Income Taxes (Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. federal	$ (73)	$ (7)	$ 35
U.S. state and local	(23)	(12)	3
Non-U.S.	112	76	111
Current tax provision (benefit), total	16	57	149
U.S. federal	(1,150)	134	306
U.S. state and local	9	27	32
Non-U.S.	40	(25)	(70)
Deferred income tax provision (benefit), net	(1,101)	136	268
Income tax provision (benefit)	$ (1,085)	$ 193	$ 417