v2.4.0.6
Fair Value, Option, Instrument Specific Credit Risk (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Fair Value, Option, Quantitative Disclosures [Line Items]      
Fair Value, Option, Credit Risk, Gains (Losses) on Assets $ (103) $ (112) $ (4)
Mortgages held for sale [Member]
     
Fair Value, Option, Quantitative Disclosures [Line Items]      
Fair Value, Option, Credit Risk, Gains (Losses) on Assets (124) (144) (28)
Loans held for sale [Member]
     
Fair Value, Option, Quantitative Disclosures [Line Items]      
Fair Value, Option, Credit Risk, Gains (Losses) on Assets $ 21 $ 32 $ 24