Fair Value Measurements (Gross Amounts and Fair Value of Debt) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Term Loan | Successor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	$ 1,243,299
Term Loan | Predecessor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale		$ 1,722,209
7.75% Senior Notes | Predecessor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale		610,000
Fair Value, Inputs, Level 2 | Term Loan | Successor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale	$ 1,182,688
Fair Value, Inputs, Level 2 | Term Loan | Predecessor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale		1,481,100
Fair Value, Inputs, Level 2 | 7.75% Senior Notes | Predecessor
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Securities, Available-for-sale		$ 105,988