Customer Deposits (Details 1) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
U.S. retail deposits:
Savings accounts - Direct	$ 23,617	$ 18,713
Certificates of deposit - Direct	654	725
Certificates of deposit - Third party	8,884	8,851
Sweep accounts - Third party	8,792	11,360
Non-U.S. deposits and U.S. non-interest bearing deposits	152	154
Card Member credit balances - U.S. and non-U.S.	388	0
Total customer deposits	$ 42,487	$ 39,803