Share-Based Compensation and Other Benefit Plans - Fair Value of Each Award Estimated on Date of Grant Using Black-Scholes-Merton Option-Pricing Formula (Detail) - Performance Restricted Stock Units [Domain] - $ / shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 0.00
Successor [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Expected volatility, min		59.63%
Expected volatility, max		62.18%
Dividend yield, min		0.00%
Dividend yield, max		0.00%
Risk-free interest rate, min		1.44%
Risk-free interest rate, max		1.51%
Share-based Compensation Award, Tranche One [Member] | Successor [Member] | Minimum
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	47.70
Share-based Compensation Award, Tranche One [Member] | Successor [Member] | Maximum
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 65.28