Unaudited Quarterly Results of Operations (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 499,798	$ 503,791	$ 514,881	$ 502,198	$ 523,899	$ 533,179	$ 546,693	$ 543,996	$ 2,020,668	$ 2,147,767	$ 2,024,130
Gross profit	223,399	223,260	231,615	226,041	229,117	234,646	241,132	244,420	904,315	949,315	873,364
Operating income	98,259	121,813	109,909	101,757	94,454	110,847	112,088	113,835	431,738	431,224	395,513
Net income	$ 67,763	$ 79,505	$ 69,585	$ 65,954	$ 61,620	$ 71,441	$ 71,777	$ 74,548	$ 282,807	$ 279,386	$ 255,215
Basic EPS (in dollar per share)	$ 0.89	$ 1.03	$ 0.89	$ 0.84	$ 0.78	$ 0.89	$ 0.89	$ 0.92	$ 3.65	$ 3.48	$ 3.11
Diluted EPS (in dollar per share)	$ 0.88	$ 1.02	$ 0.89	$ 0.84	$ 0.77	$ 0.88	$ 0.88	$ 0.91	$ 3.62	$ 3.45	$ 3.09
Basic weighted average shares outstanding	76,211	76,831	77,466	77,996	78,669	79,558	80,106	80,527	77,126	79,715	81,517
Diluted weighted average shares outstanding	77,091	77,646	78,297	78,856	79,632	80,561	81,149	81,575	77,972	80,728	82,489