Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenue	$ 39,479	$ 38,327	$ 76,149	$ 71,591
Cost of goods sold	15,347	9,820	25,111	18,789
Gross profit	24,132	28,507	51,038	52,802
Operating expenses:
Research and development	5,993	4,458	12,224	8,563
Clinical and regulatory affairs	3,597	2,722	7,047	4,922
Marketing and sales	19,842	19,167	39,441	35,311
General and administrative	6,850	5,932	14,139	13,094
Total operating expenses	36,282	32,279	72,851	61,890
Loss from operations	(12,150)	(3,772)	(21,813)	(9,088)
Other income (expense):
Interest income	37	67	82	126
Interest expense	(1,493)	(1,448)	(2,955)	(2,839)
Other income (expense), net	766	(148)	824	211
Change in fair value of contingent consideration related to acquisition	(100)	(3,772)	(200)	8,028
Total other income (expense)	(790)	(5,301)	(2,249)	5,526
Net loss before income tax (expense) benefit	(12,940)	(9,073)	(24,062)	(3,562)
Income tax (expense) benefit	(61)	80	(153)	(136)
Net loss	(13,001)	(8,993)	(24,215)	(3,698)
Other comprehensive income (loss) foreign currency translation	84	68	(1,670)	23
Comprehensive loss	$ (12,917)	$ (8,925)	$ (25,885)	$ (3,675)
Basic and diluted net loss per share	$ (0.19)	$ (0.14)	$ (0.36)	$ (0.06)
Shares used in computing basic and diluted net loss per share	67,615	62,699	67,441	62,403