AtriCure (ATRC) 10-Q 31 Jul 15 2015 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2015	Jul. 24, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q2
Trading Symbol	ATRC
Entity Registrant Name	AtriCure, Inc.
Entity Central Index Key	1,323,885
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		28,537,331

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 29,987	$ 28,384
Short-term investments	24,492	31,265
Accounts receivable, less allowance for doubtful accounts of $184 and $68, respectively	17,590	17,558
Inventories	16,073	14,257
Other current assets	2,597	2,044
Total current assets	90,739	93,508
Property and equipment, net	19,352	11,552
Long-term investments	5,209	8,894
Intangible assets, net	8,272	8,878
Goodwill	35,386	35,386
Other noncurrent assets	351	186
Total Assets	159,309	158,404
Current liabilities:
Accounts payable	9,344	7,621
Accrued liabilities	11,560	14,041
Other current liabilities and current maturities of capital leases	9,237	3,981
Total current liabilities	30,141	25,643
Capital leases	68	74
Other noncurrent liabilities	409	149
Total Liabilities	$ 30,618	$ 25,866
Commitments and contingencies (Note 7)
Stockholders' Equity:
Common stock, $0.001 par value, 90,000 shares authorized and 28,537 and 27,580 issued and outstanding, respectively	$ 28	$ 28
Additional paid-in capital	277,787	271,282
Accumulated other comprehensive loss	(543)	(348)
Accumulated deficit	(148,581)	(138,424)
Total Stockholders' Equity	128,691	132,538
Total Liabilities and Stockholders' Equity	$ 159,309	$ 158,404

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 184	$ 68
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares issued	28,537,000	27,580,000
Common stock, shares outstanding	28,537,000	27,580,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Statement [Abstract]
Revenue	$ 32,583	$ 26,514	$ 62,469	$ 51,361
Cost of revenue	9,466	7,733	17,617	14,923
Gross profit	23,117	18,781	44,852	36,438
Operating expenses:
Research and development expenses	5,862	4,569	11,471	8,570
Selling, general and administrative expenses	22,074	17,065	43,344	38,646
Total operating expenses	27,936	21,634	54,815	47,216
Loss from operations	(4,819)	(2,853)	(9,963)	(10,778)
Other income (expense):
Interest expense	(17)	(29)	(35)	(266)
Interest income	43	23	86	37
Other	(90)	172	(231)	638
Loss before income tax expense	(4,883)	(2,687)	(10,143)	(10,369)
Income tax expense	8	5	14	32
Net loss	$ (4,891)	$ (2,692)	$ (10,157)	$ (10,401)
Basic and diluted net loss per share	$ (0.18)	$ (0.10)	$ (0.37)	$ (0.40)
Weighted average shares outstanding-basic and diluted	27,304	26,849	27,187	25,813
Comprehensive loss:
Unrealized gains (losses) on investments	$ 2	$ (11)	$ 39	$ (13)
Foreign currency translation adjustment	253	(28)	(234)	(26)
Other comprehensive income (loss)	255	(39)	(195)	(39)
Net loss	(4,891)	(2,692)	(10,157)	(10,401)
Comprehensive loss	$ (4,636)	$ (2,731)	$ (10,352)	$ (10,440)

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Cash flows from operating activities:
Net loss	$ (10,157)	$ (10,401)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	4,141	3,988
Depreciation	2,087	1,506
Amortization of intangible assets	606	711
Amortization of deferred financing costs	31	80
Loss on disposal of property and equipment	63	14
Realized loss from foreign exchange on intercompany transactions	302
Amortization/accretion on investments	339	163
Change in allowance for doubtful accounts	117	32
Change in value of contingent consideration		(2,662)
Other		95
Changes in operating assets and liabilities:
Accounts receivable	(468)	(1,448)
Inventories	(1,977)	(2,457)
Other current assets	(538)	572
Accounts payable	1,128	(936)
Accrued liabilities	(2,196)	(6,704)
Other noncurrent assets and liabilities	128	(926)
Net cash used in operating activities	(6,394)	(18,373)
Cash flows from investing activities:
Purchases of available-for-sale securities	(10,302)	(27,322)
Sales and maturities of available-for-sale securities	20,460	13,749
Purchases of property and equipment	(4,077)	(2,475)
Increases in property under build-to-suit obligation	(4,806)
Net cash provided by (used in) investing activities	1,275	(16,048)
Cash flows from financing activities:
Proceeds from sale of stock, net of offering costs of $0 and $257, respectively		65,830
Payments on debt and capital leases	(25)	(6,352)
Increases in build-to-suit obligation	4,806
Payment of debt fees and premium on retirement of debt	(62)	(169)
Proceeds from stock option exercises	1,854	1,637
Shares repurchased for payment of taxes on stock awards	(572)	(153)
Proceeds from issuance of common stock under employee stock purchase plan	906	708
Net cash provided by financing activities	6,907	61,501
Effect of exchange rate changes on cash and cash equivalents	(185)	6
Net increase in cash and cash equivalents	1,603	27,086
Cash and cash equivalents-beginning of period	28,384	14,892
Cash and cash equivalents-end of period	29,987	41,978
Supplemental cash flow information:
Cash paid for interest	3	109
Cash paid for taxes	20	146
Non-cash investing and financing activities:
Accrued purchases of property and equipment	1,652	137
Assets acquired through capital lease	$ 36	$ 8

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) (Parenthetical) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Statement of Cash Flows [Abstract]
Offering cost for sale of stock	$ 0	$ 257

