v2.4.0.6
Mortgage Banking Activities , Mortgage Servicing Rights Carried at Fair Value (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2012
Mar. 31, 2011
Changes in MSRs measured at fair value    
Fair value, beginning of period $ 12,603  
Changes in fair value:    
Due to changes in valuation model inputs or assumptions (158) 499
Other changes in fair value (643) (580)
Total changes in fair value (801) (81)
Fair value, end of period 13,578  
Carried at Fair Value [Member]
   
Changes in MSRs measured at fair value    
Fair value, beginning of period 12,603 14,467
Servicing from securitizations or asset transfers 1,776 1,262
Changes in fair value:    
Due to changes in valuation model inputs or assumptions (158) 499
Other changes in fair value (643) (580)
Total changes in fair value (801) (81)
Fair value, end of period 13,578 15,648
Carried at Fair Value [Member] | Mortgage interest rates [Member]
   
Changes in fair value:    
Due to changes in valuation model inputs or assumptions 147 506
Carried at Fair Value [Member] | Servicing and foreclosure costs [Member]
   
Changes in fair value:    
Due to changes in valuation model inputs or assumptions (54) (214)
Carried at Fair Value [Member] | Discount rates [Member]
   
Changes in fair value:    
Due to changes in valuation model inputs or assumptions (344) (150)
Carried at Fair Value [Member] | Prepayment estimates and other [Member]
   
Changes in fair value:    
Due to changes in valuation model inputs or assumptions $ 93 $ 357