Borrowings - Principal Payments (Table) (Details) - USD ($)
$ in Thousands
Jun. 30, 2016
Dec. 31, 2015
BORROWINGS [Abstract]    
June 30, 2017 $ 24,403  
June 30, 2018 30,471  
June 30, 2019 414,914  
June 30, 2020 59,199  
June 30, 2021 28,623  
June 30, 2022 and thereafter 1,096,866  
Total $ 1,654,476 $ 1,608,526