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Summary of Significant Accounting Policies	1. DESCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of the Business Basis of Presentation The accompanying Condensed Consolidated Financial Statements should be read in conjunction with the audited financial statements of the Company included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 filed with the SEC. Principles of Consolidation Cash and Cash Equivalents Investments Revenue Recognition Pursuant to the Company’s standard terms of sale, revenue is recognized when title to the goods and risk of loss transfers to customers and there are no remaining obligations that will affect the customers’ final acceptance of the sale. Generally, the Company’s standard terms of sale define the transfer of title and risk of loss to occur upon shipment to the respective customer. The Company generally does not maintain any post-shipping obligations to the recipients of the products. No installation, calibration or testing of this equipment is performed by the Company subsequent to shipment to the customer in order to render it operational. Revenue includes shipping and handling revenue of $271 and $236 for the three months ended June 30, 2015 and 2014, respectively, and $518 and $463 for the six months ended June 30, 2015 and 2014, respectively. Cost of freight for shipments made to customers is included in cost of revenue. Sales and other value-added taxes collected from customers and remitted to governmental authorities are excluded from revenue. The Company sells its products primarily through a direct sales force, with certain international markets sold through distributors. Terms of sale are generally consistent for both end-users and distributors except that payment terms are generally net 30 days for end-users and net 60 days for distributors. Sales Returns and Allowances Allowance for Doubtful Accounts Receivable Inventories Inventories consist of the following: June 30, 2015 December 31, Raw materials $ 5,286 $ 4,429 Work in process 1,251 1,397 Finished goods 9,536 8,431 Inventories $ 16,073 $ 14,257 Property and Equipment Generators and other capital equipment (such as the Company’s switchbox units and cryosurgical consoles) are loaned at no cost to direct customers that use the Company’s disposable products. Depreciation of such assets is included in cost of revenue. The estimated useful lives of this equipment are based on anticipated usage by customers and the timing and impact of expected new technology rollouts by the Company. To the extent the Company experiences changes in the usage of this equipment or introduces new technologies, the estimated useful lives of this equipment may change in a future period. Depreciation related to these generators was $673 and $498 for the three months ended June 30, 2015 and 2014, respectively, and $1,293 and $959 for the six months ended June 30, 2015 and 2014, respectively. As of June 30, 2015 and December 31, 2014, the net carrying amount of loaned equipment included in net property and equipment in the Condensed Consolidated Balance Sheets was $4,799 and $4,141, respectively. The Company reviews property and equipment for impairment using its best estimates based on reasonable and supportable assumptions and projections. Intangible Assets Goodwill— Other Current Liabilities and Current Maturities of Capital Leases— Other Income The Company recorded net foreign currency transaction (losses) gains of ($46) and $16 for the three months ended June 30, 2015 and 2014, respectively, and ($209) and $21 for the six months ended June 30, 2015 and 2014, respectively, primarily in connection with settlements of its intercompany balance with AtriCure Europe. The Company periodically is awarded grants to support research and development activities or education activities. The Company recognizes grant income when the funds are earned. The Company recorded grant income of $0 and $137 during the three months ended June 30, 2015 and 2014, respectively. Grant income of $35 and $500 was recorded for the six month periods ended June 30, 2015 and 2014, respectively. The Company historically issued stock options to non-employee consultants as a form of compensation for services provided to the Company. Because the non-employee options require settlement by the Company’s delivery of registered shares and because the tax withholding provisions in the awards allow the options to be partially net-cash settled, these options, when vested, are no longer eligible for equity classification and are, thus, subsequently accounted for as derivative liabilities under FASB ASC 815, “Derivatives and Hedging” (ASC 815) until the awards are ultimately either exercised or forfeited. Accordingly, the vested non-employee options are classified as liabilities and remeasured at fair value through earnings at each reporting period. During the three months ended June 30, 2015 and 2014, $44 and ($19), respectively, of expense (income) was recorded as a result of the remeasurement of the fair value of these fully vested stock options. During the six months ended June 30, 2015 and 2014, $57 and ($117), respectively, of expense (income) was recorded as a result of the remeasurement of the fair value of these fully vested stock options. Taxes The Company’s estimate of the valuation allowance for deferred tax assets requires it to make significant estimates and judgments about its future operating results. Deferred tax assets are reduced by valuation allowances if, based on the consideration of all available evidence, it is more-likely-than-not that some portion of the deferred tax asset will not be realized. Significant weight is given to evidence that can be objectively verified. The Company evaluates deferred tax assets on a quarterly basis to determine if valuation allowances are required by considering all available evidence. Deferred tax assets are realized by having sufficient future taxable income to allow the related tax benefits to reduce taxes otherwise payable. The sources of taxable income that may be available to realize the benefit of deferred tax assets are future reversals of existing taxable temporary differences, future taxable income, exclusive of reversing temporary differences and carryforwards, taxable income in carry-back years and tax planning strategies that are both prudent and feasible. In evaluating whether to record a valuation allowance, the applicable accounting standards deem that the existence of cumulative losses in recent years is a significant piece of objectively verifiable negative evidence that must be overcome by objectively verifiable positive evidence to avoid the need to record a valuation allowance. The Company has recorded a full valuation allowance against its net deferred tax assets as it is more-likely-than-not that the benefit of the deferred tax assets will not be recognized in future periods. A provision of The Patient Protection and Affordable Care Act enacted in 2010, as amended (Affordable Care Act), requires manufacturers of medical devices to pay an excise tax on all U.S. medical device sales. The Company’s expense related to the medical device excise tax, which was recorded in cost of revenue, was $149 and $116 for the three months ended June 30, 2015 and 2014, respectively, and $304 and $230 for the six months ended June 30, 2015 and 2014, respectively. Net Loss Per Share Comprehensive Loss and Accumulated Other Comprehensive Loss Accumulated other comprehensive income (loss) consisted of the following: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Total accumulated other comprehensive (loss) income at beginning of period $ (798 ) $ (139 ) $ (348 ) $ (139 ) Unrealized Gains on Investments Balance at beginning of period $ (17 ) $ (8 ) $ (54 ) $ (6 ) Other comprehensive income (loss) before reclassifications 2 (11 ) 39 (13 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations — — — — Balance at end of period $ (15 ) $ (19 ) $ (15 ) $ (19 ) Foreign Currency Translation Adjustment Balance at beginning of period $ (781 ) $ (131 ) $ (294 ) $ (133 ) Other comprehensive income (loss) before reclassifications 392 (44 ) 68 (47 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations (139 ) 16 (302 ) 21 Balance at end of period $ (528 ) $ (159 ) $ (528 ) $ (159 ) Total accumulated other comprehensive loss at end of period $ (543 ) $ (178 ) $ (543 ) $ (178 ) Research and Development Advertising Costs — Share-Based Compensation FASB ASC 718 requires companies to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s Condensed Consolidated Statement of Operations and Comprehensive Loss. The expense has been reduced for estimated forfeitures. FASB ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company estimates the fair value of time-based options on the date of grant using the Black-Scholes option-pricing model (Black-Scholes model). The Company’s determination of fair value of share-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price, as well as assumptions regarding a number of subjective variables. These variables include, but are not limited to, the Company’s expected stock price volatility over the term of the awards and actual and projected employee stock option exercise behaviors. The fair value of market-based performance option grants is estimated at the date of grant using a Monte-Carlo simulation. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Condensed Consolidated Statements of Operations and Comprehensive Loss. The Company estimates the fair value of restricted stock based upon the grant date closing market price of the Company’s common stock. The Company’s determination of fair value is affected by the Company’s stock price as well as assumptions regarding the number of shares expected to be granted. The Company also has an employee stock purchase plan (ESPP or the Plan) which is available to all eligible employees as defined by the Plan. Under the ESPP, shares of the Company’s common stock may be purchased at a discount. The Company estimates the number of shares to be purchased under the Plan and records compensation expense based upon the fair value of the stock at the beginning of the purchase period using the Black-Scholes model. Use of Estimates Fair Value Disclosures

