Reserves for Losses (Details) (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 receivable reserve for losses
Balance, January 1			$ 438	$ 386
Additions:
Cardmember receivables provisions			434	404
Cardmember receivables provisions - other			97	129
Total provision	190	174	531	533
Deductions:
Cardmember receivables net write-offs	(487)	(406)	(487)	(406)
Cardmember receivables reserves for losses - other	(73)	(125)	(73)	(125)
Balance, September 30	$ 409	$ 388	$ 409	$ 388