Retirement benefits - accumulated other comprehensive income (Details) - Pension Plan - USD ($) $ in Millions	Aug. 31, 2022	Aug. 31, 2021	Aug. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Net actuarial (gain) loss	$ (251)	$ (506)	$ 856
Prior service cost	(1)	(1)	(1)
Total pre-tax comprehensive (income) loss	$ (252)	$ (507)	$ 855

Amount, before tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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- Definition

Amount, before tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
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-Paragraph 1
-Subparagraph (j)
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Amount, before tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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