Property and Equipment, Net - Summary of Property and Equipment, Net (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,270	$ 3,491
Less accumulated depreciation and amortization	(2,802)	(2,811)
Property and equipment, net	468	680
Laboratory equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	513	679
Software and computer equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	377	383
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	440	450
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	48	83
Vehicles [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	302	306
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,590	$ 1,590