Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)

v3.20.2
DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)
$ in Millions
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2020
USD ($)
group
Dec. 31, 2019
USD ($)
Jun. 30, 2020
USD ($)
Jun. 30, 2019
USD ($)
Dec. 31, 2019
USD ($)
Derivative [Line Items]          
Increase (decrease) to net interest income due to derivative adjustment $ 52 $ (15) $ 68 $ (29)  
Fair value hedging adjustments     (76)   $ (93)
Derivative, Notional Amount 28,819 25,927 28,819   25,927
Credit risks from interest rate swaps used for trading purposes 1,000 407 1,000   407
Derivative Liability $ 172 104 172   104
Number of primary groups | group 2        
Aggregate credit risk, net of collateral $ 92 22 92   22
Investment securities and cash collateral pledged by Huntington 231   231    
Investment securities and cash collateral pledged to Huntington 441   441    
Derivative used in trading activity          
Derivative [Line Items]          
Net derivative asset (liability) 65 87 65   87
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value 32,000 30,000 32,000   30,000
Derivative used in Mortgage Banking Activities          
Derivative [Line Items]          
Derivative, Notional Amount 540 778 540   778
Derivative, Fair Value, Net 31 6 31   6
Fair Value Hedging          
Derivative [Line Items]          
Derivative, Notional Amount 10,444 7,540 10,444   7,540
Cash Flow Hedging          
Derivative [Line Items]          
Derivative, Notional Amount 18,375 18,387 18,375   18,387
Commitments to Sell Loans [Member]          
Derivative [Line Items]          
Commitments to sell residential real estate loans 2,300 1,400 2,300   1,400
Loans Payable [Member]          
Derivative [Line Items]          
Derivative, Notional Amount 18,375 18,375 18,375   18,375
Loans Payable [Member] | Fair Value Hedging          
Derivative [Line Items]          
Derivative, Notional Amount 0   0    
Loans Payable [Member] | Cash Flow Hedging          
Derivative [Line Items]          
Derivative, Notional Amount $ 18,375 $ 18,375 $ 18,375   $ 18,375