Leases - supplemental income statement information (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Operating lease cost
Fixed	$ 3,240	$ 3,219	$ 3,252
Variable	825	664	750
Finance lease cost
Amortization	44	45	40
Interest	50	52	54
Sublease income	105	84	75
Impairment of right-of-use assets	218	86	213
Impairment of finance lease assets	0	0	24
Gains on sale-leaseback transactions	$ 619	$ 367	$ 308

Amount of impairment loss from right-of-use asset from finance lease.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 25
-Paragraph 5
-Subparagraph (c)
-URI https://asc.fasb.org/extlink&oid=123399704&loc=SL77918425-209957

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- Definition

Amount of interest expense on finance lease liability.

+ References

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-Name Accounting Standards Codification
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-SubTopic 20
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- Definition

Amount of amortization expense attributable to right-of-use asset from finance lease.

+ References

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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-Publisher FASB
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-SubTopic 20
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- Definition

Amount of loss from impairment of right-of-use asset from operating lease.

+ References

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-Publisher FASB
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- Definition

Amount of gain (loss) on sale and leaseback transaction from transfer of asset accounted for as sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount of sublease income excluding finance and operating lease expense.

+ References

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- Definition

Amount of variable lease cost, excluded from lease liability, recognized when obligation for payment is incurred for finance and operating leases.

+ References

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- Definition

Lessee, Finance Lease, Cost

+ References

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- Definition

Operating Lease, Cost

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