Segment, Concentration and Geographical Information - Wireless Revenues by Product Line (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue from External Customer [Line Items]
Total revenues	$ 58,422	$ 51,300
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	58,422	50,671
Wireless [Member] | CommSuite [Member]
Revenue from External Customer [Line Items]
Total revenues	13,717	18,163
Wireless [Member] | SafePath [Member]
Revenue from External Customer [Line Items]
Total revenues	40,981	28,027
Wireless [Member] | ViewSpot [Member]
Revenue from External Customer [Line Items]
Total revenues	3,558	4,239
Wireless [Member] | Netwise [Member]
Revenue from External Customer [Line Items]
Total revenues	117	151
Wireless [Member] | Other [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 49	$ 91