Goodwill and Intangible Assets - Intangible Assets Other than Goodwill (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Indefinite-lived Intangible Assets [Line Items]
Not amortized intangible assets, Carrying Amount	$ 2,175	$ 1,945
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	24,409	15,798
Accumulated Amortization	(5,826)	(2,525)
Total	18,583	13,273
Intangible assets, Gross Carrying Amount	26,584	17,743
Intangible assets, Net Carrying Amount	20,758	15,218
TASER trademark
Indefinite-lived Intangible Assets [Line Items]
Not amortized intangible assets, Carrying Amount	900	900
Patents and trademarks pending
Indefinite-lived Intangible Assets [Line Items]
Not amortized intangible assets, Carrying Amount	1,275	1,045
Domain names
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	3,161	3,161
Accumulated Amortization	(352)	(125)
Total	$ 2,809	3,036
Domain names | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	5 years
Domain names | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	10 years
Issued patents
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	$ 1,985	1,942
Accumulated Amortization	(874)	(780)
Total	$ 1,111	1,162
Issued patents | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	4 years
Issued patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	15 years
Issued trademarks
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	$ 714	655
Accumulated Amortization	(378)	(320)
Total	$ 336	335
Issued trademarks | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	3 years
Issued trademarks | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	11 years
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	$ 1,374	914
Accumulated Amortization	(389)	(240)
Total	$ 985	674
Customer relationships | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	4 years
Customer relationships | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	8 years
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	$ 555	465
Accumulated Amortization	(317)	(236)
Total	$ 238	229
Non-compete agreements | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	3 years
Non-compete agreements | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	4 years
Developed technology
Finite-Lived Intangible Assets [Line Items]
Amortized intangible assets, Gross Carrying Amount	$ 14,480	8,661
Accumulated Amortization	(3,159)	(824)
Total	$ 11,321	7,837
Developed technology | Minimum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	3 years
Developed technology | Maximum
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	7 years
Re-acquired distribution rights
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangible asset, useful life	2 years
Amortized intangible assets, Gross Carrying Amount	$ 2,140	0
Accumulated Amortization	(357)	0
Total	$ 1,783	$ 0