Quarterly report pursuant to Section 13 or 15(d)

Derivative Financial Instruments (Details Textuals)

v2.4.0.6
Derivative Financial Instruments (Details Textuals) (USD $)
 3 Months Ended 9 Months Ended
Sep. 30, 2012
Sep. 30, 2011
Sep. 30, 2012
Sep. 30, 2011
Dec. 31, 2011
Derivative Financial Instruments (Textuals) [Abstract]          
Credit risks from interest rate swaps used for trading purposes $ 336,900,000   $ 336,900,000   $ 309,500,000
MSR hedging gains (losses)     33,000,000 39,100,000  
Gains (losses) related to derivative instruments Included in total MSR     33,000,000 39,200,000  
Additional Derivative Financial Instruments (Textuals) [Abstract]          
Aggregate credit risk, net of collateral 16,700,000   16,700,000   36,400,000
Investment securities and cash collateral pledged by Huntington 155,800,000   155,800,000    
Investment securities and cash collateral pledged to Huntington 187,600,000   187,600,000    
Additional collateral to be provided in case of credit downgrades 0   0    
Increase (decrease) to net interest income due to derivative adjustment 28,800,000 27,400,000 81,200,000 89,300,000  
Expected after-tax unrealized gains on cash flow hedging derivatives reclassified to earnings 35,700,000   35,700,000    
Interest Rate Cap [Member]
          
Derivative Financial Instruments (Textuals) [Abstract]          
Purchase of interest rate caps and derivative financial instruments, notional value 700,000,000   700,000,000    
Interest rate caps sold, value 700,000,000   700,000,000    
Swap [Member]
          
Derivative Financial Instruments (Textuals) [Abstract]          
Total derivative liabilities 400,000   400,000    
Derivative used in trading activity [Member]
          
Derivative Financial Instruments (Textuals) [Abstract]          
Net derivative liability 62,400,000   62,400,000   53,200,000
Derivative financial instruments used by Huntington on behalf of customers including offsetting derivatives, notional value 22,600,000,000   22,600,000,000   10,600,000,000
Derivative used in Mortgage Banking Activities [Member]
          
Derivative Financial Instruments (Textuals) [Abstract]          
Net derivative liability 3,140,000   3,140,000   (1,265,000)
Purchase of interest rate caps and derivative financial instruments, notional value 1,800,000 39,200,000,000 1,800,000 39,200,000,000 1,700,000,000
Total notional amount corresponds to trading assets, fair value 20,200,000   20,200,000    
MSR hedging gains (losses) 15,400,000 30,300,000      
Gains (losses) related to derivative instruments Included in total MSR 15,400,000     30,200,000  
Total derivative liabilities $ 15,477,000   $ 15,477,000   $ 8,036,000