SEGMENT INFORMATION Table 2 - Assets by Reportable Segment (Details) - USD ($) $ in Thousands |
Mar. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Segment Information | ||
| Total assets | $ 6,586,713 | $ 6,535,233 |
| Other Partnership Assets | ||
| Segment Information | ||
| Total assets | 187,122 | 188,507 |
| Operating Segments [Member] | ||
| Segment Information | ||
| Total assets | 6,399,591 | 6,346,726 |
| Operating Segments [Member] | Pipeline Segment | ||
| Segment Information | ||
| Total assets | 3,516,435 | 3,492,417 |
| Operating Segments [Member] | Storage Segment | ||
| Segment Information | ||
| Total assets | 2,761,667 | 2,735,563 |
| Operating Segments [Member] | Fuels Marketing Segment | ||
| Segment Information | ||
| Total assets | $ 121,489 | $ 118,746 |