Supplemental Information (Income Taxes) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disclosure Text Block Supplement [Abstract]
Effective tax rate (percent)	16.60%	18.60%	17.50%	19.40%
Income tax payments, net of refunds			$ 502.2	$ 487.6
Income tax paid, tax credit			$ 50.0

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
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 23
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-23

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-22

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482913/230-10-50-2

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