Quarterly report pursuant to Section 13 or 15(d)

Leased Properties and Leases - Significant Leases (Details)

v3.5.0.2
Leased Properties and Leases - Significant Leases (Details)
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Pinedale LGS [Member]          
Operating Leased Assets [Line Items]          
Percentage of total leased properties 39.80%   39.80%   40.00%
Percentage of leased property revenue 30.40% 30.40% 30.40% 49.80%  
Grand Isle Gathering System [Member]          
Operating Leased Assets [Line Items]          
Percentage of total leased properties 50.20%   50.20%   50.10%
Percentage of leased property revenue 59.80% 59.90% 59.80% 32.70%  
Portland Terminal Facility [Member]          
Operating Leased Assets [Line Items]          
Percentage of total leased properties 9.80%   9.80%   9.60%
Percentage of leased property revenue 9.70% 9.60% 9.70% 15.30%  
Public Service Company of New Mexico [Member]          
Operating Leased Assets [Line Items]          
Percentage of total leased properties 0.00%   0.00%   0.00%
Percentage of leased property revenue 0.00% 0.00% 0.00% 2.10%