Employee Benefits (Tables)

6 Months Ended

Jun. 30, 2013

Compensation And Retirement Disclosure [Abstract]

Net Pension Cost for 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	2013		2012		2013		2012
Interest cost on PBO	$	10	$	12	$	20	$	24
Expected return on plan assets		(17)		(18)		(34)		(36)
Amortization of losses		5		4		10		8
Net pension cost (benefit)	$	(2)	$	(2)	$	(4)	$	(4)

Net Postretirement Benefit Cost for 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	2013		2012		2013		2012
Interest cost on APBO	$	1	$	1	$	2	$	2
Expected return on plan assets		(1)		(1)		(2)		(2)
Net postretirement benefit cost		—		—		—		—