Summary of Significant Accounting Policies - Weighted Average Shares of Unvested Restricted Stock (Detail) - shares shares in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested restricted stock	414
Predecessor
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested restricted stock		834

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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