Related Parties - Additional Information (Detail) - Mosaic Biosciences Inc - USD ($) $ in Millions		12 Months Ended
	May 08, 2020	Dec. 31, 2020	Jan. 10, 2020
Related Party Transaction [Line Items]
One Time Expense related to collaboration	$ 0.8
Maximum
Related Party Transaction [Line Items]
Milestone Payment Related To Regulatory And Clinical Development Events	$ 4.0
Intravitreal Anti-Complement Factor 3
Related Party Transaction [Line Items]
Payment related to collaboration		$ 3.0
Biogen Collaboration | Intravitreal Anti-Complement Factor 3
Related Party Transaction [Line Items]
Upfront license fee received from collaboration agreement			$ 15.0