Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net sales	$ 1,274,589	$ 1,149,778	$ 1,027,447
Cost of sales	685,501	634,095	608,616
Gross profit	589,088	515,683	418,831
Selling, general and administrative expense	285,849	262,761	226,716
Provision for legal settlement	0	32,000	32,000
Operating income	303,239	220,922	160,115
Interest expense	11,141	14,619	15,091
Interest income	(1,440)	(505)	(294)
Other non-operating expense, net	213	0	0
Income before income taxes	293,325	206,808	145,318
Provision for income taxes	99,796	76,567	55,930
Total income before income taxes	$ 193,529	$ 130,241	$ 89,388
Basic net income per share (in dollars per share)	$ 0.99	$ 0.66	$ 0.46
Diluted net income per share (in dollars per share)	$ 0.97	$ 0.65	$ 0.45
Basic weighted average shares (in shares)	196,256,128	196,363,084	195,933,800
Diluted weighted average shares (in shares)	198,918,417	199,348,746	198,047,453