Revenues - Schedule of Revenues on Disaggregated Basis (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019
Disaggregation Of Revenue [Line Items]
Revenues	$ 12,416	$ 12,629	$ 12,933	$ 13,322	$ 12,278	$ 11,782	$ 10,854	$ 8,432	$ 51,300	$ 43,346
Wireless [Member]
Disaggregation Of Revenue [Line Items]
Revenues									50,671	42,604
Wireless [Member] | License and Service Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues									3,575
Wireless [Member] | Hosted Environment Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues									18,209	19,517
Wireless [Member] | Cloud Based Usage Fees [Member]
Disaggregation Of Revenue [Line Items]
Revenues									25,973	20,011
Wireless [Member] | Consulting Services and Other [Member]
Disaggregation Of Revenue [Line Items]
Revenues									2,914	3,076
Graphics [Member] | Software [Member]
Disaggregation Of Revenue [Line Items]
Revenues									$ 629	$ 742