Consolidated Statement of Equities and Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2015	Aug. 31, 2014	Aug. 31, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ 6,466,844	$ 5,152,747	$ 4,473,323
Reversal of prior year patronage and redemption estimates	394,974	386,062	574,718
Patronage distribution	(271,226)	(286,789)	(380,947)
Redemptions of equities	(128,907)	(99,609)	(193,413)
Equities issued	989,728	685,087	18,211
Preferred stock dividends	(145,723)	(61,658)	(24,544)
Other, net	(1,735)	2,861	(587)
Comprehensive income
Net income	780,333	1,083,007	996,328
Net income attributable to CHS Inc.	781,045	1,081,435	992,386
Net Income (Loss) Attributable to Noncontrolling Interest	(712)	1,572	3,942
Other Comprehensive Income (Loss), Net of Tax	(57,450)	110	75,720
Patronage Refunds, Estimated	(250,177)	(264,825)	(284,769)
Equity redemptions, estimate	(107,250)	(130,149)	(101,293)
Balances	7,669,411	6,466,844	5,152,747
Capital Equity Certificates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	3,508,473	3,430,537	3,084,335
Reversal of prior year patronage and redemption estimates	(267,088)	(325,862)	(395,144)
Patronage distribution	402,560	422,670	595,022
Redemptions of equities	(127,707)	(99,204)	(193,142)
Equities issued	$ 12,365	14,278	$ 14,845
Capital Equity Certificates Exchanged for Preferred Stock		$ (200,000)
Preferred stock dividends
Other, net	$ (2,723)	$ (1,034)	$ (1,241)
Comprehensive income
Net income
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated	$ 375,267	$ 397,237	$ 427,155
Equity redemptions, estimate	(107,250)	(130,149)	(101,293)
Balances	3,793,897	3,508,473	3,430,537
Nonpatronage Equity Certificates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ 23,256	$ 23,485	$ 23,746
Reversal of prior year patronage and redemption estimates
Patronage distribution
Redemptions of equities	$ (199)	$ (229)	$ (232)
Equities issued
Capital Equity Certificates Exchanged for Preferred Stock
Preferred stock dividends
Other, net			$ (29)
Comprehensive income
Net income
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated
Equity redemptions, estimate
Balances	$ 23,057	$ 23,256	$ 23,485
Non-qualified Equity Certificates [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	284,699	134,324	$ 1,535
Reversal of prior year patronage and redemption estimates	(148,579)	(129,462)
Patronage distribution	147,710	131,661
Redemptions of equities	$ (1,021)	$ (176)	$ (39)
Equities issued			$ 3,366
Capital Equity Certificates Exchanged for Preferred Stock
Preferred stock dividends
Other, net	$ 119	$ (227)
Comprehensive income
Net income
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated		$ 148,579	$ 129,462
Equity redemptions, estimate
Balances	$ 282,928	$ 284,699	$ 134,324
Preferred Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ 1,190,177	$ 319,368	$ 319,368
Reversal of prior year patronage and redemption estimates
Patronage distribution
Redemptions of equities
Equities issued	$ 977,363	$ 670,809
Capital Equity Certificates Exchanged for Preferred Stock		$ 200,000
Preferred stock dividends
Other, net
Comprehensive income
Net income
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated
Equity redemptions, estimate
Balances	$ 2,167,540	$ 1,190,177	$ 319,368
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ (156,757)	$ (156,867)	$ (232,587)
Reversal of prior year patronage and redemption estimates
Patronage distribution
Redemptions of equities
Equities issued
Capital Equity Certificates Exchanged for Preferred Stock
Preferred stock dividends
Other, net
Comprehensive income
Net income
Other Comprehensive Income (Loss), Net of Tax	$ (57,450)	$ 110	$ 75,720
Patronage Refunds, Estimated
Equity redemptions, estimate
Balances	$ (214,207)	$ (156,757)	$ (156,867)
Capital Reserves
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	1,598,660	1,380,361	1,258,944
Reversal of prior year patronage and redemption estimates	810,641	841,386	969,862
Patronage distribution	(821,496)	$ (841,120)	$ (975,969)
Redemptions of equities	$ 20
Equities issued
Capital Equity Certificates Exchanged for Preferred Stock
Preferred stock dividends	$ (145,723)	$ (61,658)	$ (24,544)
Other, net	6,967	8,897	1,068
Comprehensive income
Net income attributable to CHS Inc.	$ 781,045	$ 1,081,435	$ 992,386
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated	$ (625,444)	$ (810,641)	$ (841,386)
Equity redemptions, estimate
Balances	$ 1,604,670	$ 1,598,660	$ 1,380,361
Noncontrolling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balances	$ 18,336	$ 21,539	$ 17,982
Reversal of prior year patronage and redemption estimates
Patronage distribution
Redemptions of equities
Equities issued
Capital Equity Certificates Exchanged for Preferred Stock
Preferred stock dividends
Other, net	$ (6,098)	$ (4,775)	$ (385)
Comprehensive income
Net Income (Loss) Attributable to Noncontrolling Interest	$ (712)	$ 1,572	$ 3,942
Other Comprehensive Income (Loss), Net of Tax
Patronage Refunds, Estimated
Equity redemptions, estimate
Balances	$ 11,526	$ 18,336	$ 21,539