Cash and Cash Equivalents (Table) (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|---|---|---|---|---|
| CASH AND CASH EQUIVALENTS [Abstract] | ||||
| Cash on hand and at banks | $ 126,584 | $ 85,570 | ||
| Short-term deposits and highly liquid funds | 9,408 | 77,842 | ||
| Cash and cash equivalents | $ 135,992 | $ 163,412 | $ 247,556 | $ 187,831 |