- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_DistributionMadeToLimitedPartnerLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Discount rate percentage used in calculating the distribution to the Class C unitholder.

+ References

No definition available.

+ Details

Name:	wgp_ClassCUnitsDiscountRatePercentageOnDistribution
Namespace Prefix:	wgp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The total cash distribution payment made to Series A Preferred unitholders.

+ References

No definition available.

+ Details

Name:	wgp_ConvertiblePreferredUnitsCashDistributions
Namespace Prefix:	wgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The quarterly cash distribution payment per unit on Series A Preferred units.

+ References

No definition available.

+ Details

Name:	wgp_ConvertiblePreferredUnitsDistributionsPerUnit
Namespace Prefix:	wgp_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of convertible preferred unit that will be converted to common units on a designated date.

+ References

No definition available.

+ Details

Name:	wgp_ConvertiblePreferredUnitsPercentageConversion
Namespace Prefix:	wgp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of common units issued for each convertible preferred unit that is converted.

+ References

No definition available.

+ Details

Name:	wgp_ConvertiblePreferredUnitsUnitsIssuedUponConversion
Namespace Prefix:	wgp_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Distribution sharing percentage the general partner is entitled to, including quarterly distributions and incentive distributions.

+ References

No definition available.

+ Details

Name:	wgp_GeneralPartnerDistributionPercentageInterest
Namespace Prefix:	wgp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Entitlement to incentive distributions after the minimum quarterly distribution and target distribution levels have been achieved.

+ References

No definition available.

+ Details

Name:	wgp_MarginalPercentageInterestInDistributions
Namespace Prefix:	wgp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of days subsequent to each quarter the Partnership is required to make distributions to unitholders of record on the applicable record date.

+ References

No definition available.

+ Details

Name:	wgp_NumberOfDaysSubsequentToQuarterEndThatCashIsRequiredToBeDistributed
Namespace Prefix:	wgp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=wgp_WesternGasPartnersMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalUnitsByClassAxis=wgp_ClassCUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CapitalUnitsByClassAxis=wgp_ConvertiblePreferredUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=wgp_ConvertiblePreferredUnitsConversion1Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=wgp_ConvertiblePreferredUnitsConversion2Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Partnership Distributions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	6 Months Ended	9 Months Ended
	May 02, 2017	Mar. 01, 2017	Mar. 31, 2017	Jun. 30, 2017	Sep. 30, 2018
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash					55 days
Western Gas Partners, LP [Member]
Distribution Made to Limited Partner [Line Items]
Partnership agreement day requirement of distribution of available cash					45 days
Incentive distributions percentage					48.00%
Western Gas Partners, LP [Member] \| Minimum [Member]
Distribution Made to Limited Partner [Line Items]
Distribution sharing percentage					1.50%
Western Gas Partners, LP [Member] \| Maximum [Member]
Distribution Made to Limited Partner [Line Items]
Distribution sharing percentage					49.50%
Western Gas Partners, LP [Member] \| Class C Units [Member]
Distribution Made to Limited Partner [Line Items]
Class C units, discount rate percentage on distribution					6.00%
Western Gas Partners, LP [Member] \| Series A Preferred Units [Member]
Distribution Made to Limited Partner [Line Items]
Series A Preferred units, quarterly distribution per unit				$ 0.68
Series A Preferred units, quarterly cash distribution			$ 7.5
Western Gas Partners, LP [Member] \| Series A Preferred Units [Member] \| Series A Preferred Units March 2017 Conversion [Member]
Distribution Made to Limited Partner [Line Items]
Series A Preferred units, percentage converted		50.00%
Series A Preferred units, common units issued upon conversion		1
Western Gas Partners, LP [Member] \| Series A Preferred Units [Member] \| Series A Preferred Units May 2017 Conversion [Member]
Distribution Made to Limited Partner [Line Items]
Series A Preferred units, percentage converted	50.00%
Series A Preferred units, common units issued upon conversion	1