Quarterly Results of Operations (Unaudited) (Detail) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 108,454	$ 108,227	$ 103,808	$ 94,317	$ 97,335	$ 93,257	$ 94,861	$ 99,173	$ 414,806	$ 384,626	$ 455,469
Cost of sales	75,741	76,023	73,867	69,376	73,438	71,113	75,537	73,485	295,007	293,573	330,243
Gross profit	32,713	32,204	29,941	24,941	23,897	22,144	19,324	25,688
Operating income (loss)	6,064	222	2,120	(5,603)	(98,629)	(14,084)	(3,748)	(6,277)	2,803	(122,738)	(69,136)
Net income (loss)	$ 7,400	$ (1,310)	$ 1,681	$ (6,051)	$ (74,912)	$ (10,358)	$ (3,042)	$ (7,383)	$ 1,720	$ (95,695)	$ (100,639)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.21	$ (0.04)	$ 0.05	$ (0.17)	$ (2.02)	$ (0.28)	$ (0.08)	$ (0.20)	$ 0.05	$ (2.58)	$ (2.69)
Diluted (in dollars per share)	$ 0.21	$ (0.04)	$ 0.05	$ (0.17)	$ (2.02)	$ (0.28)	$ (0.08)	$ (0.20)	$ 0.05	$ (2.58)	$ (2.69)
Increase (decrease) in results from operations	$ 6,064	$ 222	$ 2,120	$ (5,603)	$ (98,629)	$ (14,084)	$ (3,748)	$ (6,277)	$ 2,803	$ (122,738)	$ (69,136)