Pension and Postretirement Plans (Tables)

9 Months Ended

Sep. 30, 2021

Compensation And Retirement Disclosure [Abstract]

Schedule of Pension and Postretirement Costs (Benefits)

Pension and postretirement costs (benefits) are as follows:

	Pension Benefits									Postretirement and Other Benefits
	Successor			Predecessor			Predecessor			Successor		Predecessor			Predecessor
(dollars in millions)	September 8, 2021 to September 30, 2021			July 1, 2021 to September 7, 2021			Three Months Ended September 30, 2020			September 8, 2021 to September 30, 2021		July 1, 2021 to September 7, 2021			Three Months Ended September 30, 2020
Service cost	$	—		$	—		$	—		$	—	$	0.1		$	0.1
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		0.9			2.7			4.6			0.1		0.5			0.9
Expected return on plan assets		(2.1	)		(5.2	)		(7.1	)		—		—			—
Amortization of:
Prior service benefit		—			—			—			—		(0.4	)		(0.6	)
Actuarial loss		—			4.5			4.5			—		—			0.3
Pension / postretirement costs	$	(1.2	)	$	2.0		$	2.0		$	0.1	$	0.2		$	0.7

	Pension Benefits									Postretirement and Other Benefits
	Successor			Predecessor			Predecessor			Successor		Predecessor			Predecessor
(dollars in millions)	September 8, 2021 to September 30, 2021			January 1, 2021 to September 7, 2021			Nine Months Ended September 30, 2020			September 8, 2021 to September 30, 2021		January 1, 2021 to September 7, 2021			Nine Months Ended September 30, 2020
Service cost	$	—		$	—		$	—		$	—	$	0.3		$	0.3
Other components of pension and postretirement benefit plans expense:
Interest cost on projected benefit obligation		0.9			10.2			14.2			0.1		1.8			2.8
Expected return on plan assets		(2.1	)		(19.9	)		(21.6	)		—		—			—
Amortization of:
Prior service benefit		—			—			—			—		(1.7	)		(1.9	)
Actuarial loss		—			16.0			13.5			—		—			0.9
Pension settlement charges		—			—			1.1			—		—			—
Pension / postretirement costs	$	(1.2	)	$	6.3		$	7.2		$	0.1	$	0.4		$	2.1

Schedule of Weighted-Average Discount Rate Assumptions

The following are the weighted-average discount rate assumptions used in accounting for and measuring the projected benefit obligations:

	Pension Benefits		Postretirement and Other Benefits
	Successor	Predecessor	Successor	Predecessor
	September 8, 2021	December 31, 2020	September 8, 2021	December 31, 2020
Cincinnati plans	2.60%	2.40%	2.60%	2.40%
Hawaii plans	2.50%	2.30%	2.80%	2.60%