Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Net (loss) income attributable to Successor/Predecessor	$ (87)	$ 58	$ (273)	$ 218
Less: Undistributed earnings attributable to participating stockholders	0	0	0	0
Net (loss) income attributable to common stockholders	$ (87)	$ 58	$ (273)	$ 218
Net (loss) income per common share attributable to Successor/Predecessor:
Basic (in dollars per share)	$ (0.96)	$ 0.59	$ (3.00)	$ 2.22
Diluted (in dollars per share)	$ (0.96)	$ 0.59	$ (3.00)	$ 2.20
Weighted average shares of common stock outstanding (in thousands):
Basic (in shares)	91,054	98,203	90,978	98,037
Dilutive effect of stock awards (in shares)	0	927	0	1,086
Dilutive effect of participating securities (in shares)	0	0	0	0
Diluted (in shares)	91,054	99,130	90,978	99,123