Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Receivables [Abstract] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Receivable Type [Axis] Receivable Type [Axis] Receivable [Domain] Receivable [Domain] Loans Receivable Loans Receivable [Member] Related Party [Axis] Related Party [Axis] Related Party [Domain] Related Party [Domain] Executive Officers and Directors Executive Officers and Directors [Member] Represents information of executive officers and directors. Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Summary of loans outstanding to executive officers and directors of the holding company Loans and Leases Receivable, Related Parties [Roll Forward] Balance at beginning of period Loans and Leases Receivable, Related Parties New loans and advances Loans and Leases Receivable, Related Parties, Additions Repayments Loans and Leases Receivable, Related Parties, Proceeds Change in related party status Loans And Leases Receivable, Related Parties, Change In Status Loans And Leases Receivable, Related Parties, Change In Status Balance at end of period Accounting Policies [Abstract] Summary of Significant Accounting Policies Basis of Presentation and Significant Accounting Policies [Text Block] Income Statement [Abstract] Interest revenue: Interest and Dividend Income, Operating [Abstract] Loans, including fees Interest and Fee Income, Loans and Leases Investment securities: Interest and Dividend Income, Securities, by Taxable Status [Abstract] Taxable Interest Income, Securities, Operating, Taxable Tax exempt Interest Income, Securities, Operating, Tax Exempt Deposits in banks and short-term investments Federal Funds Sold Commercial Paper and Deposits In Banks Represents amount of federal funds sold, commercial paper and deposits in banks. Total interest revenue Interest and Dividend Income, Operating Interest expense: Interest Expense [Abstract] Deposits: Deposits [Abstract] NOW and interest-bearing demand Interest Expense, Negotiable Order of Withdrawal (NOW) Deposits Money market Interest Expense, Money Market Deposits Savings Interest Expense, Savings Deposits Time Interest Expense, Time Deposits Total deposit interest expense Interest Expense, Deposits Short-term borrowings Interest Expense, Short-term Borrowings Federal Home Loan Bank advances Interest Expense, Federal Home Loan Bank and Federal Reserve Bank Advances, Short-term Long-term debt Interest Expense, Long-term Debt Total interest expense Interest Expense Net interest revenue Interest Income (Expense), Net Provision for (release of) credit losses Provision for Loan and Lease Losses Net interest revenue after provision for credit losses Interest Income (Expense), after Provision for Loan Loss Noninterest income: Noninterest Income [Abstract] Service charges and fees Revenue from Contract with Customer, Excluding Assessed Tax Mortgage loan and other related fees Mortgage Loan Fees And Other Fees Amount of income from mortgage loan fees and other related fees. Brokerage fees Brokerage Commissions Revenue Gains from sales of SBA/USDA loans Gain (Loss) on Sale of Loans and Leases Securities (losses) gains, net Debt Securities Available For Sale Realized Gain Loss Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) Other Noninterest Income, Other Total noninterest income Noninterest Income Total revenue Revenues Noninterest expenses: Operating Expenses [Abstract] Salaries and employee benefits Labor and Related Expense Occupancy Occupancy, Net Communications and equipment Communications and Equipment Represents amount of communications and equipment expenses. FDIC assessments and other regulatory charges Fdic Assessments and Other Regulatory Charges Represents amount of FDIC assessments and other regulatory expenses. Professional fees Professional Fees Postage, printing and supplies Supplies and Postage Expense Advertising and public relations Marketing and Advertising Expense Amortization of intangibles Amortization of Intangible Assets Merger-related and other charges Business Combination, Acquisition Related Costs Other Other Noninterest Expense Total noninterest expenses Noninterest Expense 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) Attributable to Parent Net income available to common shareholders Net Income (Loss) Available to Common Stockholders, Basic Income per common share: Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Weighted average common shares outstanding: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted (in shares) Weighted Average Number of Shares Outstanding, Diluted Schedule of computation of basic and diluted net income per common share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Investments, Debt and Equity Securities [Abstract] Carrying value of securities pledged to secure public deposits, derivatives and other secured borrowings Pledged Financial Instruments, Not Separately Reported, Securities Number of available for sale securities in unrealized loss position Debt Securities Available For Sale Unrealized Loss Position Number Of Positions Number of investments in debt securities measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position. Number of held-to-maturity securities in unrealized loss position Held-to-maturity, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions Other-than-temporary impairment charges Other than Temporary Impairment Losses, Investments Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Not designated as hedging instrument, economic hedge Not Designated as Hedging Instrument, Economic Hedge [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Interest expense Interest Expense [Member] Interest revenue Interest Income [Member] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Interest rate swaps Interest Rate Swap [Member] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Cash flow hedging Cash Flow Hedging [Member] Fair value hedging of interest rate risk Fair Value Hedging [Member] Servicing Assets and Servicing Liabilities Risk [Axis] Servicing Assets and Servicing Liabilities Risk [Axis] Risks Inherent in Servicing Assets and Servicing Liabilities, Type [Domain] Risks Inherent in Servicing Assets and Servicing Liabilities, Type [Domain] Interest rate risk Interest Rate Risk [Member] Pay Fixed Receive Variable Fair Value Hedge Pay Fixed Receive Variable Fair Value Hedge [Member] Represents information about pay fixed receive variable fair value hedge. Financial Instrument [Axis] Financial Instrument [Axis] Financial Instruments [Domain] Financial Instruments [Domain] Corporate Bonds Corporate Bond Securities [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Increase to deposit interest expense over the next twelve months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Number of derivative contracts outstanding Number of Interest Rate Derivatives Held Notional amount Derivative Asset, Notional Amount Recognized net gain (loss) related to ineffectiveness of the fair value hedging relationships Derivative, Net Hedge Ineffectiveness Gain (Loss) Fair value hedge gain (loss) recognized in earnings Gain (Loss) on Fair Value Hedges Recognized in Earnings Collateral pledged toward derivatives Collateral Already Posted, Aggregate Fair Value Regulatory Capital Requirements [Abstract] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table] Consolidated Entities [Axis] Consolidated Entities [Axis] Consolidated Entities [Domain] Consolidated Entities [Domain] United Community Bank Parent Company [Member] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items] Risk-based ratios: Risk Based Ratios [Abstract] Common equity tier 1 capital, Minimum 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 1 capital, Well Capitalized Common Equity Tier 1 Capital Required To Be Well Capitalized To Risk Weighted Assets Common Equity Tier 1 Capital Required To Be Well Capitalized To Risk Weighted Assets. Common equity tier 1 capital Common Equity Tier One Capital Ratio Tier 1 capital, Minimum Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets Tier 1 capital, Well Capitalized Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets Tier 1 capital Tier One Risk Based Capital to Risk Weighted Assets Total capital, Minimum Capital Required for Capital Adequacy to Risk Weighted Assets Total capital, Well Capitalized Capital Required to be Well Capitalized to Risk Weighted Assets Total capital Capital to Risk Weighted Assets Tier 1 Leverage ratio, Minimum Tier One Leverage Capital Required for Capital Adequacy to Average Assets Tier 1 Leverage Ratio, Well Capitalized Tier One Leverage Capital Required to be Well Capitalized to Average Assets Tier 1 Leverage ratio Tier One Leverage Capital to Average Assets Common equity tier 1 capital Common Equity Tier One Capital Tier 1 capital Tier One Risk Based Capital Total capital Capital Risk-weighted assets Risk Weighted Assets Average total assets Regulatory Assets Regulatory Matters Regulatory Capital Requirements under Banking Regulations [Text Block] Offsetting [Abstract] Right to reclaim cash collateral Derivative, Collateral, Right to Reclaim Cash Obligation to return cash collateral Derivative, Collateral, Obligation to Return Cash Property, Plant and Equipment [Abstract] Schedule of premises and equipment Property, Plant and Equipment [Table Text Block] Schedule of rent commitments under operating leases Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Transfers and Servicing [Abstract] Schedule of Servicing Assets at Fair Value [Table] Schedule of Servicing Assets at Fair Value [Table] SBA/USDA Loans Insured or Guaranteed by US Government Authorities [Member] Servicing Assets at Fair Value [Line Items] Servicing Assets at Fair Value [Line Items] Fair value of retained servicing assets Servicing Asset at Fair Value, Amount Prepayment rate assumption (percent) Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Prepayment Speed 10% adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Prepayment Speed 20% adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Adverse Change in Prepayment Speed Discount rate (percent) Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Discount Rate 100 bps adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 10 Percent Adverse Change in Discount Rate 200 bps adverse change Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets, Impact of 20 Percent Adverse Change in Discount Rate Weighted-average life (years) Servicing Assets and Servicing Liabilities at Fair Value, Assumptions Used to Estimate Fair Value, Weighted Average Life Weighted-average gross margin (percent) Servicing Assets And Servicing Liabilities At Fair Value Assumptions Used To Estimate Fair Value Weighted Average Gross Margin Represents servicing assets and servicing liabilities at fair value assumptions used to estimate fair value weighted average gross margin. Supplemental Cash Flow Elements [Abstract] Cash Flow [Table] Cash Flow [Table] Disclosure of information about cash flow. Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Common Stock Common Stock [Member] Cash Flow [Line Items] Cash Flow [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Transferred to foreclosed property Real Estate Owned, Transfer to Real Estate Owned Unsettled sales of government guaranteed loans Unsettled Sales Of Government Guaranteed Loans Represents unsettled sales of government guaranteed loans. Assets acquired, fair value Fair Value of Assets Acquired Liabilities assumed, fair value Liabilities Assumed Net assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net Common stock issued as consideration Business Combination, Consideration Transferred, Equity Interests Issued and Issuable Deposits Deposit Liabilities Disclosures [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table] Exercise Price Range [Axis] Exercise Price Range [Axis] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Domain] Exercise Price Range $15.00 to 20.00 Exercise Price Range Fifteen Point Zero One To Twenty Member [Member] Represents exercise price range from 15.01 to 20 Exercise Price Range $20.01 to 25.00 Exercise Price Range Twenty Point Zero One To Twenty Five Member [Member] Represents exercise price range from 20.01 to 25. Exercise Price Range $25.01 to 30.00 Exercise Price Range Twenty Five Point Zero One To Thirty Member [Member] Represents exercise price range from 25.01 to 30.00 Exercise Price Range $30.01 to 31.50 Exercise Price Range Thirty Point Zero One To Thirty One Point Fifty Member [Member] Represents information about Exercise Price Range 30.01 to 31.50. Exercise Price Range $15.00 to 31.50 Exercise Price Range Fifteen To Thirty One Point Fifty [Member] [Member] Exercise Price Range Fifteen To Thirty One Point Fifty [Member] [Member] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] Options Outstanding, Shares Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Outstanding Options Options Outstanding, Range Minimum Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Lower Range Limit Options Outstanding, Range Maximum Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Upper Range Limit Options Outstanding, Weighted Average Price Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Exercise Price Options Outstanding, Average Remaining Life Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Outstanding Options, Weighted Average Remaining Contractual Term Options Exercisable, Shares Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Number of Exercisable Options Options Exercisable, Weighted Average Price Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range, Exercisable Options, Weighted Average Exercise Price Advances from Federal Home Loan Banks [Abstract] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Schedule of Federal Home Loan Bank Advances, by Branch of FHLB Bank [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] Federal Home Loan Bank, Advances, Branch of FHLB Bank [Line Items] 2019 Federal Home Loan Bank, Advances, Maturities Summary, Due in Next Twelve Months Total Advances from Federal Home Loan Banks Current Rate 2019 Federal Home Loan Bank, Advances, Interest Rate Subsequent Events [Abstract] Subsequent Event [Table] Subsequent Event [Table] Legal Entity [Axis] Legal Entity [Axis] Entity [Domain] Entity [Domain] First Madison Bank & Trust First Madison Bank And Trust [Member] First Madison Bank And Trust [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Subsequent Event Subsequent Event [Member] Subsequent Event [Line Items] Subsequent Event [Line Items] Total assets Assets Loans Loans Receivable, Net Deposit Deposits Number of banking offices Number Of Branches Represents number of branches operated by entity. Merger consideration expected to be received upon closing per definitive merger agreement Definitive Merger Agreement, Merger Consideration To Be Received Upon Closing Definitive Merger Agreement, Merger Consideration To Be Received Upon Closing Common stock dividends (in dollars per share) Common Stock, Dividends, Per Share, Declared Dividends, date declared Dividends Payable, Date Declared Dividends, date of record Dividends Payable, Date of Record Dividends, date payable Dividends Payable, Date to be Paid Shares repurchased (in shares) Stock Repurchased During Period, Shares Repurchase of common stock Payments for Repurchase of Common Stock Debt Disclosure [Abstract] Long-term Debt Long-term Debt [Text Block] Retirement Benefits [Abstract] Pension and Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Condensed Financial Information of Parent Company Only Disclosure [Abstract] Condensed Income Statement [Table] Condensed Income Statement [Table] Parent Condensed Income Statements, Captions [Line Items] Condensed Income Statements, Captions [Line Items] Statement of Operations Dividends from bank Dividends From Bank Represents amount related to Dividends from bank. Dividends from other subsidiaries Cash Dividends Paid to Parent Company by Consolidated Subsidiaries Shared service fees from subsidiaries Shared Service Fees From Subsidiaries Shared Service Fees From Subsidiaries Total income Interest expense Other expense Total expenses Tax benefit (expense) Income before equity in undistributed (loss) earnings of subsidiaries Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest Equity in undistributed (loss) earnings of subsidiaries Income (Loss) from Subsidiaries, Net of Tax Schedule of statement of operations Condensed Income Statement [Table Text Block] Schedule of balance sheet Condensed Balance Sheet [Table Text Block] Schedule of statement of cash flows Condensed Cash Flow Statement [Table Text Block] Servicing Rights Transfers and Servicing of Financial Assets [Text Block] Repurchase agreements / reverse repurchase agreements, gross amounts of recognized assets Securities Purchased under Agreements to Resell, Gross Repurchase agreements / reverse repurchase agreements, gross amounts offset on balance sheet Securities Purchased under Agreements to Resell, Liability Repurchase agreements / reverse repurchase agreements, net asset balance Securities Purchased under Agreements to Resell Repurchase agreements / reverse repurchase agreements, gross amounts not offset in balance sheet - financial instruments Repurchase And Reverse Repurchase Agreements Gross Amounts Not Off Set In Balance Sheet Assets Of Financial Instruments This element represents amount of gross amounts not offset in the balance sheet assets related to repurchase and reverse repurchase agreements of financial instruments. Repurchase agreements/ reverse repurchase agreements, gross amounts not offset in balance sheet - collateral received Repurchase And Reverse Repurchase Agreements Gross Amounts Not Off Set In Balance Sheet Assets Of Collateral Received This element represents amount of gross amounts not offset in the balance sheet assets related to repurchase and reverse repurchase agreements of collateral received. Repurchase agreements / reverse repurchase agreements, net amount Repurchase And Reverse Repurchase Agreements Net Assets This element represents amount of net assets related to repurchase and reverse repurchase agreements. Derivative, gross amounts of recognized assets Derivative Asset, Fair Value, Gross Asset Derivative, gross amounts offset on balance sheet Derivative Asset, Fair Value, Amount Offset Against Collateral Derivatives, net asset balance Derivative Asset, Fair Value, Amount Not Offset Against Collateral Derivatives, gross amounts not offset in balance sheet - financial instruments Derivative Asset, Not Offset, Policy Election Deduction Derivatives, gross amounts not offset in balance sheet - collateral received Derivative Asset, Fair Value of Collateral Derivatives asset, net amount Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Offsetting assets, gross amounts of recognized assets Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Gross Offsetting assets, gross amounts offset on balance sheet Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Liability Offsetting assets, net asset balance Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed Offsetting assets, gross amounts not offset in balance sheet - financial instruments Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Not Offset, Policy Election Deduction Offsetting assets, gross amounts not offset in the balance sheet - collateral received Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Amount Offset Against Collateral Offsetting assets, net amount Derivative Asset, Securities Purchased under Agreements to Resell, Securities Borrowed, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Weighted average interest rate of reverse repurchase agreements, assets (percent) Weighted Average Interest Rate Of Reverse Repurchase Agreements Assets This element represents percentage of weighted average interest rate of reverse repurchase agreements related to assets. Repurchase agreements / reverse repurchase agreements, gross amounts of recognized liabilities Securities Sold under Agreements to Repurchase, Gross Repurchase agreements / reverse repurchase agreements, gross amounts offset on balance sheet Securities Sold under Agreements to Repurchase, Asset Repurchase agreements / reverse repurchase agreements, net liability balance Securities Sold under Agreements to Repurchase Repurchase agreements / reverse repurchase agreements, gross amounts not offset in balance sheet - financial instruments Repurchase And Reverse Repurchase Agreements Gross Amounts Not Off Set In Balance Sheet Liabilities Of Financial Instruments This element represents amount of gross amounts not offset in the balance sheet liabilities related to repurchase and reverse repurchase agreements of financial instruments. Repurchase agreements / reverse repurchase agreements, gross amounts not offset in balance sheet - collateral pledged Repurchase And Reverse Repurchase Agreements Gross Amounts Not Off Set In Balance Sheet Liabilities Of Collateral Pledged This element represents amount of gross amounts not offset in the balance sheet liabilities related to repurchase and reverse repurchase agreements of collateral pledged. Repurchase agreements / reverse repurchase agreements, net amount Repurchase And Reverse Repurchase Agreements Net Liabilities This element represents amount of net liabilities related to repurchase and reverse repurchase agreements. Derivatives, gross amounts of recognized liabilities Derivative Liability, Fair Value, Gross Liability Derivatives, gross amounts offset on balance sheet Derivative Liability, Fair Value, Amount Offset Against Collateral Derivatives, net liability balance Derivative Liability, Fair Value, Amount Not Offset Against Collateral Derivatives, gross amounts not offset in balance sheet - financial instruments Derivative Liability, Not Offset, Policy Election Deduction Derivatives, gross amounts not offset in balance sheet - collateral pledged Derivative Liability, Fair Value of Collateral Derivatives, net amount Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Offsetting liabilities, gross amounts of recognized liabilities Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Gross Offsetting liabilities, gross amounts offset on balance sheet Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Asset Offsetting liabilities, net liability balance Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned Offsetting liabilities gross, amounts not offset in balance sheet - financial instruments Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Not Offset, Policy Election Deduction Offsetting liabilities gross amounts not offset in the balance sheet - collateral pledged Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Amount Offset Against Collateral Offsetting liabilities, net amount Derivative Liability, Securities Sold under Agreements to Repurchase, Securities Loaned, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election Weighted average interest rate of reverse repurchase agreements, liabilities (percent) Weighted Average Interest Rate Of Reverse Repurchase Agreements Liabilities This element represents percentage of weighted average interest rate of reverse repurchase agreements related to liabilities. Schedule of derivative financial instruments on consolidated balance sheet Schedule of Interest Rate Derivatives [Table Text Block] Schedule of effect of cash flow hedging on consolidated statements of income Schedule of Cash Flow Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of effect of fair value hedging on consolidated statements of income Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of gains and losses recognized in income on derivatives not designated as hedging instruments Schedule of Other Derivatives Not Designated as Hedging Instruments, Statements of Financial Performance and Financial Position, Location [Table Text Block] Schedule of Financing Receivables Past Due [Table] Schedule of Financing Receivables Past Due [Table] Industry Sector [Axis] Industry Sector [Axis] Industry Sector [Domain] Industry Sector [Domain] Commercial & industrial Commercial and Industrial Sector [Member] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Axis] Financing Receivable Portfolio Segment [Domain] Financing Receivable Portfolio Segment [Domain] Commercial Commercial Portfolio Segment [Member] Residential Residential Portfolio Segment [Member] Consumer direct Consumer Portfolio Segment [Member] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Axis] Class of Financing Receivable, Type [Domain] Class of Financing Receivable, Type [Domain] Owner occupied commercial real estate Owner Occupied Commercial Real Estate [Member] Represents information of owner occupied commercial real estate. Income producing commercial real estate Income Producing Commercial Real Estate [Member] Property that represents income producing commercial real estate. Construction Construction Loans [Member] Equipment financing Equipment Financing [Member] Represents information related to equipment financing. Residential mortgage Residential Mortgage [Member] Home equity lines of credit Home Equity Line of Credit [Member] Indirect auto Automobile Loan [Member] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Axis] Financing Receivables, Period Past Due [Domain] Financing Receivables, Period Past Due [Domain] Loans Past Due, 30 - 59 Days Financing Receivables, 30 to 59 Days Past Due [Member] Loans Past Due, 60 - 89 Days Financing Receivables, 60 to 89 Days Past Due [Member] Loans Past Due, > 90 Days Financing Receivables, Equal to Greater than 90 Days Past Due [Member] Financing Receivable, Recorded Investment, Past Due [Line Items] Financing Receivable, Recorded Investment, Past Due [Line Items] Recorded investment in nonaccrual loans by loan class Financing Receivable, Recorded Investment, Aging [Abstract] Loans Past Due Financing Receivable, Recorded Investment, Past Due Loans Not Past Due Financing Receivable, Recorded Investment, Current PCI Loans Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net Loans Outstanding, Ending Balance Loans and Leases Receivable, Net of Deferred Income Income Tax Disclosure [Abstract] Income Taxes Income Tax Disclosure [Text Block] Schedule Of Servicing Asset [Table] Schedule Of Servicing Asset [Table] Represents the tabular information of servicing asset. Residential mortgage servicing rights Schedule Of Servicing Asset [Line Items] Schedule Of Servicing Asset [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Servicing of asset for others, amount not included in balance sheet Continuing Involvement with Derecognized Transferred Financial Assets, Amount Outstanding Contractually specified servicing fees earned by United on servicing rights Contractually Specified Servicing Fee, Late Fee, and Ancillary Fee Earned in Exchange for Servicing Financial Asset Equity [Abstract] Common and Preferred Stock Stockholders' Equity Note Disclosure [Text Block] Commitments and Contingencies Disclosure [Abstract] Schedule of Fair Value, Off-balance Sheet Risks [Table] Schedule of Fair Value, Off-balance Sheet Risks [Table] Commitments to extend credit Commitments to Extend Credit [Member] Letters of credit Letter of Credit [Member] Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items] Financial instruments Unused Commitments to Extend Credit Minimum Lease Payments Operating Leases, Future Minimum Payments Due 2019 Time Deposit Maturities, Next Twelve Months 2020 Time Deposit Maturities, Year Two 2021 Time Deposit Maturities, Year Three 2022 Time Deposit Maturities, Year Four 2023 Time Deposit Maturities, Year Five thereafter Time Deposit Maturities, after Year Five Total Contractual Maturities Of Time Deposits Including Brokered Time Deposits Represents contractual maturities of time deposits including brokered time deposits. Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets [Table] Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets [Table] Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items] Valuation Allowance for Impairment of Recognized Servicing Assets [Line Items] Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Valuation Allowance for Impairment of Recognized Servicing Assets [Roll Forward] Valuation allowance, beginning of period Valuation Allowance for Impairment of Recognized Servicing Assets, Balance Additions charged to operations, net Valuation Allowance for Impairment of Recognized Servicing Assets, Period Increase (Decrease) Valuation allowance, end of period Condensed Cash Flow Statement [Table] Condensed Cash Flow Statement [Table] Condensed Cash Flow Statements, Captions [Line Items] Condensed Cash Flow Statements, Captions [Line Items] Statement of Cash Flows Statement of Cash Flows [Abstract] Operating activities: Net Cash Provided by (Used in) Operating Activities [Abstract] Net income Adjustments to reconcile net income to net cash provided by operating activities: Adjustments, Noncash Items, to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Equity in undistributed earnings (loss) of the subsidiaries Depreciation, amortization and accretion Depreciation, Amortization and Accretion, Net Stock based compensation Share-based Compensation Changes in assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Other assets Increase (Decrease) in Other Operating Assets Other liabilities Increase (Decrease) in Other Operating Liabilities Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Investing activities: Net Cash Provided by (Used in) Investing Activities [Abstract] Payment for acquisition Payments to Acquire Businesses, Gross Purchases of premises and equipment Payments to Acquire Property, Plant, and Equipment Purchase of available for sale securities Payments to Acquire Available-for-sale Securities, Debt Net cash used in investing activities Net Cash Provided by (Used in) Investing Activities Financing activities: Net Cash Provided by (Used in) Financing Activities [Abstract] Repayment of long-term debt Repayments of Long-term Debt Proceeds from issuance of long-term debt Proceeds from Issuance of Long-term Debt Cash paid for shares withheld to cover payroll taxes upon vesting of restricted stock Payments Related to Tax Withholding for Share-based Compensation Proceeds from issuance of common stock for dividend reinvestment and employee benefit plans Proceeds From Issuance Of Common Stock For Dividend Reinvestment and Employee Benefit Plans Represents amount of cash inflow from the amount received from the stock plan and capital contributions to an entity associated with a dividend reinvestment plan during the period. Proceeds from exercise of stock options Proceeds from Stock Options Exercised Retirement of preferred stock Payments for Repurchase of Preferred Stock and Preference Stock Repurchase of common stock Cash dividends on common stock Payments of Ordinary Dividends, Common Stock Cash dividends on Series H preferred stock Cash Dividends On Series H Preferred Stock This element represents amount of cash dividends on series H preferred stock. Net cash (used in) provided by financing activities Net Cash Provided by (Used in) Financing Activities Net change in cash Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents at beginning of year Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents at end of year Schedule of details regarding amounts reclassified out of accumulated other comprehensive income Reclassification out of Accumulated Other Comprehensive Income [Table Text Block] Nonaccrual Loans Financing Receivable, Recorded Investment, Nonaccrual Status Depreciation expense Depreciation, Nonproduction Rent expense Operating Leases, Rent Expense, Minimum Rentals Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Other Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Federal Home Loan Bank Advances Federal Home Loan Bank Advances, Disclosure [Text Block] Schedule of changes in the balances of servicing assets and servicing liabilities Schedule of Servicing Assets at Fair Value [Table Text Block] Schedule of key characteristics, inputs, and economic assumptions used to estimate the fair value of SBA Servicing Asset Schedule of Fair Value Assumption, Date of Securitization or Asset-backed Financing Arrangement, Transferor's Continuing Involvement, Servicing Assets or Liabilities [Table Text Block] Schedule of changes in residential mortgage servicing rights Servicing Asset at Amortized Cost [Table Text Block] Schedule of valuation allowance for impairment of the residential mortgage servicing rights portfolio Schedule of Valuation Allowance for Impairment of Recognized Servicing Assets [Table Text Block] Schedule of characteristics, inputs, and economic assumptions used to estimatefair value of servicing asset for residential mortgage loans sensitivity of adverse changes Schedule of Sensitivity Analysis of Fair Value, Transferor's Interests in Transferred Financial Assets [Table Text Block] Organization and Basis of Presentation Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Operating Segments Segment Reporting, Policy [Policy Text Block] Cash and Cash Equivalents Cash and Cash Equivalents, Policy [Policy Text Block] Investment Securities Marketable Securities, Policy [Policy Text Block] Loans Held for Sale Finance, Loan and Lease Receivables, Held-for-sale, Policy [Policy Text Block] Loans and Leases Finance, Loans and Leases Receivable, Policy [Policy Text Block] Allowance for Credit Losses Loans and Leases Receivable, Allowance for Loan Losses Policy [Policy Text Block] Premises and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Foreclosed Properties (Other Real Estate Owned, or OREO) Finance, Loan and Lease Receivables, Held for Investments, Foreclosed Assets Policy [Policy Text Block] Goodwill and Other Intangible Assets Goodwill and Intangible Assets, Policy [Policy Text Block] Transfers of Financial Assets Transfers and Servicing of Financial Assets, Transfers of Financial Assets, Sales, Policy [Policy Text Block] Servicing