Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Total revenue	$ 10,360	$ 10,274	$ 9,864
Income before income taxes	2,298	2,437	2,666
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	4,428	4,644	4,299
Income before income taxes	1,193	1,343	1,169
U.S.
Segment Reporting Information [Line Items]
Total revenue	5,932	5,630	5,565
Income before income taxes	$ 1,105	$ 1,094	$ 1,497