Segment, Customer Concentration and Geographical Information - Wireless Revenues by Product (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue from External Customer [Line Items]
Total revenues	$ 11,001	$ 11,699	$ 32,269	$ 37,108
Wireless
Revenue from External Customer [Line Items]
Total revenues	11,001	11,699	32,269	37,108
Wireless | Family Safety
Revenue from External Customer [Line Items]
Total revenues	9,179	9,640	27,016	30,173
Wireless | CommSuite
Revenue from External Customer [Line Items]
Total revenues	749	1,070	2,310	3,932
Wireless | ViewSpot
Revenue from External Customer [Line Items]
Total revenues	$ 1,073	$ 989	$ 2,943	$ 3,003