Axon Enterprise (AXON) 10-Q 9 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 30, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2019
Document Transition Report	false
Entity File Number	001-16391
Entity Registrant Name	Axon Enterprise, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	86-0741227
Entity Address, Address Line One	17800 North 85th Street
Entity Address, City or Town	Scottsdale
Entity Address, State or Province	AZ
Entity Address, Postal Zip Code	85255
City Area Code	480
Local Phone Number	991-0797
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common Stock, $0.00001 Par Value
Trading Symbol	AAXN
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		59,255,274
Entity Central Index Key	0001069183
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 219,720	$ 349,462
Short-term investments	116,629	0
Accounts and notes receivable, net of allowance of $1,577 and $1,882 as of June 30, 2019 and December 31, 2018, respectively	134,630	130,579
Contract assets, net	26,648	13,960
Inventory	40,999	33,763
Prepaid expenses and other current assets	36,429	30,391
Total current assets	575,055	558,155
Property and equipment, net of accumulated depreciation of $42,822 and $39,885 as of June 30, 2019 and December 31, 2018, respectively	40,500	37,893
Deferred income tax assets, net	20,658	19,347
Intangible assets, net	14,424	15,935
Goodwill	24,969	24,981
Long-term notes receivable, net of current portion	35,170	40,230
Other assets	35,594	22,999
Total assets	746,370	719,540
Current liabilities:
Accounts payable	9,064	15,164
Accrued liabilities	34,011	41,092
Contract with customer, liability, current	113,351	107,016
Other current liabilities	3,852	37
Total current liabilities	163,673	166,011
Deferred revenue, net of current portion	74,586	74,417
Liability for unrecognized tax benefits	3,462	2,849
Long-term deferred compensation	3,755	3,235
Other long-term liabilities	11,967	5,704
Total liabilities	257,443	252,216
Commitments and contingencies (Note 12)
Stockholders’ equity:
Preferred stock, $0.00001 par value; 25,000,000 shares authorized; no shares issued and outstanding as of June 30, 2019 and December 31, 2018	0	0
Common stock, $0.00001 par value; 200,000,000 shares authorized; 59,251,731 and 58,810,637 shares issued and outstanding as of June 30, 2019 and December 31, 2018, respectively	1	1
Additional paid-in capital	467,904	453,400
Treasury stock at cost, 20,220,227 shares as of June 30, 2019 and December 31, 2018	(155,947)	(155,947)
Retained earnings	178,540	171,383
Accumulated other comprehensive loss	(1,571)	(1,513)
Total stockholders’ equity	488,927	467,324
Total liabilities and stockholders’ equity	746,370	719,540
Current portion of deferred revenue
Current liabilities:
Contract with customer, liability, current	113,351	107,016
Customer deposits
Current liabilities:
Contract with customer, liability, current	$ 3,395	$ 2,702

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance on accounts receivable	$ 1,577	$ 1,882
Accumulated depreciation	$ 42,822	$ 39,885
Preferred stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Preferred stock, shares authorized (in shares)	25,000,000	25,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.00001	$ 0.00001
Common stock, shares authorized (in shares)	200,000,000	200,000,000
Common stock, shares issued (in shares)	59,251,731	58,810,637
Common stock, shares outstanding (in shares)	59,251,731	58,810,637
Treasury stock, shares (in shares)	20,220,227	20,220,227

Unaudited Condensed Consolidate

Unaudited Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Net sales	$ 112,362	$ 99,226	$ 228,172	$ 200,441
Cost of sales	46,802	36,083	93,695	72,837
Gross margin	65,560	63,143	134,477	127,604
Operating expenses:
Sales, general and administrative	43,362	39,343	86,254	75,102
Research and development	23,493	18,501	46,847	33,620
Total operating expenses	66,855	57,844	133,101	108,722
Income (loss) from operations	(1,295)	5,299	1,376	18,882
Interest and other income (expense), net	1,845	(295)	4,158	968
Income before provision for income taxes	550	5,004	5,534	19,850
Provision for (benefit from) income taxes	(188)	(3,481)	(1,623)	(1,561)
Net income	$ 738	$ 8,485	$ 7,157	$ 21,411
Net income per common and common equivalent shares:
Basic (in dollars per share)	$ 0.01	$ 0.15	$ 0.12	$ 0.39
Diluted (in dollars per share)	$ 0.01	$ 0.15	$ 0.12	$ 0.38
Weighted average number of common and common equivalent shares outstanding:
Basic (in shares)	59,187	55,527	59,051	54,330
Diluted (in shares)	60,000	57,054	59,876	55,892
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net income	$ 738	$ 8,485	$ 7,157	$ 21,411
Foreign currency translation adjustments	(108)	655	(58)	(52)
Comprehensive income	630	9,140	7,099	21,359
Product
Net sales	80,391	76,721	168,480	157,695
Cost of sales	38,220	31,087	77,820	63,521
Service
Net sales	31,971	22,505	59,692	42,746
Cost of sales	$ 8,582	$ 4,996	$ 15,875	$ 9,316

Unaudited Condensed Consolida_2

Unaudited Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated Other Comprehensive Loss
Beginning balance (in shares) at Dec. 31, 2017		52,969,869		20,220,227
Beginning balance at Dec. 31, 2017	$ 167,444	$ 1	$ 201,672	$ (155,947)	$ 123,185	$ (1,467)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee plans (in shares)		337,214
Issuance of common stock under employee plans	(3,421)		(3,421)
Stock-based compensation	4,093		4,093
Net income	12,926				12,926
Foreign currency translation adjustments	(707)					(707)
Ending balance (in shares) at Mar. 31, 2018		53,307,083		20,220,227
Ending balance at Mar. 31, 2018	199,329	$ 1	202,344	$ (155,947)	155,105	(2,174)
Beginning balance (in shares) at Dec. 31, 2017		52,969,869		20,220,227
Beginning balance at Dec. 31, 2017	167,444	$ 1	201,672	$ (155,947)	123,185	(1,467)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	21,411
Foreign currency translation adjustments	(52)
Ending balance (in shares) at Jun. 30, 2018		58,289,613		20,220,227
Ending balance at Jun. 30, 2018	448,842	$ 1	442,717	$ (155,947)	163,590	(1,519)
Beginning balance (in shares) at Mar. 31, 2018		53,307,083		20,220,227
Beginning balance at Mar. 31, 2018	199,329	$ 1	202,344	$ (155,947)	155,105	(2,174)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)		4,645,000
Issuance of common stock	233,993		233,993
Issuance of common stock for business combination (in shares)		58,843
Issuance of common stock for business combination	8,226		8,226
Issuance of common stock under employee plans (in shares)		278,687
Issuance of common stock under employee plans	(6,800)		(6,800)
Stock-based compensation	4,954		4,954
Net income	8,485				8,485
Foreign currency translation adjustments	655					655
Ending balance (in shares) at Jun. 30, 2018		58,289,613		20,220,227
Ending balance at Jun. 30, 2018	448,842	$ 1	442,717	$ (155,947)	163,590	(1,519)
Beginning balance (in shares) at Dec. 31, 2018		58,810,637		20,220,227
Beginning balance at Dec. 31, 2018	467,324	$ 1	453,400	$ (155,947)	171,383	(1,513)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under employee plans (in shares)		298,649
Issuance of common stock under employee plans	(1,159)		(1,159)
Stock-based compensation	7,905		7,905
Net income	6,419				6,419
Foreign currency translation adjustments	50					50
Ending balance (in shares) at Mar. 31, 2019		59,109,286		20,220,227
Ending balance at Mar. 31, 2019	480,539	$ 1	460,146	$ (155,947)	177,802	(1,463)
Beginning balance (in shares) at Dec. 31, 2018		58,810,637		20,220,227
Beginning balance at Dec. 31, 2018	467,324	$ 1	453,400	$ (155,947)	171,383	(1,513)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,157
Foreign currency translation adjustments	(58)
Ending balance (in shares) at Jun. 30, 2019		59,251,731		20,220,227
Ending balance at Jun. 30, 2019	488,927	$ 1	467,904	$ (155,947)	178,540	(1,571)
Beginning balance (in shares) at Mar. 31, 2019		59,109,286		20,220,227
Beginning balance at Mar. 31, 2019	480,539	$ 1	460,146	$ (155,947)	177,802	(1,463)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock for business combination (in shares)		70,613
Issuance of common stock under employee plans (in shares)		71,832
Issuance of common stock under employee plans	(869)		(869)
Stock-based compensation	8,627		8,627
Net income	738				738
Foreign currency translation adjustments	(108)					(108)
Ending balance (in shares) at Jun. 30, 2019		59,251,731		20,220,227
Ending balance at Jun. 30, 2019	$ 488,927	$ 1	$ 467,904	$ (155,947)	$ 178,540	$ (1,571)

Unaudited Condensed Consolida_3

Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Cash flows from operating activities:
Net income	$ 7,157	$ 21,411
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	5,487	5,161
Loss on disposal and impairment of property and equipment, net	1,563	153
Loss on disposal and abandonment of intangible assets	18	54
Stock-based compensation	16,532	9,047
Deferred income taxes	(1,311)	(58)
Unrecognized tax benefits	613	212
Other noncash, net	1,822	30
Change in assets and liabilities:
Accounts and notes receivable and contract assets	(11,006)	(24,791)
Inventory	(7,515)	4,508
Prepaid expenses and other assets	(5,761)	(7,429)
Accounts payable, accrued and other liabilities	(16,752)	(2,688)
Deferred revenue	6,577	10,496
Net cash provided by (used in) operating activities	(2,576)	16,106
Cash flows from investing activities:
Purchases of investments	(141,992)	(4,331)
Proceeds from maturity/call of investments	25,319	7,038
Purchases of property and equipment	(7,861)	(4,665)
Purchases of intangible assets	(344)	(254)
Business acquisitions	0	(5,014)
Net cash used in investing activities	(124,878)	(7,226)
Cash flows from financing activities:
Net proceeds from equity offering	0	233,993
Proceeds from options exercised	104	586
Income and payroll tax payments for net-settled stock awards	(2,132)	(10,807)
Payment of contingent consideration for a business acquisition	0	(575)
Net cash provided by (used in) financing activities	(2,028)	223,197
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(252)	(538)
Net increase (decrease) in cash, cash equivalents and restricted cash	(129,734)	231,539
Cash, cash equivalents and restricted cash, beginning of period	351,027	78,438
Cash, cash equivalents and restricted cash, end of period	221,293	309,977
Supplemental disclosures:
Cash and cash equivalents	219,720	307,507
Total cash, cash equivalents and restricted cash shown in the statements of cash flows	351,027	78,438
Cash paid for income taxes, net of refunds	1,331	7,758
Non-cash transactions
Property and equipment purchases in accounts payable and accrued liabilities	91	665
Non-cash purchase consideration related to business combinations	$ 0	$ 12,288

