Fair value measurements- Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) $ in Millions	May 31, 2025 USD ($)	Aug. 31, 2024 USD ($)
Level 3 | Minimum | Variable Prepaid Forward, Lower Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.342	0.245
Level 3 | Minimum | Variable Prepaid Forward, Upper Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.250	0.196
Level 3 | Maximum | Variable Prepaid Forward, Lower Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.784	0.345
Level 3 | Maximum | Variable Prepaid Forward, Upper Strike | Measurement Input, Price Volatility
Liabilities [Abstract]
Derivative liability, measurement input	0.567	0.227
Recurring
Assets
Money market funds	$ 64	$ 1,790
Investments in equity securities	28	19
Investments in debt securities	110	98
Recurring | Foreign currency forwards
Assets
Derivative assets	2	3
Liabilities [Abstract]
Derivative liability	39	67
Recurring | Total return swaps
Assets
Derivative assets	6	11
Recurring | Variable prepaid forward contracts
Liabilities [Abstract]
Derivative liability	2,535	3,919
Recurring | Cross currency interest rate swaps
Assets
Derivative assets		6
Liabilities [Abstract]
Derivative liability	7	5
Recurring | Level 1
Assets
Money market funds	64	1,790
Investments in equity securities	28	19
Investments in debt securities	0	0
Recurring | Level 1 | Foreign currency forwards
Assets
Derivative assets	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Level 1 | Total return swaps
Assets
Derivative assets	0	0
Recurring | Level 1 | Variable prepaid forward contracts
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Level 1 | Cross currency interest rate swaps
Assets
Derivative assets		0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Level 2
Assets
Money market funds	0	0
Investments in equity securities	0	0
Investments in debt securities	110	98
Recurring | Level 2 | Foreign currency forwards
Assets
Derivative assets	2	3
Liabilities [Abstract]
Derivative liability	39	67
Recurring | Level 2 | Total return swaps
Assets
Derivative assets	6	11
Recurring | Level 2 | Variable prepaid forward contracts
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Level 2 | Cross currency interest rate swaps
Assets
Derivative assets		6
Liabilities [Abstract]
Derivative liability	7	5
Recurring | Level 3
Assets
Money market funds	0	0
Investments in equity securities	0	0
Investments in debt securities	0	0
Recurring | Level 3 | Foreign currency forwards
Assets
Derivative assets	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Level 3 | Total return swaps
Assets
Derivative assets	0	0
Recurring | Level 3 | Variable prepaid forward contracts
Liabilities [Abstract]
Derivative liability	2,535	3,919
Recurring | Level 3 | Cross currency interest rate swaps
Assets
Derivative assets		0
Liabilities [Abstract]
Derivative liability	$ 0	$ 0