CONDENSED CONSOLIDATEDSTATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 699	$ 20	$ 1,230	$ 183
Cost of sales	135	0	161	0
Gross Profit	564	20	1,069	183
Costs and expenses:
Research and development	5,527	8,425	9,815	16,100
Sales, general and administrative	11,460	9,484	21,988	17,144
Total costs and expenses	16,987	17,909	31,803	33,244
Loss from operations	(16,423)	(17,889)	(30,734)	(33,061)
Interest expense and other	(5)	0	(5)	0
Foreign currency exchange loss	(7)	(117)	(33)	(73)
Interest and dividend income	153	140	290	194
Total other income	141	23	252	121
Net loss before income taxes	(16,282)	(17,866)	(30,482)	(32,940)
Provision from income taxes	(175)	0	(175)	0
Net loss	$ (16,457)	$ (17,866)	$ (30,657)	$ (32,940)
Basic and diluted net loss per share (usd per share)	$ (0.31)	$ (0.35)	$ (0.58)	$ (0.64)
Weighted average shares outstanding (shares)	53,568	51,213	52,732	51,205
Other comprehensive loss:
Net loss	$ (16,457)	$ (17,866)	$ (30,657)	$ (32,940)
Net unrealized gain on available-for-sale investments	3	29	3	81
Foreign currency translation adjustment	204	49	204	0
Comprehensive loss	$ (16,250)	$ (17,788)	$ (30,450)	$ (32,859)