Investment in affiliates and available-for-sale securities - Navios Containers (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2020
Jun. 30, 2019
Jun. 30, 2020
Jun. 30, 2019
Dec. 31, 2019
Investments In And Advances To Affiliates [Line Items]          
Equity in net (losses)/ earnings of affiliated companies $ 9,445 $ (16,779) $ 3,308 $ (12,502)  
Investments in affiliates 63,498 $ 72,512 63,498 $ 72,512 $ 64,352
Navios Containers          
Investments In And Advances To Affiliates [Line Items]          
Equity in net (losses)/ earnings of affiliated companies (77)   105    
Investments in affiliates 2,787   2,787   $ 2,682
Market value of the investment $ 1,023   $ 1,023