Deferred Revenue - Summary of Deferred Revenue (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Deferred Revenue Arrangement [Line Items]
Current	$ 60,453	$ 45,137
Long-Term	51,574	40,054
Total	112,027	85,191
Warranty
Deferred Revenue Arrangement [Line Items]
Current	17,282	13,959
Long-Term	21,967	20,245
Total	39,249	34,204
Hardware
Deferred Revenue Arrangement [Line Items]
Current	16,723	11,552
Long-Term	23,923	15,595
Total	40,646	27,147
Software and Sensor Services
Deferred Revenue Arrangement [Line Items]
Current	26,448	19,626
Long-Term	5,684	4,214
Total	32,132	23,840
TASER Weapons
Deferred Revenue Arrangement [Line Items]
Current	13,803	11,682
Long-Term	27,730	21,709
Total	41,533	33,391
TASER Weapons | Warranty
Deferred Revenue Arrangement [Line Items]
Current	10,622	9,980
Long-Term	17,156	17,319
Total	27,778	27,299
TASER Weapons | Hardware
Deferred Revenue Arrangement [Line Items]
Current	3,181	1,702
Long-Term	10,574	4,390
Total	13,755	6,092
Software and Sensors
Deferred Revenue Arrangement [Line Items]
Current	46,650	33,455
Long-Term	23,844	18,345
Total	70,494	51,800
Software and Sensors | Warranty
Deferred Revenue Arrangement [Line Items]
Current	6,660	3,979
Long-Term	4,811	2,926
Total	11,471	6,905
Software and Sensors | Hardware
Deferred Revenue Arrangement [Line Items]
Current	13,542	9,850
Long-Term	13,349	11,205
Total	$ 26,891	$ 21,055