Receivables - Narrative (Details) - USD ($) $ in Millions	6 Months Ended
	Feb. 29, 2016	Aug. 31, 2015
Notes Receivable, Long-Term
CHS Capital long-term notes receivable	$ 178.7	$ 190.4
Percentage of commercial notes to CHS Capital long-term notes receivable	42.00%	34.00%
Percentage of producer notes to CHS Capital long-term notes receivable	58.00%	66.00%
Interest Income Accrual Term, Discontinued	90 days
CHS Capital long-term notes receivable additional available credit of counterparty	$ 995.4
Minimum [Member]
Notes Receivable, Short-Term
Notes and Loans Receivable, Current, Term	12 months
Maximum [Member]
Notes Receivable, Short-Term
Notes and Loans Receivable, Current, Term	14 months
Notes Receivable, Long-Term
Notes and Loans Receivable, Non Current, Net, Term	10 years
CHS Capital Notes Receivable [Member]
Notes Receivable, Long-Term
Percentage of receivable from one customer	18.00%
CHS Capital [Member] | Maximum [Member]
Notes Receivable, Long-Term
Percentage of receivable from one customer	10.00%