Leases - Summary of Lease, Cost (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Operating leases
Operating lease cost	$ 38,000		$ 76,000
Less: sublease income	(16,000)	$ (19,000)	(32,000)	$ (28,000)
Operating lease expense	22,000		44,000
Short-term lease rent expense	5,000		10,000
Total rent expense	$ 27,000	$ 40,000	$ 54,000	$ 67,000