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	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 16,375,549	$ 15,776,855
Unrealized Gross Gains	57,957	47,626
Unrealized Gross Losses	(259,901)	(261,644)
Fair Value	16,173,605	15,562,837
U.S. Treasury
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	6,881	5,480
Unrealized Gross Gains	9	17
Unrealized Gross Losses	0	0
Fair Value	6,890	5,497
Federal agencies: Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,415,013	10,851,461
Unrealized Gross Gains	10,882	12,548
Unrealized Gross Losses	(204,028)	(190,667)
Fair Value	11,221,867	10,673,342
Federal agencies, Other agencies
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	89,530	73,012
Unrealized Gross Gains	356	536
Unrealized Gross Losses	(43)	(6)
Fair Value	89,843	73,542
Total U.S. Treasury, Federal agency securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	11,511,424	10,929,953
Unrealized Gross Gains	11,247	13,101
Unrealized Gross Losses	(204,071)	(190,673)
Fair Value	11,318,600	10,752,381
Municipal securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	3,303,594	3,260,428
Unrealized Gross Gains	39,687	28,431
Unrealized Gross Losses	(26,127)	(38,802)
Fair Value	3,317,154	3,250,057
Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	794,384	824,124
Unrealized Gross Gains	2,225	1,492
Unrealized Gross Losses	(29,672)	(32,135)
Fair Value	766,937	793,481
Corporate debt
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	194,329	194,537
Unrealized Gross Gains	4,357	4,161
Unrealized Gross Losses	(5)	(15)
Fair Value	198,681	198,683
Other securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	571,818	567,813
Unrealized Gross Gains	441	441
Unrealized Gross Losses	(26)	(19)
Fair Value	$ 572,233	$ 568,235