Segment, Customer Concentration and Geographical Information - Wireless Revenues by Product (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue from External Customer [Line Items]
Total revenues	$ 12,933	$ 10,854	$ 26,255	$ 19,286
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	12,701	10,637	25,916	18,809
Wireless [Member] | SafePath [Member]
Revenue from External Customer [Line Items]
Total revenues	7,344	3,775	15,193	5,909
Wireless [Member] | CommSuite [Member]
Revenue from External Customer [Line Items]
Total revenues	4,330	4,998	8,869	9,355
Wireless [Member] | ViewSpot [Member]
Revenue from External Customer [Line Items]
Total revenues	971	1,356	1,716	2,413
Wireless [Member] | Netwise [Member]
Revenue from External Customer [Line Items]
Total revenues	31	461	86	999
Wireless [Member] | Other [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 25	$ 47	$ 52	$ 133