Huntington Bancshares Incorporated Quarterly report pursuant to Section 13 or 15(d)

Derivative Financial Instruments (Asset and liability management) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Mar. 31, 2015
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount	$ 600,000invest_DerivativeNotionalAmount
Cash flow hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		10,034,750
Fair Value Hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		3,829,100
Loan [Member] \| Cash flow hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		10,034,750
Deposits [Member] \| Fair Value Hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		69,100
Subordinated notes \| Fair Value Hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		0
Other long-term debt \| Fair Value Hedging [Member]
Notional Amount Of Derivatives [Abstract]
Derivative, Notional Amount		$ 3,760,000