v2.4.0.6
Mortgage Banking Activities, Amortized Mortgage Servicing Rights (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Dec. 31, 2012
Changes in amortized MSRs      
Amortization $ (62) $ (58)  
Valuation Allowance      
Amortized MSRs, net 1,181   1,160
Amortized [Member]
     
Changes in amortized MSRs      
Balance, beginning of period 1,160 1,445  
Purchases 27 14  
Servicing from securitizations or asset transfers 56 (327)  
Amortization (62) (58)  
Balance, end of period 1,181 1,074  
Valuation Allowance      
Balance, beginning of period 0 (37)  
Reversal of provision for MSRs in excess of fair value 0 37  
Balance, end of period 0 0  
Amortized MSRs, net 1,181 1,074  
Fair value of amortized MSRs:      
Beginning of period 1,400 1,756  
End of period $ 1,404 $ 1,263