Revenues - Schedule of Revenues on Disaggregated Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenues	$ 15,919	$ 12,933	$ 27,300	$ 26,255
Wireless [Member]
Disaggregation Of Revenue [Line Items]
Revenues	15,919	12,933	27,300	26,255
Wireless [Member] | License and Service Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	795	1,008	2,382	1,563
Wireless [Member] | Hosted Environment Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	3,956	4,341	8,097	8,890
Wireless [Member] | Cloud Based Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	10,555	6,705	15,602	14,352
Wireless [Member] | Consulting Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 613	$ 879	$ 1,219	$ 1,450