Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 2,846	$ 2,620	$ 8,324	$ 7,677
Income before income taxes	822	636	2,182	1,775
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,219	1,117	3,494	3,278
Income before income taxes	342	314	919	835
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,627	1,503	4,830	4,399
Income before income taxes	$ 480	$ 322	$ 1,263	$ 940