Receivables - Narrative (Details) (USD $) In Millions, unless otherwise specified	Feb. 28, 2014	Aug. 31, 2013	Feb. 28, 2013
Notes Receivable, Long-Term
CHS Capital long-term notes receivable	$ 160.2	$ 127.7	$ 120.2
Percentage of commercial notes to CHS Capital long-term notes receivable	76.00%	59.00%	79.00%
Percentage of producer notes to CHS Capital long-term notes receivable	24.00%	41.00%	21.00%
Interest income accrual, discontinue, term	90 days
Minimum [Member]
Notes Receivable, Short-Term
CHS Capital short-term notes receivable, term	12 months
Maximum [Member]
Notes Receivable, Short-Term
CHS Capital short-term notes receivable, term	14 months
Notes and Loans Receivable, Net, Noncurrent, Term	10 years
CHS [Member]
Notes Receivable, Long-Term
CHS Capital long-term notes receivable additional available credit of counterparty	$ 943.7