Quarterly report pursuant to Section 13 or 15(d)

Available-for-Sale and Other Securities (Maturities/Unrealized) (Details)

v2.4.1.9
Available-for-Sale and Other Securities (Maturities/Unrealized) (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Investment maturity date range      
Non-marketable equity securities, Amortized Cost Non-marketable equity securities, Amortized Cost $ 331,770hban_AvailableForSaleSecuritiesNonMarketableEquitySecuritiesAmortizedCost   $ 331,559hban_AvailableForSaleSecuritiesNonMarketableEquitySecuritiesAmortizedCost
Marketable equity securities, Amortized Cost 536hban_AvailableForSaleSecuritiesMarketableEquitySecuritiesAmortizedCost   536hban_AvailableForSaleSecuritiesMarketableEquitySecuritiesAmortizedCost
Total investment securities, Amortized Cost 9,831,980us-gaap_AvailableForSaleSecuritiesAmortizedCost   9,359,886us-gaap_AvailableForSaleSecuritiesAmortizedCost
Non-marketable equity securities, Fair Value 331,771hban_AvailableForSaleSecuritiesNonMarketableEquitySecurities   331,559hban_AvailableForSaleSecuritiesNonMarketableEquitySecurities
Marketable equity securities, fair value 1,275hban_AvailableForSaleSecuritiesMarketableEquitySecuritiesFairValue   1,269hban_AvailableForSaleSecuritiesMarketableEquitySecuritiesFairValue
Available-for-sale and other securities 9,922,399us-gaap_AvailableForSaleSecurities   9,384,670us-gaap_AvailableForSaleSecurities
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 9,831,980us-gaap_AvailableForSaleSecuritiesAmortizedCost   9,359,886us-gaap_AvailableForSaleSecuritiesAmortizedCost
Total investment securities, Unrealized Gross Gains (167,637)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains   (117,554)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
Total investment securities, Unrealized Gross Losses (77,218)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss   (92,770)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
Available-for-sale and other securities 9,922,399us-gaap_AvailableForSaleSecurities   9,384,670us-gaap_AvailableForSaleSecurities
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 889,133us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue   1,437,360us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Total temporarily impaired securities, less than 12 months, Unrealized Losses (14,900)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses   (12,949)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
Total temporarily impaired securities, over 12 months, Fair Value 692,984us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue   1,063,142us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Total temporarily impaired securities, over 12 months, Unrealized Losses (62,318)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses   (79,821)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
Total temporarily impaired securities, Fair Value 1,582,117us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue   2,500,502us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (77,218)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss   (92,770)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
U.S. Treasury [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 5,835us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value, Under 1 year 5,835us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Amortized Cost, 1-5 years 5,440us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,435us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value, 1-5 years 5,520us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,452us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Amortized Cost, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Amortized Cost, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Fair Value, Total 11,355us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,452us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total investment securities, Amortized Cost 11,275us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,435us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Available-for-sale and other securities 11,355us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,452us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 11,275us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,435us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total investment securities, Unrealized Gross Gains (80)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  (17)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total investment securities, Unrealized Gross Losses 0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Available-for-sale and other securities 11,355us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  5,452us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total temporarily impaired securities, over 12 months, Fair Value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Total temporarily impaired securities, Fair Value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total 0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USTreasurySecuritiesMember
Federal agencies - mortgage backed securities [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 36,620us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  47,023us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, Under 1 year 36,734us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  47,190us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Amortized Cost, 1-5 years 209,862us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  216,775us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, 1-5 years 214,102us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  221,078us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Amortized Cost, 6-10 years 180,422us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  184,576us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, 6-10 years 183,552us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  186,938us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Amortized Cost, Over 10 years 5,263,901us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  4,825,525us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, Over 10 years 5,349,284us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  4,867,495us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, Total 5,783,672us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  5,322,701us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total investment securities, Amortized Cost 5,690,805us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  5,273,899us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale and other securities 5,783,672us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  5,322,701us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 5,690,805us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  5,273,899us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total investment securities, Unrealized Gross Gains (100,113)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  (63,906)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total investment securities, Unrealized Gross Losses (7,246)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  (15,104)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale and other securities 5,783,672us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  5,322,701us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 183,977us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  501,858us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (630)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  (1,909)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total temporarily impaired securities, over 12 months, Fair Value 310,854us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  527,280us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (6,616)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  (13,195)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total temporarily impaired securities, Fair Value 494,831us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  1,029,138us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (7,246)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
  (15,104)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Other Federal Agencies [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 32,248us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  33,047us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Fair Value, Under 1 year 32,328us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  33,237us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Amortized Cost, 1-5 years 9,071us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  9,122us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Fair Value, 1-5 years 9,555us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  9,575us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Amortized Cost, 6-10 years 119,696us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  103,530us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Fair Value, 6-10 years 122,886us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  105,019us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Amortized Cost, Over 10 years 181,131us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  204,016us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Fair Value, Over 10 years 185,646us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  203,712us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Fair Value, Total 350,415us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  351,543us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total investment securities, Amortized Cost 342,146us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  349,715us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Available-for-sale and other securities 350,415us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  351,543us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 342,146us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  349,715us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total investment securities, Unrealized Gross Gains (8,270)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  (2,871)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total investment securities, Unrealized Gross Losses (1)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  (1,043)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Available-for-sale and other securities 350,415us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  351,543us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 600us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  159,708us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (1)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  (1,020)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total temporarily impaired securities, over 12 months, Fair Value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  1,281us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  (23)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total temporarily impaired securities, Fair Value 600us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  160,989us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (1)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
