Revenue Recognition - Schedule of Disaggregated Revenue By Major Product Line in Single Reporting Segment (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Disaggregation Of Revenue [Line Items]
Total	$ 26,520	$ 23,990
Service [Member]
Disaggregation Of Revenue [Line Items]
Total	15,006	13,881
Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	11,514	10,109
Government [Member]
Disaggregation Of Revenue [Line Items]
Total	14,398	14,663
Government [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	13,198	13,263
Government [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	1,200	1,400
Retail [Member]
Disaggregation Of Revenue [Line Items]
Total	12,122	9,327
Retail [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	1,808	618
Retail [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	$ 10,314	$ 8,709