Annual report pursuant to Section 13 and 15(d)

Capital Stock - Additional Information (Details)

v3.10.0.1
Capital Stock - Additional Information (Details) - USD ($)
1 Months Ended 12 Months Ended
Jun. 30, 2017
Dec. 31, 2018
Dec. 31, 2017
Class Of Stock [Line Items]      
Conversion of preferred stock into common stock, value     $ 42,075,000
Reclassification of convertible preferred stock warrant liability into additional paid-in capital $ 5,700,000   $ 5,711,000
Preferred stock, shares outstanding   0 0
Common stock, shares authorized   500,000,000 500,000,000
Common stock, par value   $ 0.005 $ 0.005
Common stock, shares issued   10,864,722 9,827,129
Common stock, shares outstanding   10,864,722 9,827,129
Common stock, voting rights   Holders of common stock have voting rights equal to one vote per share of common stock held  
Preferred stock, shares authorized   20,000,000 20,000,000
Preferred stock, par value   $ 0.005 $ 0.005
Preferred stock, shares issued   0 0
Convertible Preferred Stock      
Class Of Stock [Line Items]      
Preferred stock, shares outstanding   0  
Common Stock      
Class Of Stock [Line Items]      
Conversion of preferred stock into common stock, shares 4,689,753   4,689,753
Conversion of preferred stock into common stock, value     $ 23,000
Additional Paid-in Capital      
Class Of Stock [Line Items]      
Conversion of preferred stock into common stock, value     42,052,000
Reclassification of convertible preferred stock warrant liability into additional paid-in capital $ 42,100,000   $ 42,100,000