Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 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	$ 0.9	$ 0.3	$ 1.5	$ 0.7
Operating lease not yet commenced			the Company had no leases that have not yet commenced.