Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Revenues	$ 9,586	$ 9,448	$ 29,501	$ 26,425
Cost of revenues	1,959	2,201	6,148	7,072
Gross profit	7,627	7,247	23,353	19,353
Operating expenses:
Selling and marketing	2,220	2,139	6,639	7,471
Research and development	3,480	3,188	10,268	11,046
General and administrative	2,695	3,064	8,437	10,360
Restructuring expense				2,435
Total operating expenses	8,395	8,391	25,344	31,312
Operating loss	(768)	(1,144)	(1,991)	(11,959)
Interest and other income (expense), net	4	(3)	3	(5)
Loss before provision for income taxes	(764)	(1,147)	(1,988)	(11,964)
Provision for income tax expense (benefit)	6	(5)	23	40
Net loss	(770)	(1,142)	(2,011)	(12,004)
Other comprehensive income (loss) , before tax:
Unrealized holding gains (losses) on available-for-sale securities		(1)	1
Income tax expense related to items of other comprehensive income	0	0	0	0
Other comprehensive income (loss), net of tax		(1)	1
Comprehensive loss	$ (770)	$ (1,143)	$ (2,010)	$ (12,004)
Net loss per share:
Basic and diluted	$ (0.02)	$ (0.03)	$ (0.04)	$ (0.31)
Weighted average shares outstanding:
Basic and diluted	46,160	41,225	45,975	39,165