SEGMENT INFORMATION Narrative (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Revenue, Major Customer [Line Items] | |||||||||||
| Revenue from largest customer | $ 464,919 | $ 493,566 | $ 570,611 | $ 554,944 | $ 681,738 | $ 794,422 | $ 749,745 | $ 849,213 | $ 2,084,040 | $ 3,075,118 | $ 3,463,732 |
| Sales Revenue, Net [Member] | Valero Energy Corporation [Member] | |||||||||||
| Revenue, Major Customer [Line Items] | |||||||||||
| Largest customer percentage of revenue | 16.00% | 9.00% | 15.00% | ||||||||
| Revenue from largest customer | $ 331,700 | $ 282,900 | $ 534,200 | ||||||||