Employee Benefits (Tables)

3 Months Ended

Mar. 31, 2013

Compensation And Retirement Disclosure [Abstract]

Net Pension Cost for Funded and Unfunded Plans

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

	Three months ended March 31,
in millions	2013		2012
Interest cost on PBO	$	10	$	12
Expected return on plan assets		(17)		(18)
Amortization of losses		5		4
Net pension cost	$	(2)	$	(2)

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 March 31,
in millions	2013		2012
Interest cost on APBO	$	1	$	1
Expected return on plan assets		(1)		(1)
Net postretirement benefit cost		—		—