted Cash and due from banks which is pledged as collateral or restricted as to withdrawal. Cash and cash equivalents Cash On Deposit Per Federal Reserve Bank Requirements Cash on deposit to meet Federal Reserve Bank Requirements. Interest earning deposits with banks Short Term Investments Restricted LOC Short-term investments which are pledged in connection with letters of credit. Federal funds sold Short Term Investments Restricted Derivatives Short-term investments which are pledged in connection with derivative instruments. Retail loans and commercial loans, evaluated for impairment Retail Loans and Commercial Loans, Evaluated for Impairment Retail Loans and Commercial Loans, Evaluated for Impairment Loans, net of deferred fees and costs Loans and Leases Receivable, Net Amount Useful life Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Federal Reserve Bank stock held Federal Reserve Bank Stock Federal Home Loan Bank stock held Federal Home Loan Bank Stock Vesting period Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Share-based compensation, excess tax benefit, amount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount Increase in retained earnings Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Tax Effect Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Tax Effect Increase in regulatory capital Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Effect Of Regulatory Capital Tax Cuts and Jobs Act of 2017, Reclassification from AOCI to Retained Earnings, Effect Of Regulatory Capital Operating lease commitments Operating Lease, Liability Operating lease, right-of-use asset Operating Lease, Right-of-Use Asset Cumulative effect of new accounting principle in period of adoption Cumulative Effect of New Accounting Principle in Period of Adoption Loans and Allowance for Loan Losses [Abstract] Loans and Allowance for Loan Losses [Abstract] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Schedule of Financing Receivable, Recorded Investment, Credit Quality Indicator [Table] Internal Credit Assessment [Axis] Internal Credit Assessment [Axis] Internal Credit Assessment [Domain] Internal Credit Assessment [Domain] Pass Pass [Member] Special Mention Special Mention [Member] Substandard Substandard [Member] Doubtful Doubtful [Member] Loss Loss And Charged Off [Member] Loss and Charged Off [Member] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Total commercial real estate Commercial Real Estate [Member] Total commercial and industrial Commercial And Industrial [Member] Commercial and Industrial [Member] Total consumer Retail [Member] Retail [Member] Financing Receivable, Recorded Investment, by Class of Financing Receivable [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable [Domain] Class of Financing Receivable, Type [Domain] 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] Commercial, financial and agricultural Commercial, Financial and Agricultural [Member] Commercial, Financial and Agricultural [Member] Owner-occupied Owner-Occupied [Member] Owner-Occupied [Member] Home equity lines Home Equity Line of Credit [Member] Consumer mortgages Consumer Loan [Member] Credit cards Credit Card Receivable [Member] Other consumer loans Other Consumer Loans [Member] Other Consumer Loans [Member] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [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 Interest-bearing Deposit Liabilities [Abstract] Deposits Deposit Liabilities Disclosures [Text Block] Statement of Financial Position [Abstract] Preferred stock, shares outstanding Preferred Stock, Shares Outstanding Common stock, par value (per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Treasury stock, shares at cost Treasury Stock, Shares Earnings Per Share [Abstract] Schedule of Basic And Diluted Earnings per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value by Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Fair Value, Measurements, Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Measurements, Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Collateral Dependent Impaired Loans Collateral Dependent Impaired Loans [Member] Collateral Dependent Impaired Loans [Member] Other Loans Held for Sale Other Loans Held for Sale [Member] Other Loans Held for Sale [Member] Equity securities Equity Securities [Member] Trust Preferred Securities Trust Preferred Securities [Member] Trust Preferred Securities [Member] Visa Derivative Visa Derivative [Member] Visa Derivative [Member] Private Equity Investments Private Equity Investments [Member] Private Equity Investments [Member] Other Liabilities Other Liabilities [Member] Other Real Estate Other Real Estate [Member] Other Real Estate [Member] Other Assets Held for Sale Other Assets Held for Sale [Member] Other Assets Held for Sale [Member] GGL/SBA Loans Servicing Asset SBA/GGL Servicing Asset [Member] SBA /GGL Servicing Asset [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Earnout Liabilities Earnout Liabilities [Member] Earnout Liabilities [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Valuation Technique [Axis] Valuation Technique [Axis] Valuation Technique [Domain] Valuation Technique [Domain] Discounted cash flow analysis Discounted Cash Flow [Member] Discounted Cash Flow [Member] Individual analysis of each investee company Individual Analysis of Each Investee Company [Member] Individual Analysis of Each Investee Company [Member] Third-party appraised value of collateral less estimated selling costs Third Party Appraised value of Collateral Less Estimated Selling Costs or Contracted Sales Price [Member] Third Party Appraised value of Collateral Less Estimated Selling Costs or Contracted Sales Price [Member] Third-party appraised value less estimated selling costs or BOV Third-party appraised value less estimated selling costs or BOV [Member] Third-party