Pension and Postretirement Plans (Tables)

6 Months Ended

Jun. 30, 2025

Retirement Benefits [Abstract]

Schedule of Pension and Postretirement (Benefits) Costs

Pension and postretirement (benefits) costs are as follows:

	Three Months Ended June 30,
	2025			2024			2025			2024
(dollars in millions)	Pension Benefits						Postretirement and Other Benefits
Service cost	$	—		$	—		$	—		$	0.1
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		3.7			5.0			1.2			1.3
Expected return on plan assets		(3.8	)		(5.6	)		—			—
Amortization of:
Prior service benefit		—			—			(0.2	)		(0.2	)
Actuarial gain		—			(0.1	)		(1.3	)		(1.0	)
Pension settlement gain		(0.8	)		(0.4	)		—			—
Pension / postretirement (benefit) cost	$	(0.9	)	$	(1.1	)	$	(0.3	)	$	0.2

	Six Months Ended June 30,
	2025			2024			2025			2024
(dollars in millions)	Pension Benefits						Postretirement and Other Benefits
Service cost	$	—		$	—		$	0.1		$	0.2
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		7.6			10.1			2.5			2.5
Expected return on plan assets		(7.8	)		(11.3	)		—			—
Amortization of:
Prior service benefit		—			—			(0.4	)		(0.4	)
Actuarial gain		(0.1	)		(0.1	)		(2.4	)		(1.9	)
Pension settlement gain		(1.8	)		(0.4	)		—			—
Postretirement curtailment gain		—			—			(0.2	)		—
Pension / postretirement (benefit) cost	$	(2.1	)	$	(1.7	)	$	(0.4	)	$	0.4