Organization and Summary of Sig

Organization and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Summary of Significant Accounting Policies	Organization and Summary of Significant Accounting Policies Axon Enterprise, Inc. (“Axon,” the “Company,” "we," or "us") is a market-leading provider of law enforcement technology solutions. Our core mission is to protect life. We fulfill that mission through developing hardware and software products that advance the long term objectives of a) obsoleting the bullet, b) reducing social conflict, and c) enabling a fair and effective justice system. Our headquarters in Scottsdale, Arizona houses our executive management, sales, marketing, certain engineering, manufacturing, and other administrative support functions. We also have a software engineering development center located in Seattle, Washington, and subsidiaries located in Australia, Canada, Finland, Hong Kong, Germany, India, Italy, the Netherlands, the United Kingdom, and Vietnam. The accompanying unaudited condensed consolidated financial statements include the accounts of Axon Enterprise, Inc. and our wholly owned subsidiaries. All material intercompany accounts, transactions, and profits have been eliminated. Basis of Presentation and Use of Estimates These unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. Certain information related to our organization, significant accounting policies and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) has been condensed or omitted. The accounting policies followed in the preparation of these unaudited condensed consolidated financial statements are consistent with those followed in our annual consolidated financial statements for the year ended December 31, 2018 , as filed on Form 10-K, with the exception of our adoption of certain accounting pronouncements which we describe below. In the opinion of management, these unaudited condensed consolidated financial statements contain all material adjustments, consisting only of normal recurring adjustments, necessary to fairly state our financial position, results of operations and cash flows for the periods presented and the presentations and disclosures herein are adequate when read in conjunction with our Form 10-K for the year ended December 31, 2018 . The results of operations for the six months ended June 30, 2019 and 2018 are not necessarily indicative of the results to be expected for the full year (or any other period). Significant estimates and assumptions in these unaudited condensed consolidated financial statements include: • product warranty reserves, • inventory valuation, • revenue recognition, • valuation of goodwill, intangible and long-lived assets, • recognition, measurement and valuation of current and deferred income taxes, • stock-based compensation, • recognition and measurement of lease liabilities, • recognition and measurement of contingencies and accrued litigation expense, and • fair values of identified tangible and intangible assets acquired and liabilities assumed in business combinations. Actual results could differ materially from those estimates. Segment Information Our operations are comprised of two reportable segments: the manufacture and sale of conducted electrical weapons ("CEWs"), batteries, accessories, extended warranties and other products and services (the “TASER” segment); and the development, manufacture, and sale of software and sensors, which includes the sale of devices, wearables, applications, cloud and mobile products (collectively, the “Software and Sensors” segment). Revenue from our “products” in the Software and Sensors segment are generally from sales of sensors, including on-officer body cameras, Axon Fleet cameras, other hardware sensors, warranties on sensors, and other products, and is sometimes referred to as "Sensors and Other revenue." Revenue from our “services” in the Software and Sensors segment comprise sales related to the Axon Cloud, which includes Axon Evidence, cloud-based evidence management software revenue, other recurring cloud-hosted software revenue and related professional services, and is sometimes referred to as "Axon Cloud revenue." Within the Software and Sensors segment, we include only revenues and costs attributable to that segment, which costs include: costs of sales for both products and services, direct labor, product management and research and development ("R&D") for products included, or to be included, within the Software and Sensors segment. All other costs are included in the TASER segment. Our Chief Executive Officer, who is the Chief Operating Decision Maker (the “CODM”), is not provided asset information or sales, general, and administrative expense by segment. Reportable segments are determined based on discrete financial information reviewed by the CODM. We organize and review operations based on products and services. We perform an analysis of our reportable segments on at least an annual basis. Additional information related to our business segments is summarized in Note 15. Geographic Information and Major Customers / Suppliers For the three and six months ended June 30, 2019 and 2018, no individual country outside the U.S. represented more than 10% of total net sales. Individual sales transactions in the international market are generally larger and occur more intermittently than in the domestic market due to the profile of our customers. For the three and six months ended June 30, 2019 and 2018, no customer represented more than 10% of total net sales. At June 30, 2019 and December 31, 2018 , no customer represented more than 10% of the aggregate balance of accounts and notes receivable and contract assets. We currently purchase both off the shelf and custom components, including, but not limited to, finished circuit boards, injection-molded plastic components, small machined parts, custom cartridge components, electronic components, and off the shelf sub-assemblies from suppliers located in the U.S., Mexico, China, Taiwan, Vietnam, Canada, Germany and Israel. Although we currently obtain many of these components from single source suppliers, we own the injection molded component tooling, most of the designs, and the test fixtures used in their production for all custom components. As a result, we believe we could obtain alternative suppliers in most cases without incurring significant production delays. We also strategically hold safety stock levels on custom components to further reduce this risk. For off the shelf components, we believe that in most cases there are readily available alternative suppliers who can consistently meet our needs for these components. We acquire most of our components on a purchase order basis and do not have any significant long-term contracts with component suppliers. Income per Common Share Basic income per common share is computed by dividing net income by the weighted average number of common shares outstanding during the periods presented. Potentially dilutive securities include outstanding stock options and unvested restricted stock units ("RSUs"). The dilutive effect of potentially dilutive securities is reflected in diluted earnings per share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of our common stock can result in a greater dilutive effect from potentially dilutive securities. The calculation of the weighted average number of shares outstanding and earnings per share are as follows (in thousands except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator for basic and diluted earnings per share: Net income $ 738 $ 8,485 $ 7,157 $ 21,411 Denominator: Weighted average shares outstanding 59,187 55,527 59,051 54,330 Dilutive effect of stock-based awards 813 1,527 825 1,562 Diluted weighted average shares outstanding 60,000 57,054 59,876 55,892 Anti-dilutive stock-based awards excluded 12,056 3,023 12,111 1,533 Net income per common share: Basic $ 0.01 $ 0.15 $ 0.12 $ 0.39 Diluted $ 0.01 $ 0.15 $ 0.12 $ 0.38 Standard Warranties We warranty our CEWs, Axon cameras and certain related accessories from manufacturing defects on a limited basis for a period of one year after purchase and, thereafter, will repair or replace any defective unit for a fee. Estimated costs for the standard warranty are charged to cost of products sold when revenue is recorded for the related product. Future warranty costs are estimated based on historical data related to warranty claims on a quarterly basis and this rate is applied to current product sales. Historically, reserve amounts have been increased if management becomes aware of a component failure or other issue that could result in larger than anticipated warranty claims from customers. The warranty reserve is reviewed quarterly to verify that it sufficiently reflects the remaining warranty obligations based on the anticipated expenditures over the balance of the warranty obligation period, and adjustments are made when actual warranty claim experience differs from estimates. The warranty reserve is included in accrued liabilities on the accompanying condensed consolidated balance sheets. Changes in our estimated product warranty liabilities were as follows (in thousands): Six Months Ended June 30, 2019 2018 Balance, beginning of period $ 898 $ 644 Utilization of accrual (250 ) (149 ) Warranty expense 634 10 Balance, end of period $ 1,282 $ 505 Fair Value Measurements and Financial Instruments The fair value framework prioritizes the inputs to valuation techniques for measuring financial assets and liabilities measured on a recurring basis and for non-financial assets and liabilities when these items are re-measured. Fair value is considered to be the exchange price in an orderly transaction between market participants to sell an asset or transfer a liability at the measurement date. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. We categorize each of our fair value measurements in one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. These levels are: • Level 1 – Valuation techniques in which all significant inputs are unadjusted quoted prices from active markets for assets or liabilities that are identical to the assets or liabilities being measured. • Level 2 – Valuation techniques in which significant inputs include quoted prices from active markets for assets or liabilities that are similar to the assets or liabilities being measured and/or quoted prices for assets or liabilities that are identical or similar to the assets or liabilities being measured from markets that are not active. Also, model-derived valuations in which all significant inputs and significant value drivers are observable in active markets are Level 2 valuation techniques. • Level 3 – Valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Unobservable inputs are valuation technique inputs that reflect our own assumptions about inputs that market participants would use in pricing an asset or liability. We have cash equivalents and investments, which at June 30, 2019 and December 31, 2018 were comprised of money market funds and, at June 30, 2019 , also included corporate bonds. See additional disclosure regarding the fair value of our cash equivalents and investments in Note 3. Included in the balance of other assets as of June 30, 2019 and December 31, 2018 was $4.0 million and $3.6 million , respectively, related to corporate-owned life insurance policies which are used to fund our deferred compensation plan. We determine the fair value of insurance contracts by obtaining the cash surrender value of the contracts from the issuer, a Level 2 valuation technique. Our financial instruments also include accounts and notes receivable, contract assets, accounts payable and accrued liabilities. As these instruments are generally short-term in nature, their carrying values approximate their fair values on the accompanying condensed consolidated balance sheets. Restricted Cash Restricted cash balances as of June 30, 2019 and December 31, 2018 included $0.9 million of sales proceeds related to long-term contracts with customers, which were included in prepaid expenses and other current assets on our condensed consolidated balance sheets. The proceeds are held in escrow until certain billing milestones are achieved, and then specified amounts are transferred to our operating accounts. Restricted cash balances as of June 30, 2019 and December 31, 2018 also included $0.7 million related to a performance guarantee for an international customer sales contract, which were included in other assets on our accompanying condensed consolidated balance sheets. Valuation of Goodwill, Intangibles and Long-lived Assets We evaluate whether events and circumstances have occurred that indicate the remaining estimated useful life of long-lived assets and identifiable intangible assets, excluding goodwill and intangible assets with indefinite useful lives, may warrant revision or that the remaining balance of these assets may not be recoverable. Such circumstances could include, but are not limited to, a change in the product mix, a change in the way products are created, produced or delivered, or a significant change in the way products are branded and marketed. In performing the review for recoverability, we estimate the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. The amount of the impairment loss, if impairment exists, is calculated based on the excess of the carrying amounts of the assets over their estimated fair value computed using discounted cash flows. During the three months ended June 30, 2019, we abandoned certain capitalized software related to implementation work on an enterprise resource planning system conversion, resulting in an impairment charge of $1.3 million , which was included in sales, general and administrative expense in the accompanying condensed consolidated statements of operations. We do not amortize goodwill and intangible assets with indefinite useful lives; rather such assets are required to be tested for impairment at least annually or sooner whenever events or changes in circumstances indicate that the assets may be impaired. We perform our annual goodwill and intangible asset impairment tests in the fourth quarter of each year. Recently Issued Accounting Guidance Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, Leases (Topic 842), which is intended to increase transparency and comparability among organizations by requiring the recognition of right-of-use (“ROU”) assets and lease liabilities on the balance sheet. In July 2018, the FASB issued additional guidance which provided an additional transition method for adopting the updated guidance. Most prominent among the changes in the standard is the requirement for lessees to recognize ROU assets and lease liabilities for those leases that were classified as operating leases under previous U.S. GAAP. On January 1, 2019, we adopted Topic 842 by applying the non-comparative modified retrospective method of adoption. Under this method, financial information related to periods prior to adoption will be as originally reported under the then-current standard (Topic 840, Leases). Results for reporting periods beginning on or after January 1, 2019 are presented under Topic 842, while prior period amounts are not adjusted, and continue to be reported in accordance with our historic accounting under Topic 840. We elected to apply the package of practical expedients to not reassess whether a contract is or contains a lease, lease classification, or initial lease costs for all leases that commenced before the adoption date. The adoption had a material impact to our condensed consolidated balance sheet. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while our accounting for finance leases remained substantially unchanged. There was no other impact from the adoption. The adjustments to the opening balance sheet were as follows (in thousands): December 31, 2018 Impact of Adoption of Topic 842 on Opening Balance Sheet January 1, 2019 (As reported) (As adjusted) Consolidated Balance Sheet Data: Other assets $ 22,999 $ 12,483 $ 35,482 Total assets 719,540 12,483 732,023 — Accrued liabilities 41,092 (1,138 ) 39,954 Other current liabilities 37 3,588 3,625 Total current liabilities 166,011 2,450 168,461 Other long-term liabilities 5,704 10,033 15,737 Total liabilities 252,216 12,483 264,699 Total liabilities and stockholders' equity 719,540 12,483 732,023 See Note 11 for further disclosures related to Topic 842. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718), expanding the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. We adopted this standard on January 1, 2019 and the adoption had no impact on our condensed consolidated financial statements. Effective the first quarter of 2020: In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 includes an impairment model (known as the current expected credit loss model) on financial instruments and other commitments that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses, which the FASB believes will result in more timely recognition of such losses. The use of forecasted information is intended to incorporate more timely information in the estimate of expected credit loss. This ASU will also require enhanced disclosures relating to significant estimates and judgments used in estimating credit losses, as well as credit quality. We are currently in the process of evaluating the impact of adoption of ASU 2016-13 on our investments, accounts and notes receivable, and contract assets. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. ASU 2018-13 eliminates, adds and modifies certain disclosure requirements for fair value measurements. The amendments apply to the disclosures of changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted, and an entity is also permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until their effective date. Adoption of this ASU is not expected to have a material impact on our consolidated financial statements. Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no effect on the reported results of operations.

Revenues

Revenues	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Nature of Products and Services The following tables present our revenues by primary product and service offering (in thousands): Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 TASER Software and Sensors Total TASER Software and Sensors Total TASER 7 $ 9,298 $ — $ 9,298 $ — $ — $ — TASER X26P 10,382 — 10,382 18,146 — 18,146 TASER X2 14,087 — 14,087 18,362 — 18,362 TASER Pulse and Bolt 1,118 — 1,118 1,101 — 1,101 Single cartridges 19,293 — 19,293 17,243 — 17,243 Axon Body — 5,612 5,612 — 4,780 4,780 Axon Flex — 1,623 1,623 — 1,535 1,535 Axon Fleet — 3,120 3,120 — 2,715 2,715 Axon Dock — 2,731 2,731 — 2,119 2,119 Axon Evidence and cloud services 109 31,821 31,930 — 20,357 20,357 TASER Cam — 1,044 1,044 — 762 762 Extended warranties 4,482 4,420 8,902 3,738 2,870 6,608 Other 1,803 1,419 3,222 2,034 3,464 5,498 Total $ 60,572 $ 51,790 $ 112,362 $ 60,624 $ 38,602 $ 99,226 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 TASER Software and Sensors Total TASER Software and Sensors Total TASER 7 $ 19,252 $ — $ 19,252 $ — $ — $ — TASER X26P 26,254 — 26,254 34,620 — 34,620 TASER X2 27,172 — 27,172 42,294 — 42,294 TASER Pulse and Bolt 1,788 — 1,788 2,447 — 2,447 Single cartridges 38,453 — 38,453 33,357 — 33,357 Axon Body — 12,057 12,057 — 10,338 10,338 Axon Flex — 2,847 2,847 — 3,204 3,204 Axon Fleet — 6,636 6,636 — 4,831 4,831 Axon Dock — 6,043 6,043 — 5,154 5,154 Axon Evidence and cloud services 145 59,439 59,584 — 40,598 40,598 TASER Cam — 1,947 1,947 — 2,122 2,122 Extended warranties 8,798 9,350 18,148 7,444 5,360 12,804 Other 4,101 3,890 7,991 3,986 4,686 8,672 Total $ 125,963 $ 102,209 $ 228,172 $ 124,148 $ 76,293 $ 200,441 The following table presents our revenues disaggregated by geography (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 United States $ 93,594 83 % $ 78,731 79 % $ 187,927 82 % $ 156,681 78 % Other countries 18,768 17 20,495 21 40,245 18 43,760 22 Total $ 112,362 100 % $ 99,226 100 % $ 228,172 100 % $ 200,441 100 % Contract Balances The following table presents our contract assets, contract liabilities and certain information related to these balances as of and for the three months ended June 30, 2019 (in thousands): June 30, 2019 Contract assets, net $ 26,908 Contract liabilities (deferred revenue) 187,937 Revenue recognized in the period from: Amounts included in contract liabilities at the beginning of the period 58,302 Contract liabilities (deferred revenue) consisted of the following (in thousands): June 30, 2019 December 31, 2018 Current Long-Term Total Current Long-Term Total Warranty: TASER $ 11,110 $ 16,450 $ 27,560 $ 12,797 $ 16,847 $ 29,644 Software and Sensors 9,514 4,898 14,412 8,273 6,516 14,789 20,624 21,348 41,972 21,070 23,363 44,433 Hardware: TASER 3,315 15,844 19,159 9,355 15,598 24,953 Software and Sensors 35,443 23,500 58,943 20,878 24,685 45,563 38,758 39,344 78,102 30,233 40,283 70,516 Services: TASER 77 350 427 — — — Software and Sensors 53,892 13,544 67,436 55,713 10,771 66,484 53,969 13,894 67,863 55,713 10,771 66,484 Total $ 113,351 $ 74,586 $ 187,937 $ 107,016 $ 74,417 $ 181,433 June 30, 2019 December 31, 2018 Current Long-Term Total Current Long-Term Total TASER $ 14,502 $ 32,644 $ 47,146 $ 22,152 $ 32,445 $ 54,597 Software and Sensors 98,849 41,942 140,791 84,864 41,972 126,836 Total $ 113,351 $ 74,586 $ 187,937 $ 107,016 $ 74,417 $ 181,433 Remaining Performance Obligations As of June 30, 2019 , we had approximately $1.05 billion of remaining performance obligations, which included both recognized contract liabilities as well as amounts that will be invoiced and recognized in future periods. The remaining performance obligations are limited only to arrangements that meet the definition of a contract under Topic 606 as of June 30, 2019 . We expect to recognize between 15% - 20% of this balance over the next twelve months, and generally expect the remainder to be recognized over the following five to seven years, subject to risks related to delayed deployments, budget appropriation or other contract cancellation clauses.

Cash, Cash Equivalents and Inve

Cash, Cash Equivalents and Investments	6 Months Ended
	Jun. 30, 2019
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments The following tables summarize our cash, cash equivalents, and held-to-maturity investments at June 30, 2019 and December 31, 2018 (in thousands): As of June 30, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Short-Term Investments Cash $ 129,347 $ — $ — $ 129,347 $ 129,347 $ — Level 1: Money market funds 88,375 — — 88,375 88,375 — Level 2: Corporate bonds 118,627 44 (5 ) 118,666 1,998 116,629 Total $ 336,349 $ 44 $ (5 ) $ 336,388 $ 219,720 $ 116,629 As of December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Short-Term Investments Cash $ 144,095 $ — $ — $ 144,095 $ 144,095 $ — Level 1: Money market funds 205,367 — — 205,367 205,367 — Total $ 349,462 $ — $ — $ 349,462 $ 349,462 $ — We believe unrealized losses on our investments are due to interest rate fluctuations. As these investments are short-term in nature, are expected to be redeemed at par value, and/or because we have the ability and intent to hold these investments to maturity, we do not consider these investments to be other than temporarily impaired as of June 30, 2019

Inventory

Inventory	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventory	Inventory Inventories are stated at the lower of cost and net realizable value. Cost is determined using the weighted average cost of raw materials, which approximates the first-in, first-out (“FIFO”) method and includes allocations of manufacturing labor and overhead. Included in finished goods at June 30, 2019 and December 31, 2018 was $1.7 million and $1.4 million , respectively, of trial and evaluation hardware units. Provisions are made to reduce excess, obsolete or slow-moving inventories to their net realizable value. Inventory consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 21,784 $ 19,670 Finished goods 19,215 14,093 Total inventory $ 40,999 $ 33,763

Goodwill and Intangible Assets

Goodwill and Intangible Assets	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets The changes in the carrying amount of goodwill for the six months ended June 30, 2019 were as follows (in thousands): TASER Software and Sensors Total Balance, beginning of period $ 1,338 $ 23,643 $ 24,981 Foreign currency translation adjustment (6 ) (6 ) (12 ) Balance, end of period $ 1,332 $ 23,637 $ 24,969 Intangible assets (other than goodwill) consisted of the following (in thousands): June 30, 2019 December 31, 2018 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable (definite-lived) intangible assets: Domain names 5-10 years $ 3,161 $ (884 ) $ 2,277 $ 3,161 $ (732 ) $ 2,429 Issued patents 4-15 years 2,993 (1,212 ) 1,781 2,940 (1,106 ) 1,834 Issued trademarks 3-11 years 969 (511 ) 458 1,053 (599 ) 454 Customer relationships 4-8 years 3,697 (1,155 ) 2,542 3,701 (880 ) 2,821 Non-compete agreements 3-4 years 450 (394 ) 56 540 (439 ) 101 Developed technology 3-7 years 10,660 (5,435 ) 5,225 13,404 (7,081 ) 6,323 Re-acquired distribution rights 2 years 2,006 (2,006 ) — 1,928 (1,813 ) 115 Total amortizable 23,936 (11,597 ) 12,339 26,727 (12,650 ) 14,077 Not amortizable (indefinite-lived) intangible assets: TASER trademark 900 900 900 900 Patents and trademarks pending 1,185 1,185 958 958 Total not amortizable 2,085 2,085 1,858 1,858 Total intangible assets $ 26,021 $ (11,597 ) $ 14,424 $ 28,585 $ (12,650 ) $ 15,935 Amortization expense of intangible assets for the three and six months ended June 30, 2019 was $0.9 million and $1.9 million , respectively. Amortization expense of intangible assets for the three and six months ended June 30, 2018 was $1.7 million and $3.0 million , respectively. Estimated amortization for intangible assets with definite lives for the remaining six months of 2019 , the next five years ended December 31, and thereafter, is as follows (in thousands): 2019 Remaining $ 1,653 2020 3,300 2021 2,852 2022 1,251 2023 954 2024 872 Thereafter 1,457 Total $ 12,339

Other Assets

Other Assets	6 Months Ended
	Jun. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Assets	Other Assets Other assets consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Cash surrender value of corporate-owned life insurance policies $ 4,018 $ 3,596 Deferred commissions (1) 16,597 15,530 Restricted cash 660 661 Operating lease assets 10,770 — Prepaid expenses, deposits and other 3,549 3,212 Total other long-term assets $ 35,594 $ 22,999 (1) Represents the incremental costs of obtaining contracts with customers, which consist primarily of sales commissions. These costs are ascribed to or allocated to the underlying performance obligations in the contracts and amortized consistent with the recognition timing of the revenue for the underlying performance obligations.

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Accrued salaries, benefits and bonus $ 15,106 $ 19,063 Accrued professional, consulting and lobbying fees 4,688 4,894 Accrued warranty expense 1,282 898 Accrued income and other taxes 3,448 4,167 Other accrued liabilities 9,487 12,070 Accrued liabilities $ 34,011 $ 41,092

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We file income tax returns for federal purposes and in many states, as well as in multiple foreign jurisdictions. Our tax filings remain subject to examination by applicable tax authorities for a certain length of time, generally three to four years, following the tax year to which these filings relate. Our U.S. federal income tax return for fiscal year 2016 is currently under audit by the Internal Revenue Service. Deferred Tax Assets Net deferred income tax assets at June 30, 2019 , primarily include R&D tax credits, stock-based compensation expense, deferred revenue, accruals and reserves, and net operating losses, partially offset by accelerated depreciation expense and valuation allowance reserve. Our total net deferred tax assets at June 30, 2019 were $20.7 million . In preparing our condensed consolidated financial statements, management assesses the likelihood that its deferred tax assets will be realized from future taxable income. In evaluating our ability to recover our deferred income tax assets, management considers all available positive and negative evidence, including our operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction by jurisdiction basis. A valuation allowance is established if it is determined that it is more likely than not that some portion or all of the net deferred tax assets will not be realized. Management exercises significant judgment in determining our provisions for income taxes, our deferred tax assets and liabilities, and our future taxable income for purposes of assessing our ability to utilize any future tax benefit from our deferred tax assets. As of June 30, 2019 , we continue to demonstrate three-year cumulative pre-tax income in the U.S. federal and state tax jurisdictions; however, we have Arizona R&D Tax Credits expiring unutilized each year. Therefore, management has concluded that it is more likely than not that our Arizona R&D deferred tax asset will not be realized. As of June 30, 2019 , we have cumulative pre-tax losses in Australia, the U.K., and Canada, which limits the ability to consider other subjective evidence, such as projections for future growth. On the basis of this evaluation, a full valuation allowance has been recorded for these jurisdictions. The amount of the deferred tax asset considered realizable; however, could be adjusted in future periods if objective negative evidence in the form of cumulative losses is no longer present and additional weight is given to subjective evidence such as projections for growth. We complete R&D tax credit studies for each year that an R&D tax credit is claimed for federal, Arizona, and California income tax purposes. Management has made the determination that it is more likely than not that the full benefit of the R&D tax credit will not be sustained on examination and recorded a liability for unrecognized tax benefits of $6.1 million as of June 30, 2019 . In addition, management accrued $0.1 million for estimated uncertain tax positions related to certain federal income tax liabilities. Should the unrecognized benefit of $6.2 million be recognized, our effective tax rate would be favorably impacted. Approximately $2.9 million of the unrecognized tax benefit associated with R&D credits has been netted against the R&D deferred tax asset. Effective Tax Rate Our overall effective tax rate for the six months ended June 30, 2019 , after discrete period adjustments, was (29.3)% . Before discrete adjustments, the tax rate was 21.4% , which is greater than the federal statutory rate, primarily due to state taxes and non-deductible expenses for items such as meals and entertainment, the executive compensation limitation under Internal Revenue Code ("IRC") Section 162(m), lobbying fees, and an income inclusion from global intangible low-taxed income ("GILTI"), offset by a reduction for foreign-derived intangible income ("FDII") and R&D tax credits. The effective tax rate was favorably impacted by a $3.3 million discrete tax benefit primarily associated with windfalls related to stock-based compensation for RSUs that vested or stock options that were exercised during the six months ended June 30, 2019 . This was offset by an unfavorable discrete item of $0.6 million related to the write off of certain deferred tax assets related to future stock compensation vests for certain officers for whom deductibility of compensation is limited by IRC Section 162(m).

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity Performance-based stock awards We have issued performance-based stock options and performance-based RSUs, the vesting of which is generally contingent upon the achievement of certain performance criteria related to our operating performance, as well as successful and timely development and market acceptance of future product introductions. In addition, certain of the performance RSUs have additional service requirements subsequent to the achievement of the performance criteria. Compensation expense is recognized over the requisite service period, which is defined as the longest explicit, implicit or derived service period based on management’s estimate of the probability of the performance criteria being satisfied, adjusted at each balance sheet date. For awards containing multiple service, performance or market conditions, where all conditions must be satisfied prior to vesting, compensation expense is recognized over the requisite service period, which is defined as the longest explicit, implicit or derived service period, based on management’s estimate of the probability of the performance criteria being satisfied, adjusted at each balance sheet date. For both service-based and performance-based RSUs, we account for forfeitures as they occur as a reduction to stock-based compensation expense and additional paid-in-capital. For performance-based options with a vesting schedule based entirely on the attainment of both performance and market conditions, stock-based compensation expense is recognized for each pair of performance and market conditions over the longer of the expected achievement period of the performance and market conditions, beginning at the point in time that the relevant performance condition is considered probable of achievement. The fair value of such awards is estimated on the grant date using Monte Carlo simulations. CEO Performance Award On May 24, 2018 (the “Grant Date”), our stockholders approved the Board of Directors’ grant of 6,365,856 stock option awards to Patrick W. Smith, our CEO (the “CEO Performance Award”). The CEO Performance Award consists of 12 vesting tranches with a vesting schedule based entirely on the attainment of both operational goals (performance conditions) and market capitalization goals (market conditions), assuming continued employment either as the CEO or as both Executive Chairman and Chief Product Officer and service through each vesting date. Each of the 12 vesting tranches of the CEO Performance Award have a 10-year contractual term and will vest upon certification by the Board of Directors that both (i) the market capitalization goal for such tranche, which begins at $2.5 billion for the first tranche and increases by increments of $1.0 billion thereafter, and (ii) any one of the following eight operational goals focused on revenue or eight operational goals focused on Adjusted EBITDA have been met for the previous four consecutive fiscal quarters. Adjusted EBITDA for purposes of the CEO Performance Award ("Adjusted EBITDA (CEO Performance Award)") is defined as net income (loss) attributable to common stockholders before interest expense, investment interest income, provision (benefit) for income taxes, depreciation and amortization, and stock-based compensation expense. Eight Separate Revenue Goals (1) (in thousands) Eight Separate Adjusted EBITDA (CEO Performance Award) Goals (in thousands) Goal #1, $710,058 Goal #9, $125,000 Goal #2, $860,058 Goal #10, $155,000 Goal #3, $1,010,058 Goal #11, $175,000 Goal #4, $1,210,058 Goal #12, $190,000 Goal #5, $1,410,058 Goal #13, $200,000 Goal #6, $1,610,058 Goal #14, $210,000 Goal #7, $1,810,058 Goal #15, $220,000 Goal #8, $2,010,058 Goal #16, $230,000 (1) In connection with the business acquisition that was completed during the three months ended June 30, 2018, the revenue goals have been adjusted for the acquiree's Target Revenue, as defined in the CEO Performance Award agreement. As of June 30, 2019 , the following operational goals were considered probable of achievement: • Total revenue of $710.1 million ; and • Adjusted EBITDA (CEO Performance Award) of $125.0 million The first two market capitalization goals have been achieved as of June 30, 2019 . However, none of the stock options granted under the CEO Performance Award have vested thus far as the operational goals have not yet been achieved as of June 30, 2019 . As there are two operational goals considered probable of achievement, we recorded stock-based compensation expense of $6.1 million related to the CEO Performance Award from the Grant Date through June 30, 2019 . The number of stock options that would vest related to the two tranches is approximately 1.1 million shares. As of June 30, 2019 , we had $39.1 million of total unrecognized stock-based compensation expense for the performance goals that were considered probable of achievement, which will be recognized over a weighted-average period of 7.2 years. As of June 30, 2019 , we had unrecognized stock-based compensation expense of $200.7 million for the performance goals that were considered not probable of achievement. eXponential Stock Performance Plan On February 12, 2019, our shareholders approved the 2019 Stock Incentive Plan (the “2019 Plan”), which was adopted by the Board of Directors to reserve a sufficient number of shares to facilitate our eXponential Stock Performance Plan (“XSPP”) and grants of eXponential Stock Units (“XSUs”) under the plan. Pursuant to the XSPP, all eligible full-time U.S. employees were granted an award of 60 XSUs in January 2019, and certain employees had the opportunity to elect to receive a percentage of the value of their target compensation over the next nine years (2019-2027) in the form of additional XSUs. For employees who elected to receive XSUs, the XSU grants were made as an up front, lump sum grant in January 2019, and are intended to replace that portion of the target compensation they elected to receive in the form of XSUs for the next nine years . Accordingly, their go forward target compensation will be reduced until 2027 by the amount of such compensation that the employees elected to receive in the form of the January 2019 XSU grants. A total of approximately 5.2 million XSUs were granted in the six months ended June 30, 2019 . The XSUs are grants of restricted stock units, each with a term of approximately nine years , that vest in 12 equal tranches. Each of the 12 tranches will vest upon certification by the Compensation Committee of the Board of Directors that both (i) the market capitalization goal for such tranche, which begins at $2.5 billion for the first tranche and increases by increments of $1.0 billion thereafter, and (ii) any one of eight operational goals focused on revenue or eight operational goals focused on Adjusted EBITDA (CEO Performance Award) have been met for the previous four consecutive fiscal quarters. The XSPP contains an anti-dilution provision, which is used to calculate a maximum number of shares outstanding for purposes of determining achievement of the market capitalization goals whereby the maximum number of shares used to calculate the market capitalization goal is calculated by organically growing the current number of shares outstanding by 3% per year (the "XSU Maximum"). Any shares of Stock issued to Patrick W. Smith upon the exercise of the stock options granted to Mr. Smith under the CEO Performance Award shall increase the XSU Maximum. The XSU Maximum shall also be adjusted for acquisitions, spin-offs or other changes in the number of outstanding shares of common stock, if such changes have a corresponding adjustment on the market capitalization goals. The market capitalization and operational goals are identical to the CEO Performance Award, except for the number of shares that are used to calculate the market capitalization goals if shares outstanding exceed the XSU Maximum. Additionally, because the grant date is different than that of the CEO Performance Award, the measurement period for market capitalization is not identical. Stock-based compensation expense associated with XSU awards is recognized over the longer of the expected achievement period for each pair of market capitalization and operational goals, beginning at the point in time when the relevant operational goal is considered probable of being met. The market capitalization goal period and the valuation of each tranche are determined using a Monte Carlo simulation which is also is used as the basis for determining the expected achievement period of the market capitalization goal. The probability of meeting an operational goal and the expected achievement point in time for meeting a probable operational goal are based on a subjective assessment of our forward-looking financial projections, taking into consideration statistical analysis. Even though no tranches of the XSU awards vest unless a market capitalization and a matching operational goal are both achieved, stock-based compensation expense is recognized when an operational goal is considered probable of achievement regardless of whether a market capitalization goal is actually achieved. The first market capitalization goal has been achieved as of June 30, 2019 . The second market capitalization goal was achieved on July 16, 2019. However, none of the XSU tranches have vested thus far as the operational goals have not yet been achieved as of June 30, 2019 . As there are two operational goals considered probable of achievement, we recorded stock-based compensation expense of $1.9 million related to the XSU awards from their respective grant dates through June 30, 2019 . The number of XSU awards that would vest related to the two tranches is approximately 0.9 million shares. As of June 30, 2019 , we had $35.5 million of total unrecognized stock-based compensation expense for the performance goals that were considered probable of achievement, which will be recognized over a weighted-average period of 7.2 years. As of June 30, 2019 , we had unrecognized stock-based compensation expense of $136.5 million for the performance goals that were considered not probable of achievement. Given the complexity of the awards, we utilized Monte Carlo simulations to simulate a range of possible future market capitalizations for the Company over the term of the awards. The average of all iterations of the simulation was used as the basis for the valuation and market capitalization goal derived service period for each tranche. Additionally, we applied an illiquidity discount of between 10.0% and 16.8% to the valuation of XSUs because the awards specify a post-vest holding period of 2.5 years. Certain of the XSU awards specify a post-vest holding period of the longer of 2.5 years or until the next tranche vests. The illiquidity discounts were estimated using the Finnerty model and reduced by the impact of expected payroll and income taxes due upon vesting of the awards, as the related proportion of shares are expected to be sold to satisfy such obligations. We measured the grant date fair value of the XSU awards with the following assumptions: risk-free interest rate of between 2.47% and 2.62% , expected term of approximately 9 years, expected volatility of between 44.96% and 45.47% , and dividend yield of 0.00% . Restricted Stock Units The following table summarizes RSU activity for the six months ended June 30, 2019 (number of units and aggregate intrinsic value in thousands): Number of Units Weighted Average Grant-Date Fair Value Aggregate Units outstanding, beginning of year 1,655 $ 28.34 Granted 5,732 34.65 Released (375 ) 23.15 Forfeited (104 ) 37.25 Units outstanding, end of period 6,908 33.73 $ 443,531 Aggregate intrinsic value represents our closing stock price on the last trading day of the period, which was $64.21 per share, multiplied by the number of RSUs outstanding. As of June 30, 2019 , there was $79.5 million in unrecognized compensation costs related to RSUs under our stock plans for shares that are expected to vest. We expect to recognize the cost related to the RSUs over a weighted average period of 4.49 years . RSUs are released when vesting requirements are met. During the six months ended June 30, 2019 , we granted 5.7 million RSUs, consisting of 0.4 million service-based RSUs and approximately 5.3 million performance-based RSUs, including 5.2 million XSUs. As of June 30, 2019 , the performance criteria had been met for approximately four thousand of the 5.6 million performance-based RSUs outstanding. Certain of the performance-based RSUs outstanding as of June 30, 2019 can vest with a range of shares earned being between 0% and 200% of the targeted shares granted, depending on the final achievement of pre-determined performance criteria as of the vesting date. The amount of RSUs included in the table above related to such grants is the target level. The maximum additional number of performance-based RSUs that could be earned is 0.3 million , which are not included in the table above. Certain RSUs that vested in the six months ended June 30, 2019 were net-share settled such that we withheld shares to cover the employees’ tax obligation for the applicable income and other employment taxes, and remitted the cash to the appropriate taxing authorities. Total shares withheld related to RSUs were approximately 29 thousand and had a value of $2.1 million on their respective vesting dates as determined by the closing stock price on such dates. Payments for the employees’ tax obligations are reflected as a financing activity within the condensed consolidated statements of cash flows. We record a liability for the tax withholding to be paid by us as a reduction to additional paid-in capital. Stock Option Activity The following table summarizes stock option activity for the six months ended June 30, 2019 (number of units and aggregate intrinsic value in thousands): Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Options outstanding, beginning of year 6,458 $ 28.24 Granted — — Exercised (25 ) 4.23 Expired / terminated — — Options outstanding, end of period 6,433 28.33 8.58 $ 230,820 Options exercisable, end of period 67 4.53 1.44 4,005 Aggregate intrinsic value represents the difference between the exercise price of the underlying stock option awards and the closing market price of our common stock of $64.21 on June 28, 2019. The intrinsic value of options exercised for the six months ended June 30, 2019 and 2018 was $1.1 million and $18.8 million , respectively. As of June 30, 2019 , total options outstanding included 6.4 million unvested performance-based stock options. Of this total, 1.1 million options relate to tranches of the CEO Performance Award considered probable of achievement. Stock-based Compensation Expense The following table summarizes the composition of stock-based compensation expense for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of products sold and services delivered $ 237 $ 125 $ 463 $ 266 Sales, general and administrative expenses 4,941 2,731 9,622 5,035 Research and development expenses 3,449 2,098 6,447 3,746 Total stock-based compensation expense $ 8,627 $ 4,954 $ 16,532 $ 9,047 Stock Incentive Plan In February 2019, our shareholders approved the 2019 Plan authorizing an additional 6.0 million shares, plus remaining available shares under prior plans, for issuance under the new plan. Combined with the legacy stock incentive plans, there are 2.1 million shares available for grant as of June 30, 2019 . Stock Repurchase Plan In February 2016, our Board of Directors authorized a stock repurchase program to acquire up to $50.0 million of our outstanding common stock subject to stock market conditions and corporate considerations. During the six months ended June 30, 2019 and 2018, no common shares were purchased under the program. As of June 30, 2019 , $16.3 million remains available under the plan for future purchases. Any future purchases will be discretionary.

