Summary of Significant Accounting Policies - Goodwill and Other Intangibles - Intangibles Other Than Goodwill and Foreign Currency Translation (Details) - USD ($)
$ in Thousands |
12 Months Ended |
|
|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
Sep. 30, 2018 |
Sep. 30, 2017 |
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Goodwill |
$ 160,336
|
$ 160,336
|
$ 160,336
|
$ 160,336
|
$ 160,336
|
| Foreign currency exchange gains/(losses) |
(3,000)
|
$ 1,600
|
$ 1,646
|
|
|
| Shipping Reporting Unit |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Goodwill |
56,240
|
|
|
|
|
| One of the favorable lease terms |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Impairment loss of intangible assets other than goodwill |
$ 3,397
|
|
|
|
|
| Navios Holdings | Trade name |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Useful life of assets |
32 years
|
|
|
|
|
| Finite lived intangible assets amortization method |
straight line
|
|
|
|
|
| Navios Holdings | Customer relationships |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Finite lived intangible assets amortization method |
straight line
|
|
|
|
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| Navios Logistics |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Goodwill |
$ 104,096
|
|
|
|
|
| Navios Logistics | Trade name |
|
|
|
|
|
| Acquired Finite Lived Intangible Assets [Line Items] |
|
|
|
|
|
| Useful life of assets |
10 years
|
|
|
|
|
| Finite lived intangible assets amortization method |
straight line
|
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|