Unaudited Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Net sales	$ 340,845	$ 287,996	$ 937,627	$ 854,682
Cost of sales	180,028	154,787	500,398	470,938
Gross profit	160,817	133,209	437,229	383,744
Selling, general and administrative expenses	75,188	65,493	210,799	190,849
Provision for legal settlement	0	32,000	0	32,000
Operating income	85,629	35,716	226,430	160,895
Interest expense	2,667	3,766	8,979	11,233
Interest income	488	137	787	361
Other non-operating (income) expense, net	(52)	0	32	0
Income before income taxes	83,502	32,087	218,206	150,023
Provision for income taxes	30,365	10,605	78,297	54,584
Net income	$ 53,137	$ 21,482	$ 139,909	$ 95,439
Basic net income per common share (in usd per share)	$ 0.27	$ 0.11	$ 0.71	$ 0.49
Diluted net income per common share (in usd per share)	$ 0.27	$ 0.11	$ 0.70	$ 0.48
Basic weighted average shares	196,121,691	196,445,684	196,577,436	196,311,529
Diluted weighted average shares	198,659,459	199,452,308	199,258,760	199,290,017