Restructuring Charges - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 590,000
Employee Severance [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	590,000
DEXYCU [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 590,000
DEXYCU [Member] | Sales and Marketing Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges		542,000
DEXYCU [Member] | General and Administrative Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges		$ 48,000
DEXYCU [Member] | Employee Severance [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 590,000