Goodwill (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015 USD ($)
Goodwill [Roll Forward]
Balance	$ 188,275
Finalization of purchase accounting	3,202
Balance	191,477
Biomass-based diesel
Goodwill [Roll Forward]
Balance	137,348
Finalization of purchase accounting	3,202
Balance	140,550
Services
Goodwill [Roll Forward]
Balance	16,080
Finalization of purchase accounting	0
Balance	16,080
Renewable Chemicals
Goodwill [Roll Forward]
Balance	34,847
Finalization of purchase accounting	0
Balance	$ 34,847