Line of Credit

Line of Credit	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Line of Credit	Line of Credit We have a $50.0 million unsecured revolving line of credit with a domestic bank, of which $10.0 million is available for letters of credit. The credit agreement matures on December 31, 2021 and has an accordion feature which allows for an increase in the total line of credit up to $100.0 million , subject to certain conditions, including the availability of additional bank commitments. At June 30, 2019 and December 31, 2018, there were no borrowings under the line. Under the terms of the line of credit, available borrowings are reduced by outstanding letters of credit. As of June 30, 2019 , we had letters of credit outstanding of approximately $4.4 million under the facility and available borrowing of $45.6 million , excluding amounts available under the accordion feature. Advances under the line of credit bear interest at LIBOR plus 1.0 to 1.5% per year determined in accordance with a pricing grid based on our funded debt to earnings before interest, taxes, depreciation and amortization ("EBITDA") ratio. We are required to comply with a maximum funded debt to EBITDA ratio of no greater than 2.50 to 1.00 based upon a trailing four fiscal quarter period. At June 30, 2019 , our funded debt to EBITDA ratio was 0.001 to 1.00.

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	Leases Lease Obligations We determine if an arrangement is a lease at inception. Operating lease ROU assets and liabilities are recognized based on the present value of future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. Additionally, we use the portfolio approach in determining the discount rate used to present value lease payments. We give consideration to our line of credit as well as publicly available data for instruments with similar characteristics when calculating our incremental borrowing rates. The ROU asset also includes any lease payments made and initial direct costs incurred and excludes lease incentives. We have operating and finance leases for office space and certain equipment. Leases with an initial term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term. For leases beginning on or after January 1, 2019, we account for lease components separately from non-lease components for all asset classes. Our leases have remaining terms of less than 1 to 4 years, some of which include one or more options to renew for up to 2 years, and some of which include options to terminate the leases within 1 year. The exercise of lease renewal options is at our sole discretion and such options are included in ROU assets and liabilities for renewal periods that are reasonably certain of exercise. Certain of our lease agreements include stated rental payment escalations. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. We sublease certain real estate to third parties. Finance leases as of June 30, 2019 were immaterial. Leases (in thousands) Classification June 30, 2019 Assets Operating lease assets Other assets $ 10,770 Liabilities Current Operating Other current liabilities $ 3,814 Noncurrent Operating Other long-term liabilities 8,013 Total lease liabilities $ 11,827 The components of lease expense were as follows (in thousands): Classification Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense (1) Sales, general and administrative expenses (2) $ 1,137 $ 2,154 Sublease income Other income (95 ) (137 ) Net lease expense $ 1,042 $ 2,017 (1) Includes short-term leases, which are immaterial. (2) An immaterial portion of operating lease expense is included within research and development expenses and cost of sales. Other information related to leases was as follows (in thousands, except lease term and discount rate): Six Months Ended June 30, 2019 Supplemental Cash Flows Information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,017 Right-of-use assets obtained in exchange for lease liabilities: Operating leases 84 Weighted average remaining lease term: Operating leases 3.5 years Weighted average discount rate: Operating leases 3.6 % Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows (in thousands): Operating Sublease income Net 2019 Remaining $ 2,248 $ (164 ) $ 2,084 2020 4,224 (82 ) 4,142 2021 3,340 — 3,340 2022 2,409 — 2,409 2023 1,173 — 1,173 2024 — — — Thereafter — — — Total minimum lease payments 13,394 (246 ) 13,148 Less: Amount representing interest (1,321 ) Present value of lease payments $ 11,827 As of June 30, 2019 , we do not have any leases that have not yet commenced other than the land lease purchase agreement described in Note 12. Disclosures related to periods prior to adoption of Topic 842 Rent expense under all operating leases, including both cancelable and non-cancelable leases, was $4.2 million and $2.9 million for the years ended December 31, 2018 and 2017, respectively. Future minimum lease payments under non-cancelable leases at December 31, 2018, were as follows (in thousands): Operating Capital 2019 $ 3,670 $ 40 2020 3,572 36 2021 2,961 — 2022 2,001 — 2023 573 — Thereafter — — Total minimum lease payments $ 12,777 76 Less: Amount representing interest (6 ) Capital lease obligation $ 70
Leases	Leases Lease Obligations We determine if an arrangement is a lease at inception. Operating lease ROU assets and liabilities are recognized based on the present value of future minimum lease payments over the lease term at commencement date. As most of our leases do not provide an implicit rate, we use our incremental borrowing rate based on the information available at the commencement date in determining the present value of future payments. Additionally, we use the portfolio approach in determining the discount rate used to present value lease payments. We give consideration to our line of credit as well as publicly available data for instruments with similar characteristics when calculating our incremental borrowing rates. The ROU asset also includes any lease payments made and initial direct costs incurred and excludes lease incentives. We have operating and finance leases for office space and certain equipment. Leases with an initial term of 12 months or less are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the lease term. For leases beginning on or after January 1, 2019, we account for lease components separately from non-lease components for all asset classes. Our leases have remaining terms of less than 1 to 4 years, some of which include one or more options to renew for up to 2 years, and some of which include options to terminate the leases within 1 year. The exercise of lease renewal options is at our sole discretion and such options are included in ROU assets and liabilities for renewal periods that are reasonably certain of exercise. Certain of our lease agreements include stated rental payment escalations. Our lease agreements do not contain any material residual value guarantees or material restrictive covenants. We sublease certain real estate to third parties. Finance leases as of June 30, 2019 were immaterial. Leases (in thousands) Classification June 30, 2019 Assets Operating lease assets Other assets $ 10,770 Liabilities Current Operating Other current liabilities $ 3,814 Noncurrent Operating Other long-term liabilities 8,013 Total lease liabilities $ 11,827 The components of lease expense were as follows (in thousands): Classification Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense (1) Sales, general and administrative expenses (2) $ 1,137 $ 2,154 Sublease income Other income (95 ) (137 ) Net lease expense $ 1,042 $ 2,017 (1) Includes short-term leases, which are immaterial. (2) An immaterial portion of operating lease expense is included within research and development expenses and cost of sales. Other information related to leases was as follows (in thousands, except lease term and discount rate): Six Months Ended June 30, 2019 Supplemental Cash Flows Information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,017 Right-of-use assets obtained in exchange for lease liabilities: Operating leases 84 Weighted average remaining lease term: Operating leases 3.5 years Weighted average discount rate: Operating leases 3.6 % Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows (in thousands): Operating Sublease income Net 2019 Remaining $ 2,248 $ (164 ) $ 2,084 2020 4,224 (82 ) 4,142 2021 3,340 — 3,340 2022 2,409 — 2,409 2023 1,173 — 1,173 2024 — — — Thereafter — — — Total minimum lease payments 13,394 (246 ) 13,148 Less: Amount representing interest (1,321 ) Present value of lease payments $ 11,827 As of June 30, 2019 , we do not have any leases that have not yet commenced other than the land lease purchase agreement described in Note 12. Disclosures related to periods prior to adoption of Topic 842 Rent expense under all operating leases, including both cancelable and non-cancelable leases, was $4.2 million and $2.9 million for the years ended December 31, 2018 and 2017, respectively. Future minimum lease payments under non-cancelable leases at December 31, 2018, were as follows (in thousands): Operating Capital 2019 $ 3,670 $ 40 2020 3,572 36 2021 2,961 — 2022 2,001 — 2023 573 — Thereafter — — Total minimum lease payments $ 12,777 76 Less: Amount representing interest (6 ) Capital lease obligation $ 70

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Land Lease Purchase Agreement On December 13, 2018, we entered into a Purchase and Sale Agreement ("PSA") to purchase a leasehold interest to a parcel of land located in Maricopa County, Arizona for a period of 84 years, on which we intend to construct our new headquarters. The purchase price of the land lease was $13.1 million . It is also contemplated that we will prepay the rent under the lease in the amount of $10.9 million . The PSA includes a due diligence period, during which we may terminate and forfeit our initial deposit of $0.2 million . On March 4, 2019, we entered into an amendment to the PSA which extended the due diligence period to May 3, 2019. On May 3, 2019, we entered into a second amendment to the PSA which extended the due diligence period to June 28, 2019. The second amendment also revised certain stated approval dates and removed the requirement for an additional deposit originally due at the end of the due diligence period. The land lease remains contingent upon approval by the Salt River Pima-Maricopa Indian Community. Data Storage Purchase Commitment In June 2019, we entered into a purchase agreement for cloud data storage with a three years term beginning July 1, 2019. The purchase agreement includes a total commitment of $50.0 million , with an up-front prepayment of $15.0 million in July 2019. Product Litigation We are currently named as a defendant in seven lawsuits in which the plaintiffs allege either wrongful death or personal injury in situations in which a TASER CEW was used by law enforcement officers in connection with arrests. While the facts vary from case to case, these product liability claims typically allege defective product design, manufacturing, and/or failure to warn. They seek compensatory and sometimes punitive damages, often in unspecified amounts. We continue to aggressively defend all product litigation. As a general rule, it is our policy not to settle suspect injury or death cases. Exceptions are sometimes made where the settlement is strategically beneficial to us. Due to the confidential nature of our litigation strategy and the confidentiality agreements that are executed in the event of a settlement, we do not identify or comment on specific settlements by case or amount. Based on current information, we do not believe that the outcome of any such legal proceeding will have a material effect on our financial position, results of operations, or cash flows. We are self-insured for the first $5.0 million of any product claim made after 2014. No judgment or settlement has ever exceeded this amount in any products case. We continue to maintain product liability insurance coverage, including an insurance policy fronting arrangement, above our self-insured retention with various limits depending on the policy period. Other Litigation We are a defendant in a litigation matter filed by Digital Ally Inc. (“Digital”) in the District of Kansas alleging patent infringement regarding our Axon Signal technology. Axon was granted summary judgment of non-infringement on June 17, 2019 and judgment was entered in our favor on all of Digital's claims. Digital has appealed the ruling. We are also a defendant in a consumer class action lawsuit previously filed and dismissed in California in 2018 and now refiled in the District of Nevada on April 9, 2019 (Case No. 3:1-cv-00192) by consumer weapon purchaser Douglas Richey (“Richey”). The case alleges the TASER Pulse, X2 and X26P CEWs have a faulty safety switch based on Richey’s Pulse allegedly discharging inside its neoprene case in a jacket pocket without injury. Any such discharge was likely due to static electricity, as disclosed in our consumer warnings. We will vigorously defend this claim and the propriety of any class certification. Our motion to dismiss is pending. U.S. Federal Trade Commission Investigation In June 2018 we received a letter from the U.S. Federal Trade Commission (“FTC”) with respect to its non-public investigation into our acquisition of VIEVU, LLC in May 2018. The FTC issued a subpoena for certain information and documentation relating to the acquisition on March 21, 2019. We are cooperating with the investigation. General From time to time, we are notified that we may be a party to a lawsuit or that a claim is being made against us. It is our policy to not disclose the specifics of any claim or threatened lawsuit until the summons and complaint are actually served on us. After carefully assessing the claim, and assuming we determine that we are not at fault or we disagree with the damages or relief demanded, we vigorously defend any lawsuit filed against us. We record a liability when losses are deemed probable and reasonably estimable. When losses are deemed reasonably possible but not probable, we determine whether it is possible to provide an estimate of the amount of the loss or range of possible losses for the claim, if material for disclosure. In evaluating matters for accrual and disclosure purposes, we take into consideration factors such as our historical experience with matters of a similar nature, the specific facts and circumstances asserted, the likelihood of our prevailing, the availability of insurance, and the severity of any potential loss. We reevaluate and update accruals as matters progress over time. Based on our assessment of outstanding litigation and claims as of June 30, 2019 , we have determined that it is not reasonably possible that these lawsuits will individually, or in the aggregate, materially affect our results of operations, financial condition or cash flows. However, the outcome of any litigation is inherently uncertain and there can be no assurance that any expense, liability or damages that may ultimately result from the resolution of these matters will be covered by our insurance or will not be in excess of amounts recognized or provided by insurance coverage and will not have a material adverse effect on our operating results, financial condition or cash flows. Off-Balance Sheet Arrangements Under certain circumstances, we use letters of credit and surety bonds to guarantee our performance under various contracts, principally in connection with the installation and integration of Axon cameras and related technologies. Certain of our letters of credit and surety bonds have stated expiration dates with others being released as the contractual performance terms are completed. At June 30, 2019 , we had outstanding letters of credit of $4.4 million that are expected to expire in May 2020 and September 2021. Additionally, we had $24.6 million of outstanding surety bonds at June 30, 2019 , with $0.4 million expiring in 2019, $0.7 million expiring in 2020, $2.3 million expiring in 2021, $3.2 million expiring in 2022, $7.5 million expiring in 2023 and the remaining $10.5 million

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2019
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions We subscribe to various cloud-based applications from Salesforce. Bret Taylor, who was a member of our Board of Directors through June 14, 2019, serves as President and Chief Product Officer of Salesforce. We incur costs at different times throughout the year, typically in advance of services being provided, and subsequently amortize these costs ratably to expense as services are provided over the contractual term. The cost to subscribe to various cloud-based hosting arrangements from Salesforce was $0.5 million and $0.4 million for the three months ended June 30, 2019 and 2018, respectively, and $1.0 million and $0.9 million for the six months ended June 30, 2019 and 2018, respectively. There were no amounts due to Salesforce as of June 30, 2019 . Amounts due to Salesforce as of December 31, 2018 were negligible.

