Represents the aggregate of total long-term debt, including current maturities and short-term debt.

No definition available.

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- Definition

The cash inflow during the period from additional borrowings in aggregate debt. Includes proceeds from short-term and long-term debt.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
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- Definition

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.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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- Definition

The cash inflow from a borrowing supported by a written promise to pay an obligation.

+ References

+ Details

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- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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Amount of cash outflow for payment of an obligation from a 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
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-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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The cash outflow for a borrowing supported by a written promise to pay an obligation.

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- Definition

Changes in Debt Outstanding [Roll Forward]

+ References

No definition available.

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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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- Definition

Amount of finance lease liability recorded as debt on the balance sheet.

+ References

No definition available.

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Debt and Interest Expense - Debt Activity Table (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Changes in Debt Outstanding [Roll Forward]
Beginning balance	$ 5,242,874,000	$ 5,242,874,000	$ 3,591,678,000
Other		5,286,000	(20,584,000)
Ending balance		7,959,438,000	5,242,874,000
WES Operating [Member] \| RCF [Member] \| Revolving Credit Facility [Member]
Changes in Debt Outstanding [Roll Forward]
Facility borrowings		1,160,000,000	540,000,000
Repayments of facility borrowings		(1,000,000,000)	(690,000,000)
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		7,873,000
WES Operating [Member] \| APCWH Note Payable [Member]
Changes in Debt Outstanding [Roll Forward]
APCWH Note Payable borrowings		11,000,000	321,780,000
Repayment of APCWH Note Payable		(439,595,000)
WES Operating [Member] \| 4.500% Senior Notes due 2028 [Member] \| Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes			400,000,000
WES Operating [Member] \| 5.300% Senior Notes due 2048 [Member] \| Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes			700,000,000
WES Operating [Member] \| 4.750% Senior Notes due 2028 [Member] \| Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes			400,000,000
WES Operating [Member] \| 5.500% Senior Notes due 2048 [Member] \| Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Issuance of senior notes			350,000,000
WES Operating [Member] \| 2.600% Senior Notes due 2018 [Member] \| Senior Notes [Member]
Changes in Debt Outstanding [Roll Forward]
Repayment of senior notes			$ (350,000,000)
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)