Notes Payable - Additional Information (Details) - Amended Credit Facility $ in Thousands	1 Months Ended
	Mar. 31, 2017 USD ($) tranche
Notes Payable
Outstanding borrowings under credit facility	$ 18,000
Repayments of debt	14,300
Net proceeds from credit facility	$ 3,700
Number of tranches | tranche	2
Tranche one, amount contingent upon the achievement of regulatory and commercial milestones related to DEXTENZA	$ 10,000
Tranche two, amount contingent upon the achievement of regulatory and commercial milestones related to DEXTENZA	10,000
Borrowing capacity under the agreement	$ 38,000
Final payment due (as a percent)	3.50%
Outstanding borrowings, Effective annual interest rate (as a percent)	10.50%
Additional final payment	$ 630
LIBOR
Notes Payable
Interest rate floor (as a percent)	1.00%
Basis spread (as a percent)	7.25%
Indicative interest rate (as a percent)	8.25%