Equities Changes in Equity (Details) (USD $)	3 Months Ended		9 Months Ended										1 Months Ended	9 Months Ended	1 Months Ended	9 Months Ended		9 Months Ended
	May 31, 2014	May 31, 2013	May 31, 2014	May 31, 2013	May 31, 2014 Patronage Refunds [Member]	May 31, 2013 Patronage Refunds [Member]	May 31, 2014 Capital equity certificates [Member]	May 31, 2013 Capital equity certificates [Member]	May 31, 2014 Capital Reserves [Member]	May 31, 2013 Capital Reserves [Member]	May 31, 2014 Noncontrolling Interest [Member]	May 31, 2013 Noncontrolling Interest [Member]	Sep. 30, 2013 Class B Series 1 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	May 31, 2014 Class B Series 1 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Mar. 31, 2014 Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	May 31, 2014 Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Jun. 30, 2014 Subsequent Event [Member] Class B Preferred Stock [Member] Preferred Stock [Member]	May 31, 2014 London Interbank Offered Rate (LIBOR) [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	May 31, 2014 Maximum [Member] London Interbank Offered Rate (LIBOR) [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Stock Issued During Period, Shares, New Issues													11,319,175		16,800,000
Noncontrolling Interest, Decrease from Deconsolidation			$ (4,779,000)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stockholders' Equity Attributable to Parent			5,131,208,000	4,455,341,000
Net income attributable to CHS Inc.	379,455,000	250,796,000	881,710,000	869,589,000
Other comprehensive income (loss), net of tax			(2,368,000)	5,852,000
Patronage distribution					(837,306,000)	(975,998,000)
Equities retired			(87,666,000)	(184,955,000)
Dividends and equity retirement determination					841,386,000	969,862,000	87,666,000	184,955,000	(40,366,000)	(18,408,000)
Equities issued in business combinations							45,000	18,211,000
Preferred stock dividends			(29,860,000)	(18,408,000)
Accrued dividends and equities payable			(347,000,000)	(347,491,000)
Other, net			(8,844,000)	8,008,000							584,000	1,001,000
Stockholders' Equity Attributable to Parent	6,298,310,000	4,984,966,000	6,298,310,000	4,984,966,000
Stockholders' Equity Attributable to Noncontrolling Interest			21,539,000									17,982,000
Net income attributable to noncontrolling interests	418,000	1,533,000	1,812,000	4,139,000
Stockholders' Equity Attributable to Noncontrolling Interest	18,581,000	21,887,000	18,581,000	21,887,000
Distributions to noncontrolling interests			(575,000)	(1,235,000)
Preferred Stock, Redemption Amount														283,000,000		420,000,000
Proceeds from Issuance of Preferred Stock, net of Issuance Costs			679,845,000	0										273,300,000		406,300,000
Preferred Stock, Dividend Rate, Percentage														7.875%		7.10%			8.00%
Preferred Stock, Basis Spread on Dividend Rate Percentage																		4.298%
Value of Preferred Stock available to be sold under Shelf Registration																	$ 2,000,000,000