Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue	$ 32,863	$ 27,308	$ 26,542
Grant and other revenue	25	228	671
Total revenues	32,863	27,536	27,213
Cost of goods sold	41,568	38,165	37,017
Gross loss	(8,705)	(10,629)	(9,804)
Operating expenses
Research and development expense	5,374	5,182	5,216
Selling, general and administrative expense	8,122	7,471	8,965
Total operating expenses	13,496	12,653	14,181
Loss from operations	(22,201)	(23,282)	(23,985)
Other (expense) income
Interest expense	(3,237)	(2,951)	(7,837)
(Loss) on exchange or conversion of debt	(2,202)	(4,933)	(763)
(Loss)/Gain on extinguishment of warrant liability			(918)
Gain from change in fair value of 2020 Notes embedded derivative	2,637	1,751
(Loss)/Gain from change in fair value of derivative warrant liability	(2,976)	5,101	1,783
(Loss) from change in fair value of 2017 Notes		(339)	(4,204)
Loss on issuance of equity			(1,519)
Other income	3	23	215
Total other (expense) income	(5,775)	(1,348)	(13,243)
Net loss	$ (27,976)	$ (24,630)	$ (37,228)
Net loss per share - basic and diluted (in dollars per share)	$ (5.74)	$ (30.23)	$ (193.52)
Weighted-average number of common shares outstanding - basic and diluted (in shares)	4,876,897	814,797	192,372
Ethanol Sales and Related Products [Member]
Revenue	$ 31,641	$ 26,279	$ 24,613
Total revenues	31,641	26,279	24,613
Hydrocarbon [Member]
Revenue	1,197	1,029	1,929
Total revenues	$ 1,197	$ 1,029	$ 1,929