Consolidated Statements of Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Statement [Abstract]
Revenues	$ 42,675	$ 43,329	$ 57,767
Cost of revenues	9,707	8,448	13,761
Gross profit	32,968	34,881	44,006
Operating expenses:
Selling and marketing	15,675	16,666	26,594
Research and development	21,305	24,767	41,711
General and administrative	18,216	20,211	25,279
Restructuring expenses	5,602	238	3,184
Goodwill and long-lived asset impairment			112,904
Total operating expenses	60,798	61,882	209,672
Operating loss	(27,830)	(27,001)	(165,666)
Non-operating income:
Change in fair value of contingent liability		1,210
Interest and other income, net	30	94	131
Loss before provision for income taxes	(27,800)	(25,697)	(165,535)
Provision for income tax expense (benefit)	153	(234)	(5,929)
Net loss	(27,953)	(25,463)	(159,606)
Other comprehensive income (loss), before tax:
Unrealized holding gains (losses) on available-for-sale securities	7	33	(24)
Income tax expense related to items of other comprehensive income (expense)		6	1
Other comprehensive income (expense), net of tax	7	27	(25)
Comprehensive loss	$ (27,946)	$ (25,436)	$ (159,631)
Net loss per share:
Basic and diluted	$ (0.76)	$ (0.71)	$ (4.48)
Weighted average shares outstanding:
Basic and diluted	36,982	35,849	35,617