Non-Interest Revenue and Expense Detail (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Details Of Certain Statements Of Income Lines Details [Abstract]
Foreign currency conversion fee revenue	$ 809	$ 852	$ 877
Delinquency fees	762	788	722
Loyalty Partner-related fees	410	379	383
Travel Commissions And Fees	338	349	1,118
Service fees	291	361	366
Other	143	137	160
Total Other commissions and fees	$ 2,753	$ 2,866	$ 3,626