XML 95 R64.htm IDEA: XBRL DOCUMENT v3.19.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Aug. 31, 2018
Jan. 12, 2018
Aug. 31, 2017
Aug. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Commitments And Contingencies Disclosure [Line Items]            
Lease agreement expiration date   Jan. 31, 2023     Feb. 28, 2017  
Percentage of annual increase in rent   3.00%        
Tenant incentive allowance   $ 842        
Security deposit in connection with lease         $ 209  
Rent expense         1,295 $ 335
Sub-lease Agreement [Member]            
Commitments And Contingencies Disclosure [Line Items]            
Lease agreement expiration date Oct. 31, 2020   Aug. 31, 2020      
Percentage of annual increase in rent 3.00%   3.00% 3.00%    
Security deposit in connection with lease         $ 283  
Rent expense       $ 31