Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2023

Retirement Benefits, Description [Abstract]

Schedule of Components of Net Periodic Benefit Cost

The components of net periodic benefit cost for the three and six months ended June 30 were as follows:

COMPONENTS OF NET PERIODIC BENEFIT COST
	Three months ended June 30,				Six months ended June 30,
(Dollars in millions)	2023		2022		2023		2022
Components of net periodic benefit cost
Interest cost	$	8	$	5	$	16	$	10
Expected return on plan assets	(8)		(6)		(16)		(12)
Amortization of unrecognized:
Actuarial (gain) loss	3		2		6		4
Net periodic benefit cost	$	3	$	1	$	6	$	2