Fair Value of Financial Instruments (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2019
Jun. 30, 2019
Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Impairment loss   $ 1,280  
Navios Acquisition      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Other than temporary impairment loss on investments $ 13,543    
Navios Partners      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Other than temporary impairment loss on investments     $ 55,524
Two vessels      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Vessel impairment loss $ 9,998    
Four vessels      
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]      
Impairment loss     $ 179,186