Reserves for Losses (Details 2) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Changes in the Card Member loans reserve for losses
Balance, January 1			$ 1,201	$ 1,261
Provisions	$ 309	$ 265	829	797
Cardmember loans net write-offs - principal			(733)	(786)
Cardmember loans net write-offs - interest and fees			(122)	(124)
Card Member loans reserves for losses - other			(11)	(2)
Balance, September 30	$ 1,164	$ 1,146	$ 1,164	$ 1,146