Pension and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2023

Retirement Benefits [Abstract]

Schedule of Net Benefit Costs

The following tables provide certain information regarding the Company's pension, postretirement and supplemental retirement plans as of for the three months ended March 31,:

	Defined Benefit Pension Plans				Postretirement Benefit Plan				Supplemental Retirement Plans
(Dollars in millions)	March 31, 2023		March 31, 2022		March 31, 2023		March 31, 2022		March 31, 2023		March 31, 2022
Service cost	$	—	$	—	$	—	$	—	$	—	$	—
Interest cost	2		2		—		—		—		—
Less Expected return on plan assets	(1)		(2)		—		—		—		—
Amortization of net actuarial loss (gain)	—		—		—		—		—		—
Amortization of prior service cost	—		—		—		—		—		—
Settlement expense (income)	—		1		—		—		—		—
Net periodic benefit cost	$	1	$	1	$	—	$	—	$	—	$	—