v3.8.0.1
PARTNERS' EQUITY Table 2 - Preferred Partners' Equity (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Preferred limited partners capital, beginning balance       $ 218,400         $ 218,400    
Net income (loss) $ 25,182 $ 38,592 $ 26,250 57,940 $ (11,056) $ 51,141 $ 52,517 $ 57,401 147,964 $ 150,003 $ 306,720
Distributions to partners                 (486,754) (394,887) (392,204)
Other                 (679)    
Preferred limited partners capital, ending balance 756,603       218,400       756,603 218,400  
Series A Preferred Limited Partner [Member]                      
Preferred limited partners capital, beginning balance       218,400       0 218,400 0  
Net proceeds from issuance of units                 0 218,400  
Net income (loss)                 19,253 1,925  
Distributions to partners                 (19,253) (1,925)  
Other                 (93)    
Preferred limited partners capital, ending balance 218,307       218,400       218,307 218,400 0
Series B Preferred Limited Partner [Member]                      
Preferred limited partners capital, beginning balance       0       0 0 0  
Net proceeds from issuance of units                 371,823 0  
Net income (loss)                 19,815 0  
Distributions to partners                 (19,815) 0  
Other                 (189)    
Preferred limited partners capital, ending balance 371,634       0       371,634 0 0
Series C Preferred Limited Partner [Member]                      
Preferred limited partners capital, beginning balance       0       0 0 0  
Net proceeds from issuance of units                 166,737 0  
Net income (loss)                 1,380 0  
Distributions to partners                 (1,380) 0  
Other                 (75)    
Preferred limited partners capital, ending balance 166,662       0       166,662 0 0
Preferred Limited Partner [Member]                      
Preferred limited partners capital, beginning balance       $ 218,400       $ 0 218,400 0  
Net proceeds from issuance of units                 538,560 218,400  
Net income (loss)                 40,448 1,925 0
Distributions to partners                 (40,448) (1,925) 0
Other                 (357)    
Preferred limited partners capital, ending balance $ 756,603       $ 218,400       $ 756,603 $ 218,400 $ 0