Investments - Schedule of Investments (Details) - USD ($) $ in Thousands	7 Months Ended	12 Months Ended
	Aug. 31, 2016	Aug. 31, 2017	Aug. 31, 2016	Aug. 31, 2015
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ (137,338)	$ (175,777)	$ (107,850)
Net income attributable to CHS Inc.		127,857	424,192	$ 781,045
Cost Method Investments	$ 127,577	131,605	127,577
Investments	3,795,976	3,750,993	3,795,976
CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	2,796,323	2,756,076	2,796,323
Equity Method Investment, Summarized Financial Information, Current Assets	534,878	394,089	534,878
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	7,043,121	7,314,629	7,043,121
Equity Method Investment, Summarized Financial Information, Current Liabilities	556,696	390,206	556,696
Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities	0	6	0
Equity Method Investment, Summarized Financial Information, Revenue	1,027,142	2,051,159
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	243,911	195,142
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	186,665	123,965
Net income attributable to CHS Inc.	74,700	66,530
Ventura Foods, LLC
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	369,487	$ 347,016	369,487
Ardent Mills LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		12.00%
Equity Method Investments	194,986	$ 206,529	194,986
TEMCO, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Equity Method Investments	44,578	$ 41,323	44,578
Cargill, Inc. [Member] | TEMCO, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Ownership of joint venture partner		50.00%
Miscellaneous Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 263,025	$ 268,444	263,025
Nitrogen Production [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		(66,530)	(74,700)
Nitrogen Production [Member] | CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity (income) loss from investments		$ 66,500	$ 74,700
Equity Method Investment, Ownership Percentage		11.40%