Summary of Significant Accounting Policies - Basis Of Presentation, Subsidiaries, Affiliates and Restricted Cash (Details) - USD ($)
$ in Thousands |
9 Months Ended |
12 Months Ended |
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Increase/(decrease) in cash and cash equivalents |
|
|
$ (8,360)
|
$ (27,420)
|
$ (84,144)
|
| Restricted cash |
$ 10,056
|
$ 5,040
|
$ 6,558
|
5,386
|
$ 13,480
|
| Navios Logistics |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Ownership percentage of Navios Holdings |
|
|
63.80%
|
|
|
| Letter of Credit | Navios Logistics |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Restricted cash |
|
|
|
2,900
|
|
| Retention Accounts |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Restricted cash |
|
|
$ 5,968
|
1,896
|
|
| Amount Held as Security |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Restricted cash |
|
|
$ 590
|
$ 590
|
|
| Navios Logistics |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Ownership percentage of Navios Holdings |
63.80%
|
|
|
|
|
| Navios Partners and its subsidiaries |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
20.20%
|
|
20.80%
|
|
|
| General partner interest of Navios Holdings |
2.00%
|
|
2.00%
|
|
|
| Navios Acquisition and its subsidiaries |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
48.60%
|
|
46.20%
|
|
|
| Acropolis Chartering and Shipping Inc. ("Acropolis") |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
35.00%
|
|
35.00%
|
|
|
| Ownership percentage of Navios Holdings |
50.00%
|
|
50.00%
|
|
|
| Navios Europe I and its subsidiaries |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
47.50%
|
|
|
|
|
| Navios Europe II and its subsidiaries |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
47.50%
|
|
|
|
|
| Navios Containers and its subsidiaries |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Economic interest |
3.10%
|
|
3.40%
|
|
|
| Effect of retrospective application |
|
|
|
|
|
| New Accounting Pronouncements or Change in Accounting Principle [Line Items] |
|
|
|
|
|
| Increase/ (decrease) in net cash provided by operating activities |
|
(2,836)
|
|
|
|
| Increase/ (decrease) in net cash provided financing activities |
|
(2,491)
|
|
|
|
| Increase/(decrease) in cash and cash equivalents |
|
$ (345)
|
|
|
|