Financial instruments - derivative instruments (Details) - USD ($) $ in Millions	Aug. 31, 2024	Aug. 31, 2023
Cross currency interest rate swaps | Derivatives designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 50
Fair value, assets	$ 1
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	$ 253	$ 650
Fair value, assets	$ 5	$ 28
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	$ 356	$ 102
Fair value, liabilities	$ 5	$ 2
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 current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 7	$ 31
Fair value, assets	$ 0	$ 1
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	$ 4
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	$ 923	$ 805
Fair value, liabilities	$ 15	$ 2
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	$ 2	$ 4
Fair value, liabilities	$ 0	$ 0
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities
Foreign currency forwards | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 534	$ 3,139
Fair value, assets	$ 3	$ 6
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	$ 3,606	$ 817
Fair value, liabilities	$ 52	$ 2
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other liabilities	Accrued expenses and other liabilities
Total return swaps | Derivatives not designated as hedges: | Other current assets
Derivatives, Fair Value [Line Items]
Notional amount, assets	$ 211
Fair value, assets	$ 11
Notional amount, liabilities		$ 168
Fair value, liabilities		$ 1
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other current assets	Other current assets
Total return swaps | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities		$ 26
Fair value, liabilities		$ 1
Derivative Liability, Statement of Financial Position [Extensible Enumeration]		Accrued expenses and other liabilities
Variable prepaid forward | Derivatives not designated as hedges: | Other current liabilities
Derivatives, Fair Value [Line Items]
Notional amount, liabilities	$ 1,185
Fair value, liabilities	$ 1,332
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	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	$ 2,541	$ 3,195
Fair value, liabilities	$ 2,587	$ 2,548
Derivative Liability, Statement of Financial Position [Extensible Enumeration]	Other non-current liabilities	Other non-current liabilities