Rights Transfers and Servicing of Financial Assets, Policy [Policy Text Block] Bank Owned Life Insurance Bank Owned Life Insurance [Policy Text Block] Disclosure of accounting policy for information of Bank owned life insurance. Loan Commitments and Related Financial Instruments Loan Commitments, Policy [Policy Text Block] Revenue from Contracts with Customers Revenue From Contract With Customer [Policy Text Block] Disclosure of accounting policy for revenue from contract with customer. Income Taxes Income Tax, Policy [Policy Text Block] Derivative Instruments and Hedging Activities Derivatives, Policy [Policy Text Block] Acquisition Activities Business Combinations Policy [Policy Text Block] Earnings Per Common Share Earnings Per Share, Policy [Policy Text Block] Loss Contingencies Commitments and Contingencies, Policy [Policy Text Block] Dividend Restrictions Dividend Restrictions [Policy Text Block] Represents disclosure of accounting policy for dividend restrictions. Fair Value of Financial Instruments Fair Value of Financial Instruments, Policy [Policy Text Block] Stock-Based Compensation Compensation Related Costs, Policy [Policy Text Block] Reclassifications Reclassification, Policy [Policy Text Block] Accounting Standards Updates New Accounting Pronouncements, Policy [Policy Text Block] Fair Value Disclosures [Abstract] Cumulative effect adjustment to retained earnings, net of income tax effect Cumulative Effect on Retained Earnings, Net of Tax Mortgage loans held for sale Mortgages Held-for-sale, Fair Value Disclosure Mortgage loans held for sale, outstanding principal balance Mortgage Loans Held For Sale Outstanding Principal Balance Represents mortgage loans held for sale quantified by principal amount, the principle balance held at close of period. Net gains (losses) from changes in fair value of loans Fair Value, Option, Changes in Fair Value, Gain (Loss) Percentage of written down in appraisal value of nonaccrual impaired loans Percentage Of Written Down In Appraisal Value Of Nonaccrual Impaired Loans Percentage of written down in appraisal value of nonaccrual impaired loans. Maximum remaining maturity of financial instruments having no defined maturity Maximum Remaining Maturity Of Financial Instruments Having No Defined Maturity Maximum remaining maturity of financial instruments having no defined maturity. Assets and Liabilities Measured at Fair Value Fair Value Disclosures [Text Block] Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Retirement Plan Name [Axis] Retirement Plan Name [Axis] Retirement Plan Name [Domain] Retirement Plan Name [Domain] Modified Retirement Plan Modified Retirement Plan [Member] Represents information about Modified Retirement Plan. Funded Plan United-Palmetto Funded Plan [Member] United-Palmetto Funded Plan [Member] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Axis] Retirement Plan Funding Status [Domain] Retirement Plan Funding Status [Domain] Unfunded Plan Unfunded Plan [Member] Funded Plan Funded Plan [Member] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Amortization of prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Amortization of net losses Defined Benefit Plan, Amortization of Gain (Loss) Net periodic benefit cost Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 2019 Operating Leases, Future Minimum Payments Receivable, Current 2020 Operating Leases, Future Minimum Payments Receivable, in Two Years 2021 Operating Leases, Future Minimum Payments Receivable, in Three Years 2022 Operating Leases, Future Minimum Payments Receivable, in Four Years 2023 Operating Leases, Future Minimum Payments Receivable, in Five Years Thereafter Operating Leases, Future Minimum Payments Receivable, Thereafter Total Operating Leases, Future Minimum Payments Receivable Investment Type [Axis] Investment Type [Axis] Investments [Domain] Investments [Domain] FHLB Federal Home Loan Bank Certificates and Obligations (FHLB) [Member] Overdrawn deposit accounts Bank Overdrafts Pledged as collateral to secure FHLB advances Loans Pledged as Collateral Carrying value of PCI loans Outstanding balance of PCI loans Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance Remaining accretable fair value mark on loans Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums Loan purchased Financing Receivable, Significant Purchases Criteria amount for evaluation of impairment Minimum Amount Of Loan Evaluated For Impairment This element represents minimum amount of loan evaluated for impairment. Gross additional interest income that would have been earned if the nonaccrual loans had performed as per original term Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans Specific reserves Specific Reserves Allocated To Customers Whose Loan Terms Modified In Troubled Debt Restructurings This element represents specific reserves allocated to customers whose loan terms modified in troubled debt restructurings. Loans outstanding classified as troubled debt restructurings Loans and Leases Receivable, Impaired, Commitment to Lend Differences between the provision for income taxes and statutory federal income tax rate Effective Income Tax Rate Reconciliation, Amount [Abstract] Pretax income at statutory rates Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Add (deduct): Add Deduct [Abstract] State taxes, net of federal benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Bank owned life insurance earnings Income Tax Reconciliation, Bank Owned Life Insurance Earnings Income Tax Reconciliation, Bank Owned Life Insurance Earnings Adjustment to reserve for uncertain tax positions Income Tax Reconciliation Change in Reserves for Uncertain Tax Positions This element represents amount of income tax reconciliation change in reserves for uncertain tax positions. Tax-exempt interest revenue Effective Income Tax Rate Reconciliation, Tax Exempt Income, Amount Equity compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Compensation Cost, Amount Transaction costs Income Tax Reconciliation Tax Transaction Costs Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to transaction costs. Tax credit investments Effective Income Tax Rate Reconciliation, Tax Credit, Amount Change in state statutory tax rate Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount Increase in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Release of disproportionate tax effects related to de-designated cash flow hedges Release Of Disproportionate Tax Effects Related To De-Designated Cash Flow Hedges Represents information about Release of disproportionate tax effects related to de-designated cash flow hedges Expense due to enactment of federal tax reform Effective Income Tax Rate Reconciliation, Tax Cuts And Jobs Act Of 2017, Amount Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operations, attributable to Tax Cuts and Jobs Act. Other Effective Income Tax Rate Reconciliation, Other Reconciling Items, Amount Total income tax expense Servicing Asset at Amortized Cost [Table] Servicing Asset at Amortized Cost [Table] Servicing Asset at Fair Value, Amount [Roll Forward] Servicing Asset at Fair Value, Amount [Roll Forward] Servicing rights for SBA/USDA loans, beginning of period Additions: Servicing Asset At Fair Value Additions [Abstract] Originated servicing rights capitalized upon sale of loans Servicing Asset At Fair Value Origination Of Servicing Asset Capitalized Upon Sale Amount of additions from origination of servicing assets capitalized upon sale. Subtractions: Servicing Asset At Fair Value Subtractions [Abstract] Disposals Servicing Asset at Fair Value, Disposals Changes in fair value: Changes In Fair Value [Abstract] Initial election to carry at fair value on January 1, 2017 Servicing Asset at Fair Value, Additions Due to change in inputs or assumptions used in the valuation Asset at Fair Value, Changes in Fair Value Resulting from Changes in Assumptions Servicing rights for SBA/USDA loans, end of period Servicing Asset at Amortized Cost, Balance [Roll Forward] Servicing Asset at Amortized Cost, Balance [Roll Forward] Residential mortgage servicing rights, beginning of period Servicing Asset at Amortized Cost Additions: Servicing Asset At Amortized Cost, Additions [Abstract] Originated servicing rights capitalized upon sale of loans Servicing Asset At Amortized Cost, Origination Of Servicing Asset Capitalized Upon Sale Amount of additions from origination of servicing assets capitalized upon sale. Subtractions: Servicing Asset At Amortized Cost, Subtractions [Abstract] Disposals Servicing Asset at Amortized Cost, Disposals Amortization Servicing Asset at Amortized Cost, Amortization Impairment Servicing Asset at Amortized Cost, Increase (Decrease) for Valuation Allowance Adjustment Residential mortgage servicing rights, beginning of period Cash Flows Cash Flow, Supplemental Disclosures [Text Block] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Schedule of Financing Receivable, Allowance for Credit Losses [Table] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves Type [Axis] Valuation Allowances and Reserves [Domain] Valuation Allowances and Reserves [Domain] Allowance for unfunded commitments Allowance For Unfunded Loan Commitment [Member] Represents information about allowance for unfunded loan commitment. Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Line Items] Financing Receivable, Allowance for Credit Losses [Roll Forward] Financing Receivable, Allowance for Credit Losses [Roll Forward] Beginning Balance Financing Receivable, Allowance for Credit Losses Charge-Offs Financing Receivable, Allowance for Credit Losses, Write-downs Recoveries Financing Receivable, Allowance for Credit Losses, Recovery Provision Ending Balance Schedule of major classifications of loans and lease portfolio Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Schedule of changes in the value of the accretable yield for PCI loans Schedule Of Changes In Value Of Accretable Yield For Acquired Loans [Table Text Block] Tabular disclosure of changes in value of accretable yield for acquired loans. Schedule of components of net investment in leases Schedule of Components of Leveraged Lease Investments [Table Text Block] Schedule of minimum future lease payments expected to be received from lease contracts Schedule of Financing Receivables, Minimum Payments [Table Text Block] Schedule of loans outstanding to executive officers and directors Schedule of Loans and Leases Receivable Related Parties [Table Text Block] This element represents tabular disclosure of loans and leases receivable related parties. Schedule of balance and activity in allowance for credit losses and recorded investment by portfolio segment Schedule of Credit Losses Related to Financing Receivables, Current and Noncurrent [Table Text Block] Schedule of loans individually evaluated for impairment by class of loans Impaired Financing Receivables [Table Text Block] Schedule of loans modified under the terms of a TDR Troubled Debt Restructurings on Financing Receivables [Table Text Block] Schedule of average balances of impaired loans and income recognized on impaired loans Average Balances Of Impaired Loans and Income Recognized On Impaired Loans [Table Text Block] Average balances of impaired loans and income recognized on impaired loans. Schedule of recorded investment in nonaccrual loans held for investment by loan class Schedule of Financing Receivables, Non Accrual Status [Table Text Block] Schedule of aging of the recorded investment in past due loans Past Due Financing Receivables [Table Text Block] Schedule of risk category of loans by class of loans Financing Receivable Credit Quality Indicators [Table Text Block] Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statement [Table] Condensed Balance Sheet Statements, Captions [Line Items] Condensed Balance Sheet Statements, Captions [Line Items] Balance Sheet Statement of Financial Position [Abstract] Assets Assets [Abstract] Cash Cash, Cash Equivalents, and Federal Funds Sold Investment in bank Investments In Bank Represents amount related to Investments In Bank. Investment in other subsidiaries Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures Other assets Other Assets Total assets Liabilities and Shareholders’ Equity Liabilities and Equity [Abstract] Long-term debt Long-term Debt Other liabilities Other Liabilities Total liabilities Liabilities Shareholders' equity Stockholders' Equity Attributable to Parent Total liabilities and shareholders’ equity Liabilities and Equity Equity Compensation and Related Plans Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Fair Value Inputs, Assets, Quantitative Information [Table] Fair Value Inputs, Assets, Quantitative Information [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 3 Fair Value, Inputs, Level 3 [Member] Liability Class [Axis] Liability Class [Axis] Fair Value by Liability Class [Domain] Fair Value by Liability Class [Domain] Derivative liabilities - risk participations Derivative Liabilities Risk Participations [Member] Represents derivative liabilities risk participations. Derivative liabilities - other Derivative Liability [Member] Represents Derivative Liability. Asset Class [Axis] Asset Class [Axis] Asset Class [Domain] Asset Class [Domain] Servicing rights for SBA/USDA loans SBA Servicing Rights [Member] Represents SBA servicing rights. Residential mortgage servicing rights Residential Mortgage Servicing Rights [Member] Residential Mortgage Servicing Rights [Member] Corporate bonds Corporate Debt Securities [Member] Derivative assets - mortgage Derivative Asset [Member] Represents Derivative Asset. Derivative assets - other Derivative Assets Other [Member] Represents information about Derivative assets other. Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Axis] Measurement Input Type [Domain] Measurement Input Type [Domain] [Domain] for Measurement Input Type [Axis] Discount Rate Measurement Input, Discount Rate [Member] Measurement Input, Discount Rate [Member] Prepayment Rate Measurement Input, Prepayment Rate [Member] Measurement Input, Prepayment Rate [Member] Pull Through Rate Measurement Input, Pull Through Rate [Member] Measurement Input, Pull Through Rate [Member] Probable Exposure Rate Measurement Input, Probable Exposure Rate [Member] Measurement Input, Probable Exposure Rate [Member] Probability of Default Rate Measurement Input, Default Rate [Member] Measurement Input, Default Rate [Member] Weighted Average Weighted Average [Member] Fair Value Inputs, Assets, Quantitative Information [Line Items] Fair Value Inputs, Assets, Quantitative Information [Line Items] Servicing rights for SBA/USDA loans Servicing rights for SBA/USDA loans, measurement input Servicing Asset Measurement Input Servicing Asset Measurement Input Residential mortgage servicing rights Residential Mortgage Servicing Asset at Fair Value, Amount Residential Mortgage Servicing Asset at Fair Value, Amount Residential mortgage servicing rights, measurement input Residential Mortgage Servicing Asset Measurement Input Residential Mortgage Servicing Asset, Measurement Input Debt securities available-for-sale Available-for-sale Securities, Debt Securities Derivative assets Derivative Asset Derivative assets, measurement input Derivative Asset, Measurement Input Derivative Asset, Measurement Input Derivative liabilities Derivative Liability Derivative liabilities, measurement input Derivative Liability, Measurement Input Derivative Liability, Measurement Input Valuation technique Fair Value Measurements, Valuation Processes, Description Tax Credit Carryforward [Table] Tax Credit Carryforward [Table] Tax Credit Carryforward [Axis] Tax Credit Carryforward [Axis] Tax Credit Carryforward, Name [Domain] Tax Credit Carryforward, Name [Domain] Begin to expire in 2019 Net Operating Loss Carry Forwards Begin To Expire In Two Zero One Nine [Member] Net Operating Loss Carry Forwards Begin To Expire In Two Zero One Nine [Member] Begin to expire in 2021 Net Operating Loss Carry Forwards Begin To Expire In Two Zero Two One [Member] Net Operating Loss Carry Forwards Begin To Expire In Two Zero Two One [Member] Begin to expire in 2030 Net Operating Loss Carry Forwards Begin To Expire In Two Zero Three Zero [Member] Represents information of net operating loss carryforwards begin to expire in 2030. Begin to expire in 2027 Net Operating Loss Carry Forwards Begin To Expire In Two Zero Two Seven [Member] Represents information of net operating loss carryforwards begin to expire in 2027. Income Tax Authority [Axis] Income Tax Authority [Axis] Income Tax Authority [Domain] Income Tax Authority [Domain] Federal Domestic Tax Authority [Member] State State and Local Jurisdiction [Member] Tax Credit Carryforward [Line Items] Tax Credit Carryforward [Line Items] Provisional income tax expense for impact of remeasurement of deferred tax asset Tax Cuts And Jobs Act, Incomplete Accounting, Change In Tax Rate, Deferred Tax Asset, Provisional Income Tax Expense Amount of