Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2016

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	2016			2015			2016			2015
Interest cost on PBO	$	11		$	10		$	21		$	20
Expected return on plan assets		(13	)		(14	)		(26	)		(28	)
Amortization of losses		4			5			8			9
Net pension cost	$	2		$	1		$	3		$	1

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	2016			2015			2016			2015
Interest cost on APBO	$	1		$	1		$	2		$	2
Expected return on plan assets		(1	)		—			(2	)		(1	)
Amortization of unrecognized prior service credit		—			(1	)		—			(1	)
Net postretirement benefit cost		—			—			—			—