Cash and Cash Equivalents and Restricted Cash (Table) (Details) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
CASH AND CASH EQUIVALENTS [Abstract]        
Cash on hand and at banks $ 131,432 $ 127,625    
Short-term deposits and highly liquid funds 6,450 7    
Restricted cash 12,892 6,558 $ 5,386  
Cash and cash equivalents and restricted cash $ 150,774 $ 134,190 $ 141,378 $ 176,892