CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net sales	$ 359,111	$ 321,139	$ 221,712
Cost of sales	36,386	35,219	30,938
Gross profit	322,725	285,920	190,774
Operating expenses:
Selling, general and administrative	258,528	220,119	173,412
Investigation, restatement and related	51,322	0	0
Research and development expenses	15,765	17,900	14,341
Amortization of intangible assets	1,034	1,678	2,137
Operating (loss) income	(3,924)	46,223	884
Other income (expense)
Loss on divestiture of Stability	0	(1,048)	0
Other income (expense), net	527	(87)	(339)
(Loss) income before income tax provision	(3,397)	45,088	545
Income tax provision (expense) benefit	(26,582)	19,639	(155)
Net (loss) income	$ (29,979)	$ 64,727	$ 390
Net (loss) income per common share - basic (in dollars per share)	$ (0.28)	$ 0.61	$ 0.00
Net (loss) income per common share - diluted (in dollars per share)	$ (0.28)	$ 0.56	$ 0
Weighted average shares outstanding - basic (in shares)	105,596,256	106,121,810	105,928,348
Weighted average shares outstanding - diluted (in shares)	105,596,256	116,113,736	112,645,640