Revenue from Contracts with Customers - Condensed Consolidated Statement of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	$ 205,683	$ 148,156	$ 571,180	$ 463,658
Cost of sales	156,408	111,272	431,492	340,266
Income (loss) from operations	5,881	$ 5,551	9,283	$ 32,045
Balances Without Adoption of ASC 606 | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	205,691		571,260
Cost of sales	156,424		431,544
Income (loss) from operations	5,873		9,311
Effect of Change | Accounting Standards Update 2014-09
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Net sales	(8)		(80)
Cost of sales	(16)		(52)
Income (loss) from operations	$ 8		$ (28)