Consolidated Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Consolidated Statements of Comprehensive Loss [Abstract]
Revenues	$ 10,114	$ 17,791
Cost of revenues	2,195	3,776
Gross profit	7,919	14,015
Operating expenses:
Selling and marketing	4,592	8,362
Research and development	7,104	11,680
General and administrative	5,504	6,985
Restructuring expenses	334
Total operating expenses	17,534	27,027
Operating loss	(9,615)	(13,012)
Interest and other income, net	23	43
Loss before provision for income taxes	(9,592)	(12,969)
Provision for income tax expense (benefit)	90	(5,216)
Net loss	(9,682)	(7,753)
Other comprehensive income, before tax:
Unrealized holding gains on available-for-sale securities	40	7
Income tax expense related to items of other comprehensive income	6	3
Other comprehensive income, net of tax	34	4
Comprehensive loss	$ (9,648)	$ (7,749)
Net loss per share:
Basic and diluted	$ (0.27)	$ (0.22)
Weighted average shares outstanding:
Basic and diluted	35,590	35,263