Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)

v3.19.2
DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)
$ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2019
USD ($)
group
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
Jun. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Derivative [Line Items]          
Purchase of interest rate caps and derivative financial instruments, notional value $ 20,877   $ 20,877   $ 4,877
Increase (decrease) to net interest income due to derivative adjustment (15) $ (15) (29) $ (14)  
Fair value hedging adjustments     (110)   (127)
Credit risks from interest rate swaps used for trading purposes 386   386   132
Derivative Liability $ 117   117   187
Number of primary groups | group 2        
Aggregate credit risk, net of collateral $ 34   34   37
Investment securities and cash collateral pledged by Huntington 82   82    
Investment securities and cash collateral pledged to Huntington 206   206    
Swap          
Derivative [Line Items]          
Derivative Liability 3   3    
Derivative used in trading activity          
Derivative [Line Items]          
Net derivative asset (liability) 89   89   92
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value 27,000   27,000   26,000
Derivative used in Mortgage Banking Activities          
Derivative [Line Items]          
Purchase of interest rate caps and derivative financial instruments, notional value 535   535   0
Derivative, Fair Value, Net 2   2   (4)
Fair Value Hedging          
Derivative [Line Items]          
Purchase of interest rate caps and derivative financial instruments, notional value 6,740   6,740   4,865
Cash Flow Hedging          
Derivative [Line Items]          
Purchase of interest rate caps and derivative financial instruments, notional value 11,937   11,937   12
Commitments to Sell Loans [Member]          
Derivative [Line Items]          
Commitments to sell residential real estate loans $ 1,400   $ 1,400   $ 800