PARTNERS' EQUITY Narrative 2 (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
Apr. 18, 2017 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Class of Stock [Line Items] | ||||
| Equity issuance costs | $ 500 | |||
| General partner ownership interest | 2.00% | 2.00% | 2.00% | |
| Common Limited Partner [Member] | ||||
| Class of Stock [Line Items] | ||||
| Issuance of units (units) | 14,375,000 | 14,375,000 | 595,050 | |
| Units issued, price per unit | $ 46.35 | |||
| Weighted average price per unit issued | $ 47.39 | |||
| Proceeds from common unit issuance including general partner contribution | $ 657,500 | $ 28,300 | ||
| Net proceeds from issuance of units | $ 643,878 | $ 27,710 | ||
| Unit-based compensation (units) | 185,455 | 135,100 | ||
| General Partner [Member] | ||||
| Class of Stock [Line Items] | ||||
| Net proceeds from issuance of units | $ 13,600 | $ 13,597 | $ 575 | |
| General partner ownership interest | 2.00% | |||