Balance Sheet Items - Summary of Property and Equipment (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 107	$ 93
Less: accumulated depreciation	(41)	(36)
Property, and equipment, net	66	57
Furniture and Fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	78	78
Leasehold Improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	14	15
Other Property and Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 15	$ 0

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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