Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Restricted Cash and Cash Equivalent Item [Line Items]
Cash and cash equivalents	$ 164.8	$ 199.3
Restricted Cash, Current	6.5	7.0
Restricted Cash, Noncurrent	20.1	21.6
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 191.4	$ 227.9	$ 250.2	$ 237.6

Amount of cash and cash equivalent. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.

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Amount of cash and cash equivalent, and cash and cash equivalent restricted to withdrawal or usage; attributable to continuing operation. Cash includes, but is not limited to, currency on hand, demand deposit with financial institution, and account with general characteristic of demand deposit. Cash equivalent includes, but is not limited to, short-term, highly liquid investment that is both readily convertible to known amount of cash and so near maturity that it presents insignificant risk of change in value because of change in interest rate.

+ References

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of cash restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

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Amount of cash restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.

+ References

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