Revenue Recognition (Contract Assets and Liabilities) (Details) - USD ($) $ in Millions	9 Months Ended
Jun. 30, 2025	Sep. 30, 2024
Contract Assets and Liabilities
Contract assets - current	$ 135.4	$ 76.2
Contract fulfillment costs - current	114.4	103.7
Contract assets – noncurrent	53.8	0.0
Contract liabilities - current	232.9	240.0
Contract liabilities - noncurrent	287.2	$ 290.0
Revenue recognized that was previously included in current contract liabilities	$ 90.0

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 340
-SubTopic 40
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
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- References

No definition available.

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- Definition

Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
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-Name Accounting Standards Codification
-Section 50
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-11

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- Definition

+ References

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Balance Type:	debit
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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
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- Definition

Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable, classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479806/606-10-50-11

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- Definition

Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (b)
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-URI https://asc.fasb.org/1943274/2147479806/606-10-50-8

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