Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 34,756	$ 45,986	$ 121,780	$ 137,154
Cost of goods sold	12,129	16,879	41,223	47,181
Gross profit	22,627	29,107	80,557	89,973
Operating expenses:
Research and development	5,037	5,277	16,780	16,541
Clinical and regulatory affairs	3,208	3,211	10,507	9,786
Marketing and sales	17,072	21,536	59,913	71,217
General and administrative	10,330	8,332	34,721	25,109
Restructuring costs	2,899	98	3,132	235
Total operating expenses	38,546	38,454	125,053	122,888
Loss from operations	(15,919)	(9,347)	(44,496)	(32,915)
Other income (expense):
Interest income	2	8	7	80
Interest expense	(7,225)	(6,021)	(18,895)	(16,119)
Other income (expense), net	(113)	349	(433)	525
Change in fair value of contingent consideration related to acquisition	5,000	800	4,300	3,400
Change in fair value of derivative liabilities	8,305	0	8,305	0
Loss on debt extinguishment	0	0	(2,270)	(6,512)
Total other income (expense)	5,969	(4,864)	(8,986)	(18,626)
Net loss before income tax expense	(9,950)	(14,211)	(53,482)	(51,541)
Income tax expense	(166)	(62)	(277)	(338)
Net loss	(10,116)	(14,273)	(53,759)	(51,879)
Other comprehensive income (loss) foreign currency translation	32	232	(647)	1,369
Comprehensive loss	$ (10,084)	$ (14,041)	$ (54,406)	$ (50,510)
Basic and diluted net loss per share (in dollars per share)	$ (0.12)	$ (0.17)	$ (0.64)	$ (0.62)
Shares used in computing basic and diluted net loss per share (in shares)	85,226	83,496	84,487	83,225