Revenue Recognition - Schedule of Disaggregated Revenue By Major Product Line in Single Reporting Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Total	$ 7,411	$ 6,700
Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,620	3,784
Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	3,791	2,916
Government [Member]
Disaggregation Of Revenue [Line Items]
Total	3,572	3,885
Government [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,272	3,585
Government [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	300	300
Commercial [Member]
Disaggregation Of Revenue [Line Items]
Total	3,839	2,815
Commercial [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	348	199
Commercial [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	$ 3,491	$ 2,616