Revenue, Deferred Revenue And Prepaid Commissions - Additional Information and Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2022 USD ($) revenue_component	Mar. 31, 2021 USD ($)
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 33,825	$ 36,036
Deferred revenue recognized from previous period	9,700
United States
Revenues from External Customers and Long-Lived Assets
Total revenue	32,772	35,174
International
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 1,053	862
Wireless revenue
Revenues from External Customers and Long-Lived Assets
Revenue primary component | revenue_component	2
Total revenue	$ 18,846	20,120
Paging revenue
Revenues from External Customers and Long-Lived Assets
Total revenue	18,313	19,353
Product and other revenue
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 533	767
Software revenue
Revenues from External Customers and Long-Lived Assets
Revenue primary component | revenue_component	2
Total revenue	$ 14,979	15,916
License
Revenues from External Customers and Long-Lived Assets
Total revenue	1,824	1,552
Professional services
Revenues from External Customers and Long-Lived Assets
Total revenue	3,336	4,354
Hardware
Revenues from External Customers and Long-Lived Assets
Total revenue	589	616
Operations revenue
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 5,749	6,522
Maintenance
Revenues from External Customers and Long-Lived Assets
Typical duration of revenue recognition	Maintenance revenue is for ongoing support of our software solutions or related equipment and access to when-and-if available software updates.
Total revenue	$ 9,230	$ 9,394