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
	Jun. 30, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans We have a defined contribution 401 (k) plan for eligible employees, which is qualified under Sections 401 (a) and 401 (k) of the Internal Revenue Code of 1986, as amended. Employees are entitled to make tax-deferred contributions of up to the maximum amount allowed by law of their eligible compensation. We also have a non-qualified deferred compensation plan for certain executives, employees and non-employee directors through which participants may elect to postpone the receipt and taxation of a portion of their compensation, including stock-based compensation, received from us. The non-qualified deferred compensation plan allows eligible participants to defer up to 80% of their base salary and up to 100% of other types of compensation. The plan also allows for matching and discretionary employer contributions. Employee deferrals are deemed 100% vested upon contribution. Distributions from the plan are made upon retirement, death, separation of service, specified date or upon the occurrence of an unforeseeable emergency. Distributions can be paid in a variety of forms from lump sum to installments over a period of years. Participants in the plan are entitled to select from a wide variety of investments available under the plan and are allocated gains or losses based upon the performance of the investments selected by the participant. All gains or losses are allocated fully to plan participants and we do not guarantee a rate of return on deferred balances. Assets related to this plan consist of corporate-owned life insurance contracts and are included in other assets in the condensed consolidated balance sheets; see Note 6 for balances. Participants have no rights or claims with respect to any plan assets and any such assets are subject to the claims of our general creditors. Contributions to the plans are made by both the employee and us. Our contributions to the 401(k) plan are based on the level of employee contributions and are immediately vested. Our matching contributions to the 401(k) and non-qualified deferred compensation plans were $1.1 million and $0.8 million for the three months ended June 30, 2019 and 2018 , respectively, and $2.5 million and $1.6 million for the six months ended June 30, 2019 and 2018 , respectively. Future matching contributions to the plans are at our sole discretion.

Segment Data

Segment Data	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment Data	Segment Data Our operations are comprised of two reportable segments: the manufacture and sale of CEWs, batteries, accessories, extended warranties and other products and services (the “TASER” segment); and the software and sensors business, which includes the sale of devices, wearables, applications, cloud and mobile products (collectively, the “Software and Sensors” segment). Our Chief Executive Officer, who is the CODM, is not provided asset information or sales, general, and administrative expense by segment. Information relative to our reportable segments was as follows (in thousands): Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 TASER Software and Sensors 1 Total TASER Software and Sensors Total Net sales from products $ 60,423 $ 19,968 $ 80,391 $ 60,624 $ 16,097 $ 76,721 Net sales from services 149 31,822 31,971 — 22,505 22,505 Net sales 60,572 51,790 112,362 60,624 38,602 99,226 Cost of product sales 24,262 13,958 38,220 17,681 13,406 31,087 Cost of service sales — 8,582 8,582 — 4,996 4,996 Cost of sales 24,262 22,540 46,802 17,681 18,402 36,083 Gross margin $ 36,310 $ 29,250 $ 65,560 $ 42,943 $ 20,200 $ 63,143 Research and development $ 3,087 $ 20,406 $ 23,493 $ 4,019 $ 14,482 $ 18,501 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 TASER Software and Sensors 1 Total TASER Software and Sensors Total Net sales from products $ 125,724 $ 42,756 $ 168,480 $ 124,148 $ 33,547 $ 157,695 Net sales from services 239 59,453 59,692 — 42,746 42,746 Net sales 125,963 102,209 228,172 124,148 76,293 200,441 Cost of product sales 47,540 30,280 77,820 38,224 25,297 63,521 Cost of service sales — 15,875 15,875 — 9,316 9,316 Cost of sales 47,540 46,155 93,695 38,224 34,613 72,837 Gross margin $ 78,423 $ 56,054 $ 134,477 $ 85,924 $ 41,680 $ 127,604 Research and development $ 6,799 $ 40,048 $ 46,847 $ 6,979 $ 26,641 $ 33,620 1 Cost of service sales for the three and six months ended June 30, 2019 includes approximately $0.9 million

Organization and Summary of S_2

Organization and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation and Use of Estimates These unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. Certain information related to our organization, significant accounting policies and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) has been condensed or omitted. The accounting policies followed in the preparation of these unaudited condensed consolidated financial statements are consistent with those followed in our annual consolidated financial statements for the year ended December 31, 2018 , as filed on Form 10-K, with the exception of our adoption of certain accounting pronouncements which we describe below. In the opinion of management, these unaudited condensed consolidated financial statements contain all material adjustments, consisting only of normal recurring adjustments, necessary to fairly state our financial position, results of operations and cash flows for the periods presented and the presentations and disclosures herein are adequate when read in conjunction with our Form 10-K for the year ended December 31, 2018 . The results of operations for the six months ended June 30, 2019 and 2018 are not necessarily indicative of the results to be expected for the full year (or any other period). Significant estimates and assumptions in these unaudited condensed consolidated financial statements include: • product warranty reserves, • inventory valuation, • revenue recognition, • valuation of goodwill, intangible and long-lived assets, • recognition, measurement and valuation of current and deferred income taxes, • stock-based compensation, • recognition and measurement of lease liabilities, • recognition and measurement of contingencies and accrued litigation expense, and • fair values of identified tangible and intangible assets acquired and liabilities assumed in business combinations. Actual results could differ materially from those estimates.
Use of Estimates	Basis of Presentation and Use of Estimates These unaudited condensed consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC. Certain information related to our organization, significant accounting policies and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”) has been condensed or omitted. The accounting policies followed in the preparation of these unaudited condensed consolidated financial statements are consistent with those followed in our annual consolidated financial statements for the year ended December 31, 2018 , as filed on Form 10-K, with the exception of our adoption of certain accounting pronouncements which we describe below. In the opinion of management, these unaudited condensed consolidated financial statements contain all material adjustments, consisting only of normal recurring adjustments, necessary to fairly state our financial position, results of operations and cash flows for the periods presented and the presentations and disclosures herein are adequate when read in conjunction with our Form 10-K for the year ended December 31, 2018 . The results of operations for the six months ended June 30, 2019 and 2018 are not necessarily indicative of the results to be expected for the full year (or any other period). Significant estimates and assumptions in these unaudited condensed consolidated financial statements include: • product warranty reserves, • inventory valuation, • revenue recognition, • valuation of goodwill, intangible and long-lived assets, • recognition, measurement and valuation of current and deferred income taxes, • stock-based compensation, • recognition and measurement of lease liabilities, • recognition and measurement of contingencies and accrued litigation expense, and • fair values of identified tangible and intangible assets acquired and liabilities assumed in business combinations. Actual results could differ materially from those estimates.
Segment Information	Segment Information Our operations are comprised of two reportable segments: the manufacture and sale of conducted electrical weapons ("CEWs"), batteries, accessories, extended warranties and other products and services (the “TASER” segment); and the development, manufacture, and sale of software and sensors, which includes the sale of devices, wearables, applications, cloud and mobile products (collectively, the “Software and Sensors” segment). Revenue from our “products” in the Software and Sensors segment are generally from sales of sensors, including on-officer body cameras, Axon Fleet cameras, other hardware sensors, warranties on sensors, and other products, and is sometimes referred to as "Sensors and Other revenue." Revenue from our “services” in the Software and Sensors segment comprise sales related to the Axon Cloud, which includes Axon Evidence, cloud-based evidence management software revenue, other recurring cloud-hosted software revenue and related professional services, and is sometimes referred to as "Axon Cloud revenue." Within the Software and Sensors segment, we include only revenues and costs attributable to that segment, which costs include: costs of sales for both products and services, direct labor, product management and research and development ("R&D") for products included, or to be included, within the Software and Sensors segment. All other costs are included in the TASER segment. Our Chief Executive Officer, who is the Chief Operating Decision Maker (the “CODM”), is not provided asset information or sales, general, and administrative expense by segment. Reportable segments are determined based on discrete financial information reviewed by the CODM. We organize and review operations based on products and services. We perform an analysis of our reportable segments on at least an annual basis. Additional information related to our business segments is summarized in Note 15.
Geographic Information and Major Customers	Geographic Information and Major Customers / Suppliers For the three and six months ended June 30, 2019 and 2018, no individual country outside the U.S. represented more than 10% of total net sales. Individual sales transactions in the international market are generally larger and occur more intermittently than in the domestic market due to the profile of our customers. For the three and six months ended June 30, 2019 and 2018, no customer represented more than 10% of total net sales. At June 30, 2019 and December 31, 2018 , no customer represented more than 10% of the aggregate balance of accounts and notes receivable and contract assets. We currently purchase both off the shelf and custom components, including, but not limited to, finished circuit boards, injection-molded plastic components, small machined parts, custom cartridge components, electronic components, and off the shelf sub-assemblies from suppliers located in the U.S., Mexico, China, Taiwan, Vietnam, Canada, Germany and Israel. Although we currently obtain many of these components from single source suppliers, we own the injection molded component tooling, most of the designs, and the test fixtures used in their production for all custom components. As a result, we believe we could obtain alternative suppliers in most cases without incurring significant production delays. We also strategically hold safety stock levels on custom components to further reduce this risk. For off the shelf components, we believe that in most cases there are readily available alternative suppliers who can consistently meet our needs for these components. We acquire most of our components on a purchase order basis and do not have any significant long-term contracts with component suppliers.
Income per Common Share	Income per Common Share Basic income per common share is computed by dividing net income by the weighted average number of common shares outstanding during the periods presented. Potentially dilutive securities include outstanding stock options and unvested restricted stock units ("RSUs"). The dilutive effect of potentially dilutive securities is reflected in diluted earnings per share by application of the treasury stock method. Under the treasury stock method, an increase in the fair market value of our common stock can result in a greater dilutive effect from potentially dilutive securities.
Standard Warranties	Standard Warranties We warranty our CEWs, Axon cameras and certain related accessories from manufacturing defects on a limited basis for a period of one year after purchase and, thereafter, will repair or replace any defective unit for a fee. Estimated costs for the standard warranty are charged to cost of products sold when revenue is recorded for the related product. Future warranty costs are estimated based on historical data related to warranty claims on a quarterly basis and this rate is applied to current product sales. Historically, reserve amounts have been increased if management becomes aware of a component failure or other issue that could result in larger than anticipated warranty claims from customers. The warranty reserve is reviewed quarterly to verify that it sufficiently reflects the remaining warranty obligations based on the anticipated expenditures over the balance of the warranty obligation period, and adjustments are made when actual warranty claim experience differs from estimates. The warranty reserve is included in accrued liabilities on the accompanying condensed consolidated balance sheets.
Fair Value of Financial Instruments	Fair Value Measurements and Financial Instruments The fair value framework prioritizes the inputs to valuation techniques for measuring financial assets and liabilities measured on a recurring basis and for non-financial assets and liabilities when these items are re-measured. Fair value is considered to be the exchange price in an orderly transaction between market participants to sell an asset or transfer a liability at the measurement date. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. We categorize each of our fair value measurements in one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. These levels are: • Level 1 – Valuation techniques in which all significant inputs are unadjusted quoted prices from active markets for assets or liabilities that are identical to the assets or liabilities being measured. • Level 2 – Valuation techniques in which significant inputs include quoted prices from active markets for assets or liabilities that are similar to the assets or liabilities being measured and/or quoted prices for assets or liabilities that are identical or similar to the assets or liabilities being measured from markets that are not active. Also, model-derived valuations in which all significant inputs and significant value drivers are observable in active markets are Level 2 valuation techniques. • Level 3 – Valuation techniques in which one or more significant inputs or significant value drivers are unobservable. Unobservable inputs are valuation technique inputs that reflect our own assumptions about inputs that market participants would use in pricing an asset or liability. We have cash equivalents and investments, which at June 30, 2019 and December 31, 2018 were comprised of money market funds and, at June 30, 2019 , also included corporate bonds. See additional disclosure regarding the fair value of our cash equivalents and investments in Note 3. Included in the balance of other assets as of June 30, 2019 and December 31, 2018 was $4.0 million and $3.6 million , respectively, related to corporate-owned life insurance policies which are used to fund our deferred compensation plan. We determine the fair value of insurance contracts by obtaining the cash surrender value of the contracts from the issuer, a Level 2 valuation technique. Our financial instruments also include accounts and notes receivable, contract assets, accounts payable and accrued liabilities. As these instruments are generally short-term in nature, their carrying values approximate their fair values on the accompanying condensed consolidated balance sheets.
Valuation of Goodwill, Intangibles and Long-lived Assets	Valuation of Goodwill, Intangibles and Long-lived Assets We evaluate whether events and circumstances have occurred that indicate the remaining estimated useful life of long-lived assets and identifiable intangible assets, excluding goodwill and intangible assets with indefinite useful lives, may warrant revision or that the remaining balance of these assets may not be recoverable. Such circumstances could include, but are not limited to, a change in the product mix, a change in the way products are created, produced or delivered, or a significant change in the way products are branded and marketed. In performing the review for recoverability, we estimate the future undiscounted cash flows expected to result from the use of the assets and their eventual disposition. The amount of the impairment loss, if impairment exists, is calculated based on the excess of the carrying amounts of the assets over their estimated fair value computed using discounted cash flows. During the three months ended June 30, 2019, we abandoned certain capitalized software related to implementation work on an enterprise resource planning system conversion, resulting in an impairment charge of $1.3 million , which was included in sales, general and administrative expense in the accompanying condensed consolidated statements of operations. We do not amortize goodwill and intangible assets with indefinite useful lives; rather such assets are required to be tested for impairment at least annually or sooner whenever events or changes in circumstances indicate that the assets may be impaired. We perform our annual goodwill and intangible asset impairment tests in the fourth quarter of each year.
Recently Issued Accounting Guidance	Recently Issued Accounting Guidance Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2016-02, Leases (Topic 842), which is intended to increase transparency and comparability among organizations by requiring the recognition of right-of-use (“ROU”) assets and lease liabilities on the balance sheet. In July 2018, the FASB issued additional guidance which provided an additional transition method for adopting the updated guidance. Most prominent among the changes in the standard is the requirement for lessees to recognize ROU assets and lease liabilities for those leases that were classified as operating leases under previous U.S. GAAP. On January 1, 2019, we adopted Topic 842 by applying the non-comparative modified retrospective method of adoption. Under this method, financial information related to periods prior to adoption will be as originally reported under the then-current standard (Topic 840, Leases). Results for reporting periods beginning on or after January 1, 2019 are presented under Topic 842, while prior period amounts are not adjusted, and continue to be reported in accordance with our historic accounting under Topic 840. We elected to apply the package of practical expedients to not reassess whether a contract is or contains a lease, lease classification, or initial lease costs for all leases that commenced before the adoption date. The adoption had a material impact to our condensed consolidated balance sheet. The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while our accounting for finance leases remained substantially unchanged. There was no other impact from the adoption. The adjustments to the opening balance sheet were as follows (in thousands): December 31, 2018 Impact of Adoption of Topic 842 on Opening Balance Sheet January 1, 2019 (As reported) (As adjusted) Consolidated Balance Sheet Data: Other assets $ 22,999 $ 12,483 $ 35,482 Total assets 719,540 12,483 732,023 — Accrued liabilities 41,092 (1,138 ) 39,954 Other current liabilities 37 3,588 3,625 Total current liabilities 166,011 2,450 168,461 Other long-term liabilities 5,704 10,033 15,737 Total liabilities 252,216 12,483 264,699 Total liabilities and stockholders' equity 719,540 12,483 732,023 See Note 11 for further disclosures related to Topic 842. In June 2018, the FASB issued ASU 2018-07, Compensation - Stock Compensation (Topic 718), expanding the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. We adopted this standard on January 1, 2019 and the adoption had no impact on our condensed consolidated financial statements. Effective the first quarter of 2020: In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. ASU 2016-13 includes an impairment model (known as the current expected credit loss model) on financial instruments and other commitments that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses, which the FASB believes will result in more timely recognition of such losses. The use of forecasted information is intended to incorporate more timely information in the estimate of expected credit loss. This ASU will also require enhanced disclosures relating to significant estimates and judgments used in estimating credit losses, as well as credit quality. We are currently in the process of evaluating the impact of adoption of ASU 2016-13 on our investments, accounts and notes receivable, and contract assets. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement. ASU 2018-13 eliminates, adds and modifies certain disclosure requirements for fair value measurements. The amendments apply to the disclosures of changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted, and an entity is also permitted to early adopt any removed or modified disclosures and delay adoption of the additional disclosures until their effective date. Adoption of this ASU is not expected to have a material impact on our consolidated financial statements.
Reclassification of Prior Year Presentation	Reclassification of Prior Year Presentation Certain prior year amounts have been reclassified for consistency with the current year presentation. These reclassifications had no effect on the reported results of operations.

