Restatement of Previously Issued Financial Information - Summary of Impacts of the Restatement Adjustments on Previously Reported Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	May 31, 2019	May 31, 2018
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues	$ 8,497,941			$ 9,087,328			$ 23,465,769	$ 24,099,365
Cost of goods sold	8,274,170			8,841,696			22,343,944	23,398,272
Gross profit	223,771			245,632			1,121,825	701,093
Marketing, general and administrative	183,723			162,424			523,648	490,329
Reserve and impairment charges (recoveries), net				(3,811)				(18,944)
Operating earnings (loss)	6,244			87,019			570,387	229,708
Gain (Loss) on Disposition of Business	(2,474)			(124,050)			(3,886)	(131,755)
Interest Expense	42,773			49,340			122,950	130,218
Other (income) loss	(30,464)			(15,802)			(65,949)	(54,542)
Equity (income) loss from investments	(65,170)			(59,308)			(173,394)	(137,111)
Income (loss) before income taxes	61,579			236,839			690,666	422,898
Income tax expense (benefit)	6,866			55,219			40,534	(111,863)
Net income (loss)	54,713	$ 248,304	$ 347,115	181,620	$ 165,959	$ 187,182	650,132	534,761
Net income (loss) attributable to noncontrolling interests	93			(187)			(758)	(699)
Net income (loss) attributable to CHS Inc.	$ 54,620			181,807			$ 650,890	535,460
As Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues				9,027,525				23,927,508
Cost of goods sold				8,728,914				23,173,151
Gross profit				298,611				754,357
Marketing, general and administrative				161,578				488,459
Reserve and impairment charges (recoveries), net				(3,811)				(18,944)
Operating earnings (loss)				140,844				284,842
Gain (Loss) on Disposition of Business				124,050				(131,755)
Interest Expense				49,340				130,218
Other (income) loss				(14,622)				(51,000)
Equity (income) loss from investments				(59,308)				(137,111)
Income (loss) before income taxes				289,484				474,490
Income tax expense (benefit)				60,338				(100,901)
Net income (loss)				229,146				575,391
Net income (loss) attributable to noncontrolling interests				(187)				(699)
Net income (loss) attributable to CHS Inc.				229,333				576,090
Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues				59,803				171,857
Cost of goods sold				112,447				224,116
Gross profit				(52,644)				(52,259)
Marketing, general and administrative				1				(667)
Reserve and impairment charges (recoveries), net				0				0
Operating earnings (loss)				(52,645)				(51,592)
Gain (Loss) on Disposition of Business				0				0
Interest Expense				0				0
Other (income) loss				0				0
Equity (income) loss from investments				0				0
Income (loss) before income taxes				(52,645)				(51,592)
Income tax expense (benefit)				(5,119)				(10,962)
Net income (loss)				(47,526)				(40,630)
Net income (loss) attributable to noncontrolling interests				0				0
Net income (loss) attributable to CHS Inc.				(47,526)				(40,630)
As Restated
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues				9,087,328				24,099,365
Cost of goods sold				8,841,361				23,397,267
Gross profit				245,967				702,098
Marketing, general and administrative				161,579				487,792
Reserve and impairment charges (recoveries), net				(3,811)				(18,944)
Operating earnings (loss)				88,199				233,250
Gain (Loss) on Disposition of Business				124,050				(131,755)
Interest Expense				49,340				130,218
Other (income) loss				(14,622)				(51,000)
Equity (income) loss from investments				(59,308)				(137,111)
Income (loss) before income taxes				236,839				422,898
Income tax expense (benefit)				55,219				(111,863)
Net income (loss)				181,620				534,761
Net income (loss) attributable to noncontrolling interests				(187)				(699)
Net income (loss) attributable to CHS Inc.				181,807				535,460
Other Misstatements | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold				18,800
Income (loss) before income taxes				(22,800)				1,300
Income tax expense (benefit)								(6,600)
Net income (loss)				(22,800)				7,900
Freight Derivatives And Related Misstatements [Member] | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold				29,800				52,900
Income (loss) before income taxes				(29,800)				(52,900)
Income tax expense (benefit)				(5,100)				(4,400)
Net income (loss)				(24,700)				(48,500)
Intercompany Misstatements | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues				38,800				189,000
Other Misstatements, Timing Of Revenue Recognition [Member] | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold				14,500				9,900
Revenues				11,800				7,000
Other Misstatements, Valuation of Derivatives [Member] | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold				1,300				(6,600)
Other Misstatements, Misclassification Adjustment [Member] | Restatement Adjustments
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Revenues				9,200				(24,100)
Revisions related to ASU 2017-07
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Cost of goods sold				335				1,005
Gross profit				(335)				(1,005)
Marketing, general and administrative				845				2,537
Operating earnings (loss)				(1,180)				(3,542)
Other (income) loss				$ (1,180)				$ (3,542)