v3.19.2
Common Stock - Additional Information (Detail) - USD ($)
6 Months Ended 12 Months Ended
Jun. 30, 2019
Dec. 31, 2018
Mar. 09, 2017
Equity [Abstract]      
Common stock, shares authorized 300,000,000 300,000,000 100,000,000
Common stock, par value $ 0.0001 $ 0.0001 $ 0.0001
Dividends common stock declared or paid $ 0    
Warrants outstanding 317,562 317,562  
Warrants exercise price per share $ 5.00 $ 5.00  
Warrants term 3 years 3 years  
Warrants expiration date Mar. 15, 2020 Mar. 15, 2020