Annual report pursuant to Section 13 and 15(d)

Organization and Nature of Operations - Additional Information (Details)

v3.19.1
Organization and Nature of Operations - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Thousands
12 Months Ended
Oct. 01, 2018
Dec. 31, 2018
Dec. 31, 2017
Jul. 14, 2018
Jul. 13, 2018
Organization and Nature of Operations [Line Items]          
Common stock, par value   $ 0.0001 $ 0.0001 $ 0.0001  
Common stock, shares authorized 300,000,000 300,000,000 25,000,000 25,000,000 10,000,000
Proceeds from issuance of common stock   $ 78,806 $ 10,430    
Offering costs   $ 3,556      
Preferred stock, par value $ 0.0001 $ 0.0001      
Preferred stock, shares authorized   10,000,000 0    
IPO [Member]          
Organization and Nature of Operations [Line Items]          
Common stock issued, shares 4,485,000        
Common stock, offering price per share $ 17.00        
Gross proceeds from issuance of IPO $ 76,200        
Proceeds from issuance of common stock 67,300        
Underwriting discount 5,300        
Offering costs $ 3,600        
Over Allotment Option [Member]          
Organization and Nature of Operations [Line Items]          
Common stock issued, shares 585,000