CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Statement [Abstract]
Revenue	$ 9,251	$ 8,830	$ 16,883	$ 16,522
Cost of revenue	4,976	7,028	9,239	11,742
Gross profit	4,275	1,802	7,644	4,780
Operating expenses:
Research and development	8,557	5,213	15,474	10,794
Selling, general and administrative	12,406	12,063	24,153	23,781
Amortization of intangible assets	51	51	101	101
Total operating expenses	21,014	17,327	39,728	34,676
Loss from operations	(16,739)	(15,525)	(32,084)	(29,896)
Non-operating (expense) income, net:
(Loss) gain from revaluation of warrant liability		(2,707)		3,589
Foreign exchange gain (loss)	101	499	(16)	(614)
Interest expense	(658)	(301)	(1,313)	(556)
Other income, net	113	27	179	29
Total non-operating (expense) income, net	(444)	(2,482)	(1,150)	2,448
Loss before income taxes	(17,183)	(18,007)	(33,234)	(27,448)
Provision (benefit) for income taxes	983	(2,035)	1,795	(2,016)
Net loss	$ (18,166)	$ (15,972)	$ (35,029)	$ (25,432)
Net loss per share:
Basic	$ (0.18)	$ (0.17)	$ (0.35)	$ (0.27)
Diluted	$ (0.18)	$ (0.17)	$ (0.35)	$ (0.30)
Weighted average shares outstanding used for calculating net loss per share:
Basic	101,563	95,728	100,517	94,576
Diluted	101,563	95,728	100,517	95,682