Organization and Summary of S_3

Organization and Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Weighted Average Number of Shares Outstanding and Income Per Share	The calculation of the weighted average number of shares outstanding and earnings per share are as follows (in thousands except per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator for basic and diluted earnings per share: Net income $ 738 $ 8,485 $ 7,157 $ 21,411 Denominator: Weighted average shares outstanding 59,187 55,527 59,051 54,330 Dilutive effect of stock-based awards 813 1,527 825 1,562 Diluted weighted average shares outstanding 60,000 57,054 59,876 55,892 Anti-dilutive stock-based awards excluded 12,056 3,023 12,111 1,533 Net income per common share: Basic $ 0.01 $ 0.15 $ 0.12 $ 0.39 Diluted $ 0.01 $ 0.15 $ 0.12 $ 0.38
Summary of Changes in Estimated Product Warranty Liabilities	Changes in our estimated product warranty liabilities were as follows (in thousands): Six Months Ended June 30, 2019 2018 Balance, beginning of period $ 898 $ 644 Utilization of accrual (250 ) (149 ) Warranty expense 634 10 Balance, end of period $ 1,282 $ 505
Adjustments to Opening Balance Sheet	The adjustments to the opening balance sheet were as follows (in thousands): December 31, 2018 Impact of Adoption of Topic 842 on Opening Balance Sheet January 1, 2019 (As reported) (As adjusted) Consolidated Balance Sheet Data: Other assets $ 22,999 $ 12,483 $ 35,482 Total assets 719,540 12,483 732,023 — Accrued liabilities 41,092 (1,138 ) 39,954 Other current liabilities 37 3,588 3,625 Total current liabilities 166,011 2,450 168,461 Other long-term liabilities 5,704 10,033 15,737 Total liabilities 252,216 12,483 264,699 Total liabilities and stockholders' equity 719,540 12,483 732,023

Revenues (Tables)

Revenues (Tables)	6 Months Ended
	Jun. 30, 2019
Revenue from Contract with Customer [Abstract]
Summary of Revenue by Product and Service Offering and Geography	The following tables present our revenues by primary product and service offering (in thousands): Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 TASER Software and Sensors Total TASER Software and Sensors Total TASER 7 $ 9,298 $ — $ 9,298 $ — $ — $ — TASER X26P 10,382 — 10,382 18,146 — 18,146 TASER X2 14,087 — 14,087 18,362 — 18,362 TASER Pulse and Bolt 1,118 — 1,118 1,101 — 1,101 Single cartridges 19,293 — 19,293 17,243 — 17,243 Axon Body — 5,612 5,612 — 4,780 4,780 Axon Flex — 1,623 1,623 — 1,535 1,535 Axon Fleet — 3,120 3,120 — 2,715 2,715 Axon Dock — 2,731 2,731 — 2,119 2,119 Axon Evidence and cloud services 109 31,821 31,930 — 20,357 20,357 TASER Cam — 1,044 1,044 — 762 762 Extended warranties 4,482 4,420 8,902 3,738 2,870 6,608 Other 1,803 1,419 3,222 2,034 3,464 5,498 Total $ 60,572 $ 51,790 $ 112,362 $ 60,624 $ 38,602 $ 99,226 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 TASER Software and Sensors Total TASER Software and Sensors Total TASER 7 $ 19,252 $ — $ 19,252 $ — $ — $ — TASER X26P 26,254 — 26,254 34,620 — 34,620 TASER X2 27,172 — 27,172 42,294 — 42,294 TASER Pulse and Bolt 1,788 — 1,788 2,447 — 2,447 Single cartridges 38,453 — 38,453 33,357 — 33,357 Axon Body — 12,057 12,057 — 10,338 10,338 Axon Flex — 2,847 2,847 — 3,204 3,204 Axon Fleet — 6,636 6,636 — 4,831 4,831 Axon Dock — 6,043 6,043 — 5,154 5,154 Axon Evidence and cloud services 145 59,439 59,584 — 40,598 40,598 TASER Cam — 1,947 1,947 — 2,122 2,122 Extended warranties 8,798 9,350 18,148 7,444 5,360 12,804 Other 4,101 3,890 7,991 3,986 4,686 8,672 Total $ 125,963 $ 102,209 $ 228,172 $ 124,148 $ 76,293 $ 200,441 The following table presents our revenues disaggregated by geography (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 United States $ 93,594 83 % $ 78,731 79 % $ 187,927 82 % $ 156,681 78 % Other countries 18,768 17 20,495 21 40,245 18 43,760 22 Total $ 112,362 100 % $ 99,226 100 % $ 228,172 100 % $ 200,441 100 %
Contract with Customer, Assets and Liabilities	The following table presents our contract assets, contract liabilities and certain information related to these balances as of and for the three months ended June 30, 2019 (in thousands): June 30, 2019 Contract assets, net $ 26,908 Contract liabilities (deferred revenue) 187,937 Revenue recognized in the period from: Amounts included in contract liabilities at the beginning of the period 58,302 Contract liabilities (deferred revenue) consisted of the following (in thousands): June 30, 2019 December 31, 2018 Current Long-Term Total Current Long-Term Total Warranty: TASER $ 11,110 $ 16,450 $ 27,560 $ 12,797 $ 16,847 $ 29,644 Software and Sensors 9,514 4,898 14,412 8,273 6,516 14,789 20,624 21,348 41,972 21,070 23,363 44,433 Hardware: TASER 3,315 15,844 19,159 9,355 15,598 24,953 Software and Sensors 35,443 23,500 58,943 20,878 24,685 45,563 38,758 39,344 78,102 30,233 40,283 70,516 Services: TASER 77 350 427 — — — Software and Sensors 53,892 13,544 67,436 55,713 10,771 66,484 53,969 13,894 67,863 55,713 10,771 66,484 Total $ 113,351 $ 74,586 $ 187,937 $ 107,016 $ 74,417 $ 181,433 June 30, 2019 December 31, 2018 Current Long-Term Total Current Long-Term Total TASER $ 14,502 $ 32,644 $ 47,146 $ 22,152 $ 32,445 $ 54,597 Software and Sensors 98,849 41,942 140,791 84,864 41,972 126,836 Total $ 113,351 $ 74,586 $ 187,937 $ 107,016 $ 74,417 $ 181,433

Cash, Cash Equivalents and In_2

Cash, Cash Equivalents and Investments (Tables)	6 Months Ended
	Jun. 30, 2019
Cash and Cash Equivalents [Abstract]
Summary of Cash, Cash Equivalents and Held-to-Maturity Investments by Type	The following tables summarize our cash, cash equivalents, and held-to-maturity investments at June 30, 2019 and December 31, 2018 (in thousands): As of June 30, 2019 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Short-Term Investments Cash $ 129,347 $ — $ — $ 129,347 $ 129,347 $ — Level 1: Money market funds 88,375 — — 88,375 88,375 — Level 2: Corporate bonds 118,627 44 (5 ) 118,666 1,998 116,629 Total $ 336,349 $ 44 $ (5 ) $ 336,388 $ 219,720 $ 116,629 As of December 31, 2018 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Cash and Cash Equivalents Short-Term Investments Cash $ 144,095 $ — $ — $ 144,095 $ 144,095 $ — Level 1: Money market funds 205,367 — — 205,367 205,367 — Total $ 349,462 $ — $ — $ 349,462 $ 349,462 $ —

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Jun. 30, 2019
Inventory Disclosure [Abstract]
Inventory	Inventory consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Raw materials $ 21,784 $ 19,670 Finished goods 19,215 14,093 Total inventory $ 40,999 $ 33,763

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The changes in the carrying amount of goodwill for the six months ended June 30, 2019 were as follows (in thousands): TASER Software and Sensors Total Balance, beginning of period $ 1,338 $ 23,643 $ 24,981 Foreign currency translation adjustment (6 ) (6 ) (12 ) Balance, end of period $ 1,332 $ 23,637 $ 24,969
Indefinite-Lived Intangible Assets Other than Goodwill	Intangible assets (other than goodwill) consisted of the following (in thousands): June 30, 2019 December 31, 2018 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable (definite-lived) intangible assets: Domain names 5-10 years $ 3,161 $ (884 ) $ 2,277 $ 3,161 $ (732 ) $ 2,429 Issued patents 4-15 years 2,993 (1,212 ) 1,781 2,940 (1,106 ) 1,834 Issued trademarks 3-11 years 969 (511 ) 458 1,053 (599 ) 454 Customer relationships 4-8 years 3,697 (1,155 ) 2,542 3,701 (880 ) 2,821 Non-compete agreements 3-4 years 450 (394 ) 56 540 (439 ) 101 Developed technology 3-7 years 10,660 (5,435 ) 5,225 13,404 (7,081 ) 6,323 Re-acquired distribution rights 2 years 2,006 (2,006 ) — 1,928 (1,813 ) 115 Total amortizable 23,936 (11,597 ) 12,339 26,727 (12,650 ) 14,077 Not amortizable (indefinite-lived) intangible assets: TASER trademark 900 900 900 900 Patents and trademarks pending 1,185 1,185 958 958 Total not amortizable 2,085 2,085 1,858 1,858 Total intangible assets $ 26,021 $ (11,597 ) $ 14,424 $ 28,585 $ (12,650 ) $ 15,935
Finite-Lived Intangible Assets Other than Goodwill	Intangible assets (other than goodwill) consisted of the following (in thousands): June 30, 2019 December 31, 2018 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Amortizable (definite-lived) intangible assets: Domain names 5-10 years $ 3,161 $ (884 ) $ 2,277 $ 3,161 $ (732 ) $ 2,429 Issued patents 4-15 years 2,993 (1,212 ) 1,781 2,940 (1,106 ) 1,834 Issued trademarks 3-11 years 969 (511 ) 458 1,053 (599 ) 454 Customer relationships 4-8 years 3,697 (1,155 ) 2,542 3,701 (880 ) 2,821 Non-compete agreements 3-4 years 450 (394 ) 56 540 (439 ) 101 Developed technology 3-7 years 10,660 (5,435 ) 5,225 13,404 (7,081 ) 6,323 Re-acquired distribution rights 2 years 2,006 (2,006 ) — 1,928 (1,813 ) 115 Total amortizable 23,936 (11,597 ) 12,339 26,727 (12,650 ) 14,077 Not amortizable (indefinite-lived) intangible assets: TASER trademark 900 900 900 900 Patents and trademarks pending 1,185 1,185 958 958 Total not amortizable 2,085 2,085 1,858 1,858 Total intangible assets $ 26,021 $ (11,597 ) $ 14,424 $ 28,585 $ (12,650 ) $ 15,935
Estimated Amortization Expense of Intangible Assets	Estimated amortization for intangible assets with definite lives for the remaining six months of 2019 , the next five years ended December 31, and thereafter, is as follows (in thousands): 2019 Remaining $ 1,653 2020 3,300 2021 2,852 2022 1,251 2023 954 2024 872 Thereafter 1,457 Total $ 12,339

Other Assets (Tables)

Other Assets (Tables)	6 Months Ended
	Jun. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Assets	Other assets consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Cash surrender value of corporate-owned life insurance policies $ 4,018 $ 3,596 Deferred commissions (1) 16,597 15,530 Restricted cash 660 661 Operating lease assets 10,770 — Prepaid expenses, deposits and other 3,549 3,212 Total other long-term assets $ 35,594 $ 22,999 (1) Represents the incremental costs of obtaining contracts with customers, which consist primarily of sales commissions. These costs are ascribed to or allocated to the underlying performance obligations in the contracts and amortized consistent with the recognition timing of the revenue for the underlying performance obligations.

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2019
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued liabilities consisted of the following at June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 Accrued salaries, benefits and bonus $ 15,106 $ 19,063 Accrued professional, consulting and lobbying fees 4,688 4,894 Accrued warranty expense 1,282 898 Accrued income and other taxes 3,448 4,167 Other accrued liabilities 9,487 12,070 Accrued liabilities $ 34,011 $ 41,092

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Equity Compensation Goals	Eight Separate Revenue Goals (1) (in thousands) Eight Separate Adjusted EBITDA (CEO Performance Award) Goals (in thousands) Goal #1, $710,058 Goal #9, $125,000 Goal #2, $860,058 Goal #10, $155,000 Goal #3, $1,010,058 Goal #11, $175,000 Goal #4, $1,210,058 Goal #12, $190,000 Goal #5, $1,410,058 Goal #13, $200,000 Goal #6, $1,610,058 Goal #14, $210,000 Goal #7, $1,810,058 Goal #15, $220,000 Goal #8, $2,010,058 Goal #16, $230,000 (1) In connection with the business acquisition that was completed during the three months ended June 30, 2018, the revenue goals have been adjusted for the acquiree's Target Revenue, as defined in the CEO Performance Award agreement.
Summary of Restricted Stock Unit Activity	The following table summarizes RSU activity for the six months ended June 30, 2019 (number of units and aggregate intrinsic value in thousands): Number of Units Weighted Average Grant-Date Fair Value Aggregate Units outstanding, beginning of year 1,655 $ 28.34 Granted 5,732 34.65 Released (375 ) 23.15 Forfeited (104 ) 37.25 Units outstanding, end of period 6,908 33.73 $ 443,531
Summary of the Stock Option Activity	The following table summarizes stock option activity for the six months ended June 30, 2019 (number of units and aggregate intrinsic value in thousands): Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Life (years) Aggregate Options outstanding, beginning of year 6,458 $ 28.24 Granted — — Exercised (25 ) 4.23 Expired / terminated — — Options outstanding, end of period 6,433 28.33 8.58 $ 230,820 Options exercisable, end of period 67 4.53 1.44 4,005
Stock-Based Compensation	The following table summarizes the composition of stock-based compensation expense for the three and six months ended June 30, 2019 and 2018 (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of products sold and services delivered $ 237 $ 125 $ 463 $ 266 Sales, general and administrative expenses 4,941 2,731 9,622 5,035 Research and development expenses 3,449 2,098 6,447 3,746 Total stock-based compensation expense $ 8,627 $ 4,954 $ 16,532 $ 9,047

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Balance Sheet Disclosures	Leases (in thousands) Classification June 30, 2019 Assets Operating lease assets Other assets $ 10,770 Liabilities Current Operating Other current liabilities $ 3,814 Noncurrent Operating Other long-term liabilities 8,013 Total lease liabilities $ 11,827
Components of Lease Expense	The components of lease expense were as follows (in thousands): Classification Three Months Ended June 30, 2019 Six Months Ended June 30, 2019 Operating lease expense (1) Sales, general and administrative expenses (2) $ 1,137 $ 2,154 Sublease income Other income (95 ) (137 ) Net lease expense $ 1,042 $ 2,017 (1) Includes short-term leases, which are immaterial. (2) An immaterial portion of operating lease expense is included within research and development expenses and cost of sales. Other information related to leases was as follows (in thousands, except lease term and discount rate): Six Months Ended June 30, 2019 Supplemental Cash Flows Information Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases $ 2,017 Right-of-use assets obtained in exchange for lease liabilities: Operating leases 84 Weighted average remaining lease term: Operating leases 3.5 years Weighted average discount rate: Operating leases 3.6 %
Schedule of Future Minimum Rental Payments For Operating Leases	Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows (in thousands): Operating Sublease income Net 2019 Remaining $ 2,248 $ (164 ) $ 2,084 2020 4,224 (82 ) 4,142 2021 3,340 — 3,340 2022 2,409 — 2,409 2023 1,173 — 1,173 2024 — — — Thereafter — — — Total minimum lease payments 13,394 (246 ) 13,148 Less: Amount representing interest (1,321 ) Present value of lease payments $ 11,827
Lessor, Operating Lease, Payments to be Received, Maturity	Future minimum lease payments under non-cancellable leases as of June 30, 2019 were as follows (in thousands): Operating Sublease income Net 2019 Remaining $ 2,248 $ (164 ) $ 2,084 2020 4,224 (82 ) 4,142 2021 3,340 — 3,340 2022 2,409 — 2,409 2023 1,173 — 1,173 2024 — — — Thereafter — — — Total minimum lease payments 13,394 (246 ) 13,148 Less: Amount representing interest (1,321 ) Present value of lease payments $ 11,827
Schedule of Future Minimum Lease Payments for Capital Leases	Future minimum lease payments under non-cancelable leases at December 31, 2018, were as follows (in thousands): Operating Capital 2019 $ 3,670 $ 40 2020 3,572 36 2021 2,961 — 2022 2,001 — 2023 573 — Thereafter — — Total minimum lease payments $ 12,777 76 Less: Amount representing interest (6 ) Capital lease obligation $ 70
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under non-cancelable leases at December 31, 2018, were as follows (in thousands): Operating Capital 2019 $ 3,670 $ 40 2020 3,572 36 2021 2,961 — 2022 2,001 — 2023 573 — Thereafter — — Total minimum lease payments $ 12,777 76 Less: Amount representing interest (6 ) Capital lease obligation $ 70

