v3.8.0.1
PARTNERS' EQUITY Table 5 - Cash Distributions Earned - General and Common Limited Partners (Details) - USD ($)
$ / shares in Units, $ 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
Distributions Made to Limited Partners and General Partner [Line Items]                      
General partner interest                 $ 9,252 $ 7,877 $ 7,844
General partner incentive distribution                 45,669 43,407 43,220
Total general partner distributions                 54,921 51,284 51,064
Common limited partners' distribution                 407,681 342,598 341,140
Total cash distributions applicable to common unitbolders and general partner (distribution earned) $ 115,267 $ 115,084 $ 115,083 $ 117,168         $ 462,602 $ 393,882 $ 392,204
Common Limited Partner [Member]                      
Distributions Made to Limited Partners and General Partner [Line Items]                      
Cash distributions per unit applicable to limited partners $ 1.095 $ 1.095 $ 1.095 $ 1.095 $ 1.0950 $ 1.0950 $ 1.0950 $ 1.0950 $ 4.380 $ 4.380 $ 4.380