MERGER AND RELATED PARTY AGREEMENTS Table - Merger Calculation (Details) - USD ($) $ / shares in Units, $ in Thousands |
12 Months Ended | |||
|---|---|---|---|---|
Jul. 20, 2018 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Business Combinations [Abstract] | ||||
| Fair value of incremental NS common units issued | $ 335,106 | |||
| Holdings debt and assumed net current liabilities | 52,075 | |||
| Transaction costs | 15,897 | |||
| Total consideration | 403,078 | |||
| Carrying value of general partner interest | $ 25,999 | |||
| Loss to common unitholders attributable to the Merger | $ 0 | $ 0 | $ (377,079) | |
| Basic weighted-average common units outstanding | 109,155,117 | 107,789,030 | 99,490,495 | |
| Loss per common unit attributable to the Merger | $ (3.79) | |||