Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2021

Retirement Benefits, Description [Abstract]

Schedule of Components of Net Periodic Benefit Cost

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

(Dollars in millions)	2021		2020
Components of net periodic benefit cost
Interest cost	$	4	$	6
Expected return on plan assets	(7)		(7)
Amortization of unrecognized:
Actuarial (gain) loss	2		3
Net periodic benefit cost	$	(1)	$	2

The components of net periodic benefit cost for the nine months ended September 30 were as follows:

(Dollars in millions)	2021		2020
Components of net periodic benefit cost
Interest cost	$	12	$	17
Expected return on plan assets	(15)		(19)
Amortization of unrecognized:
Actuarial (gain) loss	6		10
Other	2		—
Net periodic benefit cost	$	5	$	8