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

DERIVATIVE FINANCIAL INSTRUMENTS - Mortgage Banking Activities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Derivative assets:
Total derivative assets	$ 320,826		$ 320,826		$ 420,159
Derivative liabilities:
Total derivative liabilities	(293,650)		(293,650)		(370,647)
Interest rate lock agreements
Derivative assets:
Total derivative assets	8,425		8,425		5,747
Derivative liabilities:
Total derivative liabilities	282		282		1,598
Forward trades and options
Derivative assets:
Total derivative assets	1,562		1,562		13,319
Derivative liabilities:
Total derivative liabilities	1,782		1,782		1,173
Derivative used in Mortgage Banking Activities
Derivatives, Fair Value [Line Items]
Gains losses related to derivative instruments Included in Mortgage securities	1,000	$ (1,000)	1,000	$ 17,000
Derivative assets:
Total derivative assets	9,987		9,987		19,066
Derivative liabilities:
Total derivative liabilities	$ 2,064		$ 2,064		$ 2,771