Revenue - Additional Information (Detail) - USD ($)			1 Months Ended					3 Months Ended
	Dec. 31, 2020	Dec. 17, 2020	Aug. 31, 2020	Feb. 29, 2020	Jan. 31, 2020	Aug. 31, 2019	Nov. 30, 2018	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenue								$ 9,294,000	$ 7,323,000
Ocumension Therapeutics [Member]
Disaggregation Of Revenue [Line Items]
Receipt of upfront license fee			$ 9,500,000	$ 2,000,000.0			$ 1,750,000
Potential future payments based on achievement of development and regulatory milestones			6,000,000.0		$ 6,000,000.0			7,250,000
Potential future payments based on achievement of commercial-based milestones			6,000,000.0		$ 6,000,000.0			3,000,000.0
Development milestone payment received						$ 1,000,000.0
Potential future payments based on achievement of combined remaining development and sales milestone			11,750,000
Potential future payments based on achievement of remaining development and regulatory milestones			6,250,000
Potential future payments based on achievement of remaining commercial-based milestones			3,000,000.0
Ocumension Therapeutics [Member] | Share Offering [Member]
Disaggregation Of Revenue [Line Items]
Issuance of stock, net of issue costs, shares	3,010,722
Ocumension Therapeutics [Member] | Maximum [Member]
Disaggregation Of Revenue [Line Items]
Product supply milestones and development milestones								7,250,000
Upon achievement of milestones			$ 21,250,000
RPA [Member] | SWK [Member]
Disaggregation Of Revenue [Line Items]
Upfront cash payment		$ 16,500,000
Revenue								225,000	180,000
Royalty payments								724,000	583,000
Royalty Sale Agreement [Member] | SWK [Member]
Disaggregation Of Revenue [Line Items]
Deferred revenue		$ 16,500,000
Deferred revenue, current								1,100,000	1,100,000
Deferred revenue, non-current								14,300,000	14,600,000
Product [Member]
Disaggregation Of Revenue [Line Items]
Revenue								9,010,000	6,802,000
Product [Member] | Ocumension Therapeutics [Member]
Disaggregation Of Revenue [Line Items]
Revenue								56,000	5,000
License and Collaboration Revenue [Member] | Ocumension Therapeutics [Member]
Disaggregation Of Revenue [Line Items]
Revenue								59,000	268,000
Collaborative Research and Development [Member]
Disaggregation Of Revenue [Line Items]
Revenue								$ 0	$ 60,000