Fair value measurements (Details) $ in Millions	Aug. 31, 2024 USD ($)	Aug. 31, 2023 USD ($)
Liabilities [Abstract]
Carrying value of long-term notes outstanding	$ 9,581
Carrying Value
Liabilities [Abstract]
Carrying value of long-term notes outstanding	7,200
Estimate of Fair Value Measurement
Liabilities [Abstract]
Fair value of long-term notes outstanding	$ 6,400
Level 3 | Measurement Input, Price Volatility | Minimum | Lower Strike Price
Liabilities [Abstract]
Derivative liability, measurement input	0.245	0.232
Level 3 | Measurement Input, Price Volatility | Minimum | Upper Strike Price
Liabilities [Abstract]
Derivative liability, measurement input	0.196	0.181
Level 3 | Measurement Input, Price Volatility | Maximum | Lower Strike Price
Liabilities [Abstract]
Derivative liability, measurement input	0.345	0.247
Level 3 | Measurement Input, Price Volatility | Maximum | Upper Strike Price
Liabilities [Abstract]
Derivative liability, measurement input	0.227	0.191
Recurring
Assets [Abstract]
Money market funds	$ 1,790	$ 11
Investment in equity securities	19	17
Investments in debt securities	98	15
Recurring | Level 1
Assets [Abstract]
Money market funds	1,790	11
Investment in equity securities	19	17
Investments in debt securities	0	0
Recurring | Level 2
Assets [Abstract]
Money market funds	0	0
Investment in equity securities	0	0
Investments in debt securities	98	15
Recurring | Level 3
Assets [Abstract]
Money market funds	0	0
Investment in equity securities	0	0
Investments in debt securities	0	0
Recurring | Cross currency interest rate swaps
Assets [Abstract]
Derivative asset	6	28
Liabilities [Abstract]
Derivative liability	5	2
Recurring | Cross currency interest rate swaps | Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Cross currency interest rate swaps | Level 2
Assets [Abstract]
Derivative asset	6	28
Liabilities [Abstract]
Derivative liability	5	2
Recurring | Cross currency interest rate swaps | Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Foreign currency forwards
Assets [Abstract]
Derivative asset	3	6
Liabilities [Abstract]
Derivative liability	67	5
Recurring | Foreign currency forwards | Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Foreign currency forwards | Level 2
Assets [Abstract]
Derivative asset	3	6
Liabilities [Abstract]
Derivative liability	67	5
Recurring | Foreign currency forwards | Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Total return swaps
Assets [Abstract]
Derivative asset	11	1
Liabilities [Abstract]
Derivative liability		1
Recurring | Total return swaps | Level 1
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability		0
Recurring | Total return swaps | Level 2
Assets [Abstract]
Derivative asset	11	1
Liabilities [Abstract]
Derivative liability		1
Recurring | Total return swaps | Level 3
Assets [Abstract]
Derivative asset	0	0
Liabilities [Abstract]
Derivative liability		0
Recurring | Variable prepaid forward
Liabilities [Abstract]
Derivative liability	3,919	2,548
Recurring | Variable prepaid forward | Level 1
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Variable prepaid forward | Level 2
Liabilities [Abstract]
Derivative liability	0	0
Recurring | Variable prepaid forward | Level 3
Liabilities [Abstract]
Derivative liability	$ 3,919	$ 2,548