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

AVAILABLE-FOR-SALE AND OTHER SECURITIES - Schedule of Amortized Cost, Fair Value, and Gross Unrealized Gains and Losses (Details)

AVAILABLE-FOR-SALE AND OTHER SECURITIES - Schedule of Amortized Cost, Fair Value, and Gross Unrealized Gains and Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 15,511,976	$ 15,776,855
Unrealized Gross Gains	65,250	47,626
Unrealized Gross Losses	(188,920)	(261,644)
Fair Value	15,388,306	15,562,837
U.S. Treasury
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,641	5,480
Unrealized Gross Gains	3	17
Unrealized Gross Losses	0	0
Fair Value	10,644	5,497
Federal agencies: Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,764,505	10,851,461
Unrealized Gross Gains	8,652	12,548
Unrealized Gross Losses	(149,102)	(190,667)
Fair Value	10,624,055	10,673,342
Federal agencies, Other agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	99,650	73,012
Unrealized Gross Gains	689	536
Unrealized Gross Losses	(48)	(6)
Fair Value	100,291	73,542
Total U.S. Treasury, Federal agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,874,796	10,929,953
Unrealized Gross Gains	9,344	13,101
Unrealized Gross Losses	(149,150)	(190,673)
Fair Value	10,734,990	10,752,381
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,282,938	3,260,428
Unrealized Gross Gains	47,711	28,431
Unrealized Gross Losses	(18,149)	(38,802)
Fair Value	3,312,500	3,250,057
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	614,141	824,124
Unrealized Gross Gains	2,256	1,492
Unrealized Gross Losses	(21,598)	(32,135)
Fair Value	594,799	793,481
Corporate debt
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	138,539	194,537
Unrealized Gross Gains	5,500	4,161
Unrealized Gross Losses	(4)	(15)
Fair Value	144,035	198,683
Other securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	601,562	567,813
Unrealized Gross Gains	439	441
Unrealized Gross Losses	(19)	(19)
Fair Value	$ 601,982	$ 568,235