reasonable estimate for income tax expense for which accounting for tax effect for remeasurement of deferred tax asset from change in tax rate is incomplete pursuant to Tax Cuts and Jobs Act. Increase in deferred tax asset due to merger and acquisition Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets Net operating loss carryforwards Operating Loss Carryforwards Federal alternative minimum tax credits Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax State tax credits Tax Credit Carryforward, Amount Valuation allowance Deferred Tax Assets, Valuation Allowance Net deferred tax asset Deferred Tax Assets, Net Tax benefit related to uncertain tax positions that increases income from continuing operations Unrecognized Tax Benefits that Would Impact Effective Tax Rate Penalties and interest related to income taxes Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense Accrued penalties and interest Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Schedule of assets and liabilities measured at fair value on a recurring basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Schedule of assets measured at fair value on a recurring basis using significant unobservable inputs Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block] Schedule of quantitative information about Level 3 fair value measurements for fair value on a recurring basis Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Table Text Block] Schedule of presentation of United's assets and liabilities measured at fair value on nonrecurring basis Fair Value Measurements, Nonrecurring [Table Text Block] Schedule of summary of carrying amount and fair values for other financial instruments not measured at fair value on a recurring basis Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of income tax expense Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Schedule of differences between the provision for income taxes and statutory federal income tax rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Schedule of summarizes the sources and expected tax consequences of future taxable deductions (revenue) Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Schedule of reconciliation of the beginning and ending unrecognized tax benefit related to uncertain tax positions Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block] Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Senior debentures Senior Notes [Member] Subordinated debentures Subordinated Debt [Member] Debt Instrument [Axis] Debt Instrument [Axis] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] 2022 senior debentures Two Thousand Twenty Two Senior Debentures [Member] Represents information of 2022 senior debentures. 2027 senior debentures Two Thousand Twenty Seven Senior Debentures [Member] Represents information of 2027 senior debentures. 2025 subordinated debentures Two Thousand Twenty Five Subordinated Debentures [Member] Represents information of 2025 subordinated debentures. 2028 subordinated debentures Two Thousand Twenty Eight Subordinated Debentures [Member] Represents information of 2028 subordinated debentures. Debt Instrument [Line Items] Debt Instrument [Line Items] Percentage of principal amount redeemed Debt Instrument, Redemption Price, Percentage of Principal Amount Redeemed Maturity date Debt Instrument, Maturity Date Earliest date allowed for prepayment Debt Instrument, Prepayment, Earliest Date Earliest date when the debt instrument can be prepaid, in CCYY-MM-DD format. Aggregate principal amount Debt Instrument, Face Amount Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Schedule of Financing Receivable, Troubled Debt Restructurings [Table] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Axis] Loan Restructuring Modification [Domain] Loan Restructuring Modification [Domain] Rate Reduction Contractual Interest Rate Reduction [Member] Structure Extended Maturity [Member] Other Other Type Of Modification [Member] Represents type of modification other not defined elsewhere. Financing Receivable, Modifications [Line Items] Financing Receivable, Modifications [Line Items] Number of Contracts Financing Receivable, Modifications, Number of Contracts Pre-Modification Outstanding Recorded Investment Financing Receivable, Modifications, Pre-Modification Recorded Investment Post-Modification Outstanding Recorded Investment by Type of Modification Financing Receivable, Modifications, Post-Modification Recorded Investment Troubled Debt Restructurings That Have Subsequently Defaulted, Number of Contracts Financing Receivable, Modifications, Subsequent Default, Number of Contracts Troubled Debt Restructurings That Have Subsequently Defaulted, Recorded Investment Financing Receivable, Modifications, Subsequent Default, Recorded Investment Balance Sheet Offsetting and Repurchase Agreements Accounted for as Secured Borrowings Balance Sheet Offsetting And Repurchase Agreements Accounted For As Secured Borrowings [Text Block] The entire disclosure for balance sheet offsetting and repurchase agreements accounted for as secured borrowings. Statement of Stockholders' Equity [Abstract] Statement [Table] Statement [Table] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Series H Preferred Stock Preferred Stock [Member] Non-Voting Common Stock Common Stock, Non-Voting [Member] Common Stock, Non-Voting [Member] Common Stock Issuable Common Stock Issuable [Member] Common stock issuable. Capital Surplus Additional Paid-in Capital [Member] Retained Earnings (Accumulated Deficit) Retained Earnings [Member] Accumulated Other Comprehensive (Loss) Income AOCI Attributable to Parent [Member] Statement [Line Items] Statement [Line Items] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Beginning balance Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent Common stock issued to Dividend Reinvestment Plan and employee benefit plans (25,248 common shares in 2018, 17,826 common shares in 2017, 20,500 common shares in 2016) Common Stock Issued To Dividend Reinvestment Plan and Employee Benefit Plans Value This element represents amount of common stock issued to dividend reinvestment plan and employee benefit plans. Conversion of non-voting common stock to voting common stock (5,285,516 shares) Stock Issued During Period, Value, Conversion of Convertible Securities, Net of Adjustments Redemption of Series H preferred stock (9,992 shares) Stock Redeemed or Called During Period, Value Purchases of common stock (764,000 shares) Stock Repurchased and Retired During Period, Value Common stock issued for acquisitions (1,443,987 common shares in 2018, 6,515,505 common shares in 2017) Stock Issued During Period, Value, Acquisitions Amortization of stock options and restricted stock Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition Exercise of stock options (12,000 shares) Stock Issued During Period, Value, Stock Options Exercised Vesting of restricted stock awards, net of shares surrendered to cover payroll taxes (125,067 common shares issued and 99,779 common shares deferred in 2018, 114,837 common shares issued and 111,090 common shares deferred in 2017, 96,722 common shares issued and 106,771 common shares deferred in 2016) Stock Issued During Period, Value, Restricted Stock Award, Net of Forfeitures Deferred compensation plan, net, including dividend equivalents Deferred Compensation Plan Net Including Dividend Equivalents Represents the value of deferred compensation plan, net, including dividend equivalents. Shares issued from deferred compensation plan (48,214 shares in 2018, 32,279 shares in 2017, 61,899 shares in 2016) Stock Issued During Period, Value, Share-based Compensation, Net of Forfeitures Common stock dividends ($0.58 per share in 2018, $0.38 per share in 2017, $0.30 per share in 2016) Dividends, Common Stock, Cash Tax on option exercise and restricted stock vesting Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net Reclassification of disproportionate tax effects resulting from the Tax Cuts and Jobs Act of 2017 pursuant to ASU 2018-02 Income Tax Effects Allocated Directly to Equity, Cumulative Effect of Change in Accounting Principle Preferred stock dividends, Series H Dividends, Preferred Stock Cumulative effect of change in accounting principle Cumulative Effect of New Accounting Principle in Period of Adoption Ending balance Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Designated as Hedging Instrument Designated as Hedging Instrument [Member] Fair value hedging Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Derivative assets Derivative Financial Instruments, Assets [Member] Derivative liabilities Derivative Financial Instruments, Liabilities [Member] Brokered CD's Brokered Certificate Of Deposit [Member] Represents the brokered certificate of deposits. Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Derivative instrument hedges assets fair value Fair Value Hedge Assets Derivative instrument hedges liabilities fair value Fair Value Hedge Liabilities Investment Securities Investments in Debt and Marketable Equity Securities (and Certain Trading Assets) Disclosure [Text Block] Discount rate for disclosures (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Discount rate for net periodic benefit cost (percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Expected long-term rate of return (percent) Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets Schedule of summary of amounts outstanding under reverse repurchase agreements Schedule of Repurchase Agreements [Table Text Block] Schedule of repurchase agreements remaining contractual maturity of the agreements Schedule Of Repurchase Agreements Remaining Contractual Maturity Of Agreements [Table Text Block] The entire disclosure for repurchase Agreements Remaining Contractual maturity of the agreements. Common stock issued to Dividend Reinvestment Plan and employee benefit plans (in shares) Stock Issued During Period Shares Dividend Reinvestment Plan and Employee Benefit Plans This element represents number of common stock issued to dividend reinvestment plan and employee benefit plans. Conversion on non-voting common stock to voting common stock (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Redemption of Series H preferred stock (in shares) Stock Redeemed or Called During Period, Shares Purchases of common stock (in shares) Stock Repurchased and Retired During Period, Shares Common stock issued for acquisitions (in shares) Stock Issued During Period, Shares, Acquisitions Exercise of stock options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Vesting of restricted stock awards, net of shares surrendered to cover payroll taxes, issued (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures Vesting of restricted stock awards, net of shares surrendered to cover payroll taxes, deferred (in shares) Vesting Of Restricted Stock Shares Deferred This element represents value of common stock issued to dividend reinvestment plan and employee benefit plans. Shares issued from deferred compensation plan (in shares) Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures Cash and due from banks Cash and Due from Banks Interest-bearing deposits in banks Interest-bearing Deposits in Banks and Other Financial Institutions Cash and cash equivalents Debt securities held-to-maturity (fair value $268,803 and $321,276) Held-to-maturity Securities Loans held for sale (includes $18,935 and $26,252 at fair value) Loans Receivable Held-for-sale, Net, Not Part of Disposal Group, Mortgage Loans, net of unearned income Less allowance for loan losses Loans and Leases Receivable, Allowance Loans, net Loans and Leases Receivable, Net Amount Premises and equipment, net Property, Plant and Equipment, Net Bank owned life insurance Bank Owned Life Insurance Accrued interest receivable Accrued Investment Income Receivable Net deferred tax asset Derivative financial instruments Goodwill and other intangible assets Intangible Assets, Net (Including Goodwill) Liabilities: Liabilities [Abstract] Noninterest-bearing demand Demand Deposit Accounts NOW and interest-bearing demand Deposits, Negotiable Order of Withdrawal (NOW) Money market Deposits, Money Market Deposits Savings Deposits, Savings Deposits Time Time Deposits Brokered Brokered Represents amount of third-party deposits placed by or through the assistance of a deposit broker, also known as brokered deposit liabilities. Total deposits Short-term borrowings Short-term Debt Federal Home Loan Bank advances Derivative financial instruments Accrued expenses and other liabilities Accrued Liabilities and Other Liabilities Commitments and contingencies Commitments and Contingencies Shareholders' equity: Stockholders' Equity Attributable to Parent [Abstract] Common stock, $1 par value; 150,000,000 shares authorized; 79,234,077 and 77,579,561 shares issued and outstanding Common Stock, Value, Issued Common stock issuable; 674,499 and 607,869 shares Common Stocks Issuable Represents amount of carrying amount of common stock issuable. Capital surplus Additional Paid in Capital Accumulated deficit Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total shareholders’ equity 2019 Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months 2020 Finite-Lived Intangible Assets, Amortization Expense, Year Two 2021 Finite-Lived Intangible Assets, Amortization Expense, Year Three 2022 Finite-Lived Intangible Assets, Amortization Expense, Year Four 2023 Finite-Lived Intangible Assets, Amortization Expense, Year Five Thereafter Finite-Lived Intangible Assets, Amortization Expense, after Year Five Intangible, net Finite-Lived Intangible Assets, Net Securitized notes payable Secured Debt [Member] Trust preferred securities Trust Preferred Securities [Member] Represents information of trust preferred securities. NER 16-1 Class A-2 notes Navitas Equipment Receivables Llc 2016-1 Class A 2 Notes [Member] Represents information of Navitas Equipment Receivables LLC 2016-1 Class A-2 notes. NER 16-1 Class B notes Navitas Equipment Receivables Llc 2016-1 Class B Notes [Member] Represents information of Navitas Equipment Receivables LLC 2016-1 Class B notes. NER 16-1 Class C notes Navitas Equipment Receivables Llc 2016-1 Class C Notes [Member] Represents information of Navitas Equipment Receivables LLC 2016-1 Class C notes. NER 16-1 Class D notes Navitas Equipment Receivables Llc 2016-1 Class D Notes [Member] Represents information of Navitas Equipment Receivables LLC 2016-1 Class D notes. Southern Bancorp Capital Trust I Southern Bancorp Capital Trust One [Member] Represents information of Southern bancorp capital trust I. United Community Statutory Trust III United Community Statutory Trust Three [Member] Represents information of United community statutory trust III. Tidelands Statutory Trust I Tidelands Statutory Trust One [Member] Represents information of Tidelands statutory trust one. Tidelands Statutory Trust II Tidelands Statutory Trust Two [Member] Represents information of Tidelands statutory trust two. Four Oaks Statutory Trust I Four Oaks Statutory Trust I [Member] Represents information about Four Oaks Statutory Trust I. Variable Rate [Axis] Variable Rate [Axis] Variable Rate [Domain] Variable Rate [Domain] LIBOR London Interbank Offered Rate (LIBOR) [Member] Prime Rate Prime Rate [Member] Long-term debt, gross Long-term Debt, Gross Less discount Debt Instrument, Unamortized Discount Long-term debt Issue Date Debt Instrument Issue Year This element represents debt instrument issue year. Stated Maturity Date Debt Instruments Maturity Year This element represents debt instruments maturity year. Earliest Call Date Debt Instrument Earliest Call Year This element represents debt instrument earliest call year. Interest Rate Debt Instrument, Interest Rate, Stated Percentage Variable rate basis Debt Instrument, Description of Variable Rate Basis Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate 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] Reclassifications Out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Realized gains (losses) on available-for-sale securities Accumulated Net Investment Gain (Loss) Attributable to Parent [Member] Amortization of losses included in net income on available-for-sale securities transferred to held to maturity Accumulated Amortization Of Gains Included In Net Income On Available For Sale Securities Transferred To Held To Maturity [Member] Represents accumulated amortization of gains included in net income on available for sale securities transferred to held to maturity. Amounts included in net income on derivative financial instruments accounted for as cash flow hedges Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member] Reclassification of disproportionate tax effect related to terminated cash flow hedges Reclassification Of Disproportionate Tax Effect Related To Terminated Cash Flow Hedges [Member] Prior service cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Actuarial