Segment Information (Details) - USD ($) $ in Thousands |
Dec. 31, 2015 |
Dec. 31, 2014 |
|---|---|---|
| Segment Reporting Information [Line Items] | ||
| Net book value of long-lived assets | $ 1,823,961 | $ 1,911,143 |
| Dry bulk vessels | ||
| Segment Reporting Information [Line Items] | ||
| Net book value of long-lived assets | 1,423,147 | 1,486,486 |
| Logistics Business | ||
| Segment Reporting Information [Line Items] | ||
| Net book value of long-lived assets | $ 468,842 | $ 462,986 |