Quarterly report pursuant to Section 13 or 15(d)

Held-to-Maturity Securities (Details)

v2.4.1.9
Held-to-Maturity Securities (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
Dec. 31, 2014
Contractual maturities of held-to-maturity securities    
Held-to-maturity securities, Total $ 3,336,663us-gaap_HeldToMaturitySecurities $ 3,379,905us-gaap_HeldToMaturitySecurities
Held-to-maturity Securities, Fair Value 3,374,889us-gaap_HeldToMaturitySecuritiesFairValue 3,382,715us-gaap_HeldToMaturitySecuritiesFairValue
Amortized cost, gross unrealized gains and losses, and fair value by investment category    
Held-to-maturity securities, Total 3,336,663us-gaap_HeldToMaturitySecurities 3,379,905us-gaap_HeldToMaturitySecurities
Held-to-maturity Securities, Gross Gain (47,123)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain (26,083)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
Held-to-maturity Securities, Gross Losses (8,897)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss (23,273)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
Held-to-maturity securities, fair value 3,374,889us-gaap_HeldToMaturitySecuritiesFairValue 3,382,715us-gaap_HeldToMaturitySecuritiesFairValue
Continuous Unrealized Loss Position    
Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value 193,161us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue 752,484us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value 1,094us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss 6,135us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Total Temporarily Impaired Securities, Over Twelve Months, Fair Value 443,863us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue 693,757us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months 7,803us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss 17,138us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Total Temporarily Impaired Securities, Fair Value 637,024us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue 1,446,241us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
Total Temporarily Impaired Securities, Unrealized Losses 8,897us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss 23,273us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Federal agencies - mortgage backed securities [Member]    
Contractual maturities of held-to-maturity securities    
Held-to-maturity Securities, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, 6-10 years 24,901us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
24,901us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, Over 10 years 3,017,912us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,136,460us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity securities, Total 3,042,813us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,161,361us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, 6-10 years 24,517us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
24,263us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair Value, Over 10 years 3,053,362us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,140,194us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, Fair Value 3,077,879us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,164,457us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Amortized cost, gross unrealized gains and losses, and fair value by investment category    
Held-to-maturity securities, Total 3,042,813us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,161,361us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, Gross Gain (43,058)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
(24,832)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity Securities, Gross Losses (7,992)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
(21,736)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Held-to-maturity securities, fair value 3,077,879us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,164,457us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Continuous Unrealized Loss Position    
Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value 130,027us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
707,934us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value 748us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
5,550us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total Temporarily Impaired Securities, Over Twelve Months, Fair Value 414,559us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
622,026us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months 7,244us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
16,186us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total Temporarily Impaired Securities, Fair Value 544,586us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
1,329,960us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Total Temporarily Impaired Securities, Unrealized Losses 7,992us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
21,736us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Other Federal Agencies [Member]    
Contractual maturities of held-to-maturity securities    
Held-to-maturity Securities, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, 6-10 years 78,053us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
54,010us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, Over 10 years 208,091us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
156,553us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity securities, Total 286,144us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
210,563us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Fair Value, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Fair Value, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Fair Value, 6-10 years 80,031us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
54,843us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Fair Value, Over 10 years 209,698us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
155,821us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, Fair Value 289,729us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
210,664us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Amortized cost, gross unrealized gains and losses, and fair value by investment category    
Held-to-maturity securities, Total 286,144us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
210,563us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, Gross Gain (4,065)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
(1,251)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity Securities, Gross Losses (480)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
(1,150)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Held-to-maturity securities, fair value 289,729us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
210,664us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Continuous Unrealized Loss Position    
Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value 63,134us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
36,956us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value 346us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
198us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Total Temporarily Impaired Securities, Over Twelve Months, Fair Value 22,023us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
71,731us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months 134us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
952us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Total Temporarily Impaired Securities, Fair Value 85,157us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
108,687us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Total Temporarily Impaired Securities, Unrealized Losses 480us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
1,150us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= hban_OtherFederalAgenciesMember
Municipal securities [Member]    
Contractual maturities of held-to-maturity securities    
Held-to-maturity Securities, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, 6-10 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, Over 10 years 7,706us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,981us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsNetCarryingAmount
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity securities, Total 7,706us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,981us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Fair Value, Under 1 year 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesWithinOneYearFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Fair Value, 1-5 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Fair Value, 6-10 years 0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterFiveThroughTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Fair Value, Over 10 years 7,281us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,594us-gaap_HeldToMaturitySecuritiesDebtMaturitiesAfterTenYearsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, Fair Value 7,281us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,594us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Amortized cost, gross unrealized gains and losses, and fair value by investment category    
Held-to-maturity securities, Total 7,706us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,981us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, Gross Gain 0us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity Securities, Gross Losses (425)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
(387)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Held-to-maturity securities, fair value 7,281us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,594us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Continuous Unrealized Loss Position    
Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value 0us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,594us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value 0us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
387us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total Temporarily Impaired Securities, Over Twelve Months, Fair Value 7,281us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months 425us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
0us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total Temporarily Impaired Securities, Fair Value 7,281us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
7,594us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total Temporarily Impaired Securities, Unrealized Losses 425us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
387us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MunicipalBondsMember
Total U.S. Government backed agencies [Member]    
Contractual maturities of held-to-maturity securities    
Held-to-maturity securities, Total 3,328,957us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
3,371,924us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Held-to-maturity Securities, Fair Value 3,367,608us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
3,375,121us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Amortized cost, gross unrealized gains and losses, and fair value by investment category    
Held-to-maturity securities, Total 3,328,957us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
3,371,924us-gaap_HeldToMaturitySecurities
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Held-to-maturity Securities, Gross Gain (47,123)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
(26,083)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingGain
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Held-to-maturity Securities, Gross Losses (8,472)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
(22,886)us-gaap_HeldToMaturitySecuritiesAccumulatedUnrecognizedHoldingLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Held-to-maturity securities, fair value 3,367,608us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
3,375,121us-gaap_HeldToMaturitySecuritiesFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Continuous Unrealized Loss Position    
Total Temporarily Impaired Securities, Less Than Twelve Months, Fair Value 193,161us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
744,890us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total Temporarily Impaired Securities Unrealized Losses, Less Than Twelve Months, Fair Value 1,094us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
5,748us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total Temporarily Impaired Securities, Over Twelve Months, Fair Value 436,582us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
693,757us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total Temporarily Impaired Securites, Unrealized Losses Over Twelve Months 7,378us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
17,138us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total Temporarily Impaired Securities, Fair Value 629,743us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
1,438,647us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
Total Temporarily Impaired Securities, Unrealized Losses $ 8,472us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember
$ 22,886us-gaap_HeldToMaturitySecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentSponsoredEnterprisesDebtSecuritiesMember