CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - 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	$ 84,573	$ 64,429	$ 233,592	$ 175,139
Cost of sales	9,599	7,997	26,972	23,338
Gross margin	74,974	56,432	206,620	151,801
Operating expenses:
Research and development expenses	5,481	2,919	14,430	8,582
Selling, general and administrative expenses	60,233	48,179	168,498	131,599
Amortization of intangible assets	418	631	1,451	1,889
Operating income	8,842	4,703	22,241	9,731
Other income (expense)
Gain on divestiture	4,274	0	4,274	0
Interest expense, net	(43)	(87)	(337)	(254)
Income before income tax provision	13,073	4,616	26,178	9,477
Income tax provision (expense) benefit	4,384	(1,295)	3,675	(2,984)
Net income	$ 17,457	$ 3,321	$ 29,853	$ 6,493
Net income per common share - basic (in dollars per share)	$ 0.16	$ 0.03	$ 0.28	$ 0.06
Net income per common share - diluted (in dollars per share)	$ 0.15	$ 0.03	$ 0.26	$ 0.06
Weighted average shares outstanding - basic (in shares)	106,871,436	105,991,990	106,469,278	105,927,890
Weighted average shares outstanding - diluted (in shares)	117,501,925	112,361,179	116,547,006	112,193,701