Discontinued Operations (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended								12 Months Ended
	May 31, 2019	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on operations of discontinued operations										$ (9,667)	$ (86)	$ (12,800)
Impairment loss on assets classified as held for sale										0	(11,226)	0
Net loss from discontinuing operations		$ (995)	$ (2,193)	$ (4,462)	$ (2,017)	$ (12,196)	$ (469)	$ 4,808	$ (3,455)	(9,667)	(11,312)	(12,800)
REG Life Sciences | Assets sold
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss											(11,226)
Other revenues										1,786	5,856	3,588
Other costs of goods sold										(2,200)	(4,697)	(4,360)
Research and development expense										(8,056)	(15,152)	(11,673)
Other income (expense), net										53	13,907	(355)
Loss on sale of assets	$ 1,250									(1,250)	0	0
Loss on operations of discontinued operations										(9,667)	(86)	(12,800)
Impairment loss on assets classified as held for sale										0	(11,226)	0
Income tax expense										0	0	0
Net loss from discontinuing operations										(9,667)	(11,312)	$ (12,800)
Machinery and equipment, net		0				824				0	824
In-process research and development		0				13,652				0	13,652
Impairment loss recognized on assets classified as held for sale		0				(11,226)				0	(11,226)
Non-current assets held for sale		$ 0				$ 3,250				$ 0	$ 3,250