Income Taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
U.S. Federal		$ 2	$ 2	$ (11)
State		6	(3)	6
Foreign		69	59	48
Total current income tax provision		77	58	43
Deferred:
U.S. Federal		57	(134)	1
State		2	(2)	(2)
Foreign		(14)	(21)	(20)
Total deferred income tax provision (benefit)		45	(157)	(21)
Total income tax provision (benefit)		$ 122	(99)	$ 22
Tax cuts and jobs act of 2017, provisional amount income tax benefit	$ 173		$ 173
Tax benefit related to the revaluation of its net deferred tax liabilities	$ 10