Revenue - Additional Information (Detail) - USD ($)	1 Months Ended				3 Months Ended		6 Months Ended
	Feb. 29, 2020	Jan. 31, 2020	Aug. 31, 2019	Nov. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					$ 4,122,000	$ 7,210,000	$ 11,611,000	$ 9,222,000
Icon Bioscience Inc [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Sales-based royalty expense					0		400,000
Amended Alimera Science Inc Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					386,000	505,000	1,200,000	1,100,000
Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Receipt of upfront license fee	$ 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
Deferred revenue					0		0		$ 0
Ocumension Therapeutics [Member] | Maximum [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Product supply milestones and development milestones							7,250,000
Royalty Income [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					381,000	500,000	1,163,000	1,220,000
Royalty Income [Member] | Amended Alimera Science Inc Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					381,000	500,000	1,200,000	1,000,000.0
License and Collaboration Agreement [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					35,000	5,000	2,055,000	70,000
License and Collaboration Agreement [Member] | Ocumension Therapeutics [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					30,000		2,000,000.0
Collaborative Research and Development [Member]
Disclosure of Product Revenue Reserves and Allowances [Line Items]
Revenue					0	$ 0	0	$ 15,000
Deferred revenue					$ 0		$ 0		$ 15,000