Reserves For Losses (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Card Member Loans And Related Reserves Evaluated Separately And Collectively For Impairment [Abstract]
Card Member loans evaluated individually for impairment	$ 309	$ 378
Reserves on Card Member loans evaluated individually for impairment	70	84
Card Member loans evaluated collectively for impairment	65,748	66,860
Reserves on Card Member loans evaluated collectively for impairment	$ 1,076	$ 1,177