Quarterly report pursuant to Section 13 or 15(d)

Leased Properties and Leases - Significant Leases (Details)

v3.8.0.1
Leased Properties and Leases - Significant Leases (Details)
 3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Dec. 31, 2017
Pinedale LGS [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 39.90%   39.90%
Percentage of leased property revenue 32.80% 30.60%  
Grand Isle Gathering System [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 49.70%   49.70%
Percentage of leased property revenue 57.80% 59.60%  
Portland Terminal Facility [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 10.10%   10.10%
Percentage of leased property revenue 9.30% 9.70%