Financial instruments - derivative instruments (Details) - USD ($) $ in Millions	Aug. 31, 2023	Aug. 31, 2022
Foreign currency forwards | Derivatives designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 31	$ 448
Fair value, assets	$ 1	$ 19
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Foreign currency forwards | Derivatives designated as hedges: | Other non-current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets		$ 3
Fair value, assets		$ 0
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other non-current assets
Foreign currency forwards | Derivatives designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 805	$ 221
Fair value, liabilities	$ 2	$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Foreign currency forwards | Derivatives designated as hedges: | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 4
Fair value, liabilities	$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities
Foreign currency forwards | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 3,139	$ 2,874
Fair value, assets	$ 6	$ 49
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Foreign currency forwards | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 817	$ 1,098
Fair value, liabilities	$ 2	$ 6
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Cross currency interest rate swaps | Derivatives designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets		$ 150
Fair value, assets		$ 12
Derivative Asset, Statement of Financial Position [Extensible Enumeration]		Other current assets
Cross currency interest rate swaps | Derivatives designated as hedges: | Other non-current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 650	$ 750
Fair value, assets	$ 28	$ 83
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Cross currency interest rate swaps | Derivatives designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 102
Fair value, liabilities	$ 2
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities
Total return swaps | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 168
Fair value, assets	$ 1
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets
Total return swaps | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 26	$ 183
Fair value, liabilities	$ 1	$ 6
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Variable prepaid forward | Derivatives not designated as hedges: | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 3,195
Fair value, liabilities	$ 2,548
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities