Condensed Consolidated Statements of Operations (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Revenues:
Product revenues	$ 62,709	$ 57,904
Contract revenues	385	563
Total revenues	63,094	58,467
Operating expenses:
Cost of product revenues	9,746	9,326
Research and development	13,663	11,929
Selling and marketing	27,439	24,366
General and administrative	13,135	11,975
Total operating expenses	63,983	57,596
Income (loss) from operations	(889)	871
Interest income	65	74
Other income (expense), net	(6)	(72)
Income (loss) before income taxes	(830)	873
Income tax expense	53	96
Net income (loss)	$ (883)	$ 777
Basic net income (loss) per share (in dollars per share)	$ (0.03)	$ 0.03
Diluted net income (loss) per share (in dollars per share)	$ (0.03)	$ 0.02
Shares used in computing basic net income (loss) per share (in shares)	30,099	29,910
Shares used in computing diluted net income (loss) per share (in shares)	30,099	31,609