Segment, Customer Concentration and Geographical Information - Wireless Revenues by Product (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Revenue from External Customer [Line Items]
Total revenues	$ 12,278	$ 11,782	$ 10,854	$ 8,432	$ 7,352	$ 6,525	$ 6,945	$ 5,463	$ 43,346	$ 26,285
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 12,181	$ 11,614	$ 10,637	$ 8,172	$ 6,869	$ 6,283	$ 6,506	$ 4,816	42,604	24,474
Wireless [Member] | CommSuite [Member]
Revenue from External Customer [Line Items]
Total revenues									18,713	17,760
Wireless [Member] | SafePath [Member]
Revenue from External Customer [Line Items]
Total revenues									17,782	3,327
Wireless [Member] | ViewSpot [Member]
Revenue from External Customer [Line Items]
Total revenues									4,229
Wireless [Member] | Netwise [Member]
Revenue from External Customer [Line Items]
Total revenues									1,642	3,104
Wireless [Member] | Other [Member]
Revenue from External Customer [Line Items]
Total revenues									$ 238	$ 283