  (1,043)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherFederalAgenciesMember
Total U.S. Government backed agencies [Member]      
Investment maturity date range      
Fair Value, Total 6,145,442us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  5,679,696us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total investment securities, Amortized Cost 6,044,226us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  5,629,049us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale and other securities 6,145,442us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  5,679,696us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 6,044,226us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  5,629,049us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total investment securities, Unrealized Gross Gains (108,463)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  (66,794)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total investment securities, Unrealized Gross Losses (7,247)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  (16,147)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale and other securities 6,145,442us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  5,679,696us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 184,577us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  661,566us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (631)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  (2,929)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total temporarily impaired securities, over 12 months, Fair Value 310,854us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  528,561us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (6,616)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  (13,218)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total temporarily impaired securities, Fair Value 495,431us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  1,190,127us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (7,247)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
  (16,147)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Municipal securities [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 277,551us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  256,399us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Fair Value, Under 1 year 271,172us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  255,835us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Amortized Cost, 1-5 years 322,135us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  269,385us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Fair Value, 1-5 years 326,618us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  274,003us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Amortized Cost, 6-10 years 996,655us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  938,780us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Fair Value, 6-10 years 1,004,624us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  945,954us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Amortized Cost, Over 10 years 445,189us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  376,747us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Fair Value, Over 10 years 463,791us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  392,777us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Fair Value, Total 2,066,205us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  1,868,569us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total investment securities, Amortized Cost 2,041,530us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  1,841,311us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Available-for-sale and other securities 2,066,205us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  1,868,569us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 2,041,530us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  1,841,311us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total investment securities, Unrealized Gross Gains (40,512)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  (37,398)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total investment securities, Unrealized Gross Losses (15,837)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  (10,140)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Available-for-sale and other securities 2,066,205us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  1,868,569us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 610,486us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  568,619us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (14,089)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  (9,127)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total temporarily impaired securities, over 12 months, Fair Value 57,696us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  96,426us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (1,748)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  (1,013)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Total temporarily impaired securities, Fair Value 668,182us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  665,045us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (15,837)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
  (10,140)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MunicipalBondsMember
Private label CMO [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Fair Value, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Amortized Cost, 1-5 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Fair Value, 1-5 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Amortized Cost, 6-10 years 1,195us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  1,314us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Fair Value, 6-10 years 1,245us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  1,371us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Amortized Cost, Over 10 years 40,847us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  42,416us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Fair Value, Over 10 years 39,009us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  40,555us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Fair Value, Total 40,254us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  41,926us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total investment securities, Amortized Cost 42,042us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  43,730us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale and other securities 40,254us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  41,926us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 42,042us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  43,730us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total investment securities, Unrealized Gross Gains (1,116)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  (1,116)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total investment securities, Unrealized Gross Losses (2,904)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  (2,920)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale and other securities 40,254us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  41,926us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total temporarily impaired securities, over 12 months, Fair Value 22,491us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  22,650us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (2,904)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  (2,920)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Total temporarily impaired securities, Fair Value 22,491us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  22,650us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (2,904)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
