v2.4.0.8
Customer Deposits (Details) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2013
Dec. 31, 2012
U.S.:    
Interest-bearing $ 41,947 $ 39,649
Non-interest-bearing 178 10
Non-U.S.:    
Interest-bearing 125 135
Non-interest-bearing 237 9
Total customer deposits 42,487 39,803
Card Member Credit Balances [Member]
    
U.S.:    
Non-interest-bearing 160 0
Non-U.S.:    
Non-interest-bearing $ 228 $ 0