Derivative Financial Instruments (Details) gal in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2021 USD ($) bu gal	Oct. 31, 2020 USD ($)	Oct. 31, 2021 USD ($) bu gal	Oct. 31, 2020 USD ($)	Jan. 31, 2021 USD ($) bu
Derivative Financial Instruments (Details) [Line Items]
Debt Instrument, Collateral Amount | $	$ 1,737,000		$ 1,737,000		$ 1,657,000
Gain (Loss) on Derivative Instruments, Net, Sales and Revenue | $	2,144,000	$ 777,000	4,907,000	$ 1,076,000
Gain (Loss) on Derivative Instruments, Net, Pretax | $	$ 5,474,000	$ 26,000	$ 2,562,000	$ 1,785,000
Assets [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity	6,700,000		6,700,000
Forward Purchase Contracts, Quantity (in US Bushels)	5,700,000		5,700,000		6,400,000
Short/Sell [Member] | Liability [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity	690,000		690,000		6,900,000
Short/Sell [Member] | Liability [Member] | Ethanol [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity | gal	5.5		5.5
Long/Buy [Member] | Liability [Member] | Corn [Member]
Derivative Financial Instruments (Details) [Line Items]
Commodity Futures, Quantity	2,300,000		2,300,000		0