Asset Retirement Obligations (Tables)

3 Months Ended

Mar. 31, 2015

Asset Retirement Obligations [Abstract]

Summary Of Changes In Asset Retirement Obligations

	Three Months Ended March 31,
	2015		2014
		(Millions)
Asset retirement obligations as of beginning of period	$	1,399	$	2,228
Liabilities incurred		23		45
Liabilities settled		(13)		(14)
Revision of estimated obligation		62		69
Liabilities assumed by others		(12)		(9)
Accretion expense on discounted obligation		19		29
Foreign currency translation adjustment		(53)		(51)
Asset retirement obligations as of end of period		1,425		2,297
Less current portion		52		79
Asset retirement obligations, long-term	$	1,373	$	2,218