Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2017

Compensation and Retirement Disclosure [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 June 30,						Six months ended June 30,
in millions	2017			2016			2017			2016
Interest cost on PBO	$	12		$	11		$	24		$	21
Expected return on plan assets	(17		)	(13		)	(34		)	(26		)
Amortization of losses	4			4			8			8
Net pension cost	$	(1	)	$	2		$	(2	)	$	3

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 June 30,				Six months ended June 30,
in millions	2017	2016			2017	2016
Interest cost on APBO	—	$	1		—	$	2
Expected return on plan assets	—	(1		)	—	(2		)
Net postretirement benefit cost	—	—			—	—