Commitments and Contingencies - Legal Claims and Insurance (Details) - USD ($) $ in Millions	9 Months Ended
Jun. 30, 2022	Jun. 30, 2021
Rollforward of reserves for legal claims
Reserves for legal claims, beginning of period	$ 577.5	$ 473.8
Increase in reserves	119.1	88.8
Payments	(22.2)	(19.5)
Reserves for legal claims, end of period	$ 674.4	$ 543.1

Amount of loss contingency liability.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

Reference 2: http://www.xbrl.org/2003/role/recommendedDisclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 10
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14615-108349

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- Definition

Amount of increase (decrease) in loss contingency liability.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 1
-URI https://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349

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- Definition

Amount of cash outflow reducing loss contingency liability.

+ References

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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