Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 2,810	$ 2,573	$ 5,478	$ 5,057
Income before income taxes	776	709	1,360	1,139
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,172	1,136	2,268	2,161
Income before income taxes	324	344	583	521
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,638	1,437	3,210	2,896
Income before income taxes	$ 452	$ 365	$ 777	$ 618