Income taxes (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024
Income Tax Disclosure [Abstract]
Effective tax rate	5.00%	6.00%	3.10%	6.40%
Income taxes paid			$ 203	$ 216

Amount, after refund, of cash paid to foreign, federal, state, and local jurisdictions as income tax.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 230
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2

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