Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Income Statement [Abstract]
Revenue	$ 44,740	$ 48,556	$ 87,024	$ 91,168
Cost of goods sold	15,136	16,332	29,094	30,302
Gross profit	29,604	32,224	57,930	60,866
Operating expenses:
Research and development	6,244	5,734	11,743	11,264
Clinical and regulatory affairs	3,728	2,740	7,299	6,575
Marketing and sales	21,116	23,781	42,841	49,681
General and administrative	14,022	7,904	24,391	16,777
Restructuring costs	0	(29)	233	137
Total operating expenses	45,110	40,130	86,507	84,434
Loss from operations	(15,506)	(7,906)	(28,577)	(23,568)
Other income (expense):
Interest income	2	28	5	72
Interest expense	(5,863)	(5,803)	(11,670)	(10,098)
Other income (expense), net	(683)	223	(320)	176
Change in fair value of contingent consideration related to acquisition	(1,800)	3,800	(700)	2,600
Loss on debt extinguishment	0	(6,512)	(2,270)	(6,512)
Total other income (expense)	(8,344)	(8,264)	(14,955)	(13,762)
Net loss before income tax expense	(23,850)	(16,170)	(43,532)	(37,330)
Income tax expense	(26)	(122)	(111)	(276)
Net loss	(23,876)	(16,292)	(43,643)	(37,606)
Other comprehensive income (loss) foreign currency translation	(552)	781	(679)	1,137
Comprehensive loss	$ (24,428)	$ (15,511)	$ (44,322)	$ (36,469)
Basic and diluted net loss per share (in dollars per share)	$ (0.28)	$ (0.20)	$ (0.52)	$ (0.45)
Shares used in computing basic and diluted net loss per share (in shares)	84,462	83,247	84,112	83,087