Recent Accounting Pronouncement

Recent Accounting Pronouncements	6 Months Ended
	Jun. 30, 2015
Accounting Changes and Error Corrections [Abstract]
Recent Accounting Pronouncements	2. RECENT ACCOUNTING PRONOUNCEMENTS In May 2014 the FASB issued a final standard on revenue from contracts with customers. The standard, issued as FASB ASU 2014-09, “Revenue from Contracts with Customers” (ASU 2014-09), outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance. In July 2015 the FASB decided to defer the effective date of ASU 2014-09 for entities reporting under U.S. GAAP from interim and annual reporting periods beginning after December 15, 2016 to interim and annual reporting periods beginning after December 15, 2017 and allow early adoption as of the original effective date. A full retrospective or modified retrospective approach may be taken to adopt the guidance in the ASU. The Company is evaluating the impact of the provisions of ASU 2014-09 on its consolidated financial position, results of operations and related disclosures. In June 2015 the FASB issued ASU 2015-10, “Technical Corrections and Improvements” (ASU 2015-10), which amends a wide range of topics in the FASB Accounting Standards Codification. The amendments make minor corrections or minor improvements to the Codification and are effective for fiscal year and interim periods within those fiscal years beginning after December 15, 2015. The Company is reviewing the amendments in ASU 2015-10 and expects that the new guidance will not have a material impact on the Company’s financial reporting. In July 2015 the FASB issued ASU 2015-11, “Simplifying the Measurement of Inventory” (ASU 2015-11), which requires entities to measure most inventory at the lower of cost and net realizable value, thereby simplifying the current guidance under which an entity must measure inventory at the lower of cost or market. ASU 2015-11 is effective prospectively for annual periods beginning after December 15, 2016 and interim periods therein. Early application is permitted. The Company is reviewing the provisions of ASU 2015-11 and expects that the new guidance will not have a material impact on the Company’s financial reporting.

Fair Value

Fair Value	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value	3. FAIR VALUE FASB ASC 820, “Fair Value Measurements and Disclosures” (ASC 820) defines fair value as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value which are the following: • Level 1—Quoted prices in active markets for identical assets or liabilities that the Company has the ability to access at the measurement date. An active market for the asset or liability is a market in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an ongoing basis. The valuation under this approach does not entail a significant degree of judgment. • Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The valuation technique for the Company’s Level 2 assets is based on quoted market prices for similar assets from observable pricing sources at the reporting date. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. Unobservable inputs shall be used to measure fair value to the extent that observable inputs are not available, thereby allowing for situations in which there is little, if any, market activity for the asset or liability at the measurement date. The fair value of the Company’s Level 3 instruments are estimated on the grant date using the Black-Scholes model and they are revalued at the end of each reporting period using the Black-Scholes model. The fair value of the Company’s Level 3 contingent consideration was estimated on the acquisition date of Endoscopic Technologies, Inc. and was revalued at the end of each subsequent reporting period. In accordance with ASC 820, the following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value on a recurring basis as of June 30, 2015: Quoted Prices in Significant Other Significant Other Total Assets: Money market funds $ — $ 23,237 $ — $ 23,237 U.S. government agencies and securities 1,016 — — 1,016 Corporate bonds — 28,685 — 28,685 Total assets $ 1,016 $ 51,922 $ — $ 52,938 There were no changes in the levels or methodology of measurement of financial assets and liabilities during the three or six month periods ended June 30, 2015. In accordance with ASC 820, the following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2014: Quoted Prices in Significant Other Significant Other Total Assets: Money market funds $ — $ 23,692 $ — $ 23,692 Commercial paper — 1,800 — 1,800 U.S. government agencies and securities 3,022 — — 3,022 Corporate bonds — 35,337 — 35,337 Total assets $ 3,022 $ 60,829 $ — $ 63,851 Liabilities: Derivative instruments $ — $ — $ 120 $ 120 Acquisition-related contingent consideration — — — — Total liabilities $ — $ — $ 120 $ 120 There were no changes in the levels or methodology of measurement of financial assets and liabilities during the twelve months ended December 31, 2014. Derivative Instruments. In accordance with ASC 820, the following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for derivative instruments as of June 30, 2015: Beginning Balance–January 1, 2015 $ 120 Total losses included in earnings 57 Exercises (177 ) Reclassification from equity to liability when fully vested — Ending Balance–June 30, 2015 $ — In accordance with ASC 820, the following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for derivative instruments as of December 31, 2014: Beginning Balance–January 1, 2014 $ 350 Total gains included in earnings (183 ) Exercises (47 ) Reclassification from equity to liability when fully vested — Ending Balance–December 31, 2014 $ 120 Acquisition-Related Contingent Consideration. The following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for acquisition-related contingent consideration as of December 31, 2014: Beginning Balance – January 1, 2014 $ 8,032 Amounts acquired — Transfers in (out) of Level 3 — Changes in fair value included in earnings (8,032 ) Ending Balance – December 31, 2014 $ —

