Impairment of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2020
Goodwill [Roll Forward]
Balance as of December 31, 2019		$ 12
Goodwill impairment		(12)
Balance as of June 30, 2020		0
Gathering and Processing
Goodwill [Roll Forward]
Balance as of December 31, 2019		12
Goodwill acquired	$ 12
Goodwill impairment		(12)
Balance as of June 30, 2020		0
Transportation and Storage
Goodwill [Roll Forward]
Balance as of December 31, 2019		0
Goodwill impairment		0
Balance as of June 30, 2020		$ 0