Debt and Interest Expense - Debt Activity Table (Details) - USD ($)	3 Months Ended	9 Months Ended
Mar. 31, 2019	Sep. 30, 2019
Changes in Debt Outstanding [Roll Forward]
Beginning balance	$ 5,242,874,000	$ 5,242,874,000
Other		4,223,000
Ending balance		7,738,630,000
WES Operating [Member] \| RCF [Member] \| Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Facility borrowings		940,000,000
Repayments of facility borrowings		(1,000,000,000)
WES Operating [Member] \| Term Loan Facility [Member] \| Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Facility borrowings		3,000,000,000
WES Operating [Member] \| Finance Lease Liability [Member]
Changes in Debt Outstanding [Roll Forward]
Finance lease liabilities		8,128,000
WES Operating [Member] \| APCWH Note Payable [Member]
Changes in Debt Outstanding [Roll Forward]
APCWH Note Payable borrowings		11,000,000
Repayment of APCWH Note Payable		(439,595,000)
WES [Member] \| WGP RCF [Member] \| Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Repayments of facility borrowings	$ (28,000,000.0)	$ (28,000,000)

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Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3255-108585

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
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+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 15
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-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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Changes in Debt Outstanding [Roll Forward]

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- Definition

Represents debt issuance costs, including but not limited to legal, accounting, underwriting, printing and registration costs for debt issuances during the year, in addition to amortization of expense attributable to debt discount (premium) and debt issuance costs.

+ References

No definition available.

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