Transactions with Related Parties (Details) - USD ($)
$ in Thousands
4 Months Ended 8 Months Ended 12 Months Ended
Dec. 31, 2019
Apr. 30, 2016
Aug. 30, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Apr. 30, 2021
Oct. 30, 2020
Nov. 30, 2012
General and administrative expenses       $ 33,702 $ 36,194 $ 26,640        
Other long-term liabilities and deferred income $ 5,958     660 5,958          
Goldland Anonymos Eteria                    
Annual lease payments of office       0            
Acropolis                    
Commissions paid         0 0 $ 0      
Trade accounts payable 76     76 76          
NSM                    
General and administrative expenses 2,952     $ 9,371            
Administrative services agreement term in years       5 years            
Navios Partners Agreement                    
Maximum payout of company under Navios Partner's guarantee                   $ 20,000
Navios Partners Agreement | Guarantee claim                    
Trade accounts payable               $ 5,000 $ 5,000  
Other long-term liabilities and deferred income 10,000     $ 5,000 $ 10,000          
Navios Logistics Agreement                    
General and administrative expenses $ 381   $ 763 $ 1,144   $ 1,000        
Termination date of the administrative services agreement   December 2021