Asset Retirement Obligations (Tables)

12 Months Ended

Dec. 31, 2016

Asset Retirement Obligation Disclosure [Abstract]

Changes to Asset Retirement Obligations

The following table describes changes to our asset retirement obligations:

	2016			2015
	(In millions)
Balance at January 1	$	2,383		$	2,723
Liabilities incurred		42			57
Liabilities settled or disposed of		(196	)		(360	)
Accretion expense		117			126
Revisions of estimated liabilities		(230	)		92
Foreign currency translation		12			(255	)
Balance at December 31		2,128			2,383
Less: Current Obligations		216			225
Long-term Obligations at end of period	$	1,912		$	2,158