v2.4.0.6
Securitizations and Variable Interest Entities, Key Economic Assumptions - Mortgage Servicing Assets (Details)
12 Months Ended
Dec. 31, 2011
years
Dec. 31, 2010
years
Securitizations and Variable Interest Entities [Abstract]    
Prepayment speed (annual CPR) 12.80% 13.50%
Life (in years) 5.9 5.4
Discount rate 7.70% 8.00%