Reserves for Losses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Changes in the Card Member receivables reserve for losses
Balance, January 1	$ 465	$ 386	$ 428
Provision For Doubtful Accounts	(737)	(792)	(648)
Card Member receivables net write-offs	713	683	669
Other	27	30	21
Balance, December 31	$ 462	$ 465	$ 386