Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Revenue	$ 14,111	$ 11,703	$ 26,819	$ 22,996
Cost of goods sold	6,047	4,839	11,053	9,133
Gross profit	8,064	6,864	15,766	13,863
Operating expenses:
Sales and marketing	2,977	2,088	5,713	4,356
Research and product development	2,330	1,843	4,571	3,709
General and administrative	1,628	1,437	3,592	3,234
Total operating expenses	6,935	5,368	13,876	11,299
Operating income	1,129	1,496	1,890	2,564
Other income, net	64	47	145	33
Income before income taxes	1,193	1,543	2,035	2,597
Provision for income taxes	259	498	611	822
Net income	934	1,045	1,424	1,775
Basic earnings per common share	$ 0.10	$ 0.11	$ 0.16	$ 0.19
Diluted earnings per common share	$ 0.10	$ 0.11	$ 0.15	$ 0.19
Basic weighted average shares outstanding	9,266,071	9,093,461	9,174,816	9,122,996
Diluted weighted average shares outstanding	9,677,726	9,459,495	9,618,172	9,499,452
Unrealized gain (loss) on available-for-sale securities, net of tax	65	(87)	138	(87)
Comprehensive income	$ 999	$ 958	$ 1,562	$ 1,688