appraised value less estimated selling costs or BOV [Member] Third-party appraised value of real estate less estimated selling costs Third-party appraised value of real estate less estimated selling costs [Member] Third-party appraised value of real estate less estimated selling costs [Member] Weighted Average Weighted Average [Member] Fair Value Inputs, Assets, Quantitative Information [Line Items] Fair Value Inputs, Assets, Quantitative Information [Line Items] Assets, fair value disclosure Assets, Fair Value Disclosure Credit spread embedded in discount rate Fair Value Assumption, Credit spread embedded in discount rate Fair Value Assumption, Credit spread embedded in discount rate Discount of lack of liquidity Fair Value Inputs, Discount for Lack of Liquidity Fair Value Inputs, Discount for Lack of Liquidity Potential additional payments based on earnings, period Business Combination, Potential Additional Payments Based on Earnings, Period Business Combination, Potential Additional Payments Based on Earnings, Period Estimated timing of resolution of covered litigation Estimated timing of resolution of covered litigation Estimated timing of resolution of covered litigation Discount to appraised value Fair Value Imputs Discount to Appraised Value Fair Value Imputs Discount to Appraised Value Estimated selling costs Fair Value Inputs, Estimated selling costs Fair Value Inputs, Estimated selling costs Liabilities, Fair Value Disclosure, Nonrecurring Liabilities, Fair Value Disclosure, Nonrecurring Net Income Per Common Share Earnings Per Share [Text Block] Debt Disclosure [Abstract] Long-term Debt and Short-term Borrowings Debt and Capital Leases Disclosures [Text Block] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Investment Securities Available for Sale Available-for-sale Securities [Member] Private Equity Investments Private Equity Funds [Member] Visa derivative Other Derivative Liability Contracts [Member] Other Derivative Liability Contract [Member] Earnout Liability Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward] Beginning balance, January 1, Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis with Unobservable Inputs Included in earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Earnings Unrealized gains included in other comprehensive income Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Gain (Loss) Included in Other Comprehensive Income (Loss) Additions Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Purchases Sales Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Sales Settlements Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Settlements Transfer from amortization method to fair value Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Transfers, Net Measurement period adjustments related to Global One acquisition Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease) Ending balance, December 31, Total net gains (losses) for the year included in earnings attributable to the change in unrealized gains (losses) relating to assets and liabilities still held at December 31, Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease), Included in Earnings Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease), Included in Earnings Equity [Abstract] Other Comprehensive Income (Loss) Comprehensive Income (Loss) Note [Text Block] Statement of Stockholders' Equity [Abstract] Cash dividends declared on common stock, per share Common Stock, Dividends, Per Share, Cash Paid Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [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 Other loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Other Other real estate Real Estate Acquired Through Foreclosure Other assets held for sale Other Assets, Fair Value Disclosure 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] Condensed Financial Information of Parent Company Only 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(1) 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 Other Income 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 Allocated income tax benefit Income Tax Expense (Benefit), Intraperiod Tax Allocation Income before equity in undistributed (loss) income 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 (loss) income of subsidiaries Equity in Undistributed Income (Loss) from Continuing Operations of Subsidiaries Equity in Undistributed Income (Loss) from Continuing Operations of Subsidiaries Net income (loss) available to controlling interest Net Income (Loss) Attributable to Parent Dividends on preferred stock Preferred Stock Dividends and Other Adjustments Net income available to common shareholders Investments [Abstract] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities, Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Axis] Major Types of Debt and Equity Securities [Domain] Major Types of Debt and Equity Securities [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] State and municipal securities US States and Political Subdivisions Debt Securities [Member] Corporate debt and other securities Other Investments [Member] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Amortized Cost Available-for-sale Securities, Amortized Cost Basis Gross Unrealized Gains Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax Fair Value Available-for-sale Securities Reconciliation of Unrecognized Income Tax Benefits Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at January 1, Unrecognized Tax Benefits Additions based on income tax positions related to current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Additions for income tax positions of prior years Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Additions from acquisition Unrecognized Tax Benefits, Increase Resulting from Acquisition Reductions for income tax positions of prior years Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Statute of limitation expirations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Settlements Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities Balance at December 31, Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Award Type and Plan Name [Axis] Award Type [Axis] Award Type [Domain] Equity Award [Domain] 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] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share Units Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Outstanding, 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 Dividend equivalents granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Dividend Equivalents Grants in Period Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Dividend Equivalents Grants in Period Quantity change by TSR factor (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Quantity Change by TSR Factor Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Quantity Change by TSR Factor Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Outstanding, End of Period (in shares) Weighted-Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Outstanding, Beginning of Period, Weighted-Average Grant-date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Granted, Weighted-Average Grant-date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Dividend equivalents granted, Weighted-Average Grant-date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Dividend Equivalents Grants in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Dividend Equivalents Grants in Period, Weighted Average Grant Date Fair Value Quantity change by TSR factor, Weighted-Average Grant-date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Quantity Change by TSR Factor in Period, Weighted Average Grant Date Fair Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Quantity Change by TSR Factor in Period, Weighted Average Grant Date Fair Value Vested, Weighted-Average Grant-date Fair Value (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Outstanding, End of Period, Weighted-Average Grant-date Fair Value (in dollars per share) Schedule of Condensed Balance Sheets Schedule Of Condensed Balance Sheets [Table Text Block] Schedule Of Condensed Balance Sheets [Table Text Block] Schedule of Condensed Statements of Operations Schedule of Condensed Statements of Operations [Table Text Block] Schedule of Condensed Statements of Operations [Table Text Block] Schedule of Condensed Statements of Comprehensive Income (Loss) Schedule of Condensed Statements of Comprehensive Income (Loss) [Table Text Block] Schedule of Condensed Statements of Comprehensive Income (Loss) [Table Text Block] Schedule of Condensed Statements of Cash Flows Schedule Of Condensed Statements Of Cash Flows [Table Text Block] Schedule Of Condensed Statements Of Cash Flows [Table Text Block] Statement of Comprehensive Income [Abstract] Net income, Before-tax Amount Income (loss) before income taxes including income from discontinued operations before income taxes Income (loss) before income taxes including income from discontinued operations before income taxes Net income, Tax (Expense) Benefit Net change related to cash flow hedges: Before-tax Amount Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax [Abstract] Reclassification adjustment for losses realized in net income, Before-tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Net change related to cash flow hedges: Tax (Expense) Benefit Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Effect [Abstract] Reclassification adjustment for losses realized in net income, Tax (Expense) Benefit Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Net change related to cash flow hedges: Net of Tax Amount Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract] Reclassification adjustment for losses realized in net income, Net of Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Net unrealized gains (losses) on investment securities available for sale: Before-tax Amount Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax, [Abstract] Reclassification adjustment for net losses (gains) realized in net income, Before-tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Net unrealized gains (losses) arising during the period, Before-tax Amount Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax Net unrealized gains (losses), Before-tax Amount Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax Net unrealized gains (losses) on investment securities available for sale: Tax (Expense) Benefit Other Comprehensive Income (Loss), Available-for-sale Securities, Tax [Abstract] Reclassification adjustment for net losses (gains) realized in net income, Tax (Expense) Benefit Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Net unrealized gains (losses) arising during the period, Tax (Expense) Benefit Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Net unrealized gains (losses), Tax (Expense) Benefit Other Comprehensive Income (Loss), Available-for-sale Securities, Tax Net unrealized gains (losses) on investment securities available for sale: Net of Tax Amount Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Reclassification adjustment for net losses (gains) realized in net income, Net of Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net unrealized gains (losses) arising during the period, Net of Tax Amount Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Net unrealized gains (losses), Net of Tax Amount Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax Post-retirement unfunded health benefit: Before-tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax [Abstract] Reclassification adjustment for gains realized in net income, Before-tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax Actuarial gains arising during the period, Before-tax Amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Net unrealized (losses) gains, Before-tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax Post-retirement unfunded health benefit: Tax (Expense) Benefit Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax [Abstract] Reclassification adjustment for gains realized in net income, Tax (Expense) Benefit Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax Actuarial gains arising during the period, Tax (Expense) Benefit Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Net unrealized (losses) gains, Tax (Expense) Benefit Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Post-retirement unfunded health benefit: Net of Tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax [Abstract] Reclassification adjustment for gains realized in net income, Net of Tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, after Tax Actuarial gains arising during the period, Net of Tax Amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Net unrealized (losses) gains, Net of Tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Other comprehensive income (loss), Before-tax Amount Other Comprehensive Income (Loss), before Tax Other comprehensive income (loss), Tax (Expense) Benefit Other Comprehensive Income (Loss), Tax Net current period other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Comprehensive income, Net of Tax Amount Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Recorded Investment, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Recorded Investment Unpaid Principal Balance, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Related Allowance, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Related Allowance Impaired Financing Receivable, with No Related Allowance, Related Allowance Average Recorded Investment, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment Interest Income Recognized, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Interest Income, Accrual Method Recorded Investment, With allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Unpaid Principal Balance, With allowance recorded Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Related Allowance, With allowance recorded Impaired Financing Receivable, with Related Allowance, Related Allowance Impaired Financing Receivable, with Related Allowance, Related Allowance Average Recorded Investment, With allowance recorded Impaired Financing Receivable, with Related Allowance, Average Recorded Investment Interest Income Recognized, With allowance recorded Impaired Financing Receivable, with Related Allowance, Interest Income, Accrual Method Recorded Investment Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Related Allowance Impaired Financing Receivable, Related Allowance Average Recorded Investment in Impaired Loans Impaired Financing Receivable, Average Recorded Investment Interest Income Recognized Impaired Financing Receivable, Interest Income, Accrual Method Summary of Quarterly Financial Data (Unaudited) Quarterly Financial Information [Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Allowance for Loan and Lease Losses [Roll Forward] Allowance for Loan and Lease Losses [Roll Forward] Beginning balance Loans and Leases Receivable, Allowance Allowance for loan losses of sold Memphis loans Allowance for Loan and Lease Losses, Loans Sold Charge-offs Allowance for Loan and Lease Losses, Write-offs Recoveries Allowance for Loan and Lease Loss, Recovery of Bad Debts Ending balance Ending balance: individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Ending balance: collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Ending balance: total loans Loans Receivable, Net Ending balance: individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Ending balance: collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Premises and Equipment Property, Plant and Equipment Disclosure [Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Legal Entity [Axis] Entity [Domain] Debt Instrument [Line Items] Debt Instrument [Line Items] 2018 Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months 2019 Long-term Debt, Maturities, Repayments of Principal in Year Two 2020 Long-term Debt, Maturities, Repayments of Principal in Year Three 2021 Long-term Debt, Maturities, Repayments of Principal in Year Four 2022 Long-term Debt, Maturities, Repayments of Principal in Year Five Thereafter Long-term Debt, Maturities, Repayments of Principal after Year Five Total long-term debt Long-term Debt, before Hedge-related Basis Adjustment Long-term Debt, before Hedge-related Basis Adjustment Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] AOCI Attributable to Parent [Member] AOCI Attributable to Parent [Member] Net Unrealized Gains (Losses) on Cash Flow Hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Net Unrealized Gains (Losses) on Investment Securities Available for Sale Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Post-Retirement Unfunded Health Benefit Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Changes in Accumulated Other Comprehensive Income (Loss) by Component [Roll Forward] AOCI Attributable to Parent, Net of Tax [Roll Forward] Beginning balance Stockholders' Equity Attributable to Parent Other comprehensive income (loss) before reclassifications OCI, before Reclassifications, Net of Tax, Attributable to Parent Amounts reclassified from accumulated other comprehensive income (loss) Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Net current period other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Ending balance Other Assets Other Assets Disclosure [Text Block] Regulatory Capital Regulatory Capital Requirements under Banking Regulations [Text Block] Condensed Financial Information Of Synovus Financial Corp. (Parent Company Only) Condensed Financial Information of Parent Company Only Disclosure [Text Block] Schedule of Changes in Accumulated Other Comprehensive Income (Loss) by Component (Net of Income Taxes) Comprehensive Income (Loss) [Table Text Block] Schedule of Reclassifications out of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Income Statement [Abstract] Interest income: Loans, including fees Interest and Fee Income, Loans and Leases Investment securities available for sale Interest Income on Available for Sale Securities Interest Income on Available for Sale Securities Trading account assets Interest and Dividend Income, Securities, Operating, Trading or Measured at Fair Value 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 and securities sold under repurchase agreements Interest Expense, Short-term Borrowings Long-term debt Interest Expense, Long-term Debt Total interest expense Net interest income 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 Accounts Fiduciary and asset management fees Fees and Commissions, Fiduciary and Trust Activities Brokerage revenue Brokerage Commissions Revenue Mortgage banking income Fees and Commissions, Mortgage Banking Bankcard fees Bankcard Fees Credit Cards And Debit Cards Income earned from credit card services including late, over limit, and annual fees plus income earned from debit cards including interchange income, annual fees, and other fees. This item excludes interest income earned on credit card balances and transactions. Cabela's Transaction Fee Fees and Commissions Investment securities (losses) gains, net Gain (Loss) on Sale of Securities, Net Decrease in fair value of private equity investments, net Private Equity Investment, Fair Value Adjustment Private Equity Investment, Fair Value Adjustment Other fee income Fees and Commissions, Other Other non-interest income Noninterest Income, Other Total non-interest income Noninterest 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 expense Information Technology and Data Processing 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. Professional fees Professional Fees Advertising expense Advertising Expense Foreclosed real estate expense, net Foreclosed Real Estate Expense Loss on early extinguishment of debt, net Gain (Loss) on Extinguishment of Debt Earnout liability adjustments Earnout Liability, Fair Value Adjustment Earnout Liability, Fair Value Adjustment Fair value adjustment to Visa derivative Credit Card Litigation (Recovery) Expense Credit Card Litigation (Recovery) Expense Restructuring charges, net Restructuring Charges Other operating expenses Other Noninterest Expense Total non-interest expense Weighted average common shares outstanding, basic Weighted Average Number of Shares Outstanding, Basic Weighted average common shares outstanding, diluted Weighted Average Number of Shares Outstanding, Diluted Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] Global One Global One [Member] Global One [Member] Goodwill Number of reporting units Number of Reporting Units Intangible assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill Weighted average amortization period Accumulated amortization Amortization of Intangible Assets Aggregate estimated amortization expense in 2018 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months Aggregate estimated amortization expense in 2019 Finite-Lived Intangible Assets, Amortization Expense, Year Two Aggregate estimated amortization expense in 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Three Aggregate estimated amortization expense in 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Four Aggregate estimated amortization expense in 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Five Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Table] Valuation and Qualifying Accounts Disclosure [Line Items] Valuation and Qualifying Accounts Disclosure [Line Items] Current Financing Receivable, Recorded Investment, Current Accruing 30-89 Days Past Due Financing Receivable Recorded Investment 30 To 89 Days Past Due Financing Receivable Recorded Investment 30 To 89 Days Past Due. Accruing 90 Days or Greater Past Due Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing Total Accruing Past Due Financing Receivable, Recorded Investment, Past Due Non-accrual Financing Receivable, Recorded Investment, Nonaccrual Status Total loans Restructuring Charges [Abstract] Schedule of Restructuring and Related Costs [Table] Schedule of Restructuring and Related Costs [Table] Restructuring Type [Axis] Restructuring Type [Axis] Type of Restructuring [Domain] Type of Restructuring [Domain] Employee Severance Employee Severance [Member] Lease Termination Charges Contract Termination [Member] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Reserve [Roll Forward] Restructuring Reserve [Roll Forward] Beginning balance Restructuring Reserve Accruals for lease terminations Restructuring Reserve, Accrual Adjustment Payments Payments for Restructuring Ending balance Loss on early extinguishment of debt Federal Domestic Tax Authority [Member] Loans And Allowance For Loan Losses Loans, Net of Unearned Income [Text Block] Schedule of Loans, Net of Unearned Income [Text Block] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Financing Receivable, Troubled Debt Restructurings [Domain] Loan Restructuring Modification [Domain] Principal Forgiveness Principal Forgiveness [Member] Below Market Interest Rate Below Market Interest Rate [Member] Below Market Interest Rate [Member] Term Extensions and/or Other Concessions Term Extensions and or Other Concessions [Member] Term Extensions and/or Other Concessions [Member] Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of Contracts Financing Receivable, Modifications, by Concession Type, Number of Contracts Financing Receivable, Modifications, by Concession Type, Number of Contracts Post-modification balance for loans modified or