Revenue Recognition - Schedule of Disaggregated Revenue By Major Product Line in Single Reporting Segment (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Total	$ 6,497	$ 6,180	$ 12,686	$ 11,840
Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,892	3,575	7,630	7,389
Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	2,605	2,605	5,056	4,451
Government [Member]
Disaggregation Of Revenue [Line Items]
Total	4,074	3,873	8,117	7,935
Government [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,713	3,530	7,365	7,164
Government [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	361	343	752	771
Retail [Member]
Disaggregation Of Revenue [Line Items]
Total	1,573	1,425	2,834	2,169
Retail [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	179	45	265	225
Retail [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	1,394	1,380	2,569	1,944
Media [Member]
Disaggregation Of Revenue [Line Items]
Total	850	882	1,735	1,736
Media [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	0	0	0	0
Media [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	$ 850	$ 882	$ 1,735	$ 1,736