v2.4.0.6
Securities Available for Sale, Other-Than-Temporary Impairment (OTTI), Included in Earnings (Details) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2013
Mar. 31, 2012
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale $ 38 $ 51
Nonmarketable equity investments 40 14
Total OTTI write-downs included in earnings 78 65
Debt Securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 34 50
US States and Political Subdivisions [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 0 0
Residential [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 15 14
Commercial [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 15 30
Corporate debt securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 2 1
Collateralized loan and other debt obligations [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 0 0
Other Debt Securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 2 5
Equity Securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 4 1
Perpetual preferred securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale 0 1
Other equity securities [Member]
   
Other than Temporary Impairment Losses, Investments, Available-for-sale Securities [Abstract]    
Securities available for sale $ 4 $ 0