Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Debt and Interest Expense - Additional Information (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020	Jan. 13, 2020
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt	$ 0	$ 1,395,000		$ (289,000)	$ 8,740,000
WES Operating [Member]
Debt Instrument [Line Items]
Gain (loss) on early extinguishment of debt	0	$ 1,395,000		(289,000)	$ 8,740,000
WES Operating [Member] \| Third Parties [Member]
Debt Instrument [Line Items]
Future lease payments	$ 33,100,000			$ 33,100,000
WES Operating [Member] \| 3.100% Senior Notes due 2025 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate	3.10%			3.10%		3.10%
Senior note, effective interest rate	4.542%	3.287%		4.542%	3.287%
WES Operating [Member] \| 4.050% Senior Notes due 2030 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.05%			4.05%		4.05%
Senior note, effective interest rate	5.424%	4.168%		5.424%	4.168%
WES Operating [Member] \| 5.250% Senior Notes due 2050 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.25%			5.25%		5.25%
Senior note, effective interest rate	6.629%	5.362%		6.629%	5.362%
WES Operating [Member] \| Floating-Rate Senior Notes due 2023 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, effective interest rate	2.29%	2.66%		2.29%	2.66%
WES Operating [Member] \| 5.375% Senior Notes due 2021 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate	5.375%			5.375%
WES Operating [Member] \| 4.000% Senior Notes due 2022 [Member] \| Senior Notes [Member]
Debt Instrument [Line Items]
Senior note, interest rate	4.00%			4.00%
WES Operating [Member] \| RCF [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility, expandable maximum borrowing capacity	$ 2,500,000,000			$ 2,500,000,000
Facility, maximum borrowing capacity	2,000,000,000.0			2,000,000,000.0
Facility, outstanding borrowings	0			0
Facility, outstanding letters of credit	5,100,000			5,100,000
Facility, available borrowing capacity	$ 2,000,000,000.0			$ 2,000,000,000.0
Facility, interest rate at period end	1.60%	1.66%		1.60%	1.66%
Facility, fee rate				0.25%	0.25%
Repayments of Lines of Credit				$ 100,000,000
WES Operating [Member] \| RCF [Member] \| Revolving Credit Facility [Member] \| Non-Extending Lender [Member]
Debt Instrument [Line Items]
Facility, borrowing capacity for non-extending lender	$ 100,000,000.0			$ 100,000,000.0
WES Operating [Member] \| Term Loan Facility [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Lines of Credit			$ 3,000,000,000.0
Gain (loss) on early extinguishment of debt			$ (2,300,000)