Supplemental information - Depreciation and Amortization Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 31, 2022	May 31, 2021	May 31, 2022	May 31, 2021
Supplemental Cash Flow Elements [Abstract]
Depreciation expense	$ 331	$ 352	$ 1,014	$ 1,042
Intangible asset and other amortization	148	156	488	363
Total depreciation and amortization expense	$ 478	$ 507	$ 1,502	$ 1,404