Pension and Postretirement Plans (Tables)

6 Months Ended

Jun. 30, 2020

Compensation And Retirement Disclosure [Abstract]

Schedule of Pension and Postretirement Costs (Benefits)

For the three and six months ended June 30, 2020 and 2019, pension and postretirement costs (benefits) were as follows:

	Three Months Ended June 30,
	2020			2019			2020			2019
(dollars in millions)	Pension Benefits						Postretirement and Other Benefits
Service cost	$	—		$	—		$	0.1		$	0.1
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		4.8			6.0			1.0			1.3
Expected return on plan assets		(7.2	)		(7.5	)		—			—
Amortization of:
Prior service benefit		—			—			(0.7	)		(0.7	)
Actuarial loss		4.5			3.4			0.4			0.5
Pension settlement charges		1.1			—			—			—
Pension / postretirement costs	$	3.2		$	1.9		$	0.8		$	1.2

	Six Months Ended June 30,
	2020			2019			2020			2019
(dollars in millions)	Pension Benefits						Postretirement and Other Benefits
Service cost	$	—		$	—		$	0.2		$	0.3
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		9.6			12.0			1.9			2.5
Expected return on plan assets		(14.5	)		(15.3	)		—			—
Amortization of:
Prior service benefit		—			—			(1.3	)		(1.3	)
Actuarial loss		9.0			6.8			0.6			0.9
Pension settlement charges		1.1			—			—			—
Pension / postretirement costs	$	5.2		$	3.5		$	1.4		$	2.4