Revenues - Schedule of Revenues on Disaggregated Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 11,782	$ 6,525	$ 31,068	$ 18,933
Wireless [Member]
Disaggregation Of Revenue [Line Items]
Revenues	11,614	6,283	30,422	17,605
Wireless [Member] | CommSuite & Netwise [Member]
Disaggregation Of Revenue [Line Items]
Revenues	4,916	4,958	14,863	13,721
Wireless [Member] | SafePath [Member]
Disaggregation Of Revenue [Line Items]
Revenues	5,200	1,028	11,108	2,106
Wireless [Member] | ViewSpot [Member]
Disaggregation Of Revenue [Line Items]
Revenues	450		1,971
Wireless [Member] | Consulting Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	1,035	287	2,442	1,485
Wireless [Member] | Legacy Software Licenses [Member]
Disaggregation Of Revenue [Line Items]
Revenues	13	10	38	293
Graphics [Member]
Disaggregation Of Revenue [Line Items]
Revenues	168	242	646	1,328
Graphics [Member] | Software [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 168	$ 242	$ 646	$ 1,328