Inventories (Details) $ in Thousands, bu in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) bu	Dec. 31, 2019 USD ($) bu	Dec. 31, 2018 USD ($)
Inventory [Line Items]
Agricultural Related Inventory	$ 1,025,809	$ 907,482
Frac sand and propane	12,477	15,438
Ethanol and co-products	114,895	95,432
Plant nutrients and cob products	139,885	146,164
Railcar repair parts	7,627	6,020
Total inventories	$ 1,300,693	$ 1,170,536
Grain held in storage and excluded from inventory calculations (bushels) | bu	3.0	6.4
Inventory write-down	$ 11,676	$ 0	$ 0
COVID-19 Pandemic
Inventory [Line Items]
Inventory write-down	11,700
Readily Marketable Inventory
Inventory [Line Items]
Agricultural Related Inventory	972,800	852,600
Frac sand and propane	$ 10,400	$ 10,600