Reportable Segments and Geographic Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Net revenues:	$ 305,594	$ 230,918
Income (loss) before income taxes:	1,564	(39,201)
Depreciation and amortization expense, net:	7,835	5,726
Cash paid for purchases of property, plant and equipment:	14,770	12,178
Goodwill:	16,080		$ 16,080
Assets:	1,224,357		1,223,620
Corporate and Other
Segment Reporting Information [Line Items]
Net revenues:	16,988	7,342
Income (loss) before income taxes:	(7,188)	(3,684)
Depreciation and amortization expense, net:	396	350
Cash paid for purchases of property, plant and equipment:	0	906
Assets:	366,739		308,782
Intersegment revenues
Segment Reporting Information [Line Items]
Net revenues:	(24,893)	(16,083)
Assets:	(219,418)		(218,265)
Biomass-based Diesel | Segments
Segment Reporting Information [Line Items]
Net revenues:	292,762	224,188
Income (loss) before income taxes:	12,860	(31,676)
Depreciation and amortization expense, net:	6,929	4,971
Cash paid for purchases of property, plant and equipment:	13,604	10,410
Assets:	1,003,250		1,048,923
Biomass-based Diesel | Segments | Petrotec
Segment Reporting Information [Line Items]
Net revenues:	36,995	29,993
Income (loss) before income taxes:	407	(1,048)
Depreciation and amortization expense, net:	851	687
Cash paid for purchases of property, plant and equipment:	347	318
Assets:	52,221		45,471
Services
Segment Reporting Information [Line Items]
Goodwill:	16,080		16,080
Services | Segments
Segment Reporting Information [Line Items]
Net revenues:	20,737	15,471
Income (loss) before income taxes:	573	50
Depreciation and amortization expense, net:	96	62
Cash paid for purchases of property, plant and equipment:	1,166	722
Assets:	49,636		60,308
Renewable Chemicals | Segments
Segment Reporting Information [Line Items]
Income (loss) before income taxes:	(4,681)	(3,891)
Depreciation and amortization expense, net:	414	343
Cash paid for purchases of property, plant and equipment:	0	$ 140
Assets:	$ 24,150		$ 23,872