Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 2,668	$ 2,484
Income before income taxes	584	430
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,096	1,025
Income before income taxes	262	176
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,572	1,459
Income before income taxes	$ 322	$ 254