v2.4.0.6
Mortgage Banking Activities, Amortized Mortgage Servicing Rights (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Dec. 31, 2011
Changes in amortized MSRs      
Amortization $ (58) $ (64)  
Valuation Allowance      
Reversal of provision (provision) for mortgage servicing rights in excess of fair value 0 (6)  
Amortized mortgage servicing rights, net 1,074   1,408
Amortized [Member]
     
Changes in amortized MSRs      
Balance, beginning of period 1,445 1,422  
Purchases 14 45  
Servicing from securitizations or asset transfers (327) 29  
Amortization (58) (64)  
Balance, end of period 1,074 1,432  
Valuation Allowance      
Balance, beginning of period (37) (3)  
Reversal of provision (provision) for mortgage servicing rights in excess of fair value 37 (6)  
Balance, end of period 0 (9)  
Amortized mortgage servicing rights, net 1,074 1,423  
Fair value of amortized MSRs:      
Beginning of period 1,756 1,812  
End of period $ 1,263 $ 1,898