Annual report pursuant to Section 13 and 15(d)

Derivative Financial Instruments (Details Textuals)

v2.4.1.9
Derivative Financial Instruments (Details Textuals) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Derivative Financial Instruments (Textuals) [Abstract]      
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value $ 14,400,000hban_DerivativeFinancialInstrumentsUsedByCompanyOnBehalfOfCustomersIncludingOffsettingDerivativesNotionalValue $ 14,300,000hban_DerivativeFinancialInstrumentsUsedByCompanyOnBehalfOfCustomersIncludingOffsettingDerivativesNotionalValue  
Credit risks from interest rate swaps used for trading purposes 219,300,000hban_CreditRisksFromInterestRateSwapsUsedForTradingPurposes 160,400,000hban_CreditRisksFromInterestRateSwapsUsedForTradingPurposes  
Purchase of interest rate caps and derivative financial instruments, notional value 12,129,100,000invest_DerivativeNotionalAmount    
Interest rate caps sold, value 0hban_InterestRateCapsSoldValue    
Total notional amount corresponds to trading assets, fair value 3,000,000hban_NotionalAmountCorrespondsToTradingAssetsFairValue    
Total notional amount corresponds to trading liabilities, fair value 0hban_NotionalAmountCorrespondsToTradingLiabilitiesFairValue    
Gains (losses) related to derivative instruments Included in total MSR 0hban_GainsLossesRelatedToDerivativeInstrumentsIncludedInMortgageSecurities (100,000)hban_GainsLossesRelatedToDerivativeInstrumentsIncludedInMortgageSecurities  
Additional Derivative Financial Instruments (Textuals) [Abstract]      
Aggregate credit risk, net of collateral 19,500,000hban_AggregateCreditRiskNetOfCollateral 15,200,000hban_AggregateCreditRiskNetOfCollateral  
Investment securities and cash collateral pledged by Huntington 0us-gaap_CollateralAlreadyPostedAggregateFairValue    
Investment securities and cash collateral pledged to Huntington 0hban_InvestmentSecuritiesAndCashCollateralPledgedToCompany    
Increase (decrease) to net interest income due to derivative adjustment 97,600,000hban_IncreaseDecreaseToNetInterestIncomeDueToDerivativeAdjustment 95,400,000hban_IncreaseDecreaseToNetInterestIncomeDueToDerivativeAdjustment 107,500,000hban_IncreaseDecreaseToNetInterestIncomeDueToDerivativeAdjustment
Expected after-tax unrealized gains on cash flow hedging derivatives reclassified to earnings 21,100,000us-gaap_InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet    
Interest Rate Cap [Member]      
Derivative Financial Instruments (Textuals) [Abstract]      
Purchase of interest rate caps and derivative financial instruments, notional value 0invest_DerivativeNotionalAmount
/ us-gaap_DerivativeByNatureAxis
= us-gaap_InterestRateCapMember 		   
Swap [Member]      
Derivative Financial Instruments (Textuals) [Abstract]      
Total derivative liabilities 400,000us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= us-gaap_SwapMember 		   
Derivative used in trading activity [Member]      
Derivative Financial Instruments (Textuals) [Abstract]      
Net derivative asset (liability) 74,400,000us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInTradingActivityMember 		80,500,000us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInTradingActivityMember 		 
Derivative used in Mortgage Banking Activities [Member]      
Derivative Financial Instruments (Textuals) [Abstract]      
Net derivative asset (liability) 80,000us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInMortgageBankingActivitiesMember 		6,792,000us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInMortgageBankingActivitiesMember 		 
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value 600,000,000hban_DerivativeFinancialInstrumentsUsedByCompanyOnBehalfOfCustomersIncludingOffsettingDerivativesNotionalValue
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInMortgageBankingActivitiesMember 		   
Total derivative liabilities $ 4,019,000us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInMortgageBankingActivitiesMember 		$ 271,000us-gaap_DerivativeFairValueOfDerivativeLiability
/ us-gaap_DerivativeByNatureAxis
= hban_DerivativeUsedInMortgageBankingActivitiesMember