Consolidated Statements of Comprehensive Loss (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Consolidated Statements of Comprehensive Loss [Abstract]
Revenues	$ 10,171	$ 16,105	$ 20,285	$ 33,896
Cost of revenues	1,796	3,560	3,991	7,336
Gross profit	8,375	12,545	16,294	26,560
Operating expenses:
Selling and marketing	3,954	7,097	8,546	15,459
Research and development	6,173	11,316	13,277	22,996
General and administrative	5,149	7,178	10,653	14,163
Restructuring expense (income)	(77)		257
Total operating expenses	15,199	25,591	32,733	52,618
Operating loss	(6,824)	(13,046)	(16,439)	(26,058)
Interest and other income, net	31	42	54	85
Loss before provision for income taxes	(6,793)	(13,004)	(16,385)	(25,973)
Provision for income tax expense (benefit)	32	(5,157)	122	(10,373)
Net loss	(6,825)	(7,847)	(16,507)	(15,600)
Other comprehensive income (loss), before tax:
Unrealized holding gains (losses) on available-for-sale securities	(3)	(8)	37	(1)
Income tax expense (benefit) related to items of other comprehensive income (expense)		(3)	6
Other comprehensive income (expense), net of tax	(3)	(5)	31	(1)
Comprehensive loss	$ (6,828)	$ (7,852)	$ (16,476)	$ (15,601)
Net loss per share:
Basic and diluted	$ (0.19)	$ (0.22)	$ (0.46)	$ (0.44)
Weighted average shares outstanding:
Basic and diluted	36,045	35,775	35,818	35,520