Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Income Statement [Abstract]
Revenue	$ 36,671	$ 33,264
Cost of goods sold	9,765	8,969
Gross profit	26,906	24,295
Operating expenses:
Research and development	6,231	4,105
Clinical and regulatory affairs	3,450	2,200
Marketing and sales	19,599	16,143
General and administrative	7,289	7,163
Total operating expenses	36,569	29,611
Loss from operations	(9,663)	(5,316)
Other income (expense):
Interest income	45	59
Interest expense	(1,462)	(1,390)
Other income (expense), net	59	358
Change in fair value of contingent consideration related to acquisition	(100)	11,800
Total other income (expense)	(1,458)	10,827
Net income (loss) before income tax expense	(11,121)	5,511
Income tax expense	(92)	(216)
Net income (loss)	(11,213)	5,295
Other comprehensive loss- foreign currency translation	(1,754)	(46)
Comprehensive income (loss)	$ (12,967)	$ 5,249
Basic net income (loss) per share	$ (0.17)	$ 0.08
Diluted net income (loss) per share	$ (0.17)	$ 0.08
Shares used in computing basic net income (loss) per share	67,263,000	63,405,000
Shares used in computing diluted net income (loss) per share	67,263,000	66,017,000