Discontinued Operations (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	May 31, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net income (loss) from discontinuing operations		$ (2,193)	$ (469)	$ (8,672)	$ 885
REG Life Sciences | Assets held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment loss						$ (11,226)
Other revenues		0	1,429	0	3,929
Other costs of goods sold		0	(1,173)	0	(3,454)
Research and development expense		(2,257)	(5,476)	(7,475)	(13,498)
Other income, net		64	4,751	53	13,908
Loss on sale of assets		0	0	(1,250)	0
Pre-tax income (loss) from discontinued operations		(2,193)	(469)	(8,672)	885
Income tax expense		0	0	0	0
Net income (loss) from discontinuing operations		(2,193)	$ (469)	(8,672)	$ 885
Machinery and equipment, net		0		0		824
In-process research and development		0		0		13,652
Impairment recognized on assets classified as held for sale		0		0		(11,226)
Total assets classified as held for sale		$ 0		$ 0		$ 3,250
REG Life Sciences | Assets sold
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loss on sale of assets	$ 1,250