Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues from external customers	$ 2,325,041	$ 911,402	$ 4,301,833	$ 1,547,141
Income (loss) before income taxes, net of noncontrolling interest	40,885	29,271	21,450	27,261
Net income (loss) attributable to the noncontrolling interests	(477)	(116)	(632)	(398)
Income (loss) before income taxes	40,408	29,155	20,818	26,863
Total assets	3,571,859	2,117,788	3,571,859	2,117,788	$ 2,392,003
Operating Segments | Trade
Segment Reporting Information [Line Items]
Revenues from external customers	1,766,305	365,920	3,364,326	642,772
Income (loss) before income taxes, net of noncontrolling interest	23,731	9,877	6,268	9,847
Total assets	2,057,305	820,016	2,057,305	820,016	978,974
Operating Segments | Ethanol
Segment Reporting Information [Line Items]
Revenues from external customers	245,143	200,938	453,974	373,776
Income (loss) before income taxes, net of noncontrolling interest	2,649	6,125	5,221	7,964
Total assets	361,522	248,560	361,522	248,560	295,971
Operating Segments | Plant Nutrient
Segment Reporting Information [Line Items]
Revenues from external customers	270,577	303,106	399,102	438,723
Income (loss) before income taxes, net of noncontrolling interest	15,903	15,124	11,974	16,215
Total assets	381,924	356,166	381,924	356,166	403,780
Operating Segments | Rail
Segment Reporting Information [Line Items]
Revenues from external customers	43,016	41,438	84,431	91,870
Income (loss) before income taxes, net of noncontrolling interest	3,180	944	7,492	4,913
Total assets	657,617	535,087	657,617	535,087	590,407
Segment Reconciling Items
Segment Reporting Information [Line Items]
Revenues from external customers	2,676	800	4,152	1,664
Segment Reconciling Items | Trade
Segment Reporting Information [Line Items]
Revenues from external customers	631	462	812	993
Segment Reconciling Items | Plant Nutrient
Segment Reporting Information [Line Items]
Revenues from external customers	1,274	0	1,294	0
Segment Reconciling Items | Rail
Segment Reporting Information [Line Items]
Revenues from external customers	771	338	2,046	671
Other
Segment Reporting Information [Line Items]
Income (loss) before income taxes, net of noncontrolling interest	(4,578)	(2,799)	(9,505)	(11,678)
Total assets	$ 113,491	$ 157,959	$ 113,491	$ 157,959	$ 122,871