Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting Information [Line Items]
Total revenue	$ 2,620	$ 2,614	$ 7,677	$ 7,822
Income before income taxes	636	647	1,775	1,618
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,117	1,088	3,278	3,385
Income before income taxes	314	255	835	946
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,503	1,526	4,399	4,437
Income before income taxes	$ 322	$ 392	$ 940	$ 672