Condensed Consolidated Statements of Operations and Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Income Statement [Abstract]
Revenue	$ 33,260	$ 26,696	$ 97,008	$ 76,725
Cost of goods sold	7,362	6,444	23,578	18,148
Gross profit	25,898	20,252	73,430	58,577
Operating expenses:
Research and development	5,160	3,076	12,501	11,886
Clinical and regulatory affairs	2,005	1,462	6,558	4,727
Marketing and sales	15,191	12,705	47,235	38,923
General and administrative	5,760	4,942	16,364	13,813
Contract termination and business acquisition expenses	0	0	0	422
Settlement costs	0	5,000	0	5,000
Total operating expenses	28,116	27,185	82,658	74,771
Loss from operations	(2,218)	(6,933)	(9,228)	(16,194)
Other income (expense):
Interest income	13	34	33	24
Interest expense	(7)	0	(10)	(3)
Other income (expense), net	994	(101)	2,117	(86)
Change in fair value of contingent consideration related to acquisition	(7,600)	990	(5,200)	(12,700)
Total other income (expense)	(6,600)	923	(3,060)	(12,765)
Net loss before income tax expense	(8,818)	(6,010)	(12,288)	(28,959)
Income tax benefit (expense)	(172)	153	(367)	(297)
Net loss	(8,990)	(5,857)	(12,655)	(29,256)
Other comprehensive loss (foreign currency translation)	(477)	(139)	(334)	(32)
Comprehensive loss	$ (9,467)	$ (5,996)	$ (12,989)	$ (29,288)
Basic and diluted net loss per share (usd per share)	$ (0.14)	$ (0.10)	$ (0.20)	$ (0.49)
Shares used in computing basic and diluted net loss per share	62,730	61,327	62,407	59,224