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	Mar. 31, 2019	Nov. 30, 2018	Mar. 31, 2021	Mar. 31, 2020
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									$ 7,323,000	$ 7,489,000
Icon Bioscience Inc [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Accrued sales-based royalty expense									$ 0	400,000
Percentage of upfront payment received									20.00%
Amended Alimera Science Inc Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									$ 13,000	817,000
Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [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			7,250,000
Potential future payments based on achievement of commercial-based milestones					$ 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 extinguished			11,750,000
Potential future payments extinguished upon achievement of prescribed remaining development and regulatory milestone			6,250,000
Potential future payments extinguished upon achievement of prescribed remaining commercial sales based milestones			3,000,000.0
Potential future payments extinguished upon achievement of prescribed development and regulatory milestones			6,000,000.0
Potential future payments extinguished upon achievement of prescribed commercial sales based milestone			6,000,000.0
Ocumension Therapeutics [Member] | Icon Bioscience Inc [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Receipt of upfront license fee				$ 2,000,000
Ocumension Therapeutics [Member] | Share Offering [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Issuance of stock, net of issue costs, shares	3,010,722
Ocumension Therapeutics [Member] | Maximum [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Product supply milestones and development milestones							$ 7,250,000
Upon achievement of milestones			$ 21,250,000
Royalty Income [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									180,000	782,000
Royalty Income [Member] | Amended Alimera Science Inc Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									0	782,000
RPA [Member] | SWK [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									180,000	0
Upfront cash payment		$ 16,500,000
Deferred revenue		$ 16,500,000
Royalty payments									583,000
Royalty Sale Agreement | SWK [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Deferred revenue, current									973,000	885,000
Deferred revenue, non-current									15,300,000	15,600,000
Technical Assistance [Member] | Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									268,000
License and Collaboration Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									341,000	2,020,000
License and Collaboration Agreement [Member] | Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue										2,000,000
Product [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									6,802,000	4,687,000
Product [Member] | Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									5,000	0
Collaborative Research and Development [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue									60,000	$ 15,000
Deferred revenue	$ 60,000								$ 0