Supplemental information - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Aug. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable from related party	$ 1,300		$ 1,100
Accumulated depreciation and amortization on property, plant, and equipment	13,300		13,100
Redeemable noncontrolling interest	$ 2,787		319
Antidilutive securities excluded from EPS calculations (in shares)	16.1	18.5
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 4,600		$ 4,500