Entity tax identification number Entity Tax Identification Number Rollovers EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Mutual funds Mutual Fund [Member] Tranche One EBP, Employer Contribution, Tranche One [Member] EBP, Employer Contribution, Tranche One Dividends payable to Plan participants EBP, Liability to Participant Subsequent Event Subsequent Event [Member] EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] EBP 002 EBP 002 [Member] EBP 002 Fidelity BrokerageLink BrokerageLink accounts EBP, Self-Directed Brokerage Account [Member] Benefit distributions and other withdrawals EBP, Change in Net Asset Available for Benefit, Decrease Participant loans, maximum borrowing, amount EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Text Block] Participant loans, minimum borrowing, amount EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount Payable for administrative expenses EBP, Accrued Expense Employer contribution vesting percentage EBP, Employer Contribution Vesting Percentage EBP, Employer Contribution Vesting Percentage Prudential Core Plus Bond Fund Prudential Core Plus Bond Fund [Member] Prudential Core Plus Bond Fund Investments, at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Subsequent Event Type [Domain] Subsequent Event Type [Domain] Quoted Prices In Active Markets for Identical Assets (Level 1) Fair Value, Inputs, Level 1 [Member] EBP, Investment, Fair Value and NAV [Abstract] Forfeitures, decrease from contributions and reasonable expenses EBP, Forfeited Nonvested Account, Decrease From Employer Contribution And Administrative Expense EBP, Forfeited Nonvested Account, Decrease From Employer Contribution And Administrative Expense Summary of Party-In-Interest Transactions EBP, Related Party and Party-in-Interest Transactions [Table Text Block] Total assets EBP, Asset ASSETS EBP, Asset [Abstract] Fair Value Measurements EBP, Investment, Fair Value And NAV [Policy Text Block] EBP, Investment, Fair Value And NAV Statistical Measurement [Axis] Statistical Measurement [Axis] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Benefit Payments EBP, Payment to Participant [Policy Text Block] Total liabilities EBP, Liability Amendment Flag Amendment Flag Basis of Presentation EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] Number of shares (in shares) EBP, Investment, Number of Shares EBP, Description of Plan and Accounting Change [Abstract] Receivables: EBP, Receivable [Abstract] Summary of Fair Value Measurements EBP, Investment, Fair Value and NAV [Table Text Block] Spartan Extended Market Index Fund Spartan Extended Market Index Fund [Member] Spartan Extended Market Index Fund Employer contribution, participant compensation matched, maximum, amount EBP, Employer Contribution, Participant Compensation Matched, Maximum, Amount EBP, Employer Contribution, Participant Compensation Matched, Maximum, Amount Common stock Common Stock [Member] Investments [Domain] Investments [Domain] Use of Estimates EBP, Use of Estimate [Policy Text Block] Forfeitures, account restoration, rehiring period EBP, Forfeited Nonvested Account, Account Restoration, Rehiring Period EBP, Forfeited Nonvested Account, Account Restoration, Rehiring Period Spartan 500 Index Plus Fund Spartan 500 Index Plus Fund [Member] Spartan 500 Index Plus Fund EBP, Employer Contribution, Type [Axis] EBP, Employer Contribution, Requisite Service Period [Axis] EBP, Employer Contribution, Type [Axis] EBP, Employer Contribution, Type SCHEDULE H, LINE 4I — SCHEDULE OF ASSETS (HELD AT END OF YEAR) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] Withdrawing participant, minimum withdrawable percentage EBP, Withdrawing Participant, Maximum Withdrawable Percentage EBP, Withdrawing Participant, Maximum Withdrawable Percentage Employer EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash Dividends on Huntington common stock EBP, Change In Net Asset Available For Benefit, Decrease From Dividends EBP, Change In Net Asset Available For Benefit, Decrease From Dividends Minimum Minimum [Member] Accrued dividends and interest receivable EBP, Investment Income, Receivable Investment Type [Axis] Investment Type [Axis] Interest on notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Participant contribution, automatic annual increase deferral rate EBP, Participant Contribution, Automatic, Annual Increase Deferral Rate EBP, Participant Contribution, Automatic, Annual Increase Deferral Rate Increase from acquisition, rollover EBP, Change In Net Asset Available For Benefit, Increase From Acquisition, Rollover EBP, Change In Net Asset Available For Benefit, Increase From Acquisition, Rollover Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Employees EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover Employer contribution vesting service period EBP, Employer Contribution Vesting Service Period EBP, Employer Contribution Vesting Service Period Net appreciation in fair value of investments Realized and unrealized gain on Huntington common stock EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Gain (Loss) on Investment Dividends and interest from investments EBP, Change in Net Asset Available for Benefit, Increase from