Segment data - Summary of Operational Information Relative to the Company's Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Product sales	$ 36,268	$ 31,842	$ 71,781	$ 62,025
Service revenue	907	333	1,579	584
Net sales	37,175	32,175	73,360	62,609
Cost of products sold	13,423	11,766	26,997	23,171
Cost of services delivered	538	667	941	1,245
Gross margin	23,214	19,742	45,422	38,193
Sales, general and administrative expenses	13,547	10,941	27,293	22,122
Research and development expenses	3,455	1,992	7,061	4,005
Income (loss) from operations	6,212	6,809	11,068	12,066
Purchases of property and equipment	423	456	1,222	839
Purchases of intangible assets	42	99	109	202
Depreciation and amortization	1,105	1,530	2,267	2,948
TASER Weapons [Member]
Segment Reporting Information [Line Items]
Product sales	32,675	30,272	65,150	58,275
Net sales	32,675	30,272	65,150	58,275
Cost of products sold	10,663	10,410	21,581	20,627
Gross margin	22,012	19,862	43,569	37,648
Sales, general and administrative expenses	10,901	9,418	22,190	19,491
Research and development expenses	793	976	1,610	1,966
Income (loss) from operations	10,318	9,468	19,769	16,191
Purchases of property and equipment	336	344	1,033	598
Purchases of intangible assets	42	90	109	195
Depreciation and amortization	990	974	2,068	1,972
Evidence.com & Video [Member]
Segment Reporting Information [Line Items]
Product sales	3,593	1,570	6,631	3,750
Service revenue	907	333	1,579	584
Net sales	4,500	1,903	8,210	4,334
Cost of products sold	2,760	1,356	5,416	2,544
Cost of services delivered	538	667	941	1,245
Gross margin	1,202	(120)	1,853	545
Sales, general and administrative expenses	2,646	1,523	5,103	2,631
Research and development expenses	2,662	1,016	5,451	2,039
Income (loss) from operations	(4,106)	(2,659)	(8,701)	(4,125)
Purchases of property and equipment	87	112	189	241
Purchases of intangible assets		9		7
Depreciation and amortization	$ 115	$ 556	$ 199	$ 976