v3.8.0.1

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

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