Restatement of Previously Issued Financial Information - Summary of Impacts of the Restatement Adjustments on Previously Reported Consolidated Statements of Cash Flows (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
Cash flows from operating activities:
Net income (loss)	$ 54,713	$ 248,304	$ 347,115	$ 181,620	$ 165,959	$ 187,182	$ 650,132	$ 534,761
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization							352,838	358,134
Amortization of deferred major repair costs							48,960	43,908
Equity (income) loss from investments	(65,170)			(59,308)			(173,394)	(137,111)
Distributions from equity investments							133,720	97,665
Provision for doubtful accounts							36,874	(4,145)
Gain and recovery on disposal of business							(3,476)	(131,755)
Deferred taxes								(137,023)
Other, net							(42,681)	15,670
Changes in operating assets and liabilities, net of acquisitions:
Receivables							(446,846)	(194,546)
Inventories							(199,339)	(314,439)
Derivative assets							(70,559)	22,454
Margin and related deposits							(87,911)	(47,079)
Supplier advance payments							(157,560)	(177,373)
Other current assets and other assets							(61,999)	21,074
Customer margin deposits and credit balances							17,268	(19,914)
Customer advance payments							(58,222)	(51,180)
Accounts payable and accrued expenses							174,855	9,617
Derivative liabilities							(137,790)	11,614
Other liabilities							(20,863)	(49,842)
Net cash provided by (used in) operating activities							129,911	(194,418)
Cash flows from investing activities:
Acquisition of property, plant and equipment							(278,589)	(249,078)
Proceeds from disposition of property, plant and equipment							46,414	80,045
Proceeds from sale of business							5,044	234,914
Expenditures for major repairs							(210,837)	(39,363)
Investments redeemed								6,607
Changes in CHS Capital notes receivable, net							(112,608)	(83,908)
Financing extended to customers							(10,492)	(72,106)
Financing extended to customers								38,725
Other investing activities, net							(3,393)	12,377
Net cash provided by (used in) investing activities							(592,490)	(71,787)
Cash flows from financing activities:
Proceeds from lines of credit and long-term borrowings								29,802,708
Payments on lines of credit, long-term borrowings and capital lease obligations							(20,236,780)	(29,025,052)
Preferred stock dividends paid							(126,501)	(126,501)
Redemptions of equities							(76,397)	(6,391)
Other financing activities, net							(25,993)	(70,904)
Net cash provided by (used in) financing activities							174,343	573,860
Effect of exchange rate changes on cash and cash equivalents							(382)	1,030
Net increase (decrease) in cash and cash equivalents and restricted cash							(288,618)	308,685
Cash and cash equivalents and restricted cash at beginning of period			$ 543,940			272,272	543,940	272,272
Cash and cash equivalents and restricted cash at end of period	255,322			580,957			$ 255,322	580,957
As Previously Reported
Cash flows from operating activities:
Net income (loss)				229,146				575,391
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization								358,134
Amortization of deferred major repair costs								43,908
Equity (income) loss from investments				(59,308)				(137,111)
Distributions from equity investments								97,665
Provision for doubtful accounts								(4,145)
Gain and recovery on disposal of business								(131,755)
Deferred taxes								(135,560)
Other, net								18,272
Changes in operating assets and liabilities, net of acquisitions:
Receivables								(216,501)
Inventories								(366,858)
Derivative assets								(86,910)
Margin and related deposits								(47,079)
Supplier advance payments								(177,373)
Other current assets and other assets								75,191
Customer margin deposits and credit balances								(19,914)
Customer advance payments								(40,547)
Accounts payable and accrued expenses								73,745
Derivative liabilities								23,758
Other liabilities								(49,842)
Net cash provided by (used in) operating activities								(147,531)
Cash flows from investing activities:
Acquisition of property, plant and equipment								(249,078)
Proceeds from disposition of property, plant and equipment								80,045
Proceeds from sale of business								234,914
Expenditures for major repairs								(39,363)
Investments redeemed								6,607
Changes in CHS Capital notes receivable, net								(83,908)
Financing extended to customers								(72,106)
Financing extended to customers								38,725
Other investing activities, net								12,377
Net cash provided by (used in) investing activities								(71,787)
Cash flows from financing activities:
Proceeds from lines of credit and long-term borrowings								29,802,708
Payments on lines of credit, long-term borrowings and capital lease obligations								(29,028,104)
Preferred stock dividends paid								(126,501)
Redemptions of equities								(6,391)
Other financing activities, net								(70,916)
Net cash provided by (used in) financing activities								570,796
Effect of exchange rate changes on cash and cash equivalents								1,030
Net increase (decrease) in cash and cash equivalents and restricted cash								352,508
Cash and cash equivalents and restricted cash at beginning of period						181,379		181,379
