Fair value measurements- Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) $ in Millions	Feb. 28, 2025 USD ($)	Aug. 31, 2024 USD ($)
Recurring
Assets [Abstract]
Money market funds	$ 430	$ 1,790
Investments in equity securities	165	19
Investments in debt securities	108	98
Level 1 | Recurring
Assets [Abstract]
Money market funds	430	1,790
Investments in equity securities	165	19
Investments in debt securities	0	0
Level 2 | Recurring
Assets [Abstract]
Money market funds	0	0
Investments in equity securities	0	0
Investments in debt securities	$ 108	$ 98
Level 3 | Minimum | Variable Prepaid Forward, Lower Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.295	0.245
Level 3 | Minimum | Variable Prepaid Forward, Upper Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.208	0.196
Level 3 | Maximum | Variable Prepaid Forward, Lower Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.780	0.345
Level 3 | Maximum | Variable Prepaid Forward, Upper Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.432	0.227
Level 3 | Recurring
Assets [Abstract]
Money market funds	$ 0	$ 0
Investments in equity securities	0	0
Investments in debt securities	0	0
Cross currency interest rate swaps | Recurring
Assets [Abstract]
Total return swaps 7	12	6
Liabilities [Abstract]
Derivative liability		5
Cross currency interest rate swaps | Level 1 | Recurring
Assets [Abstract]
Total return swaps 7	0	0
Liabilities [Abstract]
Derivative liability		0
Cross currency interest rate swaps | Level 2 | Recurring
Assets [Abstract]
Total return swaps 7	12	6
Liabilities [Abstract]
Derivative liability		5
Cross currency interest rate swaps | Level 3 | Recurring
Assets [Abstract]
Total return swaps 7	0	0
Liabilities [Abstract]
Derivative liability		0
Foreign currency forwards | Recurring
Assets [Abstract]
Total return swaps 7	2	3
Liabilities [Abstract]
Derivative liability	19	67
Foreign currency forwards | Level 1 | Recurring
Assets [Abstract]
Total return swaps 7	0	0
Liabilities [Abstract]
Derivative liability	0	0
Foreign currency forwards | Level 2 | Recurring
Assets [Abstract]
Total return swaps 7	2	3
Liabilities [Abstract]
Derivative liability	19	67
Foreign currency forwards | Level 3 | Recurring
Assets [Abstract]
Total return swaps 7	0	0
Liabilities [Abstract]
Derivative liability	0	0
Total return swaps | Recurring
Assets [Abstract]
Total return swaps 7		11
Liabilities [Abstract]
Derivative liability	6
Total return swaps | Level 1 | Recurring
Assets [Abstract]
Total return swaps 7		0
Liabilities [Abstract]
Derivative liability	0
Total return swaps | Level 2 | Recurring
Assets [Abstract]
Total return swaps 7		11
Liabilities [Abstract]
Derivative liability	6
Total return swaps | Level 3 | Recurring
Assets [Abstract]
Total return swaps 7		0
Liabilities [Abstract]
Derivative liability	0
Variable prepaid forward contracts | Recurring
Liabilities [Abstract]
Derivative liability	2,610	3,919
Variable prepaid forward contracts | Level 1 | Recurring
Liabilities [Abstract]
Derivative liability	0	0
Variable prepaid forward contracts | Level 2 | Recurring
Liabilities [Abstract]
Derivative liability	0	0
Variable prepaid forward contracts | Level 3 | Recurring
Liabilities [Abstract]
Derivative liability	$ 2,610	$ 3,919