Amount of cost for defined contribution plan.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Yield on the receivable, on which interest has been imputed, as calculated from its issuance value or purchase price. The calculated effective interest rate considers factors such as the issued face value or price paid for the receivable, the time period between payments, and the time until maturity [full receipt] of the receivable.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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Description of Business and Basis of Presentation - Additional Information (Details) - USD ($)		1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2019	May 31, 2008	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2018	Jul. 01, 2019	Feb. 28, 2019
Common units outstanding	443,971,409		443,971,409
Revenues and other			$ 774,313,000	$ 671,883,000
Defined-contribution plan expense			$ 400,000
Maximum [Member]
Equity-based compensation - payout percentage			200.00%
Minimum [Member]
Equity-based compensation - payout percentage			0.00%
Executive Long-Term Incentive Plans [Member]
Units vesting period			3 years
Non-Executive Long-Term Incentive Plans [Member]
Units vesting period			3 years
Affiliates [Member]
Revenues and other			$ 482,385,000	378,437,000
Note receivable - Anadarko		$ 260,000,000.0
Fixed annual rate for note receivable bearing interest		6.50%
Allowance for expected credit loss			2,100,000
Affiliates [Member] \| Product Sales [Member]
Revenues and other			$ 31,624,000	50,443,000
Affiliates [Member] \| Product Sales [Member] \| Kitty Draw and Third Creek Gathering Systems [Member]
Revenues and other				5,500,000	$ (10,900,000)
WES Operating [Member]
Ownership interest by noncontrolling interest owner			2.00%
Chipeta [Member]
Ownership interest by noncontrolling interest owner			25.00%
WES [Member] \| WES Operating [Member]
Ownership interest			98.00%
Occidental [Member] \| WES [Member]
Ownership interest			53.40%
General partner's interest	2.00%		2.00%
Common units outstanding			242,136,976
Occidental [Member] \| WES [Member] \| Common Units [Member]
Common units outstanding	9,060,641
Occidental [Member] \| WES Operating [Member]
Ownership interest			2.00%
WES Operating [Member]
Cash contribution from related party			$ 20,000,000.0
Revenues and other			774,313,000	671,883,000
WES Operating [Member] \| Affiliates [Member]
Revenues and other			482,385,000	378,437,000
WES Operating [Member] \| Affiliates [Member] \| Product Sales [Member]
Revenues and other			$ 31,624,000	$ 50,443,000
WES Operating [Member] \| RCF [Member] \| Revolving Credit Facility [Member]
Facility, maximum borrowing capacity							$ 2,000,000,000.0
WES Operating [Member] \| Term Loan Facility [Member] \| Revolving Credit Facility [Member]
Facility, maximum borrowing capacity						$ 3,000,000,000.0