Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended
	Jun. 30, 2014 milestone_payment	Sep. 30, 2021 USD ($)	Jan. 01, 2021	Dec. 31, 2020 USD ($)	Jan. 01, 2020 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lease extension term period			8 years 2 months
Operating lease, right-of-use asset increase amount					$ 13,000
Operating leases right-of-use assets		$ 18,316		$ 15,228
Less operating lease liability, current portion		3,822		2,033
Operating lease liability, less current portion		$ 17,876		$ 16,069
Number of milestone payments | milestone_payment	6