Goodwill (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill And Intangible Assets Disclosure [Abstract]

Changes in Carrying Amount of Goodwill

The changes in the carrying amount of goodwill were as follows:

	Exploration and Production		Midstream			Total
	(In millions)
Balance at December 31, 2016	$	—	$	375		$	375
Dispositions		—		(15	)		(15	)
Balance at December 31, 2017	$	—	$	360		$	360