Equities Changes in Equity (Details) (USD $)	3 Months Ended		6 Months Ended										3 Months Ended		1 Months Ended	9 Months Ended	1 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014	Feb. 28, 2013	Feb. 28, 2014 Patronage Refunds [Member]	Feb. 28, 2013 Patronage Refunds [Member]	Feb. 28, 2014 Capital equity certificates [Member]	Feb. 28, 2013 Capital equity certificates [Member]	Feb. 28, 2014 Capital Reserves [Member]	Feb. 28, 2013 Capital Reserves [Member]	Feb. 28, 2014 Noncontrolling Interest [Member]	Feb. 28, 2013 Noncontrolling Interest [Member]	Nov. 30, 2013 Class B Series 1 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Sep. 03, 2013 Class B Series 1 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Mar. 31, 2014 Subsequent Event [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	May 31, 2014 Subsequent Event [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Mar. 31, 2014 London Interbank Offered Rate (LIBOR) [Member] Subsequent Event [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]	Mar. 31, 2014 Maximum [Member] London Interbank Offered Rate (LIBOR) [Member] Subsequent Event [Member] Class B Series 2 Cumulative Redeemable Preferred Stock [Member] Preferred Stock [Member]
Schedule of Capitalization, Equity [Line Items]
Noncontrolling Interest, Decrease from Deconsolidation			$ (4,779,000)
Preferred Stock, Shares Outstanding														11,319,175	16,800,000
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.	260,069,000	275,086,000	502,255,000	618,793,000
Other comprehensive income (loss), net of tax			(8,565,000)	2,254,000
Patronage distribution					(840,494,000)	(975,732,000)
Equities retired			(79,656,000)	(179,369,000)
Dividends and equity retirement determination					837,527,000	969,862,000	79,656,000	179,369,000	(21,867,000)	(12,272,000)
Equities issued in business combinations							45,000	18,236,000
Preferred stock dividends			(18,153,000)	(12,272,000)
Accrued dividends and equities payable			195,100,000	(249,591,000)
Other, net			(9,000)	7,022,000							680,000	1,087,000
Stockholders' Equity Attributable to Parent	5,678,325,000	4,833,913,000	5,678,325,000	4,833,913,000
Stockholders' Equity Attributable to Noncontrolling Interest			21,539,000									17,982,000
Net income attributable to noncontrolling interests	552,000	432,000	1,394,000	2,606,000
Stockholders' Equity Attributable to Noncontrolling Interest	18,259,000	20,935,000	18,259,000	20,935,000
Distributions to noncontrolling interests			(575,000)	(740,000)
Preferred Stock, Redemption Amount														283,000,000	420,000,000
Proceeds from Issuance of Preferred Stock, net of Issuance Costs			$ 273,325,000										$ 273,700,000			$ 406,400,000
Preferred Stock, Dividend Rate, Percentage													7.875%		7.10%			8.00%
Preferred Stock, Basis Spread on Dividend Rate Percentage																	4.298%