Quarterly Financial Data - Schedule of Quarterly Financial Information (Parenthetical) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Quarterly Financial Data [Line Items]
Recovery from a settlement with a vendor					$ 4,419
Gross profit (loss)	$ (12,277)	$ (9,733)	$ 19,677	$ 7,318	12,411	$ (9,742)	$ 3,073	$ 10,093	$ 4,985	$ 15,835	$ 5,466
Net income (loss)	(27,714)	(30,794)	6,631	(11,540)	(13,045)	(26,084)	(27,506)	(5,591)	(63,417)	(72,226)	(29,217)
Charge associated with assets held for sale	(9,701)
Loss on extinguishment of debt						(5,951)				(5,951)
Severance benefits and accelerated stock-based compensation					(5,300)
Benefit (provision) for income taxes	15,108	483	5,733	$ (400)	(764)	2,426	(4,324)	922	$ 20,924	$ (1,740)	$ 40,759
Turnaround Expense [Member]
Schedule Of Quarterly Financial Data [Line Items]
Gross profit (loss)	$ (5,374)	$ (7,232)	$ (604)
Net income (loss)					$ (115)	$ (7,939)	$ (1,412)	$ (302)