Annual report pursuant to Section 13 and 15(d)

Other Comprehensive Income (Activity/Rollforward) (Details)

v2.4.1.9
Other Comprehensive Income (Activity/Rollforward) (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Pretax      
Non-credit-related impairment losses (recoveries) on debt (equity) securities not expected to be sold, before-tax $ 13,583,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax $ 235,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax $ 19,215,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesBeforeTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, pretax (15,559,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax 6,211,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax (4,769,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesBeforeTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, pretax (3,971,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax (15,188,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax 14,992,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesBeforeTax
Amortization of net actuarial loss and prior service cost included in income, pretax   (13,106,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax 27,013,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossBeforeTax
Total other comprehensive income (loss), pretax (11,750,000)us-gaap_OtherComprehensiveIncomeLossBeforeTax (97,404,000)us-gaap_OtherComprehensiveIncomeLossBeforeTax 36,110,000us-gaap_OtherComprehensiveIncomeLossBeforeTax
Tax (Expense) Benefit      
Non-credit-related impairment losses (recoveries) on debt (equity) securities not expected to be sold, tax (expense) benefit (4,803,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesTax (82,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesTax (6,725,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, tax (expense) benefit 5,446,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax (2,174,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax 1,669,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, tax (expense) benefit 1,390,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax 5,316,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax (5,237,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesTax
Amortization of net actuarial loss and prior service cost included in income, tax (expense) benefit   4,588,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax (9,455,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossTax
Total other comprehensive income (loss), tax (expense) benefit 3,467,000us-gaap_OtherComprehensiveIncomeLossTax 34,212,000us-gaap_OtherComprehensiveIncomeLossTax (13,164,000)us-gaap_OtherComprehensiveIncomeLossTax
After-tax      
Transisition obligation 8,780,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesNetOfTax 153,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesNetOfTax 12,490,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForWritedownOfSecuritiesNetOfTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, after-tax (10,113,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax 4,037,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax (3,100,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIForSaleOfSecuritiesNetOfTax
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale 45,783,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax (77,593,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax 55,305,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
Less: Reclassification adjustment for net losses (gains) losses included in net income, after-tax (2,581,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax (9,872,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax 9,755,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIOnDerivativesNetOfTax
Net change in unrealized gains (losses) on derivatives used in cash flow hedging relationships, after tax 6,611,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax (65,928,000)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax 6,186,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax
Amortization of net actuarial loss and prior service cost included in income, net of tax   (8,518,000)us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax 17,558,000us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax
Change in pension and post-retirement benefit plan assets and liabilities, after-tax (69,457,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax 80,176,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax (51,035,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
Total other comprehensive income (loss) (8,283,000)us-gaap_OtherComprehensiveIncomeLossNetOfTax (63,192,000)us-gaap_OtherComprehensiveIncomeLossNetOfTax 22,946,000us-gaap_OtherComprehensiveIncomeLossNetOfTax
Activity in accumulated other comprehensive income, net of tax      
Beginning Balance (214,009,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax   (150,817,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
Period change (8,283,000)hban_AccumulatedOtherComprehensiveIncomePeriodChange (63,192,000)hban_AccumulatedOtherComprehensiveIncomePeriodChange  
OCI before reclassifications 73,868,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax (48,839,000)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax  
Amounts reclassified from accumulated OCI (82,151,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax (14,353,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax  
Ending Balance (222,292,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax (214,009,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax  
Other Comprehensive Income (Textual) [Abstract]      
Unrealized losses transferred from the available for sale securities portfolio to the held to maturity securities 200,000hban_UnrealizedLossesTransferredFromAvailableForSaleSecuritiesPortfolioToHeldToMaturitySecurities    
Unrealized gains and losses on debt securities [Member]      
Pretax      
Unrealized holding gains (losses) on debt (equity) securities available for sale arising during the period, pretax 86,618,000us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(125,919,000)us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
90,318,000us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale, pretax 84,642,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(119,473,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
104,764,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Tax (Expense) Benefit      
Unrealized holding gains (losses) on debt (equity) securities available for sale arising during the period, tax (expense) benefit (30,914,000)us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
44,191,000us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(32,137,000)us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale, tax (expense) benefit (30,271,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
41,935,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(37,193,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
After-tax      
Unrealized holding gains (losses) on debt (equity) securities available for sale arising during the period, after-tax 55,704,000us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(81,728,000)us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
58,181,000us-gaap_OtherComprehensiveIncomeUnrealizedHoldingGainLossOnSecuritiesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale 54,371,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(77,538,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
67,571,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Activity in accumulated other comprehensive income, net of tax      
Beginning Balance (39,234,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
  38,304,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
Period change 54,371,000hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(77,538,000)hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
 
