Employee Retirement Benefits (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Schedule of Defined Benefit Plans Disclosures

The following summarizes the components of net periodic benefit cost for our qualified and supplemental pension plans:

(Dollars in millions)	Three months ended March 31,
	2021		2020
Service cost	$	2	$	2
Non-service costs (benefit):
Interest cost	2		3
Expected return on plan assets	(5)		(5)
Amortization of actuarial loss and prior service cost	2		1
Other	2		—
Total non-service cost (benefit)	1		(1)
Net periodic benefit cost	$	3	$	1