Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	1 Months Ended			3 Months Ended		6 Months Ended
	Aug. 31, 2020	Feb. 29, 2020	Nov. 30, 2018	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Ocumension Therapeutics [Member]
Schedule Of Significant Accounting Policies [Line Items]
Receipt of upfront license fee	$ 9,500,000	$ 2,000,000.0	$ 1,750,000
Icon Bioscience Inc [Member] | Ocumension Therapeutics [Member]
Schedule Of Significant Accounting Policies [Line Items]
Receipt of upfront license fee		$ 2,000,000.0
DEXYCU [Member]
Schedule Of Significant Accounting Policies [Line Items]
Accrued revenue-based royalty expense				$ 648,000	$ 99,000	$ 1,100,000	$ 616,000
DEXYCU [Member] | Icon Bioscience Inc [Member]
Schedule Of Significant Accounting Policies [Line Items]
Accrued revenue-based royalty expense						$ 0	$ 400,000
Percentage of earn-out payment received		20.00%