Segment Information - Geographical Segment Revenue (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue		$ 26,520	$ 23,990
Domestic [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue		6,675	7,419
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	[1]	$ 19,845	$ 16,571

[1] Revenue from the Central Banks, consisting of a consortium of central banks around the world, is classified as international revenue. Reporting revenue by country for this customer is not practicable.