Acquisitions and Divestitures (Tables) - Divestiture [Member]

12 Months Ended

Dec. 31, 2016

Argentina [Member]

Summary of Sales and Other Operating Revenue and Loss from Discontinued Operation Related to Disposition

	For the Year Ended December 31,
	2016			2015		2014
	(In millions)
Revenues and other from discontinued operations	$	—		$	—	$	87
Loss from Argentina divestiture	$	(10	)	$	—	$	(654	)
Loss from operations in Argentina	—			—		(1		)
Income tax benefit	—			—		23
Loss from discontinued operations, net of tax	$	(10	)	$	—	$	(632	)

Australia [Member]

Summary of Sales and Other Operating Revenue and Loss from Discontinued Operation Related to Disposition

	For the Year Ended December 31,
	2016			2015			2014
	(In millions)
Revenues and other from discontinued operations	$	—		$	288		$	1,050
Impairment on Woodside sale	$	—		$	(49	)	$	(833	)
Loss on Woodside sale	(23		)	—			—
Loss on Consortium sale	—			(139		)	—
Income (loss) from divested Australian operations	—			28			(12		)
Income tax benefit (expense)	—			652			(231		)
Income (loss) from Australian discontinued operations, net of tax	$	(23	)	$	492		$	(1,076	)