Retirement benefits - balance sheet (Details) - Pension Plan - USD ($) $ in Millions	Aug. 31, 2020	Aug. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Other non-current assets	$ 0	$ 486
Accrued expenses and other liabilities	(8)	(6)
Other non-current liabilities	(327)	(183)
Net asset (liability) recognized at end of year	$ (335)	$ 297

Amount of asset (liability), recognized in statement of financial position, for defined benefit pension and other postretirement plans.

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Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent.

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For a classified balance sheet, the amount recognized in balance sheet as other liabilities and accrued expenses associated with an underfunded defined benefit plan.

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