Reserves For Losses (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Card Member Loans And Related Reserves Evaluated Separately And Collectively For Impairment [Abstract]
Card Member loans evaluated individually for impairment	$ 401	$ 633
Reserves on Card Member loans evaluated individually for impairment	86	153
Card Member loans evaluated collectively for impairment	62,569	64,596
Reserves on Card Member loans evaluated collectively for impairment	$ 1,195	$ 1,318