Income Taxes - Schedule of Components of Income Tax Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
Federal	$ 27	$ 229	$ (14)
State	144	18	30
Non-U.S.	374	380	320
Total current expense	545	627	336
Deferred:
Federal	(134)	49	(311)
State	(25)	65	38
Non-U.S.	14	(19)	(85)
Total deferred expense (benefit)	(145)	95	(358)
Total income tax expense (benefit)	$ 400	$ 722	$ (22)