Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended			3 Months Ended
	Aug. 31, 2018	Oct. 31, 2016	Jun. 30, 2016	Mar. 31, 2021	Jan. 31, 2017
Carna Collaboration Agreement [Member]
Loss Contingencies [Line Items]
Upfront payment paid			$ 0.9
Upfront License Fee				$ 0.3
Asset Purchase Agreement [Member]
Loss Contingencies [Line Items]
Upfront payment paid	$ 3.0
Aggregate milestone payment				190.0
CPF License Agreements [Member]
Loss Contingencies [Line Items]
Upfront payment paid		$ 7.0
Milestone payment					$ 2.0
Additional milestone payment payable				319.5
CPF License Agreements [Member] | First patient first trial post amendment [Member]
Loss Contingencies [Line Items]
Milestone payment				2.0
CPF License Agreement Amendment [Member]
Loss Contingencies [Line Items]
Aggregate milestone payment				$ 290.0