Consolidated Statement of Cash Flows (USD $)	9 Months Ended
	May 31, 2014	May 31, 2013
Cash flows from operating activities:
Net income	$ 883,522,000	$ 873,728,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	193,161,000	176,839,000
Amortization of deferred major repair costs	37,411,000	22,298,000
Equity (income) loss from investments	(89,249,000)	(72,406,000)
Distributions from equity investments	62,019,000	50,886,000
Noncash patronage dividends received	(5,058,000)	(4,552,000)
Gain on sale of property, plant and equipment	1,473,000	(3,899,000)
Gain on investments	(111,401,000)	(199,000)
Unrealized (gain) loss on crack spread contingent liability	(3,975,000)	18,729,000
Deferred taxes	99,574,000	157,000
Other, net	16,463,000	1,786,000
Changes in operating assets and liabilities, net of acquisitions:
Receivables	(242,348,000)	(445,132,000)
Inventories	(150,039,000)	284,424,000
Derivative assets	(67,986,000)	570,477,000
Margin deposits	(41,111,000)	782,153,000
Supplier advance payments	(241,495,000)	107,422,000
Other current assets and other assets	(10,223,000)	5,439,000
Customer margin deposits and credit balances	(48,474,000)	(597,660,000)
Customer advance payments	448,920,000	(109,606,000)
Accounts payable and accrued expenses	(211,126,000)	91,129,000
Derivative liabilities	(52,595,000)	(285,063,000)
Other liabilities	4,847,000	(20,685,000)
Net cash provided by (used in) operating activities	472,310,000	1,446,265,000
Cash flows from investing activities:
Acquisition of property, plant and equipment	(656,288,000)	(427,070,000)
Proceeds from disposition of property, plant and equipment	4,373,000	5,794,000
Expenditures for major repairs	0	(53,843,000)
Investments in joint ventures and other	(67,457,000)	(13,882,000)
Investments redeemed	130,445,000	5,780,000
Proceeds from sale of investments	2,725,000	1,250,000
Changes in notes receivable	(321,376,000)	27,676,000
Business acquisitions, net of cash acquired	(114,438,000)	(12,358,000)
Other investing activities, net	(3,558,000)	(1,339,000)
Net cash provided by (used in) investing activities	(1,025,574,000)	(467,992,000)
Cash flows from financing activities:
Changes in notes payable	241,070,000	69,636,000
Long-term debt borrowings	1,426,000	100,000,000
Principal payments on long-term debt	(141,760,000)	(56,384,000)
Mandatorily redeemable noncontrolling interest payments	(65,981,000)	(65,981,000)
Payments on crack spread contingent liability	(8,670,000)	0
Changes in checks and drafts outstanding	(4,328,000)	(18,908,000)
Preferred stock issued	702,979,000	0
Preferred stock issuance costs	(23,134,000)	0
Preferred stock dividends paid	(29,860,000)	(18,408,000)
Distributions to noncontrolling interests	(575,000)	(1,235,000)
Retirements of equities	(87,666,000)	(184,955,000)
Cash Patronage Dividends Paid	(286,718,000)	(380,975,000)
Other financing activities, net	(1,635,000)	1,110,000
Net cash provided by (used in) financing activities	295,148,000	(556,100,000)
Effect of exchange rate changes on cash and cash equivalents	(918,000)	(2,242,000)
Net increase (decrease) in cash and cash equivalents	(259,034,000)	419,931,000
Cash and cash equivalents at beginning of period	1,808,532,000	314,029,000
Cash and cash equivalents at end of period	1,549,498,000	733,960,000
Energy [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	99,577,000	86,454,000
Equity (income) loss from investments	(2,937,000)	(580,000)
Cash flows from investing activities:
Acquisition of property, plant and equipment	(367,228,000)	(290,091,000)
National Cooperative Refinery Association [Member] | Energy [Member]
Cash flows from financing activities:
Mandatorily redeemable noncontrolling interest payments	$ (66,000,000)	$ (66,000,000)