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

DERIVATIVE FINANCIAL INSTRUMENTS - Fair Value Hedges (Details)

DERIVATIVE FINANCIAL INSTRUMENTS - Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Amortized Cost	$ 14,599		$ 14,599		$ 7,578
Cumulative Amount of Fair Value Hedging Adjustment To Hedged Items	275		275		114
Fair value hedging adjustments			69		93
Investment Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amortized Cost	7,389		7,389		0
Cumulative Amount of Fair Value Hedging Adjustment To Hedged Items	1		1		0
Amortized cost basis of the closed portfolios used in hedging relationships	7,200		7,200
Designated hedged items	3,100		3,100
Subordinated notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amortized Cost	7,210		7,210		7,578
Cumulative Amount of Fair Value Hedging Adjustment To Hedged Items	274		274		$ 114
Interest income available for sale securities taxable [Member] \| Investment Securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value for derivatives designated as fair value hedges	0	$ 0	(1)	$ 0
Interest income available for sale securities taxable [Member] \| Hedged investment securities [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value for derivatives designated as fair value hedges	0	0	1	0
Interest expense subordinated notes and other long term debt [Member] \| Subordinated notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value for derivatives designated as fair value hedges	(36)	36	159	165
Interest expense subordinated notes and other long term debt [Member] \| Hedged Subordinated notes [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value for derivatives designated as fair value hedges	$ 35	$ (32)	$ (160)	$ (162)