Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2019

Retirement Benefits [Abstract]

Schedule of components of net periodic pension benefit (income) expense and post-retirement benefit expense

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

	Combined Pension Plan
	Three Months Ended March 31,
	2019			2018
	(Dollars in millions)
Service cost	$	14		16
Interest cost	110			100
Expected return on plan assets	(156		)	(173	)
Recognition of prior service credit	(2		)	(2	)
Recognition of actuarial loss	57			44
Net periodic pension benefit expense (income)	$	23		(15	)

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

	Post-Retirement Benefit Plans
	Three Months Ended March 31,
	2019		2018
	(Dollars in millions)
Service cost	$	4	4
Interest cost	27		24
Recognition of prior service cost	4		5
Net periodic post-retirement benefit expense	$	35	33