Employee Benefit Plans (Tables)

9 Months Ended

Sep. 30, 2019

Retirement Benefits [Abstract]

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

	Pension Benefits Cost
(Dollars in millions)	Third Quarters						Nine Months
	2019			2018			2019			2018
Service Cost Included in Labor and Fringe	$	8		$	8		$	24		$	24
Interest Cost	25			23			77			69
Expected Return on Plan Assets	(43		)	(44		)	(129		)	(131		)
Amortization of Net Loss	8			10			23			30
Total Included in Other Income - Net	(10		)	(11		)	(29		)	(32		)
Net Periodic Benefit Credit	$	(2	)	$	(3	)	$	(5	)	$	(8	)
	Other Post-retirement Benefits Cost
(Dollars in millions)	Third Quarters						Nine Months
	2019			2018			2019			2018
Service Cost Included in Labor and Fringe	$	—		$	—		$	1		$	1
Interest Cost	—			2			2			5
Amortization of Prior Service Costs	(2		)	—			(5		)	—
Total Included in Other Income - Net	(2		)	2			(3		)	5
Net Periodic Benefit (Credit)/Cost	$	(2	)	$	2		$	(2	)	$	6