Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenue	$ 15,739	$ 12,366	$ 42,558	$ 35,362
Cost of goods sold	6,099	4,921	17,152	14,054
Gross profit	9,640	7,445	25,406	21,308
Operating expenses:
Sales and marketing	2,791	2,220	8,504	6,575
Research and product development	2,315	1,788	6,886	5,497
General and administrative	1,487	1,405	5,079	4,639
Proceeds from litigation, net	0	(272)	0	(272)
Total operating expenses	6,593	5,141	20,469	16,439
Operating income	3,047	2,304	4,937	4,869
Other income, net	70	85	215	117
Income before income taxes	3,117	2,389	5,152	4,986
Provision for income taxes	1,471	726	2,082	1,548
Net income	1,646	1,663	3,070	3,438
Basic earnings per common share (in dollars per share)	$ 0.18	$ 0.18	$ 0.33	$ 0.38
Diluted earnings per common share (in dollars per share)	$ 0.17	$ 0.18	$ 0.32	$ 0.36
Basic weighted average shares outstanding (in shares)	9,198,730	9,027,764	9,182,875	9,090,903
Diluted weighted average shares outstanding (in shares)	9,607,644	9,406,941	9,615,878	9,485,808
Unrealized gain (loss) on available-for-sale securities, net of tax	(78)	55	60	(33)
Comprehensive income	$ 1,568	$ 1,718	$ 3,130	$ 3,405