Summary of Significant Accounting Policies - Basic and Diluted Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended							5 Months Ended	7 Months Ended	12 Months Ended
	Aug. 13, 2018	Sep. 30, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018	Aug. 13, 2018	Dec. 31, 2019	Dec. 31, 2017
Earnings Per Share [Line Items]
Basic and diluted net income attributable to common stock, Per Share		$ 0.13					$ 0.48			$ 0.61	$ (6.08)	$ 0.52	$ (7.61)
Diluted income attributable to common stock, Per Share			$ 0.19	$ (0.01)	$ 0.20	$ 0.13				$ 0.61		$ 0.52
Net income attributable to common stock										$ 64,122	$ (92,754)	$ 74,474	$ (111,405)
Income allocable to unvested restricted shares										(248)		(356)
Basic and diluted net income attributable to common stock										63,874		74,118
Effect of dilutive securities: preferred stock												22,415
Diluted income attributable to common stock										$ 63,874		$ 96,533
Basic and diluted net income attributable to common stock, Shares										105,453		142,750
Effect of Dilutive Securities: performance stock units, Shares												63
Effect of Dilutive Securities: preferred stock, Shares												44,565
Effect of Dilutive Securities: Stock warrants, Shares										6
Diluted income attributable to common stock, Shares										105,459	15,262	187,378	14,644
Basic and diluted net loss attributable to common stock										$ 63,874		$ 74,118
Basic and diluted net loss attributable to common stock, Shares										105,453		142,750
Net income (loss) per share – basic and diluted		$ 0.13					$ 0.48			$ 0.61	$ (6.08)	$ 0.52	$ (7.61)
Predecessor
Earnings Per Share [Line Items]
Basic and diluted net income attributable to common stock, Per Share	$ (1.09)							$ (2.23)	$ (2.78)		$ (6.08)		$ (7.61)
Basic and diluted net income attributable to common stock											$ (92,754)		$ (111,405)
Basic and diluted net income attributable to common stock, Shares											15,262		14,644
Basic and diluted net loss attributable to common stock											$ (92,754)		$ (111,405)
Basic and diluted net loss attributable to common stock, Shares											15,262		14,644
Net income (loss) per share – basic and diluted	$ (1.09)							$ (2.23)	$ (2.78)		$ (6.08)		$ (7.61)