Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Total revenue	$ 10,207	$ 10,360	$ 10,274
Income before income taxes	2,120	2,298	2,437
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	4,419	4,428	4,644
Income before income taxes	1,047	1,193	1,343
U.S.
Segment Reporting Information [Line Items]
Total revenue	5,788	5,932	5,630
Income before income taxes	$ 1,073	$ 1,105	$ 1,094