Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Segment Reporting Information [Line Items]
Total revenue	$ 3,019	$ 2,668
Income before income taxes	763	584
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,321	1,096
Income before income taxes	395	262
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,698	1,572
Income before income taxes	$ 368	$ 322