Huntington Bancshares Incorporated Annual report pursuant to Section 13 and 15(d)

LONG-TERM DEBT - Narrative (Details)

LONG-TERM DEBT - Narrative (Details)		1 Months Ended			12 Months Ended
LONG-TERM DEBT - Narrative (Details)	Mar. 31, 2015 securitization	Nov. 30, 2015 USD ($)	Feb. 28, 2015 USD ($)	Apr. 30, 2014	Dec. 31, 2016 USD ($)	Aug. 16, 2016 USD ($)	Aug. 09, 2016 USD ($)	Mar. 14, 2016 USD ($)	Dec. 31, 2015 USD ($)	Aug. 31, 2015 USD ($)
Debt Instrument [Line Items]
Long-term debt					$ 8,309,159,000				$ 7,041,364,000
Senior Notes \| Senior Notes Due 2022
Debt Instrument [Line Items]
Debt face amount							$ 1,000,000,000.0
Debt percent of value issued							99.849%
Stated rate							2.30%
Debt Issuance Costs, Net							$ 5,000,000
Senior Notes \| Three point One Five Percent Senior notes Due March 2021
Debt Instrument [Line Items]
Debt face amount								$ 1,000,000,000.0
Debt percent of value issued								99.803%
Stated rate								3.15%
Debt Issuance Costs, Net								$ 5,000,000
Subordinated Notes
Debt Instrument [Line Items]
Long-term debt					4,821,846,000				5,540,135,000
Other borrowings
Debt Instrument [Line Items]
Long-term debt					335,158,000				$ 452,448,000
Other borrowings \| HTF Non-recourse Debt, Effective Rate 3.20%
Debt Instrument [Line Items]
Effective rate									3.20%
Long-term debt									$ 293,400,000
Other borrowings \| HTF Non-recourse Debt, Effective Rate 1.70%
Debt Instrument [Line Items]
Effective rate									1.70%
Long-term debt									$ 255,000,000
Debt assumed number of securitizations \| securitization	2
Parent Company
Debt Instrument [Line Items]
Long-term debt					3,144,615,000				1,040,981,000
Parent Company \| Subordinated Notes
Debt Instrument [Line Items]
Long-term debt					$ 248,156,000				0
Parent Company \| Subordinated Notes \| Huntington Capital II Trust Preferred 1.14% junior subordinated debentures due 2028
Debt Instrument [Line Items]
Effective rate					1.14%
Long-term debt					$ 31,576,000				54,030,000
Parent Company \| Subordinated Notes \| Huntington Capital II Trust Preferred 1.14% junior subordinated debentures due 2028 \| Three-month LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate					0.625%
Bank \| Senior Notes
Debt Instrument [Line Items]
Debt percent of value issued			99.87%
Bank \| Senior Notes \| Senior Notes Due November 6, 2018
Debt Instrument [Line Items]
Debt face amount		$ 850,000,000.0
Debt percent of value issued		99.88%
Stated rate		2.20%
Bank \| Senior Notes \| Senior Notes Due November 6, 2018 \| One month prior to maturity date
Debt Instrument [Line Items]
Redemption price percentage		100.00%
Bank \| Senior Notes \| Senior Notes Due August 20, 2020
Debt Instrument [Line Items]
Debt face amount										$ 500,000,000.0
Debt percent of value issued										99.58%
Stated rate										2.88%
Bank \| Senior Notes \| Senior Notes Due June 30, 2018
Debt Instrument [Line Items]
Debt face amount									$ 750,000,000.0
Debt percent of value issued									99.71%
Stated rate									2.00%
Bank \| Senior Notes \| Senior Notes Due February 2018
Debt Instrument [Line Items]
Debt face amount			$ 500,000,000.0
Debt percent of value issued			99.86%
Effective rate			1.70%
Bank \| Senior Notes \| Senior Notes Due February 2018 \| One month prior to maturity date
Debt Instrument [Line Items]
Redemption price percentage			100.00%
Bank \| Senior Notes \| Senior Notes Due April 1, 2020
Debt Instrument [Line Items]
Debt face amount			$ 500,000,000.0
Stated rate			2.40%
Redemption price percentage			100.00%
Bank \| Senior Notes \| Senior Notes Due April 24, 2017, Variable Rate \| One month prior to maturity date
Debt Instrument [Line Items]
Redemption price percentage				100.00%
FirstMerit Bank
Debt Instrument [Line Items]
Long-term Debt						$ 519,971,000
FirstMerit Bank \| Subordinated Notes
Debt Instrument [Line Items]
Long-term Debt						$ 520,000,000