Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2013

Asset Retirement Obligation Disclosure [Abstract]

Schedule of Change in Asset Retirement Obligation [Table Text Block]

A reconciliation of the asset retirement obligations for the three months ended March 31, 2013 follows:

	(In millions)
Asset retirement obligations at December 31, 2012	$	1,719
Accretion	26
Asset retirement obligations at March 31, 2013	$	1,745