Summary of Significant Accounting Policies - Basic and Diluted Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Line Items]
Net income (loss)	$ 13,575
Income allocable to unvested restricted shares	(53)
Basic income attributable to common stock	13,522
Diluted income attributable to common stock	$ 13,522
Basic income attributable to common stock, Shares	105,457
Diluted income attributable to common stock, Shares	105,457
Basic income attributable to common stock, Per Share	$ 0.13
Diluted income attributable to common stock, Per Share	$ 0.13
Predecessor
Earnings Per Share [Line Items]
Net income (loss)		$ (41,886)
Basic income attributable to common stock		(41,886)
Diluted income attributable to common stock		$ (41,886)
Basic income attributable to common stock, Shares		15,084
Diluted income attributable to common stock, Shares		15,084
Basic income attributable to common stock, Per Share		$ (2.78)
Diluted income attributable to common stock, Per Share		$ (2.78)