Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)

v3.19.3
DERIVATIVE FINANCIAL INSTRUMENTS - Narrative (Details)
$ in Millions
 3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2019
USD ($)
group
Sep. 30, 2018
USD ($)
Sep. 30, 2019
USD ($)
Sep. 30, 2018
USD ($)
Dec. 31, 2018
USD ($)
Derivative [Line Items]          
Increase (decrease) to net interest income due to derivative adjustment $ (16) $ (11) $ (44) $ (25)  
Fair value hedging adjustments     (104)   $ (127)
Derivative, Notional Amount 24,702   24,702   4,877
Credit risks from interest rate swaps used for trading purposes 515   515   132
Derivative Liability $ 127   127   187
Number of primary groups | group 2        
Aggregate credit risk, net of collateral $ 46   46   37
Investment securities and cash collateral pledged by Huntington 109   109    
Investment securities and cash collateral pledged to Huntington 228   228    
Swap          
Derivative [Line Items]          
Derivative Liability 3   3    
Derivative used in trading activity          
Derivative [Line Items]          
Net derivative asset (liability) 87   87   92
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value 30,000   30,000   26,000
Derivative used in Mortgage Banking Activities          
Derivative [Line Items]          
Derivative, Notional Amount 572   572   0
Derivative, Fair Value, Net 14   14   (4)
Fair Value Hedging          
Derivative [Line Items]          
Derivative, Notional Amount 7,540   7,540   4,865
Cash Flow Hedging          
Derivative [Line Items]          
Derivative, Notional Amount 17,162   17,162   12
Commitments to Sell Loans [Member]          
Derivative [Line Items]          
Commitments to sell residential real estate loans 2,000   2,000   $ 800
Loans Payable [Member]          
Derivative [Line Items]          
Derivative, Notional Amount 17,150   17,150    
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 $ 17,150   $ 17,150