Inventories (Details) $ in Thousands, bu in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) bu	Mar. 31, 2020 USD ($) bu	Dec. 31, 2020 USD ($) bu
Inventory [Line Items]
Grain and other agricultural products	$ 971,914	$ 750,281	$ 1,025,809
Frac sand and propane	8,388	5,723	12,477
Ethanol and co-products	136,234	87,706	114,895
Plant nutrients and cob products	171,101	178,028	139,885
Railcar repair parts	7,424	6,338	7,627
Total inventories	1,295,061	1,028,076	1,300,693
Readily marketable inventory	$ 942,400	$ 712,300	$ 983,200
Bushels of grain held in storage for others and excluded from inventory calculations | bu	1.6	3.9	3.0
Inventory write down	$ 2,479	$ 10,571
COVID-19 Pandemic
Inventory [Line Items]
Inventory write down		$ 10,600