v2.4.0.8
Mortgage Banking Activities, Mortgage Servicing Rights Carried at Fair Value (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Changes in MSRs measured at fair value        
Fair value, beginning of period     $ 11,538  
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions 1,867 (1,631) 2,628 (1,789)
Other changes in fair value (643) (712) (1,393) (1,355)
Total changes in fair value 1,224 (2,343) 1,235 (3,144)
Fair value, end of period 14,185   14,185  
Mortgage interest rates [Member]
       
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions 2,223 (1,496) 3,253 (1,349)
Servicing and foreclosure costs [Member]
       
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions (82) (146) (140) (200)
Discount rates [Member]
       
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions 0 0 0 (344)
Prepayment estimates and other [Member]
       
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions (274) 11 (485) 104
Carried at Fair Value [Member]
       
Changes in MSRs measured at fair value        
Fair value, beginning of period 12,061 13,578 11,538 12,603
Servicing from securitizations or asset transfers 1,060 1,139 1,995 2,915
Sales (160) (293) (583) (293)
Net additions 900 846 1,412 2,622
Changes in fair value of MSRs carried at fair value:        
Net changes in valuation model inputs or assumptions 1,867 (1,631) 2,628 (1,789)
Other changes in fair value (643) (712) (1,393) (1,355)
Total changes in fair value 1,224 (2,343) 1,235 (3,144)
Fair value, end of period $ 14,185 $ 12,081 $ 14,185 $ 12,081