OCI before reclassifications   (81,575,000)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
 
Amounts reclassified from accumulated OCI   4,037,000us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
 
Ending Balance 15,137,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
(39,234,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
 
Unrealized gains and losses on equity securities [Member]      
Pretax      
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale, pretax 295,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
151,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
344,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
Tax (Expense) Benefit      
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale, tax (expense) benefit (103,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
(53,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
(120,000)us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
After-tax      
Net change in unrealized holding gains (losses) on debt (equity) securities available for sale 192,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
98,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
224,000us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
Activity in accumulated other comprehensive income, net of tax      
Beginning Balance 292,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
  194,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
Period change 192,000hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
98,000hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
 
OCI before reclassifications   98,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
 
Amounts reclassified from accumulated OCI   0us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
 
Ending Balance 484,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
292,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
 
Unrealized gains and losses on cash flow hedging derivatives [Member]      
Pretax      
Unrealized gains and losses on derivatives used in cash flow hedging relationships arising during the period, pretax 14,141,000us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(86,240,000)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(5,476,000)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Net change in unrealized gains (losses) on derivatives used in cash flow hedging relationships, pretax 10,170,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(101,428,000)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
9,516,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Tax (Expense) Benefit      
Unrealized gains and losses on derivatives used in cash flow hedging relationships arising during the period, tax (expense) benefit (4,949,000)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
30,184,000us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
1,907,000us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Net change in unrealized gains (losses) on derivatives used in cash flow hedging relationships (3,559,000)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
35,500,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(3,330,000)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
After-tax      
Unrealized gains and losses on derivatives used in cash flow hedging relationships arising during the period, after-tax 9,192,000us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(56,056,000)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(3,569,000)us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Net change in unrealized gains (losses) on derivatives used in cash flow hedging relationships, after tax 6,611,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(65,928,000)us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
6,186,000us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Activity in accumulated other comprehensive income, net of tax      
Beginning Balance (18,844,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
  47,084,000us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
Period change 6,611,000hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(65,928,000)hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
 
OCI before reclassifications 9,192,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(56,056,000)us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
 
Amounts reclassified from accumulated OCI (2,581,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(9,872,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
 
Ending Balance (12,233,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
(18,844,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnCashFlowHedgingDerivativesMember
 
Accumulated Unrealized Losses for Pension and Other Post-retirement obligations [Member]      
Pretax      
Net actuarial gains (losses) arising during the year, pretax   136,452,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(105,527,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansNetUnamortizedGainLossArisingDuringPeriodBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Change in pension and post-retirement benefit plan assets and liabilities, pretax (106,857,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
123,346,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(78,514,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentBeforeTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Tax (Expense) Benefit      
Net actuarial gains (losses) arising during the year, tax (expense) benefit   (47,758,000)us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
36,934,000us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Change in pension and post-retirement benefit plan assets and liabilities, tax (expense) benefit 37,400,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(43,170,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
27,479,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
After-tax      
Net actuarial gains (losses) arising during the year, net of tax   88,694,000us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(68,593,000)us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansNetUnamortizedGainLossArisingDuringPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Change in pension and post-retirement benefit plan assets and liabilities, after-tax (69,457,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
80,176,000us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(51,035,000)us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Activity in accumulated other comprehensive income, net of tax      
Beginning Balance (156,223,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
  (236,399,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
Period change (69,457,000)hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
80,176,000hban_AccumulatedOtherComprehensiveIncomePeriodChange
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
 
OCI before reclassifications 0us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
88,694,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
 
Amounts reclassified from accumulated OCI (69,457,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(8,518,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
 
Ending Balance (225,680,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
(156,223,000)us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax
/ us-gaap_StatementEquityComponentsAxis
= hban_AccumulatedUnrealizedLossesForPensionAndOtherPostretirementObligationsMember
 
Equity Securities [Member] | Unrealized gains and losses on equity securities [Member]      
Activity in accumulated other comprehensive income, net of tax      
OCI before reclassifications 192,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
   
Amounts reclassified from accumulated OCI 0us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_EquitySecuritiesMember
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnEquitySecuritiesMember
   
Debt Securities [Member] | Unrealized gains and losses on debt securities [Member]      
Activity in accumulated other comprehensive income, net of tax      
OCI before reclassifications 64,484,000us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_DebtSecuritiesMember
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember
   
Amounts reclassified from accumulated OCI $ (10,113,000)us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_DebtSecuritiesMember
/ us-gaap_StatementEquityComponentsAxis
= hban_UnrealizedGainsAndLossesOnDebtSecuritiesMember