Restructuring and Severance - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	$ 65,000	$ (12,000)
Sublease income received	200,000
3VR
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	65,000
3VR | Facility Rental
Restructuring Cost And Reserve [Line Items]
Sublease income received	190,000
3VR | Severance
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	$ 64,000