Employee Pension and Other Postretirement Benefits

9 Months Ended

Sep. 30, 2017

Compensation and Retirement Disclosure [Abstract]

Employee Pension and Other Postretirement Benefits

Employee Pension and Other Postretirement Benefits

The following tables summarize the components of net periodic benefit cost for the three and nine months ended September 30, 2017 and 2016.

	Pension Benefits						Other Postretirement Benefits						Superannuation, SERP and ESBP
	For the Three Months Ended   September 30,						For the Three Months Ended   September 30,						For the Three Months Ended   September 30,
(Dollars in millions)	2017			2016			2017			2016			2017		2016
Components of net periodic benefit cost:
Service cost	$	18		$	24		$	1		$	2		$	—	$	1
Interest cost	25			25			2			2			1		—
Expected return on plan assets	(64		)	(59		)	(5		)	(5		)	—		—
Amortization of prior service credit	(7		)	(5		)	(5		)	(3		)	—		—
Recognized net actuarial loss	19			19			2			2			—		1
Total net periodic benefit cost	$	(9	)	$	4		$	(5	)	$	(2	)	$	1	$	2

	Pension Benefits						Other Postretirement Benefits						Superannuation, SERP and ESBP
	For the Nine Months Ended September 30,						For the Nine Months Ended September 30,						For the Nine Months Ended September 30,
(Dollars in millions)	2017			2016			2017			2016			2017		2016
Components of net periodic benefit cost:
Service cost	$	53		$	69		$	4		$	6		$	—	$	2
Interest cost	75			77			6			7			2		1
Expected return on plan assets	(191		)	(177		)	(14		)	(14		)	—		—
Amortization of prior service credit	(20		)	(14		)	(16		)	(7		)	—		—
Recognized net actuarial loss	59			57			6			7			2		2
Total net periodic benefit cost	$	(24	)	$	12		$	(14	)	$	(1	)	$	4	$	5