Revenue, Deferred Revenue And Prepaid Commissions - Additional Information and Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) revenue_component	Mar. 31, 2019 USD ($)
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 37,267	$ 41,764
Deferred revenue recognized from previous period	11,800
Remaining performance obligation	49,000
United States
Revenues from External Customers and Long-Lived Assets
Total revenue	36,503	39,766
International
Revenues from External Customers and Long-Lived Assets
Total revenue	764	1,998
Wireless products and services
Revenues from External Customers and Long-Lived Assets
Total revenue	21,386	22,610
License
Revenues from External Customers and Long-Lived Assets
Total revenue	955	2,840
Services
Revenues from External Customers and Long-Lived Assets
Total revenue	4,549	5,206
Hardware
Revenues from External Customers and Long-Lived Assets
Total revenue	$ 725	963
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	$ 9,652	$ 10,145
Wireless
Revenues from External Customers and Long-Lived Assets
Revenue primary component | revenue_component	2
Software
Revenues from External Customers and Long-Lived Assets
Revenue primary component | revenue_component	2