Employee Benefits (Tables)

9 Months Ended

Sep. 30, 2017

Retirement Benefits [Abstract]

Net Pension Cost (Benefit) for All Funded and Unfunded Plans

The components of net pension cost (benefit) for all funded and unfunded plans are as follows:

	Three months ended September 30,						Nine months ended September 30,
in millions	2017			2016			2017			2016
Interest cost on PBO	$	12		$	10		$	36		$	31
Expected return on plan assets	(17		)	(13		)	(51		)	(39		)
Amortization of losses	4			4			12			12
Net pension cost	$	(1	)	$	1		$	(3	)	$	4

Net Postretirement Benefit Cost for All Funded and Unfunded Plans

The components of net postretirement benefit cost for all funded and unfunded plans are as follows:

	Three months ended September 30,						Nine months ended September 30,
in millions	2017			2016			2017			2016
Service Cost	—			$	1		—			$	1
Interest cost on APBO	$	1		—			$	1		2
Expected return on plan assets	(1		)	—			(1		)	(2		)
Amortization of unrecognized prior service credit	—			(1		)	—			(1		)
Net postretirement benefit cost	—			—			—			—