Investments Equity Method investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019	Aug. 31, 2019
Schedule of Equity Method Investments [Line Items]
Net income (loss) attributable to CHS Inc.	$ 97,648	$ 54,620	$ 400,977	$ 650,890
Ventura Foods, LLC And Ardent Mills, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Net Sales			4,101,502	4,427,127
Gross Profit			686,045	391,338
Net earnings			134,774	152,315
Net income (loss) attributable to CHS Inc.			29,770	50,415
Other Equity Method Investments [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	247,778		247,778		$ 267,247
CF Nitrogen LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 2,724,668		2,724,668		$ 2,708,942
Net Sales			1,954,660	2,219,267
Gross Profit			481,711	560,631
Net earnings			452,859	536,409
Net income (loss) attributable to CHS Inc.			$ 104,021	$ 118,415