Reserves for Losses (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Changes in the Card Member loans reserve for losses
Balance, January 1			$ 1,261	$ 1,471
Card Member loans - provisions	265	248	797	825
Card Member loans net write-offs - principal			(786)	(888)
Card Member loans net write-offs - interest and fees			(124)	(113)
Card Member loans - other			(2)	(14)
Balance, September 30	$ 1,146	$ 1,281	$ 1,146	$ 1,281