Intangible Assets

Intangible Assets	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	4. INTANGIBLE ASSETS The following table provides a summary of the Company’s intangible assets with definite lives: June 30, 2015 December 31, 2014 Cost Accumulated Cost Accumulated Non-compete agreement $ 100 $ 99 $ 100 $ 93 Fusion technology 9,242 1,386 9,242 924 Clamp & probe technology 829 414 829 276 Estech trade name 208 208 208 208 Total $ 10,379 $ 2,107 $ 10,379 $ 1,501 Amortization expense related to intangible assets with definite lives was $303 and $356 for the three months ended June 30, 2015 and 2014, respectively, and $606 and $711 for the six months ended June 30, 2015 and 2014, respectively. Future amortization expense related to intangible assets with definite lives is projected as follows: 2015 $ 602 July 1, 2015 through December 31, 2015 2016 1,201 2017 924 2018 924 2019 924 2020 and thereafter 3,697 Total $ 8,272

Accrued Liabilities

Accrued Liabilities	6 Months Ended
	Jun. 30, 2015
Payables and Accruals [Abstract]
Accrued Liabilities	5. ACCRUED LIABILITIES Accrued liabilities consisted of the following: June 30, 2015 December 31, Accrued commissions $ 4,025 $ 4,477 Accrued bonus 3,374 4,915 Accrued payroll and employee-related expenses 2,381 2,281 Accrued taxes and value-added taxes payable 735 1,272 Other accrued liabilities 535 399 Accrued royalties 377 442 Sales returns allowance 133 135 Accrued non-employee stock options — 120 Total $ 11,560 $ 14,041

Indebtedness

Indebtedness	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Indebtedness	6. INDEBTEDNESS The Company has a debt agreement with Silicon Valley Bank (SVB). The agreement, as amended, restated and modified, includes a $15,000 revolving credit facility which matures on April 30, 2018. Borrowing availability under the revolving credit facility is based on the lesser of $15,000 or a borrowing base calculation as defined by the agreement. As of June 30, 2015 the Company had no borrowings under the revolving credit facility and had borrowing availability of approximately $13,872. Effective March 31, 2015, the Company and SVB entered into an Eighth Loan Modification Agreement (Loan Modification Agreement) which sets forth certain amendments to the Company’s credit facility. The Loan Modification Agreement provides for (i) an increase in the limit of outstanding letters of credit from $1,000 to $2,000, (ii) an extension of the revolving line maturity date from April 30, 2016 to April 30, 2018 and (iii) modifications to certain covenants and other terms of the agreement. As of December 31, 2014 the Company had an outstanding letter of credit of €75 issued to its European subsidiary’s corporate credit card program provider which was due to expire on June 30, 2015. The letter of credit was cancelled in June 2015. As of June 30, 2015 the Company had capital leases for computer and office equipment that expire at various terms through 2020. The cost of the assets under lease was $197. The assets are depreciated over their estimated useful lives, which equal the terms of the leases. Accumulated amortization on the capital leases was $84 at June 30, 2015. Future maturities on capital lease obligations are projected as follows: 2015 $ 27 July 1, 2015 through December 31, 2015 2016 52 2017 32 2018 18 2019 8 2020 2 Total payments $ 139 Imputed interest (10 ) Net capital lease obligations $ 129

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2015
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	7. COMMITMENTS AND CONTINGENCIES Lease Commitments The Company leases various types of office, manufacturing and warehouse facilities and equipment under noncancelable operating leases that expire at various terms through 2021. In August 2014 the Company and LM-VP AtriCure, LLC (Landlord), a third party unrelated to the Company, entered into a new building lease (Mason Lease) in order to re-locate its headquarters and West Chester, Ohio facilities from their current location to a building to be constructed on Innovation Way in Mason, Ohio and occupied exclusively by the Company. The term of the Mason Lease is fifteen years with three separate five-year renewal options, at the Company’s option, and begins upon substantial completion of the construction of the building (Commencement Date). We expect to take possession of the building in November 2015. The amount of initial annual base rent of $1,353 is payable monthly beginning on the Commencement Date and is subject to a 2% increase each year during the Lease’s initial term. Upon each renewal, the amount of rent payable will be agreed upon by the Company and Landlord or, if not so agreed upon, by an appraiser. The size of the building subject to the Lease is expected to be approximately 92 square feet. Under the Mason Lease, the Company is responsible for paying real estate taxes, insurance, utilities, operating expenses and most building repairs and maintenance. The Company is also responsible for paying the first $750 of construction-related tenant improvement costs, as well as amounts in excess of the estimated total cost of construction, as defined by the Mason Lease. On the Commencement Date, the Company is required to provide a letter of credit to the Landlord in the amount of $1,250, which amount may decrease or be removed entirely based on the Company’s financial performance. The Company is deemed the owner of the project during the construction period. As a result, approximately $9,176 and $3,941 of project costs incurred to date to construct the building are included in property and equipment and the financing obligation is included in other current liabilities in the Condensed Consolidated Balance Sheets as of June 30, 2015 and December 31, 2014, respectively. An increase in purchases of building under construction and proceeds from the construction financing obligation were also included in the Condensed Consolidated Statement of Cash Flows as of June 30, 2015. Royalty Agreements The Company has certain royalty agreements in place with terms that include payment of royalties based on product revenue from sales of specified current products. The royalty agreements have effective dates as early as 2003 and terms ranging from three years to at least twenty years. The royalties range from 0.75% to 5% of specified product sales. One of the agreements includes minimum quarterly payments of $50 through 2015 and a maximum of $2,000 in total royalties over the term of the agreement. Parties to the royalty agreements have the right at any time to terminate the agreement immediately for cause. Royalty expense of $471 and $262 was recorded as part of cost of revenue for the three months ended June 30, 2015 and 2014, respectively, and $898 and $569 was recorded for the six months ended June 30, 2015 and 2014. Purchase Agreements The Company enters into standard purchase agreements with certain vendors in the ordinary course of business. Outstanding commitments at June 30, 2015 and 2014 were not significant. Legal The Company may, from time to time, become a party to legal proceedings.