Interest and Dividend Income on Investment EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] Wellington CIF II Wellington CIF II [Member] Wellington CIF II Plan number EBP, Plan Number Participant loans, general loan, maximum borrowing term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Note Receivable From Participant, General Loan, Maximum Borrowing Term EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] DESCRIPTION OF THE PLAN EBP, Description of Plan [Text Block] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] Requisite service period EBP, Requisite Service Period EBP, Requisite Service Period EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] Contributions EBP, Contribution [Policy Text Block] Huntington common stock EBP, Employer, Common Stock [Member] EBP, Schedule of Asset Held for Investment [Abstract] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions EBP, Change in Net Asset Available for Benefit, Increase Maximum contribution of eligible compensation, percentage EBP, Participant Contribution, Maximum Contribution To Eligible Compensation, Percentage EBP, Participant Contribution, Maximum Contribution To Eligible Compensation, Percentage Investment income: EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Investment, Identifier [Axis] Investment, Identifier [Axis] Total EBP, Asset Held for Investment Tranche Two EBP, Employer Contribution, Tranche Two [Member] EBP, Employer Contribution, Tranche Two Risks and Uncertainties EBP, Risk and Uncertainty [Policy Text Block] Document Information [Line Items] Document Information [Line Items] ADDITIONS TO (DEDUCTIONS FROM) NET ASSETS EBP, Change in Net Asset Available for Benefit, Increase (Decrease) [Abstract] Vanguard Target Retirement Funds Vanguard Target Retirement Funds [Member] Vanguard Target Retirement Funds Employer contribution, participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Significant Other Observable Inputs (Level 2) Fair Value, Inputs, Level 2 [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase in net assets available for benefits EBP, Change in Net Asset Available for Benefit, Increase (Decrease) PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Total receivables EBP, Receivable Participant contribution, automatic deferral rate EBP, Participant Contribution, Automatic, Deferral Rate Current value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Fidelity managed funds EBP, Mutual Fund And Common Collective Trust [Member] EBP, Mutual Fund And Common Collective Trust EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] Participant loans, primary residence, maximum borrowing term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term EBP, Note Receivable From Participant, Account, Primary Residence, Maximum Borrowing Term Notes Receivable from Participants EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Income Recognition EBP, Investment [Policy Text Block] Total Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type Entity Central Index Key Entity Central Index Key Notes receivable from participants, interest rates EBP, Asset Held for Investment, Participant Loan, Interest Rate Collective investment trust funds Common Collective Trust [Member] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] EBP, Subsequent Event [Table] EBP, Subsequent Event [Table] Notes receivable from participants Notes receivable from participants, principal amount EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] SIGNIFICANT ACCOUNTING POLICIES EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name Costs and expenses EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Subsequent Event [Abstract] LIABILITIES EBP, Liability [Abstract] SUBSEQUENT EVENTS EBP, Subsequent Event [Text Block] Invesco Stable Value Trust B1 Invesco Stable Value Trust B1 [Member] Invesco Stable Value Trust B1 INCOME TAXES EBP, Tax Status [Text Block] Participant loan, basis spread on variable rate EBP, Participant Loan, Basis Spread On Variable Rate EBP, Participant Loan, Basis Spread On Variable Rate Spartan Total International Index Fund Spartan Total International Index Fund [Member] Spartan Total International Index Fund Participant loans, maximum borrowing, to total account, percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Line Items] Document Information [Table] Document Information [Table] EBP, Employer Contribution, Type [Domain] EBP, Employer Contribution, Type [Domain] EBP, Employer Contribution, Type [Domain] Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment Redemption Notice Period EBP, Fair Value, Investment, NAV, Redemption, Notice Period EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] NET ASSETS AVAILABLE FOR BENEFITS Net assets available for benefits at beginning of year NET ASSETS AVAILABLE FOR BENEFITS AT END OF YEAR EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Contributions: EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Forfeited non-vested accounts EBP, Forfeited Nonvested Account Employer contribution, matching percentage EBP, Employer Contribution, Matching Percentage Fair Value Estimated Using NAV Per Share Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]