losses Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member] Amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plan Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Investment securities interest revenue Interest Income, Operating Deposits in banks and short-term investments interest revenue Money market deposit interest expense Federal Home Loan Bank advances interest expense Salaries and employee benefits expense Other expense Total before tax Net income available to common shareholders Business Combinations [Abstract] Mergers and Acquisitions Business Combination Disclosure [Text Block] Subsequent Events Subsequent Events [Text Block] Investment in limited partnerships Investment In Limited Partnerships Represents investment in limited partnerships. Commitment for additional fund Commitment For Additional Fund Represents commitment for additional fund. Schedule of summary of contractual maturities of time deposits Time Deposit Maturities [Table Text Block] Summary of sources and expected tax consequences of future taxable deductions (revenue) Components of Deferred Tax Assets and Liabilities [Abstract] Deferred 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 Deferred compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Loan purchase accounting adjustments Deferred Tax Assets Loan Purchase Accounting Adjustment Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from loan purchase accounting adjustment. Reserve for losses on foreclosed properties Deferred Tax Assets Reserve for Losses on Foreclosed Properties Amount before allocation of valuation allowances of deferred tax asset attributable to deductible Reserve for losses on foreclosed properties. Nonqualified share based compensation Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost Accrued expenses Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities Investment in partnerships Deferred Tax Assets, Investments Unamortized pension actuarial losses and prior service cost Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Pensions Unrealized losses on securities available-for-sale Deferred Tax Assets, Unrealized Losses on Available-for-Sale Securities, Gross Unrealized losses on cash flow hedges Deferred Tax Assets, Hedging Transactions Premises and equipment Deferred Tax Assets, Property, Plant and Equipment Other Deferred Tax Assets, Other Total deferred tax assets Deferred Tax Assets, Gross Deferred tax liabilities: Components of Deferred Tax Liabilities [Abstract] Acquired intangible assets Deferred Tax Liabilities, Intangible Assets Premises and equipment Deferred Tax Liabilities, Property, Plant and Equipment Loan origination costs Deferred Tax Liabilities, Deferred Expense, Debt Issuance Costs Leases Deferred Tax Liabilities, Leasing Arrangements Prepaid expenses Deferred Tax Liabilities, Prepaid Expenses Servicing assets Deferred Tax Liabilities, Mortgage Servicing Rights Derivatives Deferred Tax Liabilities, Derivatives Uncertain tax positions Deferred Tax Liability Uncertain Tax Positions This element represents amount of deferred tax liability uncertain tax position. Total deferred tax liabilities Deferred Tax Liabilities, Net Less valuation allowance Net deferred tax asset Minimum future lease payments receivable Estimated residual value of leased equipment Estimated Residual Value Of Leased Equipment Represents amount of estimated residual value of leased equipment. Initial direct costs Initial Direct Costs Represents amount of initial direct costs. Security deposits Security Deposit Liability Purchase accounting premium Investment In Leases Purchase Accounting Premium Represents amount of investment in leases purchase account premium. Unearned income Investment In Leases Unearned Income Represents amount of Unearned income. Net investment in leases Leveraged Lease Investment Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] U.S. Treasuries US Treasury Securities [Member] U.S. Government agencies US Treasury and Government [Member] State and political subdivisions US States and Political Subdivisions Debt Securities [Member] Residential mortgage-backed securities Residential Mortgage Backed Securities [Member] Commercial mortgage-backed securities Commercial Mortgage Backed Securities [Member] Asset-backed securities Asset-backed Securities [Member] Equity securities with readily determinable fair values Equity Securities [Member] Other Other Debt Obligations [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] Assets: Assets, Fair Value Disclosure [Abstract] Deferred compensation plan assets Deferred Compensation Plan Assets Total assets Assets, Fair Value Disclosure Liabilities, Fair Value Disclosure [Abstract] Liabilities, Fair Value Disclosure [Abstract] Deferred compensation plan liability Deferred Compensation Plan Liability Deferred Compensation Plan Liability Total liabilities Financial and Nonfinancial Liabilities, Fair Value Disclosure Schedule of cost basis, unrealized gains and losses, and fair value of securities held-to-maturity Held-to-maturity Securities [Table Text Block] Schedule of cost basis, unrealized gains and losses, and fair value of securities available for sale Debt Securities, Available-for-sale [Table Text Block] Debt Securities, Available-for-sale [Table Text Block] Schedule of summary of held to maturity securities in an unrealized loss position Unrealized Gain Loss On Held To Maturity Securities [Table Text Block] Unrealized gain loss on held to maturity securities. Schedule of summary of available for sale securities in an unrealized loss position Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value [Table Text Block] Schedule of summary of available-for-sale securities sales activities Schedule of Realized Gain (Loss) [Table Text Block] Schedule of amortized cost and fair value of available for sale and held to maturity securities by contractual maturity Investments Classified by Contractual Maturity Date [Table Text Block] Average balances of impaired loans and income recognized on impaired loans Average Balances Of Impaired Loans And Income Recognized On Impaired Loans [Abstract] Average Balance Impaired Financing Receivable, Average Recorded Investment Interest Revenue Recognized During Impairment Impaired Financing Receivable, Interest Income, Accrual Method Cash Basis Interest Revenue Received Impaired Financing Receivable, Interest Income, Cash Basis Method Document and Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Trading Symbol Trading Symbol Entity Current Reporting Status Entity Current Reporting Status Entity Voluntary Filers Entity Voluntary Filers Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Entity Public Float Entity Public Float Document Type Document Type Document Period End Date Document Period End Date Amendment Flag Amendment Flag Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Securities [Table] Trading Securities [Table] US Government agencies US Government Agencies Debt Securities [Member] Total securities other than mortgage-backed securities Securities Other Than Mortgage Backed Securities [Member] Securities other than mortgage backed securities. Schedule of Trading Securities and Other Trading Assets [Line Items] Schedule of Trading Securities and Other Trading Assets [Line Items] Available-for-Sale, Amortized Cost Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract] Available-for-Sale, Amortized Cost, Within 1 year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Amortized Cost Basis Available-for-Sale, Amortized Cost, 1 to 5 years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Amortized Cost Basis Available-for-Sale, Amortized Cost, 5 to 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Amortized Cost Basis Available-for-Sale, Amortized Cost, More than 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Amortized Cost Basis Amortized Cost Available-for-sale Debt Securities, Amortized Cost Basis Available-for-Sale, Fair Value Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract] Available-for-Sale, Fair Value, Within 1 year Available-for-sale Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Available-for-Sale, Fair Value, 1 to 5 years Available-for-sale Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Available-for-Sale, Fair Value, 5 to 10 years Available-for-sale Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Available-for-Sale, Fair Value, More than 10 years Available-for-sale Securities, Debt Maturities, Rolling after Year Ten, Fair Value Fair Value Held-to-Maturity, Amortized Cost Held-to-maturity Securities, Debt Maturities, Net Carrying Amount [Abstract] Held-to-Maturity, Amortized Cost, Within 1 year Held-to-maturity Securities, Debt Maturities, within One Year, Net Carrying Amount Held-to-Maturity, Amortized Cost, 1 to 5 years Held-to-maturity Securities, Debt Maturities, after One Through Five Years, Net Carrying Amount Held-to-Maturity, Amortized Cost, 5 to 10 years Held-to-maturity Securities, Debt Maturities, after Five Through Ten Years, Net Carrying Amount Held-to-Maturity, Amortized Cost, More than 10 years Held-to-maturity Securities, Debt Maturities, after Ten Years, Net Carrying Amount Amortized Cost Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment Held-to-Maturity Fair Value Held-to-maturity Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract] Held-to-Maturity, Fair Value, Within 1 year Held-to-maturity Securities, Debt Maturities, Next Rolling Twelve Months, Fair Value Held-to-Maturity, Fair Value, 1 to 5 years Held-to-maturity Securities, Debt Maturities, Rolling Year Two Through Five, Fair Value Held-to-Maturity, Fair Value, 5 to 10 years Held-to-maturity Securities, Debt Maturities, Rolling Year Six Through Ten, Fair Value Held-to-Maturity, Fair Value, More than 10 years Held-to-maturity Securities, Debt Maturities, Rolling after Ten Years, Fair Value Fair value Held-to-maturity Securities, Fair Value FHLB advances Federal Home Loan Bank, Advances, Maturities Summary, Fixed Rate Weighted average interest rate advances Federal Home Loan Bank, Advances, General Debt Obligations, Disclosures, Interest Rate at Period End Derivative Liability Derivative Asset Debt Securities Available- for-Sale Available-for-sale Securities [Member] Reconciliation of Assets at Level 3 Measurement Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value Transfer from amortization method to fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net Business combinations Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Business Combination And Provisional Adjustment Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Asset, Business Combination And Provisional Adjustment Additions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Issuances Sales and settlements Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Sales And Settlements Amount of sale and settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing. Other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss) Amounts included in earnings - fair value adjustments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings Balance at end of period Reconciliation of Liabilities at Level 3 Measurement Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward] Balance at beginning of period Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value Transfer from amortization method to fair value Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net Business combinations Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Business Combination And Provisional Adjustment Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Business Combination And Provisional Adjustment Additions Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Issuances Sales and settlements Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales And Settlements Fair Value Measurement With Unobservable Inputs Reconciliation, Recurring Basis, Liability, Sales And Settlements Other comprehensive income Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss) Amounts included in earnings - fair value adjustments Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings Balance at end of period Schedule of long-term debt Schedule of Long-term Debt Instruments [Table Text Block] Schedule of maturities and current rates of outstanding advances Federal Home Loan Bank, Advances [Table Text Block] Goodwill [Roll Forward] Goodwill [Roll Forward] Goodwill, gross, beginning balance Goodwill, Gross Accumulated Impairment Losses, beginning balance Goodwill, Impaired, Accumulated Impairment Loss Goodwill, net of Accumulated Impairment Losses, beginning balance Goodwill Acquisition of FOFN Goodwill, Acquired During Period Acquisition of HCSB Goodwill Acquired During Period Two It represent the Goodwill acquired during period. Acquisition of NLFC Goodwill Acquired During Period Three It represent Goodwill acquired during period. Measurement period adjustments Goodwill, Purchase Accounting Adjustments Goodwill, gross, ending balance Accumulated Impairment Losses, ending balance Goodwill, net of Accumulated Impairment Losses, ending balance Schedule of Held-to-maturity Securities [Table] Schedule of Held-to-maturity Securities [Table] Schedule of Held-to-maturity Securities [Line Items] Schedule of Held-to-maturity Securities [Line Items] Held-to-maturity securities: Held-to-maturity Securities, Unclassified [Abstract] Gross Unrealized Gains Held-to-maturity Securities, Accumulated Unrecognized Holding Gain Gross Unrealized Losses Held-to-maturity Securities, Accumulated Unrecognized Holding Loss Fair value Accounting Changes and Error Corrections [Abstract] Accounting Standards Updates and Recently Adopted Standards New Accounting Pronouncements and Changes in Accounting Principles [Text Block] Nonrecurring Fair Value, Measurements, Nonrecurring [Member] Loans Schedule of Business Acquisitions, by Acquisition [Table] Schedule of Business Acquisitions, by Acquisition [Table] Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] NLFC Holdings Corp NLFC Holdings Corp Acquisition [Member] Represents information about NLFC Holdings Corp acquisition. Four Oaks FinCorp, Inc Four Oaks FinCorp Inc Acquisition [Member] Represents information about Four Oaks FinCorp, Inc. acquisition. HCSB Financial Corporation HCSB Financial Corporation Acquisition [Member] Represents information about HCSB Financial Corporation acquisition. Four Oaks Fin Corp, Inc and HCSB Financial Corporation Four Oaks Fin Corp Inc Acquisition And HCSB Financial Corporation Acquisition [Member] Four Oaks Fin Corp Inc Acquisition And HCSB Financial Corporation Acquisition [Member] Tidelands Bancshares, Inc Tidelands Bancshares Inc Acquisition [Member] Represents information about Tidelands Bancshares Inc, acquisition. Four Oaks Bank Four Oaks Bank [Member] Represents information regarding Four Oaks Bank, a legal entity. Tidelands Bank Tidelands Bank [Member] Represents information about Tidelands Bank, a legal entity. Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Core deposit intangible Core Deposits [Member] Business Acquisition [Line Items] Business Acquisition [Line Items] Assets acquired Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Liabilities assumed Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities Consideration transferred Business Combination, Consideration Transferred Cash consideration Number of shares received for each share outstanding (in shares) Business Acquisition, Number Of Shares Or Fraction Of Shares Business Acquisition, Number Of Shares Or Fraction Of Shares Cash per common share outstanding (in dollars per share) Business Acquisition, Share Price Goodwill Goodwill expected to be tax deductible Business Acquisition, Goodwill, Expected Tax Deductible Amount Provisional value adjustment decrease to acquired loans Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Financial Assets Goodwill adjustment Value of loans acquired separate from the business combination Payments to Acquire Loans Receivable Number of branches Intangible assets acquired Finite-lived Intangible Assets Acquired Expected useful life of asset Acquired Finite-lived Intangible Assets, Weighted Average Useful Life Noncompete agreement Finite-Lived Noncompete Agreements, Gross Useful life of intangible asset Finite-Lived Intangible Asset, Useful Life Premises and equipment, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment Loans held for sale Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Loans Held For Sale Represents amount of loans held for sale recognized as of the acquisition date. Servicing assets Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Servicing Asset Represents amount of servicing asset recognized as of the acquisition date. Provisional value adjustment increase to loans held for sale Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Loans Held For Sale This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to loans held for sale acquired in connection with a business combination for which the initial accounting was incomplete. Provisional value adjustment decrease to servicing assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Servicing Assets This element represents the amount of any measurement period adjustment (as defined) realized during the reporting period to servicing assets acquired in connection with a business combination for which the initial accounting was incomplete. Provisional value adjustment for deferred tax asset Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Assets Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Deferred Tax Assets Provisional value adjustment decrease to premises and equipment Business Combination, Provisional Information, Initial Accounting Incomplete, Adjustment, Property, Plant, and Equipment Cash paid to redeem common stock Business Acquisition Cash Payment To Redeem Common Stock Represents business acquisition cash payment to redeem common stock. Cash paid to redeem preferred stock including unpaid dividends Business Acquisition Cash Payment To Redeem Preferred Stock Represents business acquisition cash payment to redeem preferred stock. Merger related costs included in pro forma results Business Combination, Acquisition Related Costs, Included In Pro Forma Results Business Combination, Acquisition Related Costs, Included In Pro Forma Results Merger related costs excluded from pro forma results Business Combination, Acquisition Related Costs, Excluded From Pro Forma Results Business Combination, Acquisition Related Costs, Excluded From Pro Forma Results 2019 Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months 2020 Defined Benefit Plan, Expected Future Benefit Payment, Year Two 2021 Defined Benefit Plan, Expected Future Benefit Payment, Year Three 2022 Defined Benefit Plan, Expected Future Benefit Payment, Year Four 2023 Defined Benefit Plan, Expected Future Benefit Payment, Year Five 2024-2026 Defined Benefit Plan, Expected Future Benefit Payment, Five Fiscal Years Thereafter Total Estimated Future Benefit Payments Expected To Be Paid Represents estimated future benefit payments expected to be paid. Statement of Comprehensive Income [Abstract] Net income, Before-tax Amount Net income, Tax (Expense) Benefit Net income, Net of Tax Amount Other comprehensive income (loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized (losses) gains on available-for- sale securities: Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, Net of Tax [Abstract] Unrealized holding (losses) gains arising during period, Before-tax Amount Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, before Tax Unrealized holding (losses) gains arising during period, Tax (Expense) Benefit Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax Unrealized holding (losses) gains arising during period, Net of Tax Amount Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Net of Tax Reclassification adjustment for (losses) gains included in net income, Before-tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax Reclassification adjustment for (losses) gains included in net income, Tax (Expense) Benefit Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax Reclassification adjustment for (losses) gains included in net income, Net of Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax Net unrealized (losses) gains, Before-tax Amount Other Comprehensive Income Loss Unrealized Holding Gain Loss On Securities Net Of Reclassification and Valuation Allowance Arising During Period Before Tax Other comprehensive income loss unrealized holding gain loss on securities net of reclassification and valuation allowance arising during period before tax. Net unrealized (losses) gains, Tax (Expense) Benefit Other Comprehensive Income Loss Unrealized Holding Gain Loss On Securities Net Of Reclassification and Valuation Allowance Arising During Period Tax Effect Other comprehensive income loss unrealized holding gain loss on securities net of reclassification and valuation allowance arising during period tax effect. Net unrealized (losses) gains, Net of Tax Amount Other Comprehensive Income Loss Unrealized Holding Gain Loss On Securities Net Of Reclassification and Valuation Allowance Arising During Period Net Of Tax Other comprehensive income loss unrealized holding gain loss on securities net of reclassification and valuation allowance arising during period net of tax. Amortization of losses included in net income on available-for-sale securities transferred to held to maturity, Before-tax Amount Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, before Tax Amortization of losses included in net income on available-for-sale securities transferred to held to maturity, Tax (Expense) Benefit Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Tax Amortization of losses included in net income on available-for-sale securities transferred to held to maturity, Net of Tax Amount Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Net of Tax Amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges, Before-tax Amount Other Comprehensive Income Loss Amortization Of Losses Included In Net Income On Terminated Derivative Financial Instruments Which Previously Accounted For As Cash Flow Hedges Before Tax Represents the amount before tax related to amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges. Amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges, Tax (Expense) Benefit Other Comprehensive Income Loss Amortization Of Losses Included In Net Income On Terminated Derivative Financial Instruments Which Previously Accounted For As Cash Flow Hedges Tax Represents the amount of tax expense (benefit) related to amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges. Amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges, Net of Tax Amount Other Comprehensive Income Loss Amortization Of Losses Included In Net Income On Terminated Derivative Financial Instruments Which Previously Accounted For As Cash Flow Hedges Net Of Tax Represents the amount after tax related to amortization of losses included in net income on terminated derivative financial instruments that were previously accounted for as cash flow hedges. Reclassification of disproportionate tax effect related to terminated and current cash flow hedges, Before - Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax Reclassification of disproportionate tax effect related to terminated and current cash flow hedges, Tax (Expense) Benefit Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Reclassification of disproportionate tax effect related to terminated and current cash flow hedges, Net of Tax Amount Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Net cash flow hedge activity, Before-tax Amount Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, before Tax, Portion Attributable to Parent Net cash flow hedge activity, Tax (Expense) Benefit Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Tax Net cash flow hedge activity, Net of Tax Amount Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax, Portion Attributable to Parent Amendments to defined benefit pension plan, Before-tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax Amendments to defined benefit pension plan, Tax (Expense) Benefit Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax Amendments to defined benefit pension plan, Net of Tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax Net actuarial gain (loss) on defined benefit pension plans, Before-tax Amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Net actuarial gain (loss) on defined benefit pension plans, Tax (Expense) Benefit Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Net actuarial gain (loss) on defined benefit pension plans, Net of Tax Amount Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plans, Before-tax Amount Other Comprehensive Income Loss Amortization Of Prior Service Cost And Actuarial Losses Included In Net Periodic Pension Cost For Defined Benefit Pension Plan Before Tax Amount Represents amount of other comprehensive income (loss) amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plan, before tax amount. Amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plans, Tax (Expense) Benefit Other Comprehensive Income Loss Amortization Of Prior Service Cost And Actuarial Losses Included In Net Periodic Pension Cost For Defined Benefit Pension Plan Tax Expense Benefit Represents amount of other comprehensive income (loss) amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plan, tax expense benefit. Amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plans, Net of Tax Amount Other Comprehensive Income Loss Amortization Of Prior Service Cost And Actuarial Losses Include Net Periodic Pension Cost For Defined Benefit Pension Plan Net Of Tax Other comprehensive income amortization of prior service cost and actuarial losses included in net periodic pension cost for defined benefit pension plan, net of tax. Net defined benefit pension plan activity, Before-tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, before Tax, after Reclassification Adjustment, Attributable to Parent Net defined benefit pension plan activity, Tax (Expense) Benefit Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax Net defined benefit pension plan activity, Net of Tax Amount Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent Total other comprehensive (loss) income, Before-tax Amount Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent Total other comprehensive (loss) income, Tax (Expense) Benefit Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent Total other comprehensive (loss) income, Net of Tax Amount Comprehensive income, Before-tax Amount Comprehensive Income Loss Before Tax Represents amount of comprehensive income (loss) before tax. Comprehensive income, Tax (Expense) Benefit Comprehensive Income Loss Tax Represents amount of comprehensive income loss tax. Comprehensive income, Net of Tax Amount Comprehensive Income (Loss), Net of Tax, Attributable to Parent Not Designated as Hedging Instrument Not Designated as Hedging Instrument [Member] Customer derivative positions Customer Swap Position [Member] Represents the customer swap positions. Dealer offsets to customer derivative positions Dealer Offset To Customer Swap Position [Member] Represents the dealer offset to customer swap position. Risk participations Risk Participations [Member] Represents information about risk participations. Mortgage banking - loan commitment Mortgage Banking Loan Commitment [Member] Represents information of mortgage banking - loan commitment. Mortgage banking - forward sales commitment Mortgage Banking Forward Sales Commitment [Member] Represents mortgage banking - forward sales commitment. Bifurcated embedded derivatives Bifurcated Embedded Derivative [Member] Represents the bifurcated embedded derivatives. Interest rate caps Interest Rate Cap [Member] Dealer offsets to bifurcated embedded derivatives Dealer Offsets To Bifurcated Embedded Derivatives [Member] Represents the dealer offsets to bifurcated embedded derivatives. De-designated hedges De Designated Cash Flow Hedge [Member] Represents de-designated cash flow hedge. Interest rate derivative instruments not designated as hedging instruments, assets at fair value Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Asset at Fair Value Interest rate derivative instruments not designated as hedging instruments, liabilities at fair value Interest Rate Derivative Instruments Not Designated as Hedging Instruments, Liability at Fair Value Summary of held to maturity securities in an unrealized loss position Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract] Fair Value, Less than 12 Months Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value Unrealized Loss, Less than 12 Months Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss Fair Value, 12 Months or More Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value Unrealized Loss, 12 Months or More Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss Fair Value, Total Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value Unrealized Loss, Total Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss Actual Revenue Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual Actual Net income Business Combination, Pro Forma Information, Earnings or Loss of Acquiree since Acquisition Date, Actual Supplemental consolidated pro forma Revenue Business Acquisition, Pro Forma Revenue Supplemental consolidated pro forma Net Income Business Acquisition, Pro Forma Net Income (Loss) Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Table] Schedule of Available-for-sale Securities [Line Items] Schedule of Available-for-sale Securities [Line Items] Debt securities available-for-sale and equity securities: Available-for-sale Securities [Abstract] Gross Unrealized Gains Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax Gross Unrealized Losses Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax Fair Value Schedule of minimum amounts required for capital adequacy purposes Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block] Employer match of employee contributions (percent) Defined Contribution Plan, Employer Matching Contribution, Percent of Match Employer matching contribution maximum percent of employee's eligible compensation (percent) Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Duration of service period to receive matching contribution Defined Contribution Plan, Service Period To Qualify For Matching Contributions Defined Contribution Plan, Service Period To Qualify For Matching Contributions Vesting period of benefits Defined Contribution Plan, Period Of Time Until Benefits Vest Defined Contribution Plan, Period Of Time Until Benefits Vest Compensation expense related to 401(k) Plan Defined Contribution Plan, Compensation Expense Defined Contribution Plan, Compensation Expense Employer matching contributions related to deferred compensation plan Defined Contribution Plan, Employer Matching Contribution, Compensation Expense Related To Deferred Compensation Plan Defined Contribution Plan, Employer Matching Contribution, Compensation Expense Related To Deferred Compensation Plan Employer discretionary contributions Defined Contribution Plan, Employer Discretionary Contribution Amount Discount rate for disclosures, retirees (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate, Retirees Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate, Retirees Discount rate for disclosures, nonretirees, years 1 through 5 (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years One Through Five, Discount Rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years One Through Five, Discount Rate Discount rate assessment, nonretirees, years 1 through 5, period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years One Through Five, Period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years One Through Five, Period Discount rate for disclosures, nonretirees, next 15 years (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years Six Through Twenty, Discount Rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years Six Through Twenty, Discount Rate Discount rate assessment, nonretirees, next 15 years, period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years Six Through Twenty, Period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, Years Six Through Twenty, Period Discount rate for disclosures, nonretirees, beyond 20 years (percent) Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, After Twenty Years, Discount Rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, After Twenty Years, Discount Rate Discount rate assessment, nonretirees, beyond 20 years period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, After Twenty Years, Period Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Nonretirees, After Twenty Years, Period Estimated net loss to be amortized in next fiscal year Defined Benefit Plan, Expected Amortization of Gain (Loss), Next Fiscal Year Estimated prior service costs to be amortized in next fiscal year Defined Benefit Plan, Expected Amortization of Prior Service Cost (Credit), Next Fiscal Year Expected contribution to plan in year 2018 Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Stock Options Employee Stock Option [Member] Restricted stock units Restricted Stock Units (RSUs) [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Computation of basic and diluted loss per share Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Dividends and undistributed earnings allocated to unvested shares Participating Securities, Distributed and Undistributed Earnings (Loss), Basic Preferred dividends Preferred Stock Dividends, Income Statement Impact Income per common share: Earnings Per Share, Basic and Diluted [Abstract] Weighted average common shares: Effect of dilutive securities: Dilutive Securities, Effect on Basic Earnings Per Share [Abstract] Dilutive securities (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Schedule of the contract amount