Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation - Additional Information (Detail)

v3.10.0.1
Basis of Presentation - Additional Information (Detail) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Jun. 30, 2018
Jun. 30, 2017
Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]          
Revenues     $ 0    
Net loss $ 2,281,289 $ 1,220,866 4,400,686 $ 3,203,562  
Cash used in operations     3,647,459 $ 3,665,508  
Accumulated deficit $ 105,860,153   $ 105,860,153   $ 101,400,797