Fair Value of Financial Instruments - Recurring Measurements (Table) (Details) - USD ($) $ in Thousands |
Jun. 30, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Assets | ||
| Investments in available-for-sale securities | $ 211 | $ 238 |
| Fair Value, Measurements, Recurring | ||
| Assets | ||
| Investments in available-for-sale securities | 211 | 238 |
| Total | 211 | 238 |
| Quoted Prices in Active Markets for Identical Assets (Level I) | Fair Value, Measurements, Recurring | ||
| Assets | ||
| Investments in available-for-sale securities | 211 | 238 |
| Total | $ 211 | $ 238 |