Consolidated Statements of Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenues	$ 10,529	$ 8,449
Cost of revenues	2,118	2,420
Gross profit	8,411	6,029
Operating expenses:
Selling and marketing	2,191	3,036
Research and development	3,341	4,249
General and administrative	2,877	3,878
Total operating expenses	8,409	11,163
Operating income (loss)	2	(5,134)
Interest and other income (expense), net	(1)
Income (loss) before provision for income taxes	1	(5,134)
Provision for income tax expense	11	33
Net loss	(10)	(5,167)
Other comprehensive income, before tax:
Unrealized holding gains on available-for-sale securities	1
Income tax expense related to items of other comprehensive income	0	0
Other comprehensive income, net of tax	1
Comprehensive loss	$ (9)	$ (5,167)
Net loss per share:
Basic and diluted	$ 0.00	$ (0.14)
Weighted average shares outstanding:
Basic and diluted	45,501	37,714