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Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Mar. 17, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Mar. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Contract liabilities		$ 8,031		$ 8,031			$ 0
Revenues and other		507,762	$ 574,695	1,432,483	$ 1,616,338
Western Gas Partners, LP [Member]
Loss Contingencies [Line Items]
Rent expense associated with office and equipment leases		14,600	$ 12,000	40,500	$ 32,700
Western Gas Partners, LP [Member] \| DBJV Arbitration [Member] \| Pending Litigation [Member]
Loss Contingencies [Line Items]
Contract liabilities						$ 7,500
Western Gas Partners, LP [Member] \| Delaware Basin JV Gathering LLC [Member] \| DBJV Arbitration [Member]
Loss Contingencies [Line Items]
Percentage ownership interest	50.00%
Percentage third-party ownership interest	50.00%
Service Revenues - Fee Based [Member]
Loss Contingencies [Line Items]
Revenues and other		409,106		$ 1,146,099
Service Revenues - Fee Based [Member] \| Western Gas Partners, LP [Member] \| DBJV Arbitration [Member] \| Settled Litigation [Member]
Loss Contingencies [Line Items]
Revenues and other		$ 7,500