Related-Party Transactions - Additional Information (Details) - USD ($)			1 Months Ended	3 Months Ended	12 Months Ended
		Sep. 11, 2020	May 31, 2008	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Administrative services fee under the omnibus agreement					$ 155,769,000	$ 114,591,000	$ 67,195,000
Unrecognized equity-based compensation expense					$ 16,900,000
Weighted-average term of unvested awards					1 year 7 months 6 days
Accrued capital expenditures					$ 25,126,000	140,954,000	274,632,000
Materials and supplies inventory					0	23,444,000
Capital contribution for the above-market component of swap agreements with Anadarko	[1]					7,407,000	51,618,000
WES Operating [Member]
Related Party Transaction [Line Items]
Cash contribution from related party				$ 20,000,000.0
Administrative services fee under the omnibus agreement					152,217,000	107,772,000	63,166,000
Accrued capital expenditures					25,126,000	140,954,000	274,632,000
Materials and supplies inventory					0	23,444,000
Capital contribution for the above-market component of swap agreements with Anadarko	[2]					7,407,000	51,618,000
Related Parties [Member]
Related Party Transaction [Line Items]
Administrative services fee under the omnibus agreement					40,295,000	101,485,000	49,672,000
Anadarko note receivable			$ 260,000,000.0
Anadarko note receivable - fixed annual rate			6.50%
Accrued capital expenditures					2,000,000.0
Materials and supplies inventory						18,400,000
Related Parties [Member] | Commodity-Price Swap Agreements [Member]
Related Party Transaction [Line Items]
Net gains (losses) on commodity-price swap agreements						(700,000)	(7,900,000)
Related Parties [Member] | Anadarko [Member]
Related Party Transaction [Line Items]
Anadarko note receivable - percentage interest transferred		98.00%
Related Parties [Member] | WGRAH [Member]
Related Party Transaction [Line Items]
Anadarko note receivable - percentage interest transferred		2.00%
Related Parties [Member] | Incentive Plans [Member]
Related Party Transaction [Line Items]
Allocated equity-based compensation expense					14,600,000	12,900,000	6,600,000
Unrecognized equity-based compensation expense					$ 12,500,000
Weighted-average term of unvested awards					8 months 12 days
Related Parties [Member] | WES Operating [Member]
Related Party Transaction [Line Items]
Administrative services fee under the omnibus agreement					$ 41,609,000	99,613,000	$ 48,819,000
Related Parties [Member] | WES [Member] | Limited Partner [Member] | WES [Member]
Related Party Transaction [Line Items]
Units redeemed from a related party		27,855,398
Omnibus Agreement [Member]
Related Party Transaction [Line Items]
Administrative services fee under the omnibus agreement						$ 250,000
Natural Gas [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage					41.00%	38.00%	36.00%
Crude Oil and NGLs Member]
Related Party Transaction [Line Items]
Related-party throughput percentage					88.00%	84.00%	80.00%
Produced water [Member]
Related Party Transaction [Line Items]
Related-party throughput percentage					87.00%	82.00%	91.00%

[1] See Note 6.

[2] See Note 6.