Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2013

Compensation and Retirement Disclosure [Abstract]

Components of net periodic cost (benefit)

Net Periodic Cost (Benefit)

Three months ended March 31
(In millions)	2013			2012
Pension cost (benefit)
Service cost	$	3		$	3
Interest cost on projected benefit obligation	30			34
Expected return on plan assets	(45		)	(43		)
Amortization of net actuarial (gain) loss	12			10
Net periodic pension cost (benefit)	$	—		$	4
Postretirement cost (benefit)
Amortization of prior service credit	$	(4	)	$	(4	)
Net periodic postretirement cost (benefit)	$	(4	)	$	(4	)