Consolidated Statements of Changes in Equities - USD ($) $ in Thousands	12 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	$ 9,461,266	$ 9,017,326	$ 8,819,173
Reversal of prior year patronage and redemption estimates	1,000,000	150,000	63,000
Cash patronage dividends payable	(503,057)	(51,026)	(30,042)
Redemptions of equities	(495,790)	(111,818)	(79,381)
Preferred stock dividends	(168,668)	(168,668)	(168,668)
Other, net	(1,426)	(13,505)	(7,858)
Net income	1,900,124	1,677,901	553,569
Other comprehensive income, net of tax	(10,060)	(38,944)	17,533
Estimated patronage refunds	(365,000)	(500,000)	(50,000)
Estimated equity redemptions	(365,000)	(500,000)	(100,000)
Balance	10,452,389	9,461,266	9,017,326
Capital Equity Certificates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	3,587,131	3,583,911	3,724,187
Reversal of prior year patronage and redemption estimates	(8,803)	100,000	28,000
Redemptions of equities	(482,662)	(101,420)	(67,403)
Other, net	(1,821)	(4,163)	(873)
Estimated patronage refunds	706,125	508,803
Estimated equity redemptions	(365,000)	(500,000)	(100,000)
Balance	3,951,385	3,587,131	3,583,911
Distribution of patronage refunds	516,415
Nonpatronage Equity Certificates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	27,933	28,431	28,727
Redemptions of equities	(331)	(501)	(290)
Other, net	(44)	3	(6)
Balance	27,558	27,933	28,431
Nonqualified Equity Certificates
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	1,776,172	1,634,896	1,408,696
Reversal of prior year patronage and redemption estimates	(153,858)	(230,290)	(206,970)
Distribution of patronage refunds	154,548	235,576	214,733
Redemptions of equities	(12,797)	(9,897)	(11,688)
Other, net	(518)	(7,971)	(165)
Estimated patronage refunds	169,159	153,858	230,290
Estimated equity redemptions		0	0
Balance	1,932,706	1,776,172	1,634,896
Preferred Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	2,264,038	2,264,038	2,264,038
Balance	2,264,038	2,264,038	2,264,038
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(255,335)	(216,391)	(233,924)
Other comprehensive income, net of tax	(10,060)	(38,944)	17,533
Balance	(265,395)	(255,335)	(216,391)
Capital Reserves
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	2,055,682	1,713,976	1,618,147
Reversal of prior year patronage and redemption estimates	1,162,661	280,290	241,970
Distribution of patronage refunds	(1,174,020)	(286,602)	(244,775)
Preferred stock dividends	(168,668)	(168,668)	(168,668)
Other, net	1,677	585	(6,360)
Net income	1,900,438	1,678,762	553,952
Estimated patronage refunds	(1,240,284)	(1,162,661)	(280,290)
Balance	2,537,486	2,055,682	1,713,976
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	5,645	8,465	9,302
Other, net	(720)	(1,959)	(454)
Net income	(314)	(861)	(383)
Balance	$ 4,611	$ 5,645	$ 8,465