  (2,920)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Other Asset Backed Securities [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Fair Value, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Amortized Cost, 1-5 years 165,319us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  228,852us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Fair Value, 1-5 years 166,277us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  229,364us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Amortized Cost, 6-10 years 123,591us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  144,163us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Fair Value, 6-10 years 124,807us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  144,193us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Amortized Cost, Over 10 years 589,189us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  641,984us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Fair Value, Over 10 years 540,999us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  582,441us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Fair Value, Total 832,083us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  955,998us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total investment securities, Amortized Cost 878,099us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  1,014,999us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Available-for-sale and other securities 832,083us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  955,998us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 878,099us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  1,014,999us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total investment securities, Unrealized Gross Gains (4,626)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  (2,061)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total investment securities, Unrealized Gross Losses (50,642)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  (61,062)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Available-for-sale and other securities 832,083us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  955,998us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 61,741us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  157,613us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (125)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  (641)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total temporarily impaired securities, over 12 months, Fair Value 278,236us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  325,691us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (50,517)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  (60,421)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Total temporarily impaired securities, Fair Value 339,977us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  483,304us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (50,642)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
  (61,062)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherAssetBackedSecuritiesMember
Covered Bonds [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Fair Value, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Amortized Cost, 1-5 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Fair Value, 1-5 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Amortized Cost, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Fair Value, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Amortized Cost, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Fair Value, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Fair Value, Total 0us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total investment securities, Amortized Cost 0us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Available-for-sale and other securities 0us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 0us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total investment securities, Unrealized Gross Gains 0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total investment securities, Unrealized Gross Losses 0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Available-for-sale and other securities 0us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total temporarily impaired securities, over 12 months, Fair Value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total temporarily impaired securities, over 12 months, Unrealized Losses 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Total temporarily impaired securities, Fair Value 0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total 0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
  0us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_BondsMember
Corporate debt [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 38,801us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  18,767us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fair Value, Under 1 year 39,075us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  18,953us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Amortized Cost, 1-5 years 313,507us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  314,773us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fair Value, 1-5 years 324,116us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  323,503us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Amortized Cost, 6-10 years 125,689us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  145,611us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fair Value, 6-10 years 126,429us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  143,720us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Amortized Cost, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fair Value, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Fair Value, Total 489,620us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  486,176us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total investment securities, Amortized Cost 477,997us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  479,151us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Available-for-sale and other securities 489,620us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  486,176us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 477,997us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  479,151us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total investment securities, Unrealized Gross Gains (12,167)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  (9,442)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total investment securities, Unrealized Gross Losses (544)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  (2,417)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Available-for-sale and other securities 489,620us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  486,176us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 31,556us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  49,562us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (28)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  (252)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total temporarily impaired securities, over 12 months, Fair Value 22,224us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  88,398us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (516)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  (2,165)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Total temporarily impaired securities, Fair Value 53,780us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  137,960us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total (544)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
  (2,417)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= us-gaap_CorporateDebtSecuritiesMember
Other Securities [Member]      
Investment maturity date range      
Amortized Cost, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  250us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Fair Value, Under 1 year 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  250us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Amortized Cost, 1-5 years 3,950us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  3,150us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Fair Value, 1-5 years 3,906us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  3,066us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Amortized Cost, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Fair Value, 6-10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Amortized Cost, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Fair Value, Over 10 years 0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Fair Value, Total 348,795us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  352,305us-gaap_AvailableForSaleSecuritiesDebtSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total investment securities, Amortized Cost 348,086us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  351,646us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Available-for-sale and other securities 348,795us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  352,305us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Amortized cost, fair value, and gross unrealized gains and losses recognized in accumulated other comprehensive income      
Total investment securities, Amortized Cost 348,086us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  351,646us-gaap_AvailableForSaleSecuritiesAmortizedCost
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total investment securities, Unrealized Gross Gains (753)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  (743)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGains
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total investment securities, Unrealized Gross Losses (44)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  (84)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Available-for-sale and other securities 348,795us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  352,305us-gaap_AvailableForSaleSecurities
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Investment securities in unrealized loss position      
Total temporarily impaired securities, less than 12 months, Fair value 773us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total temporarily impaired securities, less than 12 months, Unrealized Losses (27)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  0us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total temporarily impaired securities, over 12 months, Fair Value 1,483us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  1,416us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total temporarily impaired securities, over 12 months, Unrealized Losses (17)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  (84)us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Total temporarily impaired securities, Fair Value 2,256us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  1,416us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Losses, Total $ (44)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember
  $ (84)us-gaap_AvailableForSaleSecuritiesGrossUnrealizedLoss
/ us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis
= hban_OtherSecuritiesMember