Inventories (Details) $ in Thousands, bu in Millions	3 Months Ended	6 Months Ended
	Mar. 31, 2020 USD ($)	Jun. 30, 2020 USD ($) bu	Jun. 30, 2019 USD ($) bu	Dec. 31, 2019 USD ($) bu
Inventory [Line Items]
Grain and other agricultural products		$ 452,339	$ 603,318	$ 907,482
Frac sand and propane		6,498	9,287	15,438
Ethanol and co-products		63,195	26,185	95,432
Plant nutrients and cob products		87,346	109,156	146,164
Railcar repair parts		6,945	5,695	6,020
Total inventories		$ 616,323	$ 753,641	$ 1,170,536
Bushels of grain held in storage for others and excluded from inventory calculations | bu		1.7	1.3	6.4
Inventory write down		$ 10,922	$ 0
COVID-19 Pandemic
Inventory [Line Items]
Inventory write down	$ 10,600	$ 10,900