renewed Financing Receivable, Modifications, Post-Modification Recorded Investment, by Concession Type Financing Receivable, Modifications, Post-Modification Recorded Investment, by Concession Type Write-down Financing Receivables, Impaired, Troubled Debt Restructuring, Write-down Restricted Share Units Restricted Stock Units (RSUs) [Member] 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 Statement [Table] Statement [Table] Preferred Stock Preferred Stock [Member] Common Stock Common Stock [Member] Additional Paid-in Capital Additional Paid-in Capital [Member] Treasury Stock Treasury Stock [Member] Accumulated Other Comprehensive Income (Loss) 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] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Net income Cash dividends declared on common stock Dividends, Common Stock, Cash Cash dividends paid on Series C Preferred Stock Dividends, Preferred Stock, Cash Repurchases of common stock Stock Repurchased During Period, Value Issuance of common stock Stock Issued During Period, Value, Acquisitions Restricted share unit activity 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 Share-based compensation tax benefit (deficiency) Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Share-based compensation expense Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Balance Schedule of Interest Bearing Deposits Schedule of Interest Bearing Deposits [Table Text Block] Schedule of Interest Bearing Deposits [Table Text Block] Schedule of Cash Maturities of Time Deposits Schedule of Cash Maturities of Time Deposits [Table Text Block] Schedule of Cash Maturities of Time Deposits [Table Text Block] Schedule of Long-term Debt Instruments Schedule of Long-term Debt Instruments [Table Text Block] Schedule of Principal Payments on Long-term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Components of Short-term Borrowings Schedule of Short-term Debt [Table Text Block] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Interest expense Loss on early extinguishment of debt, net Salaries and other personnel expense Income tax (expense) benefit Available-for-sale securities, transfers, gains Available-for-sale Securities, Transfers to Trading, Gains (Losses) Investment securities available for sale transferred to trading account assets at fair value Investment securities available for sale transferred to trading account assets at fair value Investment securities available for sale transferred to trading account assets at fair value Severance charges Severance Costs Asset impairment charges Asset Impairment Charges Gain on sale of assets held for sale, net Gain (Loss) on Disposition of Other Assets Other charges Other Restructuring Costs Total restructuring charges Plan Name [Axis] Plan Name [Axis] Plan Name [Domain] Plan Name [Domain] Shareholder approved equity compensation plans for shares of Synovus stock Shareholder Approved Equity Compensation Plans for Shares of Synovus Stock [Member] Shareholder Approved Equity Compensation Plans for Shares of Synovus Stock [Member] Number of securities to be issued upon vesting of restricted share units (in shares) Number of securities to be issued upon exercise of outstanding options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Number Weighted-average exercise price of outstanding options (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Number of shares remaining available for issuance excluding shares discussed (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Interest bearing demand deposits Interest-bearing Domestic Deposit, Demand Money market accounts, excluding brokered deposits Deposits, Money Market Deposits Savings accounts Deposits, Savings Deposits Time deposits, excluding brokered deposits Time Deposits, Excluding Brokered Deposits Time Deposits, Excluding Brokered Deposits Brokered deposits Interest-bearing Domestic Deposit, Brokered Total interest bearing deposits Interest-bearing Deposit Liabilities 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 Time deposits Time Deposits Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Schedule of Other Assets Schedule of Other Assets [Table Text Block] Supplemental Income Statement Elements [Abstract] Schedule of Income Statement, Supplemental Disclosure Schedule of Income Statement, Supplemental Disclosure [Table Text Block] Schedule of Income Statement, Supplemental Disclosure [Table Text Block] Net Deferred Tax Assets Components of Deferred Tax Assets and Liabilities [Abstract] Deferred income tax assets Components of Deferred Tax Assets [Abstract] Allowance for loan losses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Provision for Loan Losses Net operating loss carryforwards Deferred Tax Assets, Operating Loss Carryforwards Tax credit carryforwards Deferred Tax Assets, Tax Credit Carryforwards Employee benefits and deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Net unrealized losses on investment securities available for sale Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross Deferred revenue Deferred Tax Assets, Deferred Income Non-performing loan interest Deferred Tax Assets, Non-Performing Loan Interest Deferred Tax Assets, Non-Performing Loan Interest Other Deferred Tax Assets, Other Total gross deferred tax assets Deferred Tax Assets, Gross Less valuation allowance Total deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Deferred tax liabilities Components of Deferred Tax Liabilities [Abstract] Other properties held for sale Deferred Tax Liabilities, Fixed Assets Held-for-Sale Deferred Tax Liabilities, Fixed Assets Held-for-Sale Excess tax over financial statement depreciation Deferred Tax Liabilities, Depreciation Deferred Tax Liabilities, Depreciation Other Deferred Tax Liabilities, Other Total gross deferred tax liabilities Deferred Tax Liabilities, Net Net