Income Taxes - Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current
U.S. federal and state	$ 14	$ 6	$ (18)
Non-U.S.	128	98	74
Total current	142	104	56
Deferred
U.S. federal and state	(47)	164	(497)
Non-U.S.	(17)	15	17
Total deferred	(64)	179	(480)
Total expense (benefit)	$ 78	$ 283	$ (424)