QUARTERLY FINANCIAL DATA (UNAUDITED) (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 |
|
| Quarterly Financial Data [Abstract] | |||||||||||
| Revenues | $ 450,535 | $ 440,566 | $ 435,488 | $ 487,430 | $ 471,757 | $ 441,418 | $ 437,804 | $ 405,703 | $ 1,814,019 | $ 1,756,682 | $ 2,084,040 |
| Operating income (loss) | 74,018 | 91,717 | 73,404 | 97,139 | 85,373 | 87,954 | 91,217 | 94,565 | 336,278 | 359,109 | 390,704 |
| 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 |
| Basic net income per common unit | $ 0.00 | $ 0.15 | $ 0.05 | $ 0.49 | $ (0.31) | $ 0.49 | $ 0.52 | $ 0.57 | $ 0.64 | $ 1.27 | $ 3.30 |
| Diluted net income per common unit | 0.00 | 0.15 | 0.05 | 0.49 | $ (0.31) | 0.49 | 0.52 | 0.57 | $ 0.64 | $ 1.27 | $ 3.30 |
| Impairment loss on Axeon Term Loan | $ 58,700 | $ 0 | $ 58,655 | $ 0 | |||||||
| Common Limited Partner [Member] | |||||||||||
| Distribution Made to Limited 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 |
| Quarterly Financial Data [Abstract] | |||||||||||
| Net income (loss) | $ 60,610 | $ 102,580 | $ 258,230 | ||||||||