Fair Value of Financial Instruments - Assets measured at Fair Value on a Non-Recurring Basis (Table) (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Vessels, port terminals and other fixed assets, net | $ 16,500 | |
| Investments in affiliates | $ 148,095 | |
| Quoted Prices in Active Markets for Identical Assets (Level I) | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Investments in affiliates | $ 148,095 | |
| Significant Other Observable Inputs (Level II) | ||
| Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] | ||
| Vessels, port terminals and other fixed assets, net | $ 16,500 |