Segment Data (Tables)

Segment Data (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Summary of Operational Information Relative to the Company's Reportable Segments	Information relative to our reportable segments was as follows (in thousands): Three Months Ended June 30, 2019 Three Months Ended June 30, 2018 TASER Software and Sensors 1 Total TASER Software and Sensors Total Net sales from products $ 60,423 $ 19,968 $ 80,391 $ 60,624 $ 16,097 $ 76,721 Net sales from services 149 31,822 31,971 — 22,505 22,505 Net sales 60,572 51,790 112,362 60,624 38,602 99,226 Cost of product sales 24,262 13,958 38,220 17,681 13,406 31,087 Cost of service sales — 8,582 8,582 — 4,996 4,996 Cost of sales 24,262 22,540 46,802 17,681 18,402 36,083 Gross margin $ 36,310 $ 29,250 $ 65,560 $ 42,943 $ 20,200 $ 63,143 Research and development $ 3,087 $ 20,406 $ 23,493 $ 4,019 $ 14,482 $ 18,501 Six Months Ended June 30, 2019 Six Months Ended June 30, 2018 TASER Software and Sensors 1 Total TASER Software and Sensors Total Net sales from products $ 125,724 $ 42,756 $ 168,480 $ 124,148 $ 33,547 $ 157,695 Net sales from services 239 59,453 59,692 — 42,746 42,746 Net sales 125,963 102,209 228,172 124,148 76,293 200,441 Cost of product sales 47,540 30,280 77,820 38,224 25,297 63,521 Cost of service sales — 15,875 15,875 — 9,316 9,316 Cost of sales 47,540 46,155 93,695 38,224 34,613 72,837 Gross margin $ 78,423 $ 56,054 $ 134,477 $ 85,924 $ 41,680 $ 127,604 Research and development $ 6,799 $ 40,048 $ 46,847 $ 6,979 $ 26,641 $ 33,620 1 Cost of service sales for the three and six months ended June 30, 2019 includes approximately $0.9 million

Organization and Summary of S_4

Organization and Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)segment	Dec. 31, 2018USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Number of reportable segments | segment		2
Warranty period		1 year
Corporate owned life insurance policies fair value	$ 4,018	$ 4,018	$ 3,596
Restricted cash balance	660	660	661
Impairment charge	1,300
Prepaid Expenses and Other Current Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash balance	900	900	900
Other Current Assets
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Restricted cash balance	$ 700	$ 700	$ 700

Organization and Summary of S_5

Organization and Summary of Significant Accounting Policies - Weighted Average Number of Shares Outstanding and Income Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2018	Mar. 31, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator for basic and diluted earnings per share:
Net income	$ 738	$ 6,419	$ 8,485	$ 12,926	$ 7,157	$ 21,411
Denominator:
Weighted average shares outstanding—basic (in shares)	59,187		55,527		59,051	54,330
Dilutive effect of stock-based awards (in shares)	813		1,527		825	1,562
Diluted weighted average shares outstanding (in shares)	60,000		57,054		59,876	55,892
Anti-dilutive stock-based awards excluded (in shares)	12,056		3,023		12,111	1,533
Net income per common share:
Basic (in dollars per share)	$ 0.01		$ 0.15		$ 0.12	$ 0.39
Diluted (in dollars per share)	$ 0.01		$ 0.15		$ 0.12	$ 0.38

Organization and Summary of S_6

Organization and Summary of Significant Accounting Policies - Summary of Changes in Estimated Product Warranty Liabilities (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Movement in Standard and Extended Product Warranty Accrual, Increase (Decrease) [Roll Forward]
Balance, beginning of period	$ 898	$ 644
Utilization of accrual	(250)	(149)
Warranty expense	634	10
Balance, end of period	$ 1,282	$ 505

Organization and Summary of S_7

Organization and Summary of Significant Accounting Policies Organization and Summary of Significant Accounting Policies - Adjustments to Opening Balance Sheet (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Other assets	$ 35,594	$ 35,482	$ 22,999
Total assets	746,370	732,023	719,540
Liabilities and Equity
Accrued liabilities	34,011	39,954	41,092
Other current liabilities	3,852	3,625	37
Total current liabilities	163,673	168,461	166,011
Other long-term liabilities	11,967	15,737	5,704
Total liabilities	257,443	264,699	252,216
Total liabilities and stockholders’ equity	$ 746,370	732,023	$ 719,540
Accounting Standards Update 2016-02
Assets
Other assets		12,483
Total assets		12,483
Liabilities and Equity
Accrued liabilities		(1,138)
Other current liabilities		3,588
Total current liabilities		2,450
Other long-term liabilities		10,033
Total liabilities		12,483
Total liabilities and stockholders’ equity		$ 12,483

Revenues - Revenues By Products

Revenues - Revenues By Products And Service Offerings (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 112,362	$ 99,226	$ 228,172	$ 200,441
TASER 7
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	9,298	0	19,252	0
TASER X26P
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	10,382	18,146	26,254	34,620
TASER X2
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	14,087	18,362	27,172	42,294
TASER Pulse and Bolt
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,118	1,101	1,788	2,447
Single cartridges
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	19,293	17,243	38,453	33,357
Axon Body
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	5,612	4,780	12,057	10,338
Axon Flex
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,623	1,535	2,847	3,204
Axon Fleet
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	3,120	2,715	6,636	4,831
Axon Dock
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	2,731	2,119	6,043	5,154
Axon Evidence and cloud services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	31,930	20,357	59,584	40,598
TASER Cam
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,044	762	1,947	2,122
Extended warranties
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	8,902	6,608	18,148	12,804
Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	3,222	5,498	7,991	8,672
TASER
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	60,572	60,624	125,963	124,148
TASER | TASER 7
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	9,298	0	19,252	0
TASER | TASER X26P
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	10,382	18,146	26,254	34,620
TASER | TASER X2
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	14,087	18,362	27,172	42,294
TASER | TASER Pulse and Bolt
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,118	1,101	1,788	2,447
TASER | Single cartridges
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	19,293	17,243	38,453	33,357
TASER | Axon Body
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
TASER | Axon Flex
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
TASER | Axon Fleet
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
TASER | Axon Dock
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
TASER | Axon Evidence and cloud services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	109	0	145	0
TASER | TASER Cam
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
TASER | Extended warranties
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	4,482	3,738	8,798	7,444
TASER | Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,803	2,034	4,101	3,986
Software and Sensors
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	51,790	38,602	102,209	76,293
Software and Sensors | TASER 7
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
Software and Sensors | TASER X26P
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
Software and Sensors | TASER X2
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
Software and Sensors | TASER Pulse and Bolt
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
Software and Sensors | Single cartridges
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	0	0	0	0
Software and Sensors | Axon Body
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	5,612	4,780	12,057	10,338
Software and Sensors | Axon Flex
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,623	1,535	2,847	3,204
Software and Sensors | Axon Fleet
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	3,120	2,715	6,636	4,831
Software and Sensors | Axon Dock
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	2,731	2,119	6,043	5,154
Software and Sensors | Axon Evidence and cloud services
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	31,821	20,357	59,439	40,598
Software and Sensors | TASER Cam
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	1,044	762	1,947	2,122
Software and Sensors | Extended warranties
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	4,420	2,870	9,350	5,360
Software and Sensors | Other
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from contract with customers	$ 1,419	$ 3,464	$ 3,890	$ 4,686

Revenues - Revenues By Geograph

Revenues - Revenues By Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 112,362	$ 99,226	$ 228,172	$ 200,441
United States
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	93,594	78,731	187,927	156,681
Other countries
Disaggregation of Revenue [Line Items]
Revenue from contract with customers	$ 18,768	$ 20,495	$ 40,245	$ 43,760
Revenue from Contract with Customer | Geographic Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	100.00%	100.00%	100.00%	100.00%
Revenue from Contract with Customer | Geographic Concentration Risk | United States
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	83.00%	79.00%	82.00%	78.00%
Revenue from Contract with Customer | Geographic Concentration Risk | Other countries
Disaggregation of Revenue [Line Items]
Concentration risk, percentage	17.00%	21.00%	18.00%	22.00%

Revenues - Contract Assets, Con

Revenues - Contract Assets, Contract Liabilities (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Contract assets, net	$ 26,908
Contract liabilities (deferred revenue)	187,937	$ 181,433
Revenue recognized in the period from:
Amounts included in contract liabilities at the beginning of the period	$ 58,302

Revenues - Schedule Of Contract

Revenues - Schedule Of Contract Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Current	$ 113,351	$ 107,016
Long-Term	74,586	74,417
Total	187,937	181,433
TASER
Disaggregation of Revenue [Line Items]
Current	14,502	22,152
Long-Term	32,644	32,445
Total	47,146	54,597
Software and Sensors
Disaggregation of Revenue [Line Items]
Current	98,849	84,864
Long-Term	41,942	41,972
Total	140,791	126,836
Warranty
Disaggregation of Revenue [Line Items]
Current	20,624	21,070
Long-Term	21,348	23,363
Total	41,972	44,433
Warranty | TASER
Disaggregation of Revenue [Line Items]
Current	11,110	12,797
Long-Term	16,450	16,847
Total	27,560	29,644
Warranty | Software and Sensors
Disaggregation of Revenue [Line Items]
Current	9,514	8,273
Long-Term	4,898	6,516
Total	14,412	14,789
Hardware
Disaggregation of Revenue [Line Items]
Current	38,758	30,233
Long-Term	39,344	40,283
Total	78,102	70,516
Hardware | TASER
Disaggregation of Revenue [Line Items]
Current	3,315	9,355
Long-Term	15,844	15,598
Total	19,159	24,953
Hardware | Software and Sensors
Disaggregation of Revenue [Line Items]
Current	35,443	20,878
Long-Term	23,500	24,685
Total	58,943	45,563
Software and Sensors
Disaggregation of Revenue [Line Items]
Current	53,969	55,713
Long-Term	13,894	10,771
Total	67,863	66,484
Software and Sensors | TASER
Disaggregation of Revenue [Line Items]
Current	77	0
Long-Term	350	0
Total	427	0
Software and Sensors | Software and Sensors
Disaggregation of Revenue [Line Items]
Current	53,892	55,713
Long-Term	13,544	10,771
Total	$ 67,436	$ 66,484

Revenues - Revenue Performance

Revenues - Revenue Performance Obligations (Details) $ in Millions	Jun. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	5 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, expected timing of satisfaction, period	7 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 1,050
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Minimum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation to be recognized in the next twelve months, percent	15.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil) | Maximum
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation to be recognized in the next twelve months, percent	20.00%

Cash, Cash Equivalents, and Inv

Cash, Cash Equivalents, and Investments - Summary of Cash, Cash Equivalents and Held-to-Maturity Investments by Type (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	$ 336,349	$ 349,462
Gross Unrealized Gains	44	0
Gross Unrealized Losses	(5)	0
Fair Value	336,388	349,462
Cash and Cash Equivalents	219,720	349,462
Short-term investments	116,629	0
Fair Value, Inputs, Level 2
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	118,627
Gross Unrealized Gains	44
Gross Unrealized Losses	(5)
Fair Value	118,666
Cash and Cash Equivalents	1,998
Short-term investments	116,629
Cash
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	129,347	144,095
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	129,347	144,095
Cash and Cash Equivalents	129,347	144,095
Short-term investments	0	0
Money market funds | Fair Value, Inputs, Level 1
Restricted Cash and Cash Equivalents Items [Line Items]
Amortized Cost	88,375	205,367
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	88,375	205,367
Cash and Cash Equivalents	88,375	205,367
Short-term investments	$ 0	$ 0

Inventory (Detail)

Inventory (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventory, finished goods, trial and evaluation, gross	$ 1,700	$ 1,400
Raw materials	21,784	19,670
Finished goods	19,215	14,093
Total inventory	$ 40,999	$ 33,763

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Schedule of Goodwill (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Goodwill [Roll Forward]
Balance, beginning of period	$ 24,981
Foreign currency translation adjustment	(12)
Balance, end of period	24,969
TASER Weapons
Goodwill [Roll Forward]
Balance, beginning of period	1,338
Foreign currency translation adjustment	(6)
Balance, end of period	1,332
Software and Sensors
Goodwill [Roll Forward]
Balance, beginning of period	23,643
Foreign currency translation adjustment	(6)
Balance, end of period	$ 23,637

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Intangible Assets Other than Goodwill (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Indefinite-lived Intangible Assets [Line Items]
Not amortized intangible assets, Carrying Amount	$ 2,085	$ 1,858
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	23,936	26,727
Accumulated Amortization	(11,597)	(12,650)
Total	12,339	14,077
Intangible assets, Gross Carrying Amount	26,021	28,585
Intangible assets, Net Carrying Amount	14,424	15,935
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	1,185	958
Domain names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,161	3,161
Accumulated Amortization	(884)	(732)
Total	$ 2,277	2,429
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]
Gross Carrying Amount	$ 2,993	2,940
Accumulated Amortization	(1,212)	(1,106)
Total	$ 1,781	1,834
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]
Gross Carrying Amount	$ 969	1,053
Accumulated Amortization	(511)	(599)
Total	$ 458	454
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]
Gross Carrying Amount	$ 3,697	3,701
Accumulated Amortization	(1,155)	(880)
Total	$ 2,542	2,821
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]
Gross Carrying Amount	$ 450	540
Accumulated Amortization	(394)	(439)
Total	$ 56	101
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]
Gross Carrying Amount	$ 10,660	13,404
Accumulated Amortization	(5,435)	(7,081)
Total	$ 5,225	6,323
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
Gross Carrying Amount	$ 2,006	1,928
Accumulated Amortization	(2,006)	(1,813)
Total	$ 0	$ 115

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense of intangible assets	$ 0.9	$ 1.7	$ 1.9	$ 3

Goodwill and Intangible asset_5

Goodwill and Intangible assets - Estimated Amortization Expense of Intangible Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
2019 Remaining	$ 1,653
2020	3,300
2021	2,852
2022	1,251
2023	954
2024	872
Thereafter	1,457
Total	$ 12,339	$ 14,077

Other Assets (Details)

Other Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Cash surrender value of corporate-owned life insurance policies	$ 4,018		$ 3,596
Deferred commissions	16,597		15,530
Restricted cash	660		661
Operating lease assets	10,770
Prepaid expenses, deposits and other	3,549		3,212
Total other long-term assets	$ 35,594	$ 35,482	$ 22,999

Accrued Liabilities (Detail)

Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued salaries, benefits and bonus	$ 15,106		$ 19,063
Accrued professional, consulting and lobbying fees	4,688		4,894
Accrued warranty expense	1,282		898	$ 505	$ 644
Accrued income and other taxes	3,448		4,167
Other accrued liabilities	9,487		12,070
Accrued liabilities	$ 34,011	$ 39,954	$ 41,092

