Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2015

Asset Retirement Obligation Disclosure [Abstract]

Changes to Asset Retirement Obligations

The following table describes changes to our asset retirement obligations:

	2015			2014
	(In millions)
Asset retirement obligations at beginning of period	$	2,723		$	2,772
Liabilities incurred		57			63
Liabilities settled or disposed of		(360	)		(420	)
Accretion expense		126			136
Revisions of estimated liabilities		92			263
Foreign currency translation		(255	)		(91	)
Asset retirement obligations at end of period		2,383			2,723
Less: Current obligations		225			442
Long-term obligations at end of period	$	2,158		$	2,281