Quarterly Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017	Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule Of Quarterly Financial Information [Line Items]
Net sales	$ 350,562	$ 345,591	$ 329,002	$ 317,377	$ 308,502	$ 296,692	$ 303,052	$ 267,024	$ 1,342,532	$ 1,175,270	$ 1,081,121
Gross profit	163,679	155,407	150,303	139,596	131,800	122,980	139,205	114,706	608,985	508,691	470,231
Net (loss) income	$ (28,341)	$ 40,902	$ 39,991	$ 32,514	$ 26,098	$ 21,947	$ 32,890	$ 16,212	$ 85,066	$ 97,147	$ 80,296
Basic net income (loss) per common share	$ (0.20)	$ 0.29	$ 0.28	$ 0.23	$ 0.18	$ 0.16	$ 0.23	$ 0.12	$ 0.60	$ 0.69	$ 0.57
Diluted net income (loss) per common share	$ (0.20)	$ 0.28	$ 0.28	$ 0.23	$ 0.18	$ 0.15	$ 0.23	$ 0.11	$ 0.59	$ 0.68	$ 0.57