EQUITY METHOD INTERESTS - Rollforward Activity (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	$ 1,258
Equity method interest, ending balance	1,408
Breviloba, LLC
Movement In Equity Method Interests [Roll Forward]
Distributions	(16)
Altus Midstream Company
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	1,258
Capital contributions	154
Distributions	(42)
Capitalized interest	5
Equity income (loss), net	34
Accumulated other comprehensive loss	(1)
Equity method interest, ending balance	1,408
Altus Midstream Company | Gulf Coast Express Pipeline LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	291
Capital contributions	1
Distributions	(26)
Capitalized interest	0
Equity income (loss), net	21
Accumulated other comprehensive loss	0
Equity method interest, ending balance	287
Altus Midstream Company | EPIC Crude Holdings, LP
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	163
Capital contributions	15
Distributions	0
Capitalized interest	0
Equity income (loss), net	(2)
Accumulated other comprehensive loss	(1)
Equity method interest, ending balance	175
Altus Midstream Company | Permian Highway Pipeline LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	311
Capital contributions	138
Distributions	0
Capitalized interest	5
Equity income (loss), net	0
Accumulated other comprehensive loss	0
Equity method interest, ending balance	454
Altus Midstream Company | Breviloba, LLC
Movement In Equity Method Interests [Roll Forward]
Equity method interest, beginning balance	493
Capital contributions	0
Capitalized interest	0
Equity income (loss), net	15
Accumulated other comprehensive loss	0
Equity method interest, ending balance	$ 492