Equity-Based Compensation (Successor) (Stock Compensation Expense) (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		5 Months Ended	6 Months Ended
	Feb. 08, 2018	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2018	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 840	$ 4,263	$ 7,729	$ 3,519
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		660	1,722	2,787	1,899
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		35	1,260	2,493	1,468
Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense		$ 145	$ 1,281	$ 2,449	$ 152
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