Consolidated Statements of operations and Comprehensive Income (loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Product revenue	$ 78,377	$ 75,651	$ 233,744	$ 225,274
Service revenue	10,153	0	29,627
Total revenue	88,530	75,651	263,371	225,274
Product cost of goods sold	36,979	29,646	109,667	89,249
Service costs	3,443	0	10,247	0
Gross profit	48,108	46,005	143,457	136,025
Operating expenses:
Selling expenses	22,175	24,354	66,119	72,964
General and administrative expenses	28,199	20,561	72,213	58,790
Total SG&A	50,374	44,915	138,332	131,754
Gain on sale of property	0	0	0	(5,422)
Operating expenses	50,374	44,915	138,332	126,332
Operating income (loss)	(2,266)	1,090	5,125	9,693
Interest expense	(251)	(133)	(755)	(393)
Other (expense) income, net	170	843	(320)	953
Income (loss) before income taxes	(2,347)	1,800	4,050	10,253
Income tax (benefit) expense	$ (1,531)	$ 479	$ 436	$ 802
Basic income (loss) per share of common stock	$ (0.09)	$ 0.15	$ 0.41	$ 1.07
Diluted income (loss) per share of common stock	$ (0.09)	$ 0.14	$ 0.39	$ 1.04
Weighted average shares outstanding:
Basic weighted average shares outstanding	8,919	8,880	8,904	8,856
Effect of dilutive securities outstanding	0	253	346	256
Diluted weighted average shares outstanding	8,919	9,133	9,250	9,112
Comprehensive income (loss):
Net (loss) income	$ (816)	$ 1,321	$ 3,614	$ 9,451
Adjustment for foreign currency translation	692	139	(769)	941
Net comprehensive income (loss)	$ (124)	$ 1,460	$ 2,845	$ 10,392