Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2020

Retirement Benefits [Abstract]

Schedule of Components of Net Periodic Pension Benefit (Income) Expense and Post-retirement Benefit Expense

Net periodic benefit expense (income) for our combined pension plan includes the following components:

	Combined Pension Plan
	Three Months Ended March 31,
	2020			2019
	(Dollars in millions)
Service cost	$	16		14
Interest cost	82			110
Expected return on plan assets	(149		)	(156	)
Recognition of prior service credit	(3		)	(2	)
Recognition of actuarial loss	50			57
Net periodic pension benefit (income) expense	$	(4	)	23

Net periodic benefit expense for our post-retirement benefit plans includes the following components:

	Post-Retirement Benefit Plans
	Three Months Ended March 31,
	2020		2019
	(Dollars in millions)
Service cost	$	4	4
Interest cost	20		27
Recognition of prior service cost	4		4
Net periodic post-retirement benefit expense	$	28	35