Non-U.S. Activities - Schedule Of Results From Non-U.S. Operations (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Segment Reporting Information [Line Items]
Total revenue	$ 2,873	$ 3,063	$ 5,805	$ 6,119
Income before income taxes	718	891	1,353	1,679
Non-U.S.
Segment Reporting Information [Line Items]
Total revenue	1,237	1,322	2,468	2,643
Income before income taxes	313	427	562	846
U.S.
Segment Reporting Information [Line Items]
Total revenue	1,636	1,741	3,337	3,476
Income before income taxes	$ 405	$ 464	$ 791	$ 833