Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Sales and merchandising revenues	$ 1,976,792	$ 635,739
Income (loss) before income taxes	(19,590)	(2,292)
Total assets	3,660,252	2,363,528	$ 2,392,003
Operating Segments | Trade
Segment Reporting Information [Line Items]
Sales and merchandising revenues	1,598,021	276,852
Income (loss) before income taxes	(17,464)	(1,244)
Total assets	2,116,254	1,031,150	978,974
Operating Segments | Ethanol
Segment Reporting Information [Line Items]
Sales and merchandising revenues	208,831	172,838
Income (loss) before income taxes	2,572	3,053
Total assets	333,060	210,169	295,971
Operating Segments | Plant Nutrient
Segment Reporting Information [Line Items]
Sales and merchandising revenues	128,525	135,617
Income (loss) before income taxes	(3,929)	1,091
Total assets	455,529	455,148	403,780
Operating Segments | Rail
Segment Reporting Information [Line Items]
Sales and merchandising revenues	41,415	50,432
Income (loss) before income taxes	4,312	3,969
Total assets	642,596	530,994	590,407
Segment Reconciling Items
Segment Reporting Information [Line Items]
Sales and merchandising revenues	1,476	864
Segment Reconciling Items | Trade
Segment Reporting Information [Line Items]
Sales and merchandising revenues	181	531
Segment Reconciling Items | Plant Nutrient
Segment Reporting Information [Line Items]
Sales and merchandising revenues	20	0
Segment Reconciling Items | Rail
Segment Reporting Information [Line Items]
Sales and merchandising revenues	1,275	333
Other
Segment Reporting Information [Line Items]
Income (loss) before income taxes	(4,926)	(8,879)
Total assets	112,813	136,067	$ 122,871
Noncontrolling interests
Segment Reporting Information [Line Items]
Income (loss) before income taxes	$ (155)	$ (282)