v2.4.0.6
Securities Available for Sale, Credit Loss Component (Details) (Debt Securities [Member], USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Debt Securities [Member]
     
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]      
Credit loss component, beginning of period $ 1,272 $ 1,043 $ 1,187
Initial credit impairments 55 87 122
Subsequent credit impairments 182 335 278
Total Additions 237 422 400
For securities sold (194) (160) (263)
For securities derecognized due to changes in consolidation status of variable interest entities 0 (2) (242)
Due to change in intent to sell or requirement to sell 0 0 (2)
For recoveries of previous credit impairments (26) (31) (37)
Total reductions (220) (193) (544)
Credit loss component, end of period $ 1,289 $ 1,272 $ 1,043