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Equity-Based Compensation - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total fair value of units vested	$ 0.5	$ 1.2	$ 0.6
Unvested equity-based compensation expense	$ 16.9
Weighted-average term of unvested awards	1 year 7 months 6 days
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation - payout percentage	0.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation - payout percentage	200.00%
Western Gas Equity Partners 2012 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units available under LTIP	2,823,967
Common unit in-kind distributions, number of units	48,070
Western Gas Partners 2017 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units available under LTIP	3,431,251
Executive Long-Term Incentive Plans [Member] \| Time-vested [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vesting period	3 years
Executive Long-Term Incentive Plans [Member] \| TUR award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vesting period	3 years
Executive Long-Term Incentive Plans [Member] \| ROA Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vesting period	3 years
Non-Executive Long-Term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vesting period	3 years
Independent Director Long-Term Incentive Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units vesting period	1 year
Long-Term Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation expense	$ 7.9	$ 1.0	$ 0.7