Segment, Customer Concentration and Geographical Information - Wireless Revenues by Product (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue from External Customer [Line Items]
Total revenues	$ 13,322	$ 8,432
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	13,215	8,172
Wireless [Member] | SafePath [Member]
Revenue from External Customer [Line Items]
Total revenues	7,848	1,987
Wireless [Member] | CommSuite [Member]
Revenue from External Customer [Line Items]
Total revenues	4,539	4,357
Wireless [Member] | ViewSpot [Member]
Revenue from External Customer [Line Items]
Total revenues	745	1,057
Wireless [Member] | Netwise [Member]
Revenue from External Customer [Line Items]
Total revenues	55	538
Wireless [Member] | Other [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 28	$ 233