Quarterly report pursuant to Section 13 or 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.19.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
3 Months Ended
Mar. 31, 2019
Mar. 31, 2018
Commitments And Contingencies [Line Items]    
Operating lease remaining lease term 2 years 6 months  
Operating lease beginning date Mar. 01, 2014  
Operating lease ending date Jul. 31, 2019  
Rent expense $ 51,000 $ 19,000
Minimum [Member]    
Commitments And Contingencies [Line Items]    
Operating lease remaining lease term 1 year  
Maximum [Member]    
Commitments And Contingencies [Line Items]    
Operating lease remaining lease term 3 years