Income Tax Provision

Income Tax Provision	6 Months Ended
	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Income Tax Provision	8. INCOME TAX PROVISION The Company files federal, state, and foreign income tax returns in jurisdictions with varying statutes of limitations. Income taxes are computed using the asset and liability method in accordance with FASB ASC 740, “Income Taxes”, under which deferred income taxes are provided for the temporary differences between the financial reporting basis and the tax basis of the Company’s assets and liabilities. Deferred taxes are measured using provisions of currently enacted tax laws. A valuation allowance against deferred tax assets is recorded when it is more-likely-than-not that such assets will not be fully realized. The Company has recorded a full valuation allowance against its net deferred tax assets as it is more-likely-than-not that the benefit of the deferred tax assets will not be recognized in future periods. Tax credits are accounted for as a reduction of income taxes in the year in which the credit originates. The Company does not expect any significant unrecognized tax benefits to arise over the next twelve months. The Company’s provision for income taxes for continuing operations in interim periods is computed by applying its estimated annual effective rate against its loss before income tax (expense) benefit for the period. In addition, non-recurring or discrete items are recorded during the period in which they occur. The effective tax rate for the three months ended June 30, 2015 and 2014 was (0.17%) and (0.19%), respectively. The effective tax rate for the six months ended June 30, 2015 and 2014 was (0.14%) and (0.31%), respectively. The Company has not had to accrue any interest and penalties related to unrecognized income tax benefits as a result of offsetting net operating losses. However, if the situation occurs, the Company will recognize interest and penalties within the income tax expense (benefit) line in the accompanying Condensed Consolidated Statements of Operations and Comprehensive Loss and within the related tax liability line in the Condensed Consolidated Balance Sheets.

Equity Compensation Plans

Equity Compensation Plans	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Compensation Plans	9. EQUITY COMPENSATION PLANS The Company has several share-based incentive plans: the 2001 Stock Option Plan (2001 Plan), the 2005 Equity Incentive Plan (2005 Plan), the Amended and Restated 2014 Stock Incentive Plan (2014 Plan) and the 2008 Employee Stock Purchase Plan (ESPP). 2001 Plan, 2005 Plan and 2014 Plan Neither the 2001 Plan nor 2005 Plan is currently used for granting incentives. The Company granted awards under the 2005 Plan until the 2014 Annual Meeting of Stockholders at which stockholders adopted the 2014 Plan. Pursuant to its terms, the 2014 Plan supersedes and replaces the 2005 Plan. Under the 2014 Plan, the Board of Directors may grant incentive stock options to employees and any parent or subsidiary’s employees, and may grant nonstatutory stock options, restricted stock or stock appreciation rights to employees, directors and consultants of the Company and any parent or subsidiary’s employees, directors and consultants. The administrator (currently the Compensation Committee of the Board of Directors) has the power to determine the terms of any awards, including the number of shares subject to each award, the exercisability of the awards and the form of consideration. As of June 30, 2015, 8,949 shares of common stock had been reserved for issuance under the 2014 Plan. Options granted under the plans generally expire ten years from the date of grant. Options granted from the 2005 Plan and 2014 Plan generally vest at a rate of 25% on the first anniversary date of the grant and ratably each month thereafter over the following three years. Restricted stock awards granted under the 2005 Plan and 2014 Plan generally vest 25% annually over four years from date of grant. Employee Stock Purchase Plan (ESPP) During 2008 the Company established the Employee Stock Purchase Plan which is available to eligible employees as defined in the ESPP. Under the ESPP, shares of the Company’s common stock may be purchased at a discount (currently 15%) of the lesser of the closing price of the Company’s common stock on the first trading day or the last trading day of the offering period. The offering period (currently six months) and the offering price are subject to change. Participants may not purchase more than $25 of the Company’s common stock in a calendar year and, effective January 1, 2014, may not purchase more than 3 shares during an offering period. Beginning on January 1, 2009 and on the first day of each fiscal year thereafter during the term of the ESPP, the number of shares available for sale under the ESPP shall be increased by the lesser of (i) two percent (2%) of the Company’s outstanding shares of common stock as of the close of business on the last business day of the prior calendar year, not to exceed 600 shares, or (ii) a lesser amount determined by the Board of Directors. At June 30, 2015 there were 524 shares available for future issuance under the ESPP. Valuation and Expense Information Under FASB ASC 718 The following table summarizes share-based compensation expense related to employee share-based compensation under FASB ASC 718 for the three and six months ended June 30, 2015 and 2014. This expense was allocated as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Cost of revenue $ 106 $ 93 $ 196 $ 164 Research and development expenses 347 267 636 399 Selling, general and administrative expenses 1,964 1,486 3,309 3,425 Total share-based compensation expense related to employees $ 2,417 $ 1,846 $ 4,141 $ 3,988

Segment and Geographic Informat

Segment and Geographic Information	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Segment and Geographic Information	10. SEGMENT AND GEOGRAPHIC INFORMATION The Company evaluates reporting segments in accordance with FASB ASC 280, “Segment Reporting”. The Company develops, manufactures, and sells devices designed primarily for the surgical ablation of cardiac tissue and systems designed for the exclusion of the left atrial appendage. These devices are developed and marketed to a broad base of medical centers in the United States and internationally. Management considers all such sales to be part of a single reportable segment. Revenue attributed to geographic areas is based on the location of the customers to whom products are sold. Revenue by geographic area was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 United States $ 25,744 $ 19,903 $ 48,667 $ 38,046 Europe 4,122 4,303 8,538 8,607 Asia 2,538 2,175 4,838 4,471 Other international 179 133 426 237 Total international 6,839 6,611 13,802 13,315 Total revenue $ 32,583 $ 26,514 $ 62,469 $ 51,361 Domestic revenue by product type was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Open-heart ablation $ 13,648 $ 10,856 $ 26,002 $ 21,233 Minimally invasive ablation 5,057 4,393 9,404 7,841 AtriClip 6,286 3,951 11,789 7,571 Total ablation and AtriClip 24,991 19,200 47,195 36,645 Valve tools 753 703 1,472 1,401 Total domestic $ 25,744 $ 19,903 $ 48,667 $ 38,046 International revenue by product type was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Open-heart ablation $ 4,088 $ 4,054 $ 8,304 $ 8,025 Minimally invasive ablation 1,858 1,966 3,826 3,969 AtriClip 789 404 1,460 847 Total ablation and AtriClip 6,735 6,424 13,590 12,841 Valve tools 104 187 212 474 Total international $ 6,839 $ 6,611 $ 13,802 $ 13,315 The majority of the Company’s long-lived assets are located in the United States.

