Debt - Text (Detail) - USD ($) $ in Millions	3 Months Ended
Dec. 31, 2024	Sep. 30, 2024
Debt Instrument [Line Items]
Long-term Line of Credit	$ 100.0	$ 0.0
Debt	806.8	706.4
Line of Credit Facility, Current Borrowing Capacity	640.0	410.0
Line of Credit Facility, Maximum Borrowing Capacity	1,000.0
Letter of Credit, Maximum Borrowing Capacity	$ 100.0
Letter of Credit, Maximum Borrowing Capacity, Percentage of Revolving Credit Commitment	50.00%
Letters of Credit Outstanding, Amount	$ 27.5
Line of Credit Facility, Remaining Borrowing Capacity	512.5
Debt Repurchase Program, Authorized Amount	30.0
Debt Repurchase Authorization Remaining	$ 30.0
Line of Credit Facility, Interest Rate at Period End	5.90%
Credit Facility Maturing December 18, 2029
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 575.0
Credit Facility Maturing October 28, 2026
Debt Instrument [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 65.0
Senior Notes 3.85% [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.85%
Debt	$ 398.6	398.4
Debt Instrument, Face Amount	$ 400.0
Debt Instrument, Redemption Price, Percentage	101.925%
Debt Instrument, Frequency of Periodic Payment	semi-annually
Debt Instrument, Interest Rate, Effective Percentage	4.10%
Senior Notes 5.0% [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	5.00%
Debt	$ 298.3	298.1
Debt Instrument, Face Amount	$ 300.0
Debt Instrument, Redemption Price, Percentage	102.50%
Debt Instrument, Frequency of Periodic Payment	semi-annually
Debt Instrument, Interest Rate, Effective Percentage	5.20%
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Net	$ 3.1	3.5
Unsecured Debt
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Debt	$ 9.9	$ 9.9

Debt Repurchase Authorization Remaining

No definition available.

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Balance Type:	credit
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- Definition

Debt Repurchase Program, Authorized Amount

+ References

No definition available.

+ Details

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- Definition

Maximum borrowing capacity of letter of credit.

+ References

No definition available.

+ Details

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- Definition

Letter of Credit, Maximum Borrowing Capacity, Percentage of Revolving Credit Commitment

+ References

No definition available.

+ Details

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- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

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- Definition

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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- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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- Definition

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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- Definition

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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- Definition

The effective interest rate at the end of the reporting period.

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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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