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) $ in Millions	6 Months Ended
	Jun. 30, 2019USD ($)
Tax Credit Carryforward [Line Items]
Deferred tax assets, net	$ 20.7
Unrecognized tax benefits	6.2
Research and development tax credit studies	$ 2.9
Overall effective tax rate, after discrete period adjustments (as a percentage)	(29.30%)
Effective tax rate, before discrete period adjustment (as a percentage)	21.40%
Write off of certain deferred tax assets	$ 0.6
Restricted Stock Units (RSUs)
Tax Credit Carryforward [Line Items]
Discrete tax benefit, stock-based compensation	3.3
State Tax
Tax Credit Carryforward [Line Items]
Unrecognized tax benefits recognized during period	6.1
Federal Income Tax
Tax Credit Carryforward [Line Items]
Unrecognized tax benefits recognized during period	$ 0.1

Shareholders' Equity - CEO Perf

Shareholders' Equity - CEO Performance Award - Additional Information (Details) $ in Thousands	May 24, 2018USD ($)trancheshares	Jun. 30, 2019USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
First tranche	$ 2,500,000
Tranche incremental increase	$ 1,000,000
Revenue goal number 1		$ 710,058
Revenue goal number 2		860,058
Revenue goal number 3		1,010,058
Revenue goal number 4		1,210,058
Revenue goal number 5		1,410,058
Revenue goal number 6		1,610,058
Revenue goal number 7		1,810,058
Revenue goal number 8		2,010,058
Adjusted EBITDA goal number 9		125,000
Adjusted EBITDA goal number 10		155,000
Adjusted EBITDA goal number 11		175,000
Adjusted EBITDA goal number 12		190,000
Adjusted EBITDA goal number 13		200,000
Adjusted EBITDA goal number 14		210,000
Adjusted EBITDA goal number 15		220,000
Adjusted EBITDA goal number 16		230,000
Total revenue		710,100
Adjusted EBITDA		125,000
Recorded share-based compensation expense		$ 6,100
Number of options expected to vest | shares		1,100,000
Weighted average period over which costs are recognized		7 years 2 months 12 days
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of vesting tranches | tranche	12
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares	6,365,856
Unrecognized share-based compensation cost related to unvested stock option awards, probable of achievement		$ 39,100
Unrecognized share-based compensation cost related to unvested stock option awards, not probable of achievement		$ 200,700

Stockholders' Equity Stockholde

Stockholders' Equity Stockholders' Equity - eXponential Stock Performance Plan (Details) $ in Millions	Feb. 12, 2019	May 24, 2018USD ($)shares	Jan. 31, 2019shares	Jun. 30, 2019USD ($)trancheshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
First tranche		$ 2,500
Tranche incremental increase		$ 1,000
Recorded share-based compensation expense				$ 6.1
Number of options expected to vest | shares				1,100,000
Weighted average period over which costs are recognized				7 years 2 months 12 days
eXponential Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units, granted (in shares) | shares			60	5,200,000
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares		6,365,856
Unrecognized share-based compensation cost related to unvested stock option awards, probable of achievement				$ 39.1
Unrecognized share-based compensation cost related to unvested stock option awards, not probable of achievement				$ 200.7
2019 eXponential Stock Performance Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period over which costs are recognized				7 years 2 months 12 days
2019 eXponential Stock Performance Plan | eXponential Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares authorized (in shares) | shares				5,200,000
Number of vesting tranches | tranche				12
First tranche				$ 2,500
Tranche incremental increase				1,000
Recorded share-based compensation expense				$ 1.9
Number of options expected to vest | shares				900,000
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period	9 years
Post-vest holding period				2 years 6 months
Expected term				9 years
Dividend yield (as a percentage)				0.00%
2019 eXponential Stock Performance Plan | Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized share-based compensation cost related to unvested stock option awards, probable of achievement				$ 35.5
Unrecognized share-based compensation cost related to unvested stock option awards, not probable of achievement				$ 136.5
2019 eXponential Stock Performance Plan | Minimum | eXponential Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liquidity discount (as a percentage)				10.00%
Risk-free interest rate (as a percentage)				2.47%
Expected volatility (as a percentage)				44.96%
2019 eXponential Stock Performance Plan | Maximum | eXponential Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liquidity discount (as a percentage)				16.80%
Risk-free interest rate (as a percentage)				2.62%
Expected volatility (as a percentage)				45.47%

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Restricted Stock Unit Activity (Detail) - Restricted Stock $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Number of Units outstanding, beginning of year (in shares) | shares	1,655
Units released due to performance criteria threshold (in shares) | shares	(375)
Number of Units, Forfeited (in shares) | shares	(104)
Number of Units outstanding, end of period (in shares) | shares	6,908
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Units outstanding, beginning of year (in dollars per share)	$ 28.34
Weighted Average Grant Date Fair Value, Granted (in dollars per share)	34.65
Weighted Average Grant Date Fair Value, Released (in dollars per share)	23.15
Weighted Average Grant Date Fair Value, Forfeited (in dollars per share)	37.25
Weighted Average Grant Date Fair Value, Units outstanding, end of period (in dollars per share)	$ 33.73
Aggregate intrinsic value at end of period | $	$ 443,531

Stockholders' Equity - Restrict

Stockholders' Equity - Restricted Stock Units - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	6 Months Ended
	Jan. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period over which costs are recognized		7 years 2 months 12 days
Tax payments, for net share settlement of share based award		$ 2,132	$ 10,807
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value price per share (in dollars per share)		$ 64.21
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized stock-based compensation expense related to non-vested stock options		$ 79,500
Weighted average period over which costs are recognized		4 years 5 months 26 days
Units released due to performance criteria threshold (in shares)		375,000
Number of units outstanding (as a percentage)		6,908,000		1,655,000
Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units, granted (in shares)		5,300,000
Units released due to performance criteria threshold (in shares)		4,000,000
Number of units outstanding (as a percentage)		5,600,000
Maximum additional shares to be issued (in shares)		300,000
eXponential Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units, granted (in shares)	60	5,200,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units, granted (in shares)		5,732,000
Shares withheld, for net share settlement of share based award (in shares)		29,000
Tax payments, for net share settlement of share based award		$ 2,100
Service Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of units, granted (in shares)		400,000
Minimum | Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of targeted shares vested		0.00%
Maximum | Performance Based Restricted Stock Unit
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of targeted shares vested		200.00%

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of the Company's Stock Options Activity (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options expected to vest	1,100
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Number of options, Options outstanding, beginning of year (in shares)	6,458
Number of options, Granted (in shares)	0
Number of options, Exercised (in shares)	(25)
Number of options, Expired / terminated (in shares)	0
Number of options, Options outstanding, end of year (in shares)	6,433
Number of options, Options exercisable, end of period (in shares)	67
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted average exercise price, Options outstanding, beginning of year (in dollars per share) | $ / shares	$ 28.24
Weighted average exercise price, Granted (in dollars per share) | $ / shares	0
Weighted average exercise price, Exercised (in dollars per share) | $ / shares	4.23
Weighted average exercise price, Expired / terminated (in dollars per share) | $ / shares	0
Weighted average exercise price, Options outstanding, end of period (in dollars per share) | $ / shares	28.33
Weighted average exercise price, Options exercisable, end of period (in dollars per share) | $ / shares	$ 4.53
Weighted average remaining contractual life, Options outstanding, end of period	8 years 6 months 29 days
Weighted average remaining contractual life, Options exercisable, end of period	1 year 5 months 8 days
Aggregate intrinsic value, Options outstanding, end of period | $	$ 230,820
Aggregate intrinsic value, Options exercisable, end of period | $	$ 4,005

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value price per share (in dollars per share)	$ 64.21
Total intrinsic value of options exercised	$ 1.1	$ 18.8
Number of options outstanding (in shares)	6,433		6,458
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of options outstanding (in shares)	6,400
Options related to tranches considered probable of achievement	1,100

Stockholders' Equity - Reported

Stockholders' Equity - Reported Share-Based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,627	$ 4,954	$ 16,532	$ 9,047
Cost of products sold and services delivered
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	237	125	463	266
Sales, general and administrative expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,941	2,731	9,622	5,035
Research and development expenses
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 3,449	$ 2,098	$ 6,447	$ 3,746

Stockholders' Equity - Stock Re

Stockholders' Equity - Stock Repurchase Plan - Additional Information (Detail) - USD ($)	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Feb. 01, 2019	Feb. 29, 2016
2019 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional authorized shares (in shares)	2,100,000		6,000,000
2016 Stock Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding common stock repurchase program authorized amount (up to)				$ 50,000,000
Shares repurchased during period (in shares)	0	0
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 16,300,000

Line of Credit - Additional Inf

Line of Credit - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Maximum ratio of total liabilities to tangible net worth	2.50
Line of Credit
Debt Instrument [Line Items]
Available borrowing under letter of credit	$ 45,600,000
Line of credit facility, increase (decrease), net	100,000,000
Line of credit borrowings	0	$ 0
Letters of credit outstanding amount	$ 4,400,000
Company's leverage ratio	0.001
Unsecured Revolving Line of Credit | Line of Credit
Debt Instrument [Line Items]
Total availability under line of credit agreement	$ 50,000,000
Letter of Credit | Line of Credit
Debt Instrument [Line Items]
Available borrowing under letter of credit	$ 10,000,000
Minimum | London Interbank Offered Rate (LIBOR) | Line of Credit
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate	1.00%
Maximum | London Interbank Offered Rate (LIBOR) | Line of Credit
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate	1.50%

Leases Leases - Narrative (Deta

Leases Leases - Narrative (Details) - USD ($) $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Lessee, Lease, Description [Line Items]
Renewal term	2 years
Termination period	1 year
Rent expense		$ 4.2	$ 2.9
Minimum
Lessee, Lease, Description [Line Items]
Remaining terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining terms	4 years

Leases Leases - Balance Sheet (

Leases Leases - Balance Sheet (Details) $ in Thousands	Jun. 30, 2019USD ($)
ASSETS
Operating lease assets, other assets	$ 10,770
Current
Operating lease, current liabilities	3,814
Noncurrent
Operating lease, noncurrent liabilites	8,013
Total lease liabilities	$ 11,827

Leases Leases - Lease Expense (

Leases Leases - Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 1,137	$ 2,154
Sublease income	(95)	(137)
Net lease expense	$ 1,042	$ 2,017

Leases Leases - Supplemental Ca

Leases Leases - Supplemental Cash Flow and Balance Sheet Information (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019USD ($)
Cash Flow, Lessee [Abstract]
Operating cash flows from operating leases	$ 2,017
Right-Of-Use Asset Obtained In Exchange For Lease Liability [Abstract]
Operating leases	$ 84
Weighted Average Remaining Lease Term [Abstract]
Operating leases (in years)	3 years 6 months
Leases, Weighted Average Discount Rate [Abstract]
Operating leases (as a percentage)	3.60%

Leases Leases - Minimum Lease P

Leases Leases - Minimum Lease Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Operating Leases, After Adoption of 842
2019 Remaining	$ 2,248
2020	4,224
2021	3,340
2022	2,409
2023	1,173
2024	0
Thereafter	0
Total minimum lease payments	13,394
Sublease income, After Adoption of 842
2019 Remaining	(164)
2020	(82)
2021	0
2022	0
2023	0
2024	0
Thereafter	0
Total minimum lease payments	(246)
Net, After Adoption of 842
2019 Remaining	2,084
2020	4,142
2021	3,340
2022	2,409
2023	1,173
2024	0
Thereafter	0
Total minimum lease payments	13,148
Less: Amount representing interest	(1,321)
Present value of lease payments	$ 11,827
Operating Leases, Before Adoption of 842
2019		$ 3,670
2020		3,572
2021		2,961
2022		2,001
2023		573
Thereafter		0
Total minimum lease payments		12,777
Capital Leases, Before Adoption of 842
2019		40
2020		36
2021		0
2022		0
2023		0
Thereafter		0
Total minimum lease payments		76
Less: Amount representing interest		(6)
Capital lease obligation		$ 70

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended		6 Months Ended
	Jul. 31, 2019USD ($)	Jun. 30, 2019USD ($)lawsuit	Jun. 30, 2019USD ($)lawsuit	Jun. 30, 2018USD ($)
Loss Contingencies [Line Items]
Purchases of intangible assets			$ 344	$ 254
Prepaid rent under the lease			10,900
Initial deposit		$ 200	200
Purchase commitment period		3 years
Purchase obligation		$ 50,000	$ 50,000
Number of lawsuits against Company | lawsuit		7	7
Self insurance on product claim		$ 5,000	$ 5,000
Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		24,600	24,600
Expiring in 2019 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		400	400
Expiring in 2020 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		700	700
Expiring in 2021 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		2,300	2,300
Expiring in 2022 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		3,200	3,200
Expiring in 2023 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		7,500	7,500
Expiring in 2024 | Surety Bond
Loss Contingencies [Line Items]
Bonds outstanding		10,500	10,500
Line of Credit
Loss Contingencies [Line Items]
Letters of credit outstanding amount		$ 4,400	4,400
Lease Agreements
Loss Contingencies [Line Items]
Purchases of intangible assets			$ 13,100
Subsequent Event
Loss Contingencies [Line Items]
Up-front prepayment	$ 15,000

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Related Party Transaction [Line Items]
Outstanding amount due to related parties	$ 0		$ 0
Software Licensing and Subscription | Officer
Related Party Transaction [Line Items]
Quarterly payments	$ 500,000	$ 400,000	$ 1,000,000	$ 900,000

Employee Benefit Plans - Additi

Employee Benefit Plans - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Employee deferrals deemed vested percentage upon contribution			100.00%
Defined contribution plan, cost	$ 1.1	$ 0.8	$ 2.5	$ 1.6
Maximum
Defined Benefit Plan Disclosure [Line Items]
Deferral percentage of base salary (up to)			80.00%
Deferral percentage of other compensation (up to)			100.00%

Segment Data - Additional Infor

Segment Data - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)segment	Jun. 30, 2018USD ($)
Segment Reporting [Abstract]
Number of reportable segments of company | segment			2
Segment Reporting Information [Line Items]
Net sales	$ 112,362	$ 99,226	$ 228,172	$ 200,441
Cost of sales	46,802	36,083	93,695	72,837
Gross margin	65,560	63,143	134,477	127,604
Research and development	23,493	18,501	46,847	33,620
TASER
Segment Reporting Information [Line Items]
Net sales	60,572	60,624	125,963	124,148
Cost of sales	24,262	17,681	47,540	38,224
Gross margin	36,310	42,943	78,423	85,924
Research and development	3,087	4,019	6,799	6,979
Software and Sensors
Segment Reporting Information [Line Items]
Net sales	51,790	38,602	102,209	76,293
Cost of sales	22,540	18,402	46,155	34,613
Gross margin	29,250	20,200	56,054	41,680
Research and development	20,406	14,482	40,048	26,641
Product
Segment Reporting Information [Line Items]
Net sales	80,391	76,721	168,480	157,695
Cost of sales	38,220	31,087	77,820	63,521
Product | TASER
Segment Reporting Information [Line Items]
Net sales	60,423	60,624	125,724	124,148
Cost of sales	24,262	17,681	47,540	38,224
Product | Software and Sensors
Segment Reporting Information [Line Items]
Net sales	19,968	16,097	42,756	33,547
Cost of sales	13,958	13,406	30,280	25,297
Service
Segment Reporting Information [Line Items]
Net sales	31,971	22,505	59,692	42,746
Cost of sales	8,582	4,996	15,875	9,316
Service | TASER
Segment Reporting Information [Line Items]
Net sales	149	0	239	0
Cost of sales	0	0	0	0
Service | Software and Sensors
Segment Reporting Information [Line Items]
Net sales	31,822	22,505	59,453	42,746
Cost of sales	$ 8,582	$ 4,996	15,875	$ 9,316
Service, Installation Costs | Software and Sensors
Segment Reporting Information [Line Items]
Cost of sales			$ 900

Uncategorized Items - aaxnq2201

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 18,994,000
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	2,470,000
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	1,573,000
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 18,994,000