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Commitments and Contingencies - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2019
Sep. 30, 2018
Sep. 30, 2019
Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]        
Minimum term of non-cancellable operating leases     1 year  
Expiration of non-cancellable operating leases maximum year     2030  
Operating lease expenses $ 0.8 $ 0.3 $ 2.3 $ 1.0
Operating lease not yet commenced     the Company had no leases that have not yet commenced.