Investments in Affiliates and Available-for-Sale Securities (Details) - USD ($)
$ / shares in Units, $ in Thousands
 2 Months Ended 3 Months Ended 5 Months Ended 6 Months Ended
Feb. 28, 2015
Jun. 30, 2017
Mar. 31, 2017
Mar. 20, 2017
Mar. 16, 2017
Jun. 30, 2016
Jun. 08, 2017
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Schedule Of Equity Method Investments [Line Items]                    
Equity in net (losses)/earnings of affiliated companies   $ (3,775)       $ 3,424   $ 1,307 $ 16,376  
Investments in affiliates   $ 189,195       388,772   $ 189,195 388,772 $ 160,071
Common stock par value | $ / shares   $ 0.0001           $ 0.0001   $ 0.0001
Navios Revolving Loans I Transfer                    
Schedule Of Equity Method Investments [Line Items]                    
Proceeds from transfer of debt         $ 4,050          
Consideration received         $ 33,473          
Navios Partners                    
Schedule Of Equity Method Investments [Line Items]                    
General partner interest of Navios Holdings     2.00% 2.00%            
Common Units issued in public offering     1,200,442              
Payments to acquire investment     $ 110 $ 2,048            
Stock Issued During Period Shares New Issues | shares       47,795,000            
Equity in net (losses)/earnings of affiliated companies   $ 473       473   $ 946 887  
Private placement of units to Navios Holdings     2,040,000              
Partners capital account units acquisitions | shares     66,131 975,408            
Common stock par value | $ / shares       $ 2.1            
Issuance of common stock       $ 100,369            
Navios Partners | Navios Revolving Loans I Transfer                    
Schedule Of Equity Method Investments [Line Items]                    
General partner interest of Navios Holdings         2.00%          
Payments to acquire investment         $ 468          
Stock Issued During Period Shares New Issues | shares         13,076,923          
Partners capital account units acquisitions | shares         266,876          
Navios Containers                    
Schedule Of Equity Method Investments [Line Items]                    
Equity in net (losses)/earnings of affiliated companies   88                
Investments in affiliates   $ 5,088           $ 5,088    
Price per share offered             $ 5      
Proceeds from private placement of units to Navios Holdings             $ 50,288      
Investements on the equity             $ 5,000      
Ownership interest             9.90%      
Navios Containers | Warrants                    
Schedule Of Equity Method Investments [Line Items]                    
Ownership interest             1.70%      
Warrants, Expected term             5 years      
Exercise price             $ 5      
Common units | Navios Containers                    
Schedule Of Equity Method Investments [Line Items]                    
Common Units issued in public offering             10,057,645      
Navios Partners                    
Schedule Of Equity Method Investments [Line Items]                    
Common Units issued in public offering 4,600,000                  
Proceeds From Issuance Of Common Limited Partners Units $ 60,214                  
Proceeds from private placement of units to Navios Holdings $ 14,967                  
Navios Partners | Navios Containers                    
Schedule Of Equity Method Investments [Line Items]                    
Ownership percentage             59.70%      
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Changes, Purchase of Interest by Parent             $ 30,000      
Navios Partners | Navios Containers | Warrants                    
Schedule Of Equity Method Investments [Line Items]                    
Ownership percentage             6.80%      
Navios Partners | Private placement | Common units                    
Schedule Of Equity Method Investments [Line Items]                    
Private placement of units to Navios Holdings 1,120,547                  
Navios Partners | Private placement | General partner units                    
Schedule Of Equity Method Investments [Line Items]                    
Private placement of units to Navios Holdings 22,868                  
Navios Partners                    
Schedule Of Equity Method Investments [Line Items]                    
General partner interest of Navios Holdings               2.00%    
General Partner units held by Navios Holdings   3,008,908           3,008,908    
Common units held by Navios Holdings   28,421,233           28,421,233    
Difference between carrying amount of investment and underlying equity in net assets of equity method investee   $ 109,751           $ 109,751   $ 112,417
Equity in net (losses)/earnings of affiliated companies   2,432       (2,421)   3,339 (1,467)  
Investments in affiliates   58,475           58,475   24,033
Dividends received   $ 0       0   $ 0 0  
Ownership percentage of Navios Holdings   20.90%           20.90%    
Market value of the investment   $ 49,974           $ 49,974    
Acropolis                    
Schedule Of Equity Method Investments [Line Items]                    
Investments in affiliates   147           147   105
Dividends received   $ 55       85   $ 55 85  
Ownership percentage of Navios Holdings   35.00%           35.00%    
Ownership Interest               50.00%    
Profit Sharing Arrangement               Navios Holdings has a 50% interest in Acropolis, a brokerage firm for freight and shipping charters. Although Navios Holdings owns 50% of Acropolis' stock, Navios Holdings agreed with the other shareholder that the earnings and amounts declared by way of dividends will be allocated 35% to the Company with the balance to the other shareholder.    
Navios Acquisition                    
Schedule Of Equity Method Investments [Line Items]                    
Difference between carrying amount of investment and underlying equity in net assets of equity method investee   $ 115,562           $ 115,562   140,131
Equity in net (losses)/earnings of affiliated companies   (6,507)       5,474   (2,575) 17,038  
Investments in affiliates   114,189           114,189   $ 124,062
Dividends received   $ 3,649       $ 3,649   $ 7,298 $ 7,298  
Ownership percentage of Navios Holdings   46.20%           46.20%    
Percentage of voting stock of Navios Holdings in Navios Acquisition               43.40%    
Market value of the investment   $ 107,277           $ 107,277    
Recognision of impairment losses               $ 22,603