Quarterly report pursuant to Section 13 or 15(d)

Leases - Additional Information (Detail)

v3.19.2
Leases - Additional Information (Detail)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2019
USD ($)
Facility
Jun. 30, 2018
USD ($)
Jun. 30, 2019
USD ($)
ft²
Facility
Jun. 30, 2018
USD ($)
Lessee Lease Description [Line Items]        
Weighted average remaining lease term 4 years 7 months 6 days   4 years 7 months 6 days  
Lease, option to extend     option to extend for an additional 5 years  
Weighted average lease discount rate 12.60%   12.60%  
Operating lease right-of-use asset $ 199   $ 199  
Operating lease liability 2,327   2,327  
Short term portion of operating lease liability $ 373   $ 373  
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List] us-gaap:OtherAccruedLiabilitiesCurrent   us-gaap:OtherAccruedLiabilitiesCurrent  
Long-term portion of operating lease liability $ 1,954   $ 1,954  
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List] us-gaap:OperatingLeaseLiabilityNoncurrent   us-gaap:OperatingLeaseLiabilityNoncurrent  
Rent expenses   $ 100   $ 200
Operating Expense [Member]        
Lessee Lease Description [Line Items]        
Lease costs $ 100   $ 200  
Lease Facility [Member]        
Lessee Lease Description [Line Items]        
Number of leased facilities | Facility 1   1  
Area of office space | ft²     17,698  
Lease start date     Jan. 16, 2014