v3.19.3
Property and Equipment - Additional Information (Detail) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Property Plant And Equipment [Abstract]        
Depreciation and amortization expense $ 140 $ 51 $ 374 $ 140