Annual report pursuant to Section 13 and 15(d)

Basis of Presentation - Additional Information (Detail)

v3.8.0.1
Basis of Presentation - Additional Information (Detail) - USD ($)
3 Months Ended 12 Months Ended
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2016
Sep. 30, 2016
Jun. 30, 2016
Mar. 31, 2016
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2013
Dec. 31, 2012
Organization, Consolidation and Presentation of Financial Statements [Abstract]                        
Net loss $ 1,460,733 $ 2,067,230 $ 1,220,866 $ 1,982,696 $ 2,674,797 $ 1,963,007 $ 312,615 $ 2,062,885 $ 6,731,525 $ 7,013,304    
Cash used in operations                 6,363,853 7,075,085    
Accumulated deficit $ (101,400,797)       $ (94,669,272)       (101,400,797) (94,669,272)    
Gross proceeds from issuance of preferred and common stock                 $ 9,684,799 $ 4,666,667 $ 14,900,000 $ 13,000,000