Reserves For Losses (Details 3) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Cardmember Loans And Related Reserves Evaluated Separately And Collectively For Impairment [Abstract]
Cardmember loans evaluated separately for impairment	$ 673	$ 744
Reserves on cardmember loans evaluated separately for impairment	151	176
Cardmember loans evaluated collectively for impairment	61,077	61,877
Reserves on cardmember loans evaluated collectively for impairment	$ 1,308	$ 1,698