Investments Equity Method investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Schedule of Equity Method Investments [Line Items]
Net income (loss) attributable to CHS Inc.	$ 229,333	$ (45,185)	$ 576,090	$ 178,532
Ardent Mills, Ventura, CF Nitrogen [Member] [Member]
Schedule of Equity Method Investments [Line Items]
Net Sales			6,238,495	5,807,777
Gross Profit			719,555	651,705
Net earnings			435,192	317,674
Net income (loss) attributable to CHS Inc.			$ 109,266	$ 104,568