deferred tax asset Deferred Tax Assets, Net Business Combinations [Abstract] Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Line Items] Business Acquisition [Line Items] Deposits portfolio, weighted average maturity, period Deposits portfolio, weighted average maturity, period Deposits portfolio, weighted average maturity, period Weighted average rate of deposit, brokered Weighted Average Rate Domestic Deposit, Brokered Proceeds from fees Proceeds from Fees Received Consideration transferred Business Combination, Consideration Transferred Assets acquired: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Cash and due from banks Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Commercial and industrial loans Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Commercial and industrial loans Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Commercial and industrial loans Other intangible assets Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets Total assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Liabilities assumed: Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Notes payable Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Earnout liability Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Contingent Liability Deferred tax liability, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Other Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Other Total liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Consideration paid Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net Cash paid Payments to Acquire Businesses, Gross Adjustment in goodwill Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Goodwill Fair value of common stock issued Common Stock, Value, Issued Loans, unpaid principal balance Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Loans Payable, Unpaid Principal Balance Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Loans Payable, Unpaid Principal Balance Long-term debt Long-term Debt Adjustment in contingent consideration Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Contingent Consideration Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Contingent Consideration Useful life Finite-Lived Intangible Asset, Useful Life Other intangible assets Finite-Lived Intangible Assets, Net 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 [Member] Portion at Fair Value Measurement [Member] Carrying Value Reported Value Measurement [Member] Estimated Fair Value Estimate of Fair Value Measurement [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] Cash and cash equivalents 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 Trading account assets Trading Securities Mortgage loans held for sale Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage Other loans held for sale Investment securities available for sale Mutual funds held in rabbi trusts Mutual Funds Held In Rabbi Trusts Mutual funds held In Rabbi Trusts. GGL/SBA loans servicing asset Servicing Asset at Fair Value, Amount Derivative assets Financial Liabilities Financial Liabilities Fair Value Disclosure [Abstract] Trading account liabilities Trading Liabilities Non-interest bearing deposits Noninterest-bearing Deposit Liabilities Interest bearing 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 Earnout Liabilities, Fair Value Disclosure Earnout Liabilities, Fair Value Disclosure Earnout Liabilities, Fair Value Disclosure Earnout liability Other Liabilities, Fair Value Disclosure Derivative liabilities Derivative Liability, Fair Value, Gross Liability 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] Legal Proceedings Disclosure [Abstract] Legal Proceedings Disclosure [Abstract] Legal Proceedings Legal Matters and Contingencies [Text Block] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Legal Entity [Axis] Entity [Domain] 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 Capital conservation buffer period Implementation of Capital Conservation Buffer Period Implementation of Capital Conservation Buffer Period Well-capitalized status,Tier 1 capital ratio Tier One Capital to be Well Capitalized to Risk Weighted Assets Tier One Capital to be Well Capitalized to Risk Weighted Assets Significant subsidiary, assets or net income as percentage of consolidated total, threshold Significant Subsidiary, Assets or Net Income as Percentage of Consolidated Total, Threshold Significant Subsidiary, Assets or Net Income as Percentage of Consolidated Total, Threshold Common equity tier 1 capital Common equity tier 1 capital (transitional) [Abstract] Common equity tier 1 capital (transitional) [Abstract] Common equity tier 1 capital, Actual Common Equity Tier One Common Equity Tier One Common equity tier 1 capital, For Capital Adequacy Purposes Common Equity Tier One Required for Capital Adequacy Common Equity Tier One Required for Capital Adequacy Common equity tier 1 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 capital Tier One Leverage Capital [Abstract] Tier I capital, Actual Tier One Risk Based Capital Tier I capital, For Capital Adequacy Purposes Tier One Risk Based Capital Required for Capital Adequacy Tier I 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 Common equity tier 1 capital ratio Common equity tier I capital ratio (transitional) [Abstract] Common equity tier I capital ratio (transitional) [Abstract] Common equity tier I capital ratio, Actual Common Equity Tier One to Risk Weighted Assets Common Equity Tier One to Risk Weighted Assets Common equity tier I 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 Common equity tier I 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 capital ratio Capital [Abstract] Tier 1 capital ratio, Actual Tier One Risk Based Capital to Risk Weighted Assets Tier 1 capital ratio, For Capital Adequacy Purposes Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets