Condensed Consolidated Statements of Operations and Comprehensive Loss (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Revenue	$ 38,327	$ 33,964	$ 71,591	$ 63,748
Cost of goods sold	9,820	8,960	18,789	16,216
Gross profit	28,507	25,004	52,802	47,532
Operating expenses:
Research and development	4,458	3,822	8,563	7,341
Clinical and regulatory affairs	2,722	2,189	4,922	4,553
Marketing and sales	19,167	16,520	35,311	32,044
General and administrative	5,932	4,993	13,094	10,604
Total operating expenses	32,279	27,524	61,890	54,542
Loss from operations	(3,772)	(2,520)	(9,088)	(7,010)
Other income (expense):
Interest income	67	10	126	20
Interest expense	(1,448)	(3)	(2,839)	(3)
Other income (expense), net	(148)	439	211	1,123
Change in fair value of contingent consideration related to acquisition	(3,772)	7,600	8,028	2,400
Total other income (expense)	(5,301)	8,046	5,526	3,540
Net income (loss) before income tax benefit (expense)	(9,073)	5,526	(3,562)	(3,470)
Income tax benefit (expense)	80	144	(136)	(195)
Net income (loss)	(8,993)	5,670	(3,698)	(3,665)
Other comprehensive income (loss) foreign currency translation	68	(185)	23	143
Comprehensive income (loss)	$ (8,925)	$ 5,485	$ (3,675)	$ (3,522)
Basic net income (loss) per share (usd per share)	$ (0.14)	$ 0.09	$ (0.06)	$ (0.06)
Diluted net income (loss) per share (usd per share)	$ (0.14)	$ 0.09	$ (0.06)	$ (58.87)
Shares used in computing basic net income (loss) per share	62,699	62,330	62,403	62,260
Shares used in computing diluted net income (loss) per share	62,699	65,496	62,403	62