Annual report pursuant to Section 13 and 15(d)

- Significant Leases (Details)

v3.3.1.900
- Significant Leases (Details)
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Pinedale Liquids Gathering System [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 40.00% 79.20%  
Percentage of leased property revenue 42.90% 71.90% 88.70%
Grand Isle Gathering System [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 50.10% 0.00%  
Percentage of leased property revenue 42.30% 0.00% 0.00%
Portland Terminal Facility [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 9.60% 17.20%  
Percentage of leased property revenue 13.30% 19.00% 0.00%
Public Service Company of New Mexico [Member]      
Operating Leased Assets [Line Items]      
Percentage of total leased properties 0.00% 3.10%  
Percentage of leased property revenue 1.30% 9.10% 11.30%