Summary of Company's Net Revenues (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net revenue	$ 60,219	$ 56,168
Logical and physical access control readers
Segment Reporting Information [Line Items]
Net revenue	18,601	17,671
Controller panels
Segment Reporting Information [Line Items]
Net revenue	14,637	14,919
Tags and transponders
Segment Reporting Information [Line Items]
Net revenue	13,089	10,890
Access cards and provisioning
Segment Reporting Information [Line Items]
Net revenue	8,396	7,107
Services
Segment Reporting Information [Line Items]
Net revenue	3,816	3,258
Third party access control products
Segment Reporting Information [Line Items]
Net revenue	1,014	1,645
Software
Segment Reporting Information [Line Items]
Net revenue	$ 666	100
Other
Segment Reporting Information [Line Items]
Net revenue		$ 578