Interim Financial Data (Unaudited) - Summary of Interim Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Data [Abstract]
Net sales	$ 122,212	$ 140,194	$ 157,941	$ 144,806	$ 95,322	$ 106,168	$ 146,450	$ 131,676	$ 565,153	$ 479,616	$ 440,804
Gross profit	50,906	55,284	72,014	65,169	38,113	29,945	61,410	57,627	243,373	187,095	154,869
Net income	$ 18,299	$ 20,098	$ 28,782	$ 27,949	$ 12,629	$ 7,787	$ 23,725	$ 23,706	$ 95,128	$ 67,847	$ 48,098
Basic net income per share	$ 0.62	$ 0.68	$ 0.98	$ 0.95	$ 0.43	$ 0.27	$ 0.81	$ 0.80	$ 3.24	$ 2.31	$ 1.53
Basic weighted average common shares outstanding	29,412,848	29,404,049	29,389,458	29,363,210	29,318,915	29,295,284	29,264,362	29,697,722	29,392,559	29,394,559	31,350,542
Diluted net income per share	$ 0.62	$ 0.68	$ 0.97	$ 0.95	$ 0.43	$ 0.26	$ 0.80	$ 0.79	$ 3.22	$ 2.29	$ 1.52
Diluted weighted average common shares outstanding	29,611,129	29,578,216	29,550,418	29,561,406	29,543,842	29,516,718	29,477,870	29,910,292	29,575,460	29,612,669	31,682,509