Revenues - Schedule of Revenues on Disaggregated Basis (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenues	$ 16,443	$ 12,629	$ 43,743	$ 38,883
Wireless [Member]
Disaggregation Of Revenue [Line Items]
Revenues	16,443	12,629	43,743	38,883
Wireless [Member] | License and Service Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	818	1,006	3,199	2,569
Wireless [Member] | Hosted Environment Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	3,475	4,554	11,573	13,444
Wireless [Member] | Cloud Based Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues	11,446	6,068	27,047	20,420
Wireless [Member] | Consulting Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 704	$ 1,001	$ 1,924	$ 2,450