Retirement Plans

6 Months Ended

Jun. 30, 2025

Retirement Benefits [Abstract]

Retirement Plans

(10) Retirement Plans

The components of the net periodic benefit cost (credit) for our retirement plans were as follows:

	Defined Benefit Pension Plan
	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2025			2024			2025			2024
Service cost	$	3.8		$	4.0		$	7.4		$	8.1
Interest cost		5.0			4.8			9.7			9.6
Expected return on assets		(5.2	)		(4.6	)		(10.0	)		(9.3	)
Net loss (gain)		0.1			(0.4	)		0.2			(0.8	)
Prior service cost		0.2			0.1			0.3			0.3
Curtailments		—			(1.3	)		—			(1.3	)
Total benefit cost	$	3.9		$	2.6		$	7.6		$	6.6
	Retiree Health Care Plan
	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2025			2024			2025			2024
Interest cost	$	0.1		$	0.1		$	0.2		$	0.2
Prior service credit		(0.2	)		(0.2	)		(0.4	)		(0.4	)
Total benefit credit	$	(0.1	)	$	(0.1	)	$	(0.2	)	$	(0.2	)

During the three and six months ended June 30, 2025, contributions made to our pension plans were $6.0 and $11.5, respectively, and contributions made to our retiree health care plan were $0.2 and $0.5, respectively. During 2025, we expect to make total contributions of approximately $23.0 to our pension plans and to fund our retiree health care payments as incurred.