Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Consolidated Statements of Operations [Abstract]
Revenues	$ 16,105	$ 31,357	$ 33,896	$ 61,219
Cost of revenues	3,560	3,965	7,336	7,697
Gross profit	12,545	27,392	26,560	53,522
Operating expenses:
Selling and marketing	7,097	7,398	15,459	14,688
Research and development	11,316	10,095	22,996	20,223
General and administrative	7,178	6,217	14,163	12,023
Total operating expenses	25,591	23,710	52,618	46,934
Operating income (loss)	(13,046)	3,682	(26,058)	6,588
Interest and other income (expense)	42	(7)	85	33
Income (loss) before taxes	(13,004)	3,675	(25,973)	6,621
Income tax expense (benefit)	(5,157)	1,790	(10,373)	3,144
Net income (loss)	$ (7,847)	$ 1,885	$ (15,600)	$ 3,477
Net income (loss) per share:
Basic	$ (0.22)	$ 0.06	$ (0.44)	$ 0.10
Diluted	$ (0.22)	$ 0.05	$ (0.44)	$ 0.10
Weighted average shares outstanding:
Basic	35,775	34,264	35,520	33,999
Diluted	35,775	34,781	35,520	34,480