Public Offerings of Common Stoc

Public Offerings of Common Stock	6 Months Ended
	Jun. 30, 2015
Equity [Abstract]
Public Offerings of Common Stock	11. PUBLIC OFFERINGS OF COMMON STOCK In February 2014 the Company completed a public offering of common stock under its January 2014 shelf registration. The Company sold 3,661 shares of common stock, par value $0.001 per share, at a price of $19.25 per share, generating proceeds of $65,830 after expenses. Offering costs were recorded in additional paid in capital to offset proceeds.

Description of Business and S18

Description of Business and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	Nature of the Business
Basis of Presentation	Basis of Presentation The accompanying Condensed Consolidated Financial Statements should be read in conjunction with the audited financial statements of the Company included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2014 filed with the SEC.
Principles of Consolidation	Principles of Consolidation
Cash and Cash Equivalents	Cash and Cash Equivalents
Investments	Investments
Revenue Recognition	Revenue Recognition Pursuant to the Company’s standard terms of sale, revenue is recognized when title to the goods and risk of loss transfers to customers and there are no remaining obligations that will affect the customers’ final acceptance of the sale. Generally, the Company’s standard terms of sale define the transfer of title and risk of loss to occur upon shipment to the respective customer. The Company generally does not maintain any post-shipping obligations to the recipients of the products. No installation, calibration or testing of this equipment is performed by the Company subsequent to shipment to the customer in order to render it operational. Revenue includes shipping and handling revenue of $271 and $236 for the three months ended June 30, 2015 and 2014, respectively, and $518 and $463 for the six months ended June 30, 2015 and 2014, respectively. Cost of freight for shipments made to customers is included in cost of revenue. Sales and other value-added taxes collected from customers and remitted to governmental authorities are excluded from revenue. The Company sells its products primarily through a direct sales force, with certain international markets sold through distributors. Terms of sale are generally consistent for both end-users and distributors except that payment terms are generally net 30 days for end-users and net 60 days for distributors.
Sales Returns and Allowances	Sales Returns and Allowances
Allowance for Doubtful Accounts Receivable	Allowance for Doubtful Accounts Receivable
Inventories	Inventories Inventories consist of the following: June 30, 2015 December 31, Raw materials $ 5,286 $ 4,429 Work in process 1,251 1,397 Finished goods 9,536 8,431 Inventories $ 16,073 $ 14,257
Property and Equipment	Property and Equipment Generators and other capital equipment (such as the Company’s switchbox units and cryosurgical consoles) are loaned at no cost to direct customers that use the Company’s disposable products. Depreciation of such assets is included in cost of revenue. The estimated useful lives of this equipment are based on anticipated usage by customers and the timing and impact of expected new technology rollouts by the Company. To the extent the Company experiences changes in the usage of this equipment or introduces new technologies, the estimated useful lives of this equipment may change in a future period. Depreciation related to these generators was $673 and $498 for the three months ended June 30, 2015 and 2014, respectively, and $1,293 and $959 for the six months ended June 30, 2015 and 2014, respectively. As of June 30, 2015 and December 31, 2014, the net carrying amount of loaned equipment included in net property and equipment in the Condensed Consolidated Balance Sheets was $4,799 and $4,141, respectively. The Company reviews property and equipment for impairment using its best estimates based on reasonable and supportable assumptions and projections.
Intangible Assets	Intangible Assets
Goodwill	Goodwill—
Other Current Liabilities and Current Maturities of Capital Leases	Other Current Liabilities and Current Maturities of Capital Leases—
Other Income	Other Income The Company recorded net foreign currency transaction (losses) gains of ($46) and $16 for the three months ended June 30, 2015 and 2014, respectively, and ($209) and $21 for the six months ended June 30, 2015 and 2014, respectively, primarily in connection with settlements of its intercompany balance with AtriCure Europe. The Company periodically is awarded grants to support research and development activities or education activities. The Company recognizes grant income when the funds are earned. The Company recorded grant income of $0 and $137 during the three months ended June 30, 2015 and 2014, respectively. Grant income of $35 and $500 was recorded for the six month periods ended June 30, 2015 and 2014, respectively. The Company historically issued stock options to non-employee consultants as a form of compensation for services provided to the Company. Because the non-employee options require settlement by the Company’s delivery of registered shares and because the tax withholding provisions in the awards allow the options to be partially net-cash settled, these options, when vested, are no longer eligible for equity classification and are, thus, subsequently accounted for as derivative liabilities under FASB ASC 815, “Derivatives and Hedging” (ASC 815) until the awards are ultimately either exercised or forfeited. Accordingly, the vested non-employee options are classified as liabilities and remeasured at fair value through earnings at each reporting period. During the three months ended June 30, 2015 and 2014, $44 and ($19), respectively, of expense (income) was recorded as a result of the remeasurement of the fair value of these fully vested stock options. During the six months ended June 30, 2015 and 2014, $57 and ($117), respectively, of expense (income) was recorded as a result of the remeasurement of the fair value of these fully vested stock options.
Taxes	Taxes The Company’s estimate of the valuation allowance for deferred tax assets requires it to make significant estimates and judgments about its future operating results. Deferred tax assets are reduced by valuation allowances if, based on the consideration of all available evidence, it is more-likely-than-not that some portion of the deferred tax asset will not be realized. Significant weight is given to evidence that can be objectively verified. The Company evaluates deferred tax assets on a quarterly basis to determine if valuation allowances are required by considering all available evidence. Deferred tax assets are realized by having sufficient future taxable income to allow the related tax benefits to reduce taxes otherwise payable. The sources of taxable income that may be available to realize the benefit of deferred tax assets are future reversals of existing taxable temporary differences, future taxable income, exclusive of reversing temporary differences and carryforwards, taxable income in carry-back years and tax planning strategies that are both prudent and feasible. In evaluating whether to record a valuation allowance, the applicable accounting standards deem that the existence of cumulative losses in recent years is a significant piece of objectively verifiable negative evidence that must be overcome by objectively verifiable positive evidence to avoid the need to record a valuation allowance. The Company has recorded a full valuation allowance against its net deferred tax assets as it is more-likely-than-not that the benefit of the deferred tax assets will not be recognized in future periods. A provision of The Patient Protection and Affordable Care Act enacted in 2010, as amended (Affordable Care Act), requires manufacturers of medical devices to pay an excise tax on all U.S. medical device sales. The Company’s expense related to the medical device excise tax, which was recorded in cost of revenue, was $149 and $116 for the three months ended June 30, 2015 and 2014, respectively, and $304 and $230 for the six months ended June 30, 2015 and 2014, respectively.
Net Loss Per Share	Net Loss Per Share
Comprehensive Loss and Accumulated Other Comprehensive Loss	Comprehensive Loss and Accumulated Other Comprehensive Loss Accumulated other comprehensive income (loss) consisted of the following: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Total accumulated other comprehensive (loss) income at beginning of period $ (798 ) $ (139 ) $ (348 ) $ (139 ) Unrealized Gains on Investments Balance at beginning of period $ (17 ) $ (8 ) $ (54 ) $ (6 ) Other comprehensive income (loss) before reclassifications 2 (11 ) 39 (13 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations — — — — Balance at end of period $ (15 ) $ (19 ) $ (15 ) $ (19 ) Foreign Currency Translation Adjustment Balance at beginning of period $ (781 ) $ (131 ) $ (294 ) $ (133 ) Other comprehensive income (loss) before reclassifications 392 (44 ) 68 (47 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations (139 ) 16 (302 ) 21 Balance at end of period $ (528 ) $ (159 ) $ (528 ) $ (159 ) Total accumulated other comprehensive loss at end of period $ (543 ) $ (178 ) $ (543 ) $ (178 )
Research and Development	Research and Development
Advertising Costs	Advertising Costs —
Share-Based Compensation	Share-Based Compensation FASB ASC 718 requires companies to estimate the fair value of share-based payment awards on the date of grant using an option-pricing model. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Company’s Condensed Consolidated Statement of Operations and Comprehensive Loss. The expense has been reduced for estimated forfeitures. FASB ASC 718 requires forfeitures to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. The Company estimates the fair value of time-based options on the date of grant using the Black-Scholes option-pricing model (Black-Scholes model). The Company’s determination of fair value of share-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price, as well as assumptions regarding a number of subjective variables. These variables include, but are not limited to, the Company’s expected stock price volatility over the term of the awards and actual and projected employee stock option exercise behaviors. The fair value of market-based performance option grants is estimated at the date of grant using a Monte-Carlo simulation. The value of the portion of the award that is ultimately expected to vest is recognized as expense over the requisite service periods in the Condensed Consolidated Statements of Operations and Comprehensive Loss. The Company estimates the fair value of restricted stock based upon the grant date closing market price of the Company’s common stock. The Company’s determination of fair value is affected by the Company’s stock price as well as assumptions regarding the number of shares expected to be granted. The Company also has an employee stock purchase plan (ESPP or the Plan) which is available to all eligible employees as defined by the Plan. Under the ESPP, shares of the Company’s common stock may be purchased at a discount. The Company estimates the number of shares to be purchased under the Plan and records compensation expense based upon the fair value of the stock at the beginning of the purchase period using the Black-Scholes model.
Use of Estimates	Use of Estimates
Fair Value Disclosures	Fair Value Disclosures

