Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenues	$ 9,386	$ 8,528	$ 19,915	$ 16,977
Cost of revenues	2,071	2,451	4,189	4,871
Gross profit	7,315	6,077	15,726	12,106
Operating expenses:
Selling and marketing	2,228	2,296	4,419	5,332
Research and development	3,447	3,609	6,788	7,858
General and administrative	2,865	3,418	5,742	7,296
Restructuring expense		2,435		2,435
Total operating expenses	8,540	11,758	16,949	22,921
Operating loss	(1,225)	(5,681)	(1,223)	(10,815)
Interest and other income (expense), net		(2)	(1)	(2)
Loss before provision for income taxes	(1,225)	(5,683)	(1,224)	(10,817)
Provision for income tax expense	6	12	17	45
Net loss	(1,231)	(5,695)	(1,241)	(10,862)
Other comprehensive income, before tax:
Unrealized holding gains on available-for-sale securities		1	1	1
Income tax expense related to items of other comprehensive income	0	0	0	0
Other comprehensive income, net of tax		1	1	1
Comprehensive loss	$ (1,231)	$ (5,694)	$ (1,240)	$ (10,861)
Net loss per share:
Basic and diluted	$ (0.03)	$ (0.15)	$ (0.03)	$ (0.28)
Weighted average shares outstanding:
Basic and diluted	46,257	38,518	45,881	38,118