Consolidated Statements of Income and Comprehensive Income (loss) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total revenue	$ 94,779	$ 88,530	$ 282,219	$ 263,371
Gross profit	50,574	48,108	150,540	143,457
Operating expenses:
Selling expenses	21,255	22,175	64,864	66,119
General and administrative expenses	22,873	28,199	72,063	72,213
Operating expenses	44,128	50,374	136,927	138,332
Operating income (loss)	6,446	(2,266)	13,613	5,125
Interest expense	(138)	(251)	(481)	(755)
Other income (expense), net	13	(170)	(798)	320
Income (loss) before income taxes	6,295	(2,347)	13,930	4,050
Income tax expense (benefit)	1,521	(1,531)	3,703	436
Net income	$ 4,774	$ (816)	$ 10,227	$ 3,614
Basic income per share of common stock	$ 0.53	$ (0.09)	$ 1.14	$ 0.41
Diluted income per share of common stock	$ 0.51	$ (0.09)	$ 1.09	$ 0.39
Weighted average shares outstanding:
Basic weighted average shares outstanding	8,974	8,919	8,971	8,904
Effect of dilutive securities outstanding	415	0	399	346
Diluted weighted average shares outstanding	9,389	8,919	9,370	9,250
Comprehensive income (loss):
Net income	$ 4,774	$ (816)	$ 10,227	$ 3,614
Adjustment for foreign currency translation	(427)	692	965	(769)
Net comprehensive income (loss)	4,347	(124)	11,192	2,845
Product [Member]
Revenue	84,440	78,377	252,351	233,744
Cost of goods sold	39,635	36,979	118,222	109,667
Service [Member]
Revenue	10,339	10,153	29,868	29,627
Cost of goods sold	$ 4,570	$ 3,443	$ 13,457	$ 10,247