Derivative Financial Instruments (Details) $ in Thousands, gal in Millions, bu in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2020 USD ($) bu gal	Oct. 31, 2019 USD ($)	Oct. 31, 2020 USD ($) bu gal	Oct. 31, 2019 USD ($)	Jan. 31, 2020 USD ($) bu
Derivative Financial Instruments (Details) [Line Items]
Debt Instrument, Collateral Amount | $	$ 884		$ 884		$ 1,113
Gain (Loss) on Derivative Instruments, Net, Pretax | $	(26)	$ 248	(1,785)	$ 1,478
Gain (Loss) on Derivative Instruments, Net, Sales and Revenue | $	$ 777		$ 1,076
Assets [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Forward Purchase Contracts, Quantity (in US Bushels)	5.4		5.4
Liability [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Forward Purchase Contracts, Quantity (in US Bushels)					1.6
Short/Sell [Member] | Assets [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity	4.6		4.6		3.7
Short/Sell [Member] | Assets [Member] | Ethanol [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity | gal	4.2		4.2
Long/Buy | Assets [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity	4.8		4.8		2.2