Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Segment Reporting Information [Line Items]
Total revenue	$ 2,932	$ 3,056
Income before income taxes	635	788
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,231	1,321
Income before income taxes	249	395
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,701	1,735
Income before income taxes	$ 386	$ 393