Schedule of Phantom Stock Compensation Expense And Grant Date Fair Value (Detail) - Phantom Stock Plan - USD ($) $ in Thousands	4 Months Ended	5 Months Ended	12 Months Ended
Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Grant date fair value of stock vested			$ 1,055	$ 2,957
Compensation expense	$ 68	$ 94	$ 30	$ 214

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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