Accrued Liabilities - Schedule of Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2025	Jun. 30, 2025
Accrued Liabilities, Current [Abstract]
Accrued compensation and benefits	$ 67.9	$ 142.6
Accrued postretirement benefits	15.3	15.3
Current portion of lease liabilities	8.5	8.0
Contract liabilities	7.7	5.2
Accrued interest expense	6.4	18.5
Accrued taxes	4.5	5.7
Accrued income taxes	3.9	3.3
Accrued pension liabilities	3.3	3.3
Derivative financial instruments	1.8	2.2
Other	11.3	12.2
Total accrued liabilities	$ 130.6	$ 216.3

Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations.

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Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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No definition available.

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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
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-Name Accounting Standards Codification
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- Definition

Amount of liability, recognized in statement of financial position, for defined benefit pension plan, classified as current. Excludes other postretirement benefit plan.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Present value of lessee's discounted obligation for lease payments from operating lease, classified as current.

+ References

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-Topic 842
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Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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- Definition

For a classified balance sheet, the carrying amount as of the balance sheet date of the portion of the obligations recognized for the various benefits provided to former or inactive employees, their beneficiaries, and covered dependents after employment but before retirement that is payable within one year of the balance sheet date.

+ References

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-SubTopic 10
-Name Accounting Standards Codification
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-Subparagraph (SX 210.5-02(20))
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Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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