Restructuring and Severance - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	$ 388,000	$ 65,000
Impairment of right-of-use operating lease asset	281,000
3VR
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	388,000
3VR | Facility Rental
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	329,000
Impairment of right-of-use operating lease asset	281,000
3VR | Severance
Restructuring Cost And Reserve [Line Items]
Restructuring and severance expenses	$ 59,000	$ 65,000