Reserves for Losses (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Changes in the cardmember loans reserve for losses
Balance, January 1			$ 1,874	$ 3,646
Additions:
Cardmember loans provisions			669	23
Cardmember loans provisions - other			84	81
Total provision	264	48	753	104
Deductions:
Cardmember loans net write-offs - principal			(970)	(1,375)
Cardmember loans net write-offs - interest and fees			(121)	(159)
Cardmember loans reserves for losses - other			(77)	(77)
Balance, September 30	$ 1,459	$ 2,139	$ 1,459	$ 2,139