Quarterly report pursuant to Section 13 or 15(d)

Leases - Additional Information (Detail)

v3.19.1
Leases - Additional Information (Detail)
$ in Millions
3 Months Ended
Mar. 31, 2019
USD ($)
ft²
Facility
Mar. 31, 2018
USD ($)
Lessee Lease Description [Line Items]    
Weighted average remaining lease term 4 years 9 months 18 days  
Lease, option to extend option to extend for an additional 5 years  
Weighted average lease discount rate 12.60%  
Rent expenses   $ 0.1
Operating Expense [Member]    
Lessee Lease Description [Line Items]    
Lease costs $ 0.1  
Lease Facility [Member]    
Lessee Lease Description [Line Items]    
Number of leased facilities | Facility 1  
Area of office space | ft² 17,698  
Lease start date Jan. 16, 2014