Description of Business and S19

Description of Business and Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Inventories	Inventories consist of the following: June 30, 2015 December 31, Raw materials $ 5,286 $ 4,429 Work in process 1,251 1,397 Finished goods 9,536 8,431 Inventories $ 16,073 $ 14,257
Accumulated Other Comprehensive Income (Loss)	Accumulated other comprehensive income (loss) consisted of the following: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Total accumulated other comprehensive (loss) income at beginning of period $ (798 ) $ (139 ) $ (348 ) $ (139 ) Unrealized Gains on Investments Balance at beginning of period $ (17 ) $ (8 ) $ (54 ) $ (6 ) Other comprehensive income (loss) before reclassifications 2 (11 ) 39 (13 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations — — — — Balance at end of period $ (15 ) $ (19 ) $ (15 ) $ (19 ) Foreign Currency Translation Adjustment Balance at beginning of period $ (781 ) $ (131 ) $ (294 ) $ (133 ) Other comprehensive income (loss) before reclassifications 392 (44 ) 68 (47 ) Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations (139 ) 16 (302 ) 21 Balance at end of period $ (528 ) $ (159 ) $ (528 ) $ (159 ) Total accumulated other comprehensive loss at end of period $ (543 ) $ (178 ) $ (543 ) $ (178 )

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	In accordance with ASC 820, the following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value on a recurring basis as of June 30, 2015: Quoted Prices in Significant Other Significant Other Total Assets: Money market funds $ — $ 23,237 $ — $ 23,237 U.S. government agencies and securities 1,016 — — 1,016 Corporate bonds — 28,685 — 28,685 Total assets $ 1,016 $ 51,922 $ — $ 52,938 There were no changes in the levels or methodology of measurement of financial assets and liabilities during the three or six month periods ended June 30, 2015. In accordance with ASC 820, the following table represents the Company’s fair value hierarchy for its financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2014: Quoted Prices in Significant Other Significant Other Total Assets: Money market funds $ — $ 23,692 $ — $ 23,692 Commercial paper — 1,800 — 1,800 U.S. government agencies and securities 3,022 — — 3,022 Corporate bonds — 35,337 — 35,337 Total assets $ 3,022 $ 60,829 $ — $ 63,851 Liabilities: Derivative instruments $ — $ — $ 120 $ 120 Acquisition-related contingent consideration — — — — Total liabilities $ — $ — $ 120 $ 120
Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Derivative Instruments	In accordance with ASC 820, the following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for derivative instruments as of June 30, 2015: Beginning Balance–January 1, 2015 $ 120 Total losses included in earnings 57 Exercises (177 ) Reclassification from equity to liability when fully vested — Ending Balance–June 30, 2015 $ — In accordance with ASC 820, the following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for derivative instruments as of December 31, 2014: Beginning Balance–January 1, 2014 $ 350 Total gains included in earnings (183 ) Exercises (47 ) Reclassification from equity to liability when fully vested — Ending Balance–December 31, 2014 $ 120
Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Acquisition Related Contingent Consideration	The following table represents the Company’s Level 3 fair value measurements using significant other unobservable inputs for acquisition-related contingent consideration as of December 31, 2014: Beginning Balance – January 1, 2014 $ 8,032 Amounts acquired — Transfers in (out) of Level 3 — Changes in fair value included in earnings (8,032 ) Ending Balance – December 31, 2014 $ —

