Interim Financial Data (Unaudited) - Summary of Interim Financial Data (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Quarterly Financial Data [Abstract]
Net sales	$ 74,202	$ 95,502	$ 121,311	$ 100,645	$ 63,831	$ 72,249	$ 98,551	$ 107,880	$ 391,660	$ 342,511	$ 307,354
Gross profit	26,635	30,369	45,026	38,167	19,685	151	36,922	41,860	140,196	98,618	84,582
Net income (loss)	$ 5,153	$ 8,913	$ 15,161	$ 12,295	$ 15,103	$ (15,298)	$ 13,224	$ 21,569	$ 41,521	$ 34,598	$ 2,720
Basic net income (loss) per share	$ 0.16	$ 0.28	$ 0.46	$ 0.37	$ 0.46	$ (0.45)	$ 0.39	$ 0.64	$ 1.28	$ 1.03	$ 0.08
Diluted net income (loss) per share	$ 0.16	$ 0.28	$ 0.46	$ 0.37	$ 0.45	$ (0.45)	$ 0.38	$ 0.62	$ 1.27	$ 1.01	$ 0.08