Cash and cash equivalents and restricted cash at end of period				533,887				533,887
Restatement Adjustments
Cash flows from operating activities:
Net income (loss)				(47,526)				(40,630)
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization								0
Amortization of deferred major repair costs								0
Equity (income) loss from investments				0				0
Distributions from equity investments								0
Provision for doubtful accounts								0
Deferred taxes								(1,463)
Other, net								(2,602)
Changes in operating assets and liabilities, net of acquisitions:
Receivables								21,955
Inventories								52,419
Derivative assets								64,456
Margin and related deposits								0
Supplier advance payments								0
Other current assets and other assets								(10,294)
Customer margin deposits and credit balances								0
Customer advance payments								(10,633)
Accounts payable and accrued expenses								(64,128)
Derivative liabilities								(12,144)
Other liabilities								0
Net cash provided by (used in) operating activities								(3,064)
Cash flows from investing activities:
Acquisition of property, plant and equipment								0
Proceeds from disposition of property, plant and equipment								0
Proceeds from sale of business								0
Expenditures for major repairs								0
Investments redeemed								0
Changes in CHS Capital notes receivable, net								0
Financing extended to customers								0
Financing extended to customers								0
Other investing activities, net
Net cash provided by (used in) investing activities								0
Cash flows from financing activities:
Proceeds from lines of credit and long-term borrowings								0
Payments on lines of credit, long-term borrowings and capital lease obligations								3,052
Preferred stock dividends paid								0
Redemptions of equities								0
Other financing activities, net								12
Net cash provided by (used in) financing activities								3,064
Effect of exchange rate changes on cash and cash equivalents								0
Net increase (decrease) in cash and cash equivalents and restricted cash								0
Cash and cash equivalents and restricted cash at beginning of period	$ 0					0		0
Cash and cash equivalents and restricted cash at end of period		$ 0
As Restated
Cash flows from operating activities:
Net income (loss)				181,620				534,761
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization								358,134
Amortization of deferred major repair costs								43,908
Equity (income) loss from investments				(59,308)				(137,111)
Distributions from equity investments								97,665
Provision for doubtful accounts								(4,145)
Gain and recovery on disposal of business								(131,755)
Deferred taxes								(137,023)
Other, net								15,670
Changes in operating assets and liabilities, net of acquisitions:
Receivables								(194,546)
Inventories								(314,439)
Derivative assets								(22,454)
Margin and related deposits								(47,079)
Supplier advance payments								(177,373)
Other current assets and other assets								64,897
Customer margin deposits and credit balances								(19,914)
Customer advance payments								(51,180)
Accounts payable and accrued expenses								9,617
Derivative liabilities								11,614
Other liabilities								(49,842)
Net cash provided by (used in) operating activities								(150,595)
Cash flows from investing activities:
Acquisition of property, plant and equipment								(249,078)
Proceeds from disposition of property, plant and equipment								80,045
Proceeds from sale of business								234,914
Expenditures for major repairs								(39,363)
Investments redeemed								6,607
Changes in CHS Capital notes receivable, net								(83,908)
Financing extended to customers								(72,106)
Financing extended to customers								38,725
Other investing activities, net								12,377
Net cash provided by (used in) investing activities								(71,787)
Cash flows from financing activities:
Proceeds from lines of credit and long-term borrowings								29,802,708
Payments on lines of credit, long-term borrowings and capital lease obligations								(29,025,052)
Preferred stock dividends paid								(126,501)
Redemptions of equities								(6,391)
Other financing activities, net								(70,904)
Net cash provided by (used in) financing activities								573,860
Effect of exchange rate changes on cash and cash equivalents								1,030
Net increase (decrease) in cash and cash equivalents and restricted cash								352,508
Cash and cash equivalents and restricted cash at beginning of period						181,379		181,379
Cash and cash equivalents and restricted cash at end of period				533,887				533,887
Accounting Standards Update 2016-18
Changes in operating assets and liabilities, net of acquisitions:
Other current assets and other assets								(43,823)
Net cash provided by (used in) operating activities								(43,823)
Cash flows from financing activities:
Net increase (decrease) in cash and cash equivalents and restricted cash								(43,823)
Cash and cash equivalents and restricted cash at beginning of period						$ 90,893		90,893
Cash and cash equivalents and restricted cash at end of period				47,070				47,070
Other Misstatements | Restatement Adjustments
Cash flows from operating activities:
Net income (loss)				$ (22,800)				$ 7,900