Segment data - Summary of Operational Information Relative to the Company's Reportable Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Product sales	$ 43,191	$ 34,730	$ 114,972	$ 96,755
Service revenue	1,158	467	2,737	1,051
Net sales	44,349	35,197	117,709	97,806
Cost of products sold	15,138	12,804	42,135	35,975
Cost of services delivered	498	297	1,439	1,542
Gross margin	28,713	22,096	74,135	60,289
Sales, general and administrative expenses	12,441	12,776	39,734	34,898
Research and development expenses	3,759	2,439	10,820	6,444
Income (loss) from operations	12,513	6,881	23,581	18,947
Purchases of property and equipment	844	335	2,066	1,174
Purchases of intangible assets	16	69	125	271
Depreciation and amortization	1,101	1,088	3,368	4,036
TASER Weapons [Member]
Segment Reporting Information [Line Items]
Product sales	40,010	31,627	105,160	89,902
Net sales	40,010	31,627	105,160	89,902
Cost of products sold	12,443	10,908	34,024	31,535
Gross margin	27,567	20,719	71,136	58,367
Sales, general and administrative expenses	10,028	11,131	32,218	30,622
Research and development expenses	1,050	1,160	2,660	3,126
Income (loss) from operations	16,489	8,428	36,258	24,619
Purchases of property and equipment	803	230	1,836	828
Purchases of intangible assets	14	67	123	260
Depreciation and amortization	1,010	1,025	3,078	2,998
Evidence.com & Video [Member]
Segment Reporting Information [Line Items]
Product sales	3,181	3,103	9,812	6,853
Service revenue	1,158	467	2,737	1,051
Net sales	4,339	3,570	12,549	7,904
Cost of products sold	2,695	1,896	8,111	4,440
Cost of services delivered	498	297	1,439	1,542
Gross margin	1,146	1,377	2,999	1,922
Sales, general and administrative expenses	2,413	1,645	7,516	4,276
Research and development expenses	2,709	1,279	8,160	3,318
Income (loss) from operations	(3,976)	(1,547)	(12,677)	(5,672)
Purchases of property and equipment	41	105	230	346
Purchases of intangible assets	2	2	2	11
Depreciation and amortization	$ 91	$ 63	$ 290	$ 1,038