THE ACQUISITION - NARRATIVE (Details) - USD ($)		1 Months Ended	5 Months Ended	12 Months Ended
	Aug. 08, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Jun. 26, 2020	Aug. 07, 2019	Jul. 01, 2019	Jun. 30, 2019
Business Acquisition [Line Items]
Debt instrument issued			$ 37,401,000,000	$ 35,235,000,000	$ 37,401,000,000
WES | Public Ownership | WES
Business Acquisition [Line Items]
Limited partner interest				44.60%	44.60%
Revolving Credit Facility
Business Acquisition [Line Items]
Revolving credit facility, maximum borrowing capacity							$ 3,000,000,000.0
Common Stock
Business Acquisition [Line Items]
Exercise price of warrant (in dollars per share)						$ 59.624
Senior notes
Business Acquisition [Line Items]
Debt instrument issued				$ 7,000,000,000.0
Line of Credit | Revolving Credit Facility
Business Acquisition [Line Items]
Revolving credit facility, maximum borrowing capacity								$ 5,000,000,000.0	$ 3,000,000,000.0
Anadarko Petroleum Corporation
Business Acquisition [Line Items]
Cash of acquirer in exchange for acquiree (usd per share)	$ 59.00
Exchange ratio (per share of Anadarko common stock)	0.2934
Closing price per share, common stock (usd per share)	$ 46.31
Debt instrument issued	$ 21,800,000,000
Shares issued (in shares)	144,000,000
Amount from exercise of warrants	$ 10,000,000,000
Assumed debt	13,240,000,000
Property, plant and equipment	49,125,000,000
Revenues from date of merger			4,200,000,000
Net loss attributable to common shareholders from date of merger			1,700,000,000
Long-term debt	11,900,000,000
Anadarko Petroleum Corporation | WES
Business Acquisition [Line Items]
Revenues from date of merger			$ 1,100,000,000
Anadarko Petroleum Corporation | Proved gas and oil properties
Business Acquisition [Line Items]
Property, plant and equipment	19,100,000,000
Anadarko Petroleum Corporation | Unproved Properties
Business Acquisition [Line Items]
Property, plant and equipment	27,400,000,000
Anadarko Petroleum Corporation | Land, Mineral Interests And Corporate Properties
Business Acquisition [Line Items]
Property, plant and equipment	$ 2,500,000,000
Anadarko Petroleum Corporation | Customer Relationships
Business Acquisition [Line Items]
Amortization period	30 years
Anadarko Petroleum Corporation | Level 2
Business Acquisition [Line Items]
Assumed debt	$ 2,500,000,000
Anadarko Petroleum Corporation | WES
Business Acquisition [Line Items]
Assumed debt	7,407,000,000
Property, plant and equipment	10,160,000,000
Anadarko Petroleum Corporation | WES | Level 2
Business Acquisition [Line Items]
Assumed debt	730,000,000
Anadarko Petroleum Corporation | Revolving Credit Facility
Business Acquisition [Line Items]
Revolving credit facility, additional commitment	$ 2,000,000,000.0
Anadarko Petroleum Corporation | Series A Preferred Stock
Business Acquisition [Line Items]
Shares issued (in shares)	100,000
Anadarko Petroleum Corporation | Common Stock
Business Acquisition [Line Items]
Number of securities called by warrant (in shares)	80,000,000
Exercise price of warrant (in dollars per share)	$ 62.50
Anadarko Petroleum Corporation | Senior notes
Business Acquisition [Line Items]
Debt instrument issued	$ 13,000,000,000.0
Long-term debt	11,900,000,000
Amount tendered and accepted in exchange offers, percentage		97.00%
Amount tendered and accepted in exchange offers,		$ 11,500,000,000
Portion not exchanged		$ 400,000,000
Anadarko Petroleum Corporation | Secured Debt
Business Acquisition [Line Items]
Debt instrument issued	8,800,000,000
Anadarko Petroleum Corporation | Line of Credit | Senior Unsecured Term Loan Facility, 364-Day
Business Acquisition [Line Items]
Debt instrument issued	4,400,000,000
Anadarko Petroleum Corporation | Line of Credit | Term Loan Facility
Business Acquisition [Line Items]
Debt instrument issued	$ 4,400,000,000
Debt instrument, term	2 years