Reserves for Losses (Details 2) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Changes in the Card Member receivables reserve for losses
Balance, January 1			$ 462	$ 465
Card Member receivables - provisions	$ 153	$ 165	322	339
Card Member receivables - net write-offs			(359)	(370)
Card Member receivables - other			(2)	(14)
Balance, March 31	$ 423	$ 420	$ 423	$ 420