Equity-Based Compensation (Successor) (Stock Compensation Expense) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		8 Months Ended	9 Months Ended
	Feb. 08, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2018	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 1,506	$ 604	$ 8,333	$ 5,025
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		859	1,782	4,569	2,758
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		600	1,271	3,764	2,068
Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 47	$ (2,449)	$ 0	$ 199
Predecessor
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 0
Predecessor | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	0
Predecessor | Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	0
Predecessor | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 0