of off-balance sheet instruments Schedule of Fair Value, Off-balance Sheet Risks [Table Text Block] Loans and Leases and Allowance for Credit Losses Loans, Notes, Trade and Other Receivables Disclosure [Text Block] Defined Benefit Plan, Asset Categories [Axis] Defined Benefit Plan, Asset Categories [Axis] Plan Asset Categories [Domain] Plan Asset Categories [Domain] Money market fund Money Market Funds [Member] Mutual funds Mutual Fund [Member] U.S. Treasuries Corporate stocks Defined Benefit Plan, Equity Securities [Member] Security representing ownership in corporation or other legal entity for which ownership is represented by share of stock, in which defined benefit plan asset is invested. Includes, but is not limited to, common stock, preferred stock, convertible security, stock right and stock warrant. Exchange traded funds Exchange Traded Funds [Member] Total plan assets Defined Benefit Plan, Fair Value of Plan Assets Restricted Stock Restricted Stock [Member] Restricted Stock, Shares Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Beginning balance, outstanding (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 Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Expired (in shares) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Expired In Period Represents the number of equity-based payment instruments, excluding stock (or unit) options, that were expired during the reporting period. Cancelled (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Ending balance, outstanding (in shares) Vested / Exercisable (in shares) Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other Than Options Exercisable Number This element represents share based compensation arrangement by share based payment award equity instruments other than option exercisable number. Restricted Stock, 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] Beginning balance, outstanding (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 (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 Vested (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 Expired (in dollars per share) Share-Based Compensation Arrangement By Share-Based Payment Award, Equity Instruments Other Than Options, Expired, Weighted Average Grant Date Fair Value Represents the weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. Cancelled (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Ending balance, outstanding (in dollars per share) Vested / Exercisable (in dollars per share) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other than Options Exercisable Weighted Average Grant Date Fair Value This element represents share based compensation arrangement by share based payment award equity instruments other than options exercisable weighted average grant date fair value. Shares Vested, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested Shares Outstanding, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Outstanding Stock Option, Shares Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Beginning balance, options outstanding (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Granted options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Vested options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested, Number of Shares Exercised options (in shares) Expired options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Expirations in Period Cancelled options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Ending balance, options outstanding (in shares) Vested / Exercisable, options (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number Stock Option, Weighted Average Exercise Price Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Beginning balance, options outstanding (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Granted options (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Vested options (in dollars per share) Share-Based Compensation Arrangements By Share-Based Payment Award, Options, Vested In Period, Weighted Average Exercise Price Weighted average per share amount at which vested shares of common stock by exercise of options. Exercised options (in dollars per shares) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Expired options (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Expirations in Period, Weighted Average Exercise Price Cancelled options (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Ending balance, options outstanding (in dollars per share) Vested / Exercisable, options (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price Options Outstanding, Weighted Average Remaining Term (Yrs.) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Options, Exercisable, Weighted-Average Remaining Contractual Term (Yrs.) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Remaining Contractual Term Options Outstanding, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Options, Exercisable, Aggregate Intrinsic Value Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Intrinsic Value Fair Value Of Purchased Assets And Assumed Liabilities Recorded [Axis] Fair Value Of Purchased Assets And Assumed Liabilities Recorded [Axis] Represents purchased assets and assumed liabilities were recorded at their acquisition date fair values. Fair Value Of Purchased Assets And Assumed Liabilities Recorded [Domain] Fair Value Of Purchased Assets And Assumed Liabilities Recorded [Domain] Represents information of purchased assets and assumed liabilities were recorded at their acquisition date fair values. As Recorded by NLFC As Recorded By Nlfc [Member] Represents information pertaining to information as Recorded by NLFC. As Recorded by FOFN As Recorded By Four Oaks Fincorp Inc [Member] Represents information pertaining to information as Recorded by Four Oaks FinCorp, Inc. As Recorded by HCSB As Recorded By Horry County State Bank [Member] Represent As recorded by Horry County State Bank. As Recorded by Tidelands As Recorded By Tidelands Bancshares Inc [Member] Fair Value Adjustments Fair Value Adjustments, Acquisition [Member] Fair Value Adjustments, Acquisition [Member] NLFC Holdings Corp NLFC Holdings Corp [Member] Represents information about NLFC Holdings Corp. Horry County State Bank Horry County State Bank [Member] Represents information about Horry County State Bank , a legal entity. Assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets [Abstract] Cash and cash equivalents Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents Securities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities Loans, net Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables Bank owned life insurance Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Bank Owned Life Insurance Represents amount of Bank owned life insurance recognized as of the acquisition date. Net deferred tax asset Intangibles Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles Other real estate owned Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Real Estate Owned Represents amount of Other real estate owned expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date. Other assets Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets Total assets acquired Liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities [Abstract] Short-term borrowings Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Short Term Borrowings Represents amount of Short-term borrowings recognized as of the acquisition date. Deposits Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Deposits Represents amount of deposit recognized as of the acquisition date. Repurchase agreements Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Repurchase Agreements Represents amount of repurchase agreements due after one year or the normal operating cycle, if longer, assumed at the acquisition date. Federal Home Loan Bank advances Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Federal Home Loan Bank Advances Represents amount of Federal Home Loan Bank advances recognized as of the acquisition date. Long-term debt Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt Other liabilities Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other Total liabilities assumed Excess of assets acquired over liabilities assumed Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Excess Of Assets Acquired Over Liabilities Assumed Represents amount recognized for assets including goodwill in excess of (less than) the aggregate liabilities assumed. Aggregate fair value adjustments Aggregate Fair Value Adjustments Represents aggregate fair value adjustments. Total identifiable net assets Consideration transferred Business Combination, Consideration Transferred [Abstract] Cash Common stock issued Common stock issued (in shares) Business Acquisition, Equity Interest Issued or Issuable, Number of Shares Total fair value of consideration transferred Equity interest held before the business combination Business Combination, Step Acquisition, Equity Interest in Acquiree, Fair Value Cash paid to redeem preferred stock issued under the Treasury's Capital Purchase Program Goodwill Leverage ratio for supervisory rating of 1 Leverage Ratio Adequately Capitalized Represents leverage ratio adequately capitalized. Approved cash dividend Statutory Accounting Practices, Statutory Amount Available for Dividend Payments with Regulatory Approval Maximum percentage of credit to affiliate under federal reserve act Maximum Percentage of Credit to Affiliate Under Federal Reserve Act This elements represents maximum percentage of credit to affiliate under federal reserve act. Maximum percentage of credit to all affiliates under federal reserve act Maximum Percentage of Credit to all Affiliates under Federal Reserve Act This elements represents maximum percentage of credit to all affiliates under federal reserve act. Number of shares repurchased under the program Repurchase program remaining authorization Stock Repurchase Program, Remaining Authorized Repurchase Amount Preferred stock authorized (in shares) Preferred Stock, Shares Authorized Preferred stock outstanding (in shares) Preferred Stock, Shares Outstanding Additions: Servicing Asset Additions [Abstract] Acquired servicing rights Servicing Asset at Fair Value, Other Changes in Fair Value Acquired servicing rights Originated servicing rights capitalized upon sale of loans Servicing Asset At Fair Value Originated Servicing Rights Capitalized Upon Sale Of Loans Represents servicing asset at fair value originated servicing rights capitalized upon sale of loans. Subtractions: Servicing Asset Subtractions [Abstract] Changes in fair value: Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions [Abstract] Due to change in valuation inputs or assumptions used in the valuation model Servicing Asset at Fair Value, Changes in Fair Value Resulting from Changes in Valuation Inputs or Changes in Assumptions Premises and Equipment Property, Plant and Equipment Disclosure [Text Block] Schedule of carrying amount of goodwill and other intangible assets Schedule of Intangible Assets and Goodwill [Table Text Block] Schedule of changes in the carrying amounts of goodwill Schedule of Goodwill [Table Text Block] Schedule of amortization expense for future periods Finite-lived Intangible Assets Amortization Expense [Table Text Block] Schedule of purchased assets and assumed liabilities Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block] Additional information related to acquired loan portfolio at acquisition date Additional Information Related To Acquired Loan [Table Text Block] Tabular disclosure of the amounts recognized as additional information related to the acquired loan. Schedule of actual results and pro forma information Business Acquisition, Pro Forma Information, Nonrecurring Adjustments [Table Text Block] 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] Watch Watch [Member] Represents watch. Substandard Substandard [Member] Doubtful / Loss Doubtful [Member] Financing Receivable, Recorded Investment [Line Items] Financing Receivable, Recorded Investment [Line Items] Risk category of loans by class of loans Risk Category Of Loans By Class Of Loans [Abstract] Risk category of loans by class of loans. Total loans, excluding PCI loans Loans And Leases Receivable Excluding Purchased Credit Impaired Loans Represents loans and leases receivable excluding purchased credit impaired loans. Total loans Rent commitments under operating leases Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] 2019 Operating Leases, Future Minimum Payments Due, Next Twelve Months 2020 Operating Leases, Future Minimum Payments, Due in Two Years 2021 Operating Leases, Future Minimum Payments, Due in Three Years 2022 Operating Leases, Future Minimum Payments, Due in Four Years 2023 Operating Leases, Future Minimum Payments, Due in Five Years Thereafter Operating Leases, Future Minimum Payments, Due Thereafter Total Customer derivatives and dealer offsets Customer Derivatives And Dealer Offsets [Member] Information of Customer Derivatives And Dealer Offsets. Bifurcated embedded derivatives and dealer offsets Bifurcated Embedded Derivatives And Dealer Offsets [Member] Bifurcated embedded derivatives and dealer offsets. Mortgage banking derivatives Mortgage Banking Derivatives [Member] Information of Mortgage banking derivatives. Other noninterest income Other Noninterest Income [Member] Information of other noninterest income [Member] Mortgage loan revenue Mortgage Loan Revenue [Member] Information of mortgage loan revenue. Total gains and losses Derivative, Gain (Loss) on Derivative, Net Gain (Loss) Reclassified from Accumulated Other Comprehensive Income into Income (Effective Portion) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Schedule of Assets Sold under Agreements to Repurchase [Table] Schedule of Assets Sold under Agreements to Repurchase [Table] Mortgage-backed securities Collateralized Mortgage Backed Securities [Member] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Axis] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Repurchase Agreements and Similar Transactions, Maturity Periods [Domain] Overnight and Continuous Maturity Overnight [Member] Up to 30 Days Maturity Less than 30 Days [Member] 30 to 90 Days Maturity 30 to 90 Days [Member] 91 to 110 days Maturity Greater than 90 Days [Member] Assets Sold under Agreements to Repurchase [Line Items] Assets Sold under Agreements to Repurchase [Line Items] Remaining Contractual Maturity of the Agreements Securities Sold under Agreements to Repurchase, Gross Including Not Subject to Master Netting Arrangement Gross amount of recognized liabilities for repurchase agreements in offsetting disclosure Securities Loaned, Gross Including Not Subject to Master Netting Arrangement Amounts related to agreements not included in offsetting disclosure Securities Loaned and Securities Sold under Agreement to Repurchase, Gross Including Not Subject to Master Netting Arrangement New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] ASU No. 2016-02 Accounting Standards Update 2016-02 [Member] Scenario [Axis] Scenario [Axis] Scenario, Unspecified [Domain] Scenario, Unspecified [Domain] Forecast Scenario, Forecast [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Right-of-use asset Operating Lease, Right-of-Use Asset Lease liability Operating Lease, Liability Effect on retained earnings in period of adoption Schedule of weighted-average assumptions used to determine pension benefit obligations Schedule of Assumptions Used [Table Text Block] Schedule of changes in obligations and plan assets Schedule of Defined Benefit Plans Disclosures [Table Text Block] Schedule of components of net periodic benefit cost and other amounts recognized in other comprehensive income Schedule of Net Benefit Costs [Table Text Block] Schedule of estimated future benefit payments Schedule of Expected Benefit Payments [Table Text Block] Schedule of funded plan assets Schedule of Allocation of Plan Assets [Table Text Block] Proceeds from sales Proceeds from Sale of Available-for-sale Securities, Debt Gross gains on sales Debt Securities Available For Sale Realized Gain Amount of realized gain on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). Gross losses on sales Debt Securities Available For Sale Realized Loss Amount of realized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) Net (losses) gains on sales of securities Income tax (benefit) expense attributable to sales Allowance for Loan Losses, Individually evaluated for impairment Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment Allowance for Loan Losses, Collectively evaluated for impairment Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment Allowance for Loan Losses, PCI Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Allowance for Loan Losses Allowance for Loan Losses, Ending balance Loans Outstanding, Individually evaluated for impairment Financing Receivable, Individually Evaluated for Impairment Loans Outstanding, Collectively evaluated for impairment Financing Receivable, Collectively Evaluated for Impairment Loans and Leases Receivable Disclosure [Table] Loans and Leases Receivable Disclosure [Table] Loans and Leases Receivable Disclosure [Line Items] Loans and Leases Receivable Disclosure [Line Items] Classifications of loans Loans and Leases Receivable, Net Amount [Abstract] Reclassifications Out of Accumulated Other Comprehensive Income Disclosure of Reclassification Amount [Text Block] Summary of available for sale securities in an unrealized loss position Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract] Fair Value, Less than 12 Months Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than 12 Months Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months. Unrealized Loss, Less than 12 Months Debt Securities Available For Sale Continuous Unrealized Loss Position Less Than 12 Months Accumulated Loss Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for less than 12 months. Fair Value, 12 Months or More Debt Securities Available For Sale Continuous Unrealized Loss Position 12 Months Or Longer Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months. Unrealized Loss, 12 Months or More Debt Securities Available For Sale Continuous Unrealized Loss Position 12 Months Or Longer Accumulated Loss Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for 12 months or longer. Fair Value, Total Debt Securities Available For Sale Unrealized Loss Position Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position. Unrealized Loss, Total Debt Securities Available For Sale Unrealized Loss Position Accumulated Loss Amount of accumulated unrealized loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in unrealized loss position. Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Schedule of Impaired Financing Receivable [Table] Schedule of Impaired Financing Receivable [Table] Construction Loans Financing Receivable, Impaired [Line Items] Financing Receivable, Impaired [Line Items] Loans individually evaluated for impairment by class of loans Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance [Abstract] Unpaid Principal Balance, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Unpaid Principal Balance Unpaid Principal Balance, With an allowance recorded Impaired Financing Receivable, with Related Allowance, Unpaid Principal Balance Unpaid Principal Balance Impaired Financing Receivable, Unpaid Principal Balance Recorded Investment Impaired Financing Receivable, Recorded Investment [Abstract] Recorded Investment, With no related allowance recorded Impaired Financing Receivable, with No Related Allowance, Recorded Investment Recorded Investment, With an allowance recorded Impaired Financing Receivable, with Related Allowance, Recorded Investment Recorded Investment Impaired Financing Receivable, Recorded Investment Allowance for loan losses, With an allowance recorded Impaired Financing Receivable, Related Allowance Performance-based Restricted Stock Units Performance-Based Restricted Stock Units [Member] Performance-Based Restricted Stock Units [Member] Merger related and other charges Merger Related And Other Charges [Member] Represents merger related and other charges. Compensation expense Compensation Expense [Member] Compensation Expense [Member] Other operating expenses Other Operating Income (Expense) [Member] Vesting period under plan Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period Maximum exercisable period Share Based Compensation Arrangement by Share Based Payment Award Exercisable Period This element represents share based compensation arrangement by share based payment award exercisable period. Additional awards granted under plan Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Compensation expense Allocated Share-based Compensation Expense Accelerated compensation cost Share-based Compensation Arrangement by Share-based Payment Award Accelerated Compensation Cost Deferred income tax benefit related to compensation expense for options and restricted stock Deferred Income Tax Benefit Related To Compensation Expense For Options And Restricted Stock Represents amount of deferred income tax benefit related to compensation expense for options and restricted stock. Unrecognized compensation cost related to nonvested stock options Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Weighted average period over which compensation cost is expected to be recognized Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Shares issued in connection with DRIP (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan Discount offered to employees under United has an Employee Stock Purchase Program (ESPP) to purchase shares of common stock Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Discount for Postvesting Restrictions Stock issued through Employee Stock Purchase Program (in shares) Stock Issued During Period, Shares, Employee Stock Purchase Plans Common stock issuable shares under deferred compensation plan (in shares) Common Stock Issuable Shares Under Deferred Compensation Plan This element represents common stock issuable shares under deferred compensation plan. Noninterest income Effect of fair value hedging derivative financial instruments on the consolidated statement of operations Derivative, Gain (Loss) on Derivative, Net [Abstract] Amount of Gain (Loss) Recognized in Income on Derivative Change in Unrealized Gain (Loss) on Fair Value Hedging Instruments Amount of Gain (Loss) Recognized in Income on Hedged Item Change in Unrealized Gain (Loss) on Hedged Item in Fair Value Hedge Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Noncompete agreement Noncompete Agreements [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Intangible, gross Intangible Assets, Gross (Excluding Goodwill) Less: accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Total goodwill and other intangible assets, net Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward] Balance at beginning of period Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Additions due to acquisitions Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Additions Accretion Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Accretion Reclassification from nonaccretable difference Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference Changes in expected cash flows that do not affect nonaccretable difference Changes In Expected Cash Flows That Do Not Affect Nonaccretable Difference Represents changes in expected cash flows that do not affect nonaccretable difference. Balance at end of period Schedule of Stock by Class [Table] Schedule of Stock by Class [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Warrant Warrant [Member] Class of Stock [Line Items] Class of Stock [Line Items] Antidilutive securities excluded from computation (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Exercise of price warrants Class of Warrant or Right, Exercise Price of Warrants or Rights 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 and land improvements Land and Land Improvements [Member] Buildings and improvements Building and Building 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] Premises and equipments Property, Plant and Equipment, Net, by Type [Abstract] Premises and equipment, gross Property, Plant and Equipment, Gross Less accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Premises and equipment, net Accounting Policies [Table] Accounting Policies [Table] Represents information of accounting policies of the organization. Concentration Risk Type [Axis] Concentration Risk Type [Axis] Concentration Risk Type [Domain] Concentration Risk Type [Domain] Credit Concentration Risk Credit Concentration Risk [Member] Buildings and improvements Land improvements Land Improvements [Member] Furniture and equipment Accounting Policies [Line Items] Accounting Policies [Line Items] Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. Number of operating segments Number of Operating Segments Number of reportable segments Number of Reportable Segments Total assets of NER 16-1 VIE included in consolidated financial statements Variable Interest Entity, Consolidated, Carrying Amount, Assets Total liabilities of NER 16-1 VIE included in consolidated financial statements Variable Interest Entity, Consolidated, Carrying Amount, Liabilities Restricted cash balance Restricted Cash Loans received through acquisition Loans Receivable, Gross, Commercial, Acquisition Concentration risk, percentage Concentration Risk, Percentage Minimum nonaccrual loan relationships Minimum Nonaccrual Loan Amount Needed for Evaluation of Specific Reserves This element represents minimum nonaccrual loan amount needed for evaluation of specific reserves. Depreciation method used Property, Plant and Equipment, Depreciation Methods Estimated useful life Property, Plant and Equipment, Useful Life Reconciliation of the beginning and ending unrecognized tax benefit Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance at beginning of year Unrecognized Tax Benefits Additions based on tax positions related to the current year Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Decreases resulting from a lapse in the applicable statute of limitations Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations Remeasurement due to enactment of federal tax reform Unrecognized Tax Benefits Decreases Remeasurement Due To Enactment Of Federal Tax Reform Represents information about Remeasurement due to enactment of federal tax reform Balance at end of year Accounted for pursuant to ASC 310-30 Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period [Abstract] Contractually required principal and interest Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period, Contractually Required Payments Receivable at Acquisition Non-accretable difference Certain Loans Acquired in Transfer, Nonaccretable Difference Cash flows expected to be collected Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period, Cash Flows Expected to be Collected at Acquisition Accretable yield Certain Loans Acquired in Transfer, Accretable Yield Fair value Certain Loans Acquired in Transfer Accounted for as Held-to-maturity Debt Securities, Acquired During Period, at Acquisition, at Fair Value Excluded from ASC 310-30 Business Combination, Acquired Receivables [Abstract] Fair value Business Combination, Acquired Receivable, Fair Value Gross contractual amounts receivable Business Combination, Acquired Receivables, Gross Contractual Amount Estimate of contractual cash flows not expected to be collected Business Combination, Acquired Receivables, Estimated Uncollectible Debt securities held to maturity, fair value Loans held for sale, fair value Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, authorized (in shares) Common Stock, Shares Authorized Common stock, issued (in shares) Common Stock, Shares, Issued Common stock, outstanding (in shares) Common Stock, Shares, Outstanding Common stock issuable (in shares) Common Stock Issuable, Shares Represents number of shares of common stock issuable. Measurement Basis [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 Amount Reported Value Measurement [Member] Fair Value Estimate of Fair Value Measurement [Member] Assets: Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract] Loans, net Loans Receivable, Fair Value Disclosure Loans held for sale Loans Held-for-sale, Fair Value Disclosure Liabilities: Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract] Deposits Deposits, Fair Value Disclosure Federal Home Loan Bank advances Federal Home Loan Bank Borrowings, Fair Value Disclosure Long-term debt Long-term Debt, Fair Value Schedule of restricted stock and options outstanding and activity Share-based Compensation, Activity [Table Text Block] Schedule of summary of stock options outstanding Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Table Text Block] Current Current Income Tax Expense (Benefit) Deferred Deferred Other Tax Expense (Benefit) Increase in valuation allowance Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount Expense due to enactment of federal tax reform Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability Condensed Financial Statements of United Community Banks, Inc. (Parent Only) Condensed Financial Information of Parent Company Only Disclosure [Text Block] FDIC insurance limit Time Deposits, FDIC Insurance Limit Time Deposits, FDIC Insurance Limit Time deposits (excluding brokered time deposits) that met or exceeded FDIC insurance limit Time Deposits, at or Above FDIC Insurance Limit Brokered deposits, certificates of deposit Interest-bearing Domestic Deposit, Brokered Daily average balance of brokered deposits Daily Average Balance of Brokered Deposits This element represents average balance of brokered deposits. Description of fair value hedging instrument Description of Types of Fair Value Hedging Instruments Used Deferred income tax expense Deferred Income Tax Expense (Benefit) Securities losses (gains), net Gain (Loss) on Sale of Investments Gains from sales of government guaranteed loans Net (gains) losses on sales and write downs of other assets Gain (Loss) on Disposition of Other Assets Net losses (gains) on sales and write downs of other real estate owned Gains (Losses) on Sales of Other Real Estate Decrease (increase) in other assets and accrued interest receivable Increase Decrease In Other Assets And Accrued Interest Receivable This element represents amount of other assets and accrued interest receivable. Increase in accrued expenses and other liabilities Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities Decrease (increase) in loans held for sale Increase (Decrease) in Loans Held-for-sale Net cash provided by operating activities Debt securities held-to-maturity: Debt Securities Held To Maturity [Abstract] Debt Securities Held To Maturity [Abstract] Proceeds from maturities and calls Proceeds from Maturities, Prepayments and Calls of Held-to-maturity Securities Purchases Payments to Acquire Held-to-maturity Securities Debt securities available-for-sale and equity securities: Debt Securities Available-For-Sale And Equity Securities [Abstract] Debt Securities Available-For-Sale And Equity Securities [Abstract] Proceeds from maturities and calls Proceeds from Maturities, Prepayments and Calls of Available-for-sale Securities Purchases Net increase in loans Payments to Acquire Loans and Leases Held-for-investment Net cash (paid) received for acquisitions Payments to Acquire Businesses, Net of Cash Acquired Purchase of bank owned life insurance Payment to Acquire Life Insurance Policy, Investing Activities Proceeds from sales of premises and equipment Proceeds from Sale of Property, Plant, and Equipment Proceeds from sale of other real estate owned Proceeds from Sale of Other Real Estate Net cash used in investing activities Financing activities: Net increase in deposits Increase (Decrease) in Deposits Net (decrease) increase in short-term borrowings Repayments of Short-term Debt Net (decrease) increase in short-term borrowings Proceeds from Short-term Debt Proceeds from Federal Home Loan Bank advances Proceeds from Federal Home Loan Bank Advances Repayment of Federal Home Loan Bank advances Repayments of Federal Home Loan Bank Borrowings Proceeds from issuance of long-term debt, net of issuance costs Cash dividends on preferred stock Payments of Ordinary Dividends, Preferred Stock and Preference Stock Net cash provided by (used in) financing activities Net change in cash and cash equivalents, including restricted cash Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Cash and cash equivalents, including restricted cash, at beginning of year Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Cash and cash equivalents, including restricted cash, at end of year Supplemental disclosures of cash flow information: Supplemental Cash Flow Information [Abstract] Cash paid during the period for: Payments for Operating Activities [Abstract] Interest Interest Paid, Net Income taxes paid Income Taxes Paid, Net Derivatives and Hedging Activities Derivative Instruments and Hedging Activities Disclosure [Text Block] Accumulated benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Accumulated benefit obligation - beginning of year Defined Benefit Plan, Benefit Obligation Plan amendments Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment Actuarial (gains) losses Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Accumulated benefit obligation - end of year Change in plan assets, at fair value Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Beginning plan assets Actual return Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Employer contribution Defined Benefit Plan, Plan Assets, Contributions by Employer Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid Plan assets - end of year Funded status - end of year (plan assets less benefit obligations) Defined Benefit Plan, Funded (Unfunded) Status of Plan