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Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)
1 Months Ended 3 Months Ended 6 Months Ended
May 31, 2016
Jun. 30, 2016
Jun. 30, 2015
Jun. 30, 2016
Jun. 30, 2015
Property, Plant and Equipment [Line Items]          
Short-term investment maturity period       Three months or less  
Weighted average number of common shares outstanding   7,544,345 7,469,455 7,542,728 7,340,272
Odyssey Explorer [Member]          
Property, Plant and Equipment [Line Items]          
Cash proceeds from sale of vessel $ 200,000        
Vessel In-kind [Member]          
Property, Plant and Equipment [Line Items]          
Value of vessel received in-kind $ 350,000        
Minimum [Member]          
Property, Plant and Equipment [Line Items]          
Property and Equipment, estimated useful life       3 years  
Maximum [Member]          
Property, Plant and Equipment [Line Items]          
Property and Equipment, estimated useful life       30 years