Supplemental information - Narrative (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2022	May 31, 2021	Feb. 28, 2022	Aug. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable from related party	$ 1,100		$ 1,100
Accumulated depreciation and amortization on property, plant, and equipment	13,000		13,000			$ 13,100
Redeemable non-controlling interest	$ 775		$ 775		$ 812	319
Antidilutive securities excluded from EPS calculations (in shares)	17.4	15.9	17.2	17.1
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Receivables	$ 3,900		$ 3,900			$ 4,500