Segments Summary of the operating segments (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Segments	Jun. 30, 2011
Segment Reporting Information [Line Items]
Number of reportable segments			2
Total revenue	$ 24,878	$ 19,073	$ 47,997	$ 37,396
Gross profit	15,584	11,501	29,705	23,010
Research and development	2,694	2,433	5,205	4,591
Sales and marketing	8,002	6,702	15,532	13,175
General and administrative	3,617	2,842	6,704	5,081
Income (loss) from operations	1,271	(476)	2,264	163
Interest income	14	3	26	8
Interest expense and other finance charges	(3)	(61)	(74)	(122)
Other income (expense), net	105	(752)	(1,492)	(1,217)
Income (loss) before income taxes	1,387	(1,286)	724	(1,168)
Products
Segment Reporting Information [Line Items]
Total revenue	16,155	11,925	30,792	23,561
Gross profit	10,683	7,899	19,891	15,883
Services
Segment Reporting Information [Line Items]
Total revenue	8,723	7,148	17,205	13,835
Gross profit	$ 4,901	$ 3,602	$ 9,814	$ 7,127