v3.25.2

Pensions and Post-Retirement Benefit Plans - Components of Net Periodic Benefit Cost for Pension Plans (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Postemployment Benefits [Abstract]
Service cost	$ 1.3	$ 0.4	$ 1.6	$ 0.8
Interest cost	0.7	2.1	1.9	4.0
Expected return on plan assets	(0.5)	(1.6)	(1.3)	(3.1)
Amortization of net loss	0.2	0.5	0.6	1.0
Loss on pension settlement	0.0	0.0	29.0	0.0
Net periodic benefit cost	1.7	1.4	31.8	2.7
Defined contribution plan expense	$ 1.2	$ 1.7	$ 4.5	$ 4.7

Amount of gain (loss) recognized in net periodic benefit (cost) credit of defined benefit plan.

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Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan.

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Amount of cost recognized for passage of time related to defined benefit plan.

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Amount of net periodic benefit cost (credit) for defined benefit plan.

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Amount of gain (loss) recognized in net periodic benefit (cost) credit from irrevocable action relieving primary responsibility for benefit obligation and eliminating risk related to obligation and assets used to effect settlement.

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Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan.

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Amount of cost for defined contribution plan.

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