Segments and Geographic Information - Summary of Significant Revenues in Following Regions (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 7,176	$ 7,128
North America [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	5,980	6,277
Asia [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	806	538
Europe [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	345	290
All Other Regions [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues	$ 45	$ 23