Income taxes - unrecognized tax benefits (Details) - USD ($) $ in Millions	12 Months Ended
Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Reconciliation of Unrecognized Tax Benefits
Balance at beginning of year	$ 1,098	$ 494	$ 455
Gross increases related to tax positions in a prior period	63	229	60
Gross decreases related to tax positions in a prior period	(51)	(52)	(23)
Gross increases related to tax positions in the current period	21	446	9
Settlements with taxing authorities	(19)	(13)	(4)
Lapse of statute of limitations	(2)	(6)	(3)
Balance at end of year	$ 1,110	$ 1,098	$ 494

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

No definition available.

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- Definition

Amount of unrecognized tax benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of decrease in unrecognized tax benefits resulting from settlements with taxing authorities.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return.

+ References

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Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns.

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Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations.

+ References

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