v2.4.0.6
Securities Available for Sale, Other-Than-Temporary Impairment (OTTI), Included in Earnings (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale $ 256 $ 541 $ 692
Nonmarketable equity investments 160 170 248
Total OTTI write-downs included in earnings 416 711 940
Debt Securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 240 423 672
US States and Political Subdivisions [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 16 2 16
Residential [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 84 252 175
Commercial [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 86 101 120
Federal agencies [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 0 0 267
Corporate debt securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 11 3 10
Collateralized debt obligations [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 1 1 15
Other Debt Securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 42 64 69
Equity Securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 16 118 20
Perpetual preferred securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale 12 96 15
Other equity securities [Member]
     
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]      
Securities available for sale $ 4 $ 22 $ 5