Annual report pursuant to Section 13 and 15(d)

Business and Organization (Details)

v3.8.0.1
Business and Organization (Details) - item
12 Months Ended
Dec. 31, 2017
Feb. 06, 2017
Jun. 30, 2016
Water Handling and Treatment      
Business and Organization      
Number of independent fresh water systems 2    
Stonewall Gas Gathering LLC      
Business and Organization      
Ownership percentage 15.00%   15.00%
Appalachia Joint venture      
Business and Organization      
Ownership percentage   50.00%  
Mark West | Appalachia Joint venture      
Business and Organization      
Ownership percentage 50.00%