Derivative Financial Instruments and Hedging Activities - Purchase and Sales Contracts Outstanding (Details) - Not Designated as Hedging Instrument t in Thousands, T in Thousands, Bushels in Thousands, Barrels in Thousands	Aug. 31, 2021 t T Bushels Barrels	Aug. 31, 2020 T t Barrels Bushels
Grain and oilseed contracts [Member] | Long [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | Bushels	666,726	664,673
Grain and oilseed contracts [Member] | Short [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | Bushels	851,582	892,303
Energy products [Member] | Long [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | Barrels	9,881	10,028
Energy products [Member] | Short [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | Barrels	7,656	6,570
Processed grain and oilseed contracts [Member] | Long [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	559	657
Processed grain and oilseed contracts [Member] | Short [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	3,418	3,304
Crop nutrient contracts | Long [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	66	74
Crop nutrient contracts | Short [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount	12	127
Ocean freight contracts | Long [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | t	210	1,140
Ocean freight contracts | Short [Member]
Derivative [Line Items]
Derivative, Nonmonetary Notional Amount | t	0	95