Revenue Recognition - Schedule of Disaggregated Revenue By Major Product Line in Single Reporting Segment (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Disaggregation Of Revenue [Line Items]
Total	$ 6,189	$ 5,660
Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,738	3,814
Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	2,451	1,846
Government [Member]
Disaggregation Of Revenue [Line Items]
Total	4,043	4,062
Government [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	3,652	3,634
Government [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	391	428
Retail [Member]
Disaggregation Of Revenue [Line Items]
Total	1,261	744
Retail [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	86	180
Retail [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	1,175	564
Media [Member]
Disaggregation Of Revenue [Line Items]
Total	885	854
Media [Member] | Service [Member]
Disaggregation Of Revenue [Line Items]
Total	0	0
Media [Member] | Subscription [Member]
Disaggregation Of Revenue [Line Items]
Total	$ 885	$ 854