Equity and Distributions, Noncontrolling Interests (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)
Whitehorn Pipeline Company LLC [Member]
Noncontrolling Interest
Noncontrolling Interest, Increase from Sale of Parent Equity Interest	$ 189.6
Western Gas Partners, LP [Member] | Whitehorn Pipeline Company LLC [Member]
Noncontrolling Interest
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	20.00%
Navigator Holdings Ltd. [Member] | Enterprise Navigator Ethylene Terminal LLC [Member]
Noncontrolling Interest
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	50.00%
Apache Corporation [Member] | Shin Oak NGL Pipeline [Member] | Maximum [Member]
Noncontrolling Interest
Percentage Of Option To Purchase Equity Interest	33.00%