Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2021

Retirement Benefits [Abstract]

Schedule of Components of Expense/(Income) Related to Net Benefit Expense

	Pension Benefits Cost
	First Quarters
(Dollars in millions)	2021		2020
Service Cost Included in Labor and Fringe	$	9	$	10
Interest Cost	14		20
Expected Return on Plan Assets	(46)		(43)
Amortization of Net Loss	18		14
Total Included in Other Income - Net	(14)		(9)
Net Periodic Benefit (Credit)/Cost	$	(5)	$	1
	Other Post-retirement Benefits Cost
	First Quarters
(Dollars in millions)	2021		2020
Service Cost Included in Labor and Fringe	$	—	$	—
Interest Cost	—		1
Amortization of Prior Service Credits	(1)		(2)
Total Included in Other Income - Net	(1)		(1)
Net Periodic Benefit Credit	$	(1)	$	(1)