Income Taxes - Income Tax Expense (Benefit) by Current and Deferred (Details) - USD ($) $ in Millions	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Federal
Current	$ 0	$ 0	$ 12	$ 0
Deferred	231	193	186	199
State
Current	2	7	4	(9)
Deferred	6	16	41	28
Foreign
Current	4	39	17	30
Deferred	(9)	13	(5)	(52)
Total income tax expense	$ 234	$ 268	$ 255	$ 196