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Stockholders' Equity - Additional Information (Detail) - USD ($)
 1 Months Ended 3 Months Ended
Feb. 28, 2018
Jan. 31, 2018
Mar. 31, 2019
Mar. 31, 2018
Feb. 15, 2018
Stockholders Equity [Line Items]          
Gross proceeds on sale of shares of common stock       $ 1,100,000  
Issuance costs     $ 237,403    
Common stock, shares issued and sold (in shares) 5,000,000   0 375,000  
Price per share (in usd per share) $ 0.70        
Class of warrant or right exercisable period 5 years        
Warrants exercised (in shares)     0 0  
Accounting Standards Update 2017-11 [Member]          
Stockholders Equity [Line Items]          
Estimated fair value of warrants, recorded in equity         $ 3,000,000
Maximum [Member]          
Stockholders Equity [Line Items]          
Gross proceeds on sale of shares of common stock   $ 10,000,000      
Aggregate commission rate   3.00%      
Warrants to purchase common stock (in shares) 3,500,000.0        
Underwritten Offering [Member]          
Stockholders Equity [Line Items]          
Underwriters overallotment option to purchase additional shares of common stock and warrants period 30 days        
Gross proceeds from offering of common stock and warrants $ 10,300,000        
Proceeds from offering of common stock and warrants, net of costs $ 9,400,000        
Exercise price (in usd per share) $ 3.00        
Underwritten Offering [Member] | Maximum [Member]          
Stockholders Equity [Line Items]          
Common stock, shares issued and sold (in shares) 220,500        
Warrants to purchase common stock (in shares) 525,000        
Underwriters option to purchase additional shares (in shares) 750,000