Equities Changes in Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Nov. 30, 2016	Nov. 30, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	$ 7,866,250
Reversal of prior year redemption estimate	9,528
Redemptions of equities	(9,528)
Preferred stock dividends	(41,825)
Other, net	(647)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	208,942	$ 266,174
Net income (loss) attributable to CHS Inc.	209,150	266,475
Net income (loss) attributable to noncontrolling interests	(208)	(301)
Other comprehensive income (loss), net of tax	(14,494)	$ (3,553)
Estimated 2017 cash patronage refunds	(58,238)
Estimated 2017 equity redemptions	(28,708)
Ending Balance	7,931,280
Capital equity certificates [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	3,932,513
Reversal of prior year redemption estimate	9,528
Redemptions of equities	(8,946)
Other, net	(47)
Estimated 2017 equity redemptions	(28,708)
Ending Balance	3,904,340
Nonpatronage Equity Certificates [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	22,894
Reversal of prior year redemption estimate	0
Redemptions of equities	(60)
Other, net	(59)
Ending Balance	22,775
Non-qualified Equity Certificates [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	281,767
Reversal of prior year redemption estimate	0
Redemptions of equities	(522)
Other, net	(24)
Ending Balance	281,221
Preferred Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	2,244,132
Reversal of prior year redemption estimate	0
Redemptions of equities	0
Ending Balance	2,244,132
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	(211,726)
Reversal of prior year redemption estimate	0
Redemptions of equities	0
Other comprehensive income (loss), net of tax	(14,494)
Ending Balance	(226,220)
Capital Reserves [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	1,582,380
Reversal of prior year redemption estimate	0
Redemptions of equities	0
Preferred stock dividends	(41,825)
Other, net	136
Net income (loss) attributable to CHS Inc.	209,150
Estimated 2017 cash patronage refunds	(58,238)
Ending Balance	1,691,603
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning Balance	14,290
Other, net	(653)
Net income (loss) attributable to noncontrolling interests	(208)
Ending Balance	$ 13,429