Condensed Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 29,697	$ 26,787	$ 84,838	$ 78,599
Operating expenses:
Cost of product revenue	5,951	8,282	20,098	24,279
Research & development	4,158	4,232	12,581	14,126
Selling, general & administrative	7,539	5,700	22,713	28,207
Total operating expenses	17,648	18,214	55,392	66,612
Income from operations	12,049	8,573	29,446	11,987
Interest and other income, net	482	522	1,513	907
Income before income taxes	12,531	9,095	30,959	12,894
Provision for income taxes	3,331	1,496	7,817	1,890
Net income	$ 9,200	$ 7,599	$ 23,142	$ 11,004
Basic net income per share:
Net income (in dollars per share)	$ 0.65	$ 0.53	$ 1.65	$ 0.76
Basic weighted average common shares outstanding (in shares)	14,070	14,237	14,065	14,524
Diluted net income per share:
Net income (in dollars per share)	$ 0.64	$ 0.53	$ 1.62	$ 0.74
Diluted weighted average common shares outstanding (in shares)	14,387	14,377	14,266	14,820
Net income	$ 9,200	$ 7,599	$ 23,142	$ 11,004
Foreign currency translation adjustment	(622)	(113)	(792)	(444)
Comprehensive income	8,578	7,486	22,350	10,560
Product [Member]
Revenue	29,615	26,781	84,745	78,581
Service [Member]
Revenue	$ 82	$ 6	$ 93	$ 18