Receivables - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
CHS Capital long-term notes receivable	$ 55.4	$ 101.5
Percentage of commercial notes to CHS Capital long-term notes receivable	28.00%	33.00%
Percentage of producer notes to CHS Capital long-term notes receivable	72.00%	67.00%
Interest income accrual, discontinued, term	90 days
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
CHS Capital short-term notes receivable, term	12 months
Long-term notes receivable, term	10 years
CHS Capital
Accounts, Notes, Loans and Financing Receivable [Line Items]
Additional available credit	$ 706.9
CHS Capital Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan loss reserves	0.0
Note receivables sold under loan participations	$ 40.8	$ 70.6