Intangible Assets (Tables)

Intangible Assets (Tables)	6 Months Ended
	Jun. 30, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Company's Intangible Assets with Definite Lives	The following table provides a summary of the Company’s intangible assets with definite lives: June 30, 2015 December 31, 2014 Cost Accumulated Cost Accumulated Non-compete agreement $ 100 $ 99 $ 100 $ 93 Fusion technology 9,242 1,386 9,242 924 Clamp & probe technology 829 414 829 276 Estech trade name 208 208 208 208 Total $ 10,379 $ 2,107 $ 10,379 $ 1,501
Future Amortization Expense Related to Intangible Assets with Definite Lives	Future amortization expense related to intangible assets with definite lives is projected as follows: 2015 $ 602 July 1, 2015 through December 31, 2015 2016 1,201 2017 924 2018 924 2019 924 2020 and thereafter 3,697 Total $ 8,272

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	6 Months Ended
	Jun. 30, 2015
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued liabilities consisted of the following: June 30, 2015 December 31, Accrued commissions $ 4,025 $ 4,477 Accrued bonus 3,374 4,915 Accrued payroll and employee-related expenses 2,381 2,281 Accrued taxes and value-added taxes payable 735 1,272 Other accrued liabilities 535 399 Accrued royalties 377 442 Sales returns allowance 133 135 Accrued non-employee stock options — 120 Total $ 11,560 $ 14,041

Indebtedness (Tables)

Indebtedness (Tables)	6 Months Ended
	Jun. 30, 2015
Debt Disclosure [Abstract]
Future Maturities on Debt, Including Capital Lease Obligations	Future maturities on capital lease obligations are projected as follows: 2015 $ 27 July 1, 2015 through December 31, 2015 2016 52 2017 32 2018 18 2019 8 2020 2 Total payments $ 139 Imputed interest (10 ) Net capital lease obligations $ 129

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	6 Months Ended
	Jun. 30, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Share-Based Compensation Expense Related to Employee Share-Based Compensation	The following table summarizes share-based compensation expense related to employee share-based compensation under FASB ASC 718 for the three and six months ended June 30, 2015 and 2014. This expense was allocated as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Cost of revenue $ 106 $ 93 $ 196 $ 164 Research and development expenses 347 267 636 399 Selling, general and administrative expenses 1,964 1,486 3,309 3,425 Total share-based compensation expense related to employees $ 2,417 $ 1,846 $ 4,141 $ 3,988

Segment and Geographic Inform25

Segment and Geographic Information (Tables)	6 Months Ended
	Jun. 30, 2015
Segment Reporting [Abstract]
Summary of Revenue by Geographic Area	Revenue by geographic area was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 United States $ 25,744 $ 19,903 $ 48,667 $ 38,046 Europe 4,122 4,303 8,538 8,607 Asia 2,538 2,175 4,838 4,471 Other international 179 133 426 237 Total international 6,839 6,611 13,802 13,315 Total revenue $ 32,583 $ 26,514 $ 62,469 $ 51,361
Revenue by Product	Domestic revenue by product type was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Open-heart ablation $ 13,648 $ 10,856 $ 26,002 $ 21,233 Minimally invasive ablation 5,057 4,393 9,404 7,841 AtriClip 6,286 3,951 11,789 7,571 Total ablation and AtriClip 24,991 19,200 47,195 36,645 Valve tools 753 703 1,472 1,401 Total domestic $ 25,744 $ 19,903 $ 48,667 $ 38,046 International revenue by product type was as follows: Three Months Ended June 30, Six Months Ended June 30, 2015 2014 2015 2014 Open-heart ablation $ 4,088 $ 4,054 $ 8,304 $ 8,025 Minimally invasive ablation 1,858 1,966 3,826 3,969 AtriClip 789 404 1,460 847 Total ablation and AtriClip 6,735 6,424 13,590 12,841 Valve tools 104 187 212 474 Total international $ 6,839 $ 6,611 $ 13,802 $ 13,315

Description of Business and S26

Description of Business and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Description Of Business And Significant Accounting Policies [Line Items]
Maturity period of short term investment			1 year
Shipping and handling revenue	$ 271	$ 236	$ 518	$ 463
Payment terms for end-users			30 days
Payment terms for distributors			60 days
Depreciation			$ 2,087	1,506
Net carrying amount of loaned equipment	19,352		19,352		$ 11,552
Grant income	0	137	35	500
(Income) expense related to remeasurement of fair value of fully vested stock options	44	(19)	57	(117)
Company's expense related to the medical device excise tax	149	116	$ 304	$ 230
Options, restricted stock and performance based shares excluded from calculation of net loss per share			4,290	3,799
Share-based compensation expense recognized	2,417	1,846	$ 4,141	$ 3,988
Subsidiaries [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Net foreign currency transaction (losses) gains	(46)	16	$ (209)	21
Computer and Other Office Equipment [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category			3 years
Generators [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Depreciation	673	$ 498	$ 1,293	$ 959
Carrying Amount of Loaned Equipment [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Net carrying amount of loaned equipment	$ 4,799		$ 4,799		$ 4,141
Minimum [Member] | Generators and Other Capital Equipment, Machinery, Equipment and Vehicles [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category			3 years
Minimum [Member] | Furniture and Fixtures [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category			3 years
Maximum [Member] | Generators and Other Capital Equipment, Machinery, Equipment and Vehicles [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category			7 years
Maximum [Member] | Furniture and Fixtures [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category			7 years

Description of Business and S27

Description of Business and Summary of Significant Accounting Policies - Summary of Inventories (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Raw materials	$ 5,286	$ 4,429
Work in process	1,251	1,397
Finished goods	9,536	8,431
Inventories	$ 16,073	$ 14,257

Description of Business and S28

Description of Business and Summary of Significant Accounting Policies - Accumulated Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (798)	$ (139)	$ (348)	$ (139)
Ending Balance	(543)	(178)	(543)	(178)
Unrealized Gains on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(17)	(8)	(54)	(6)
Other comprehensive income (loss) before reclassifications	2	(11)	39	(13)
Ending Balance	(15)	(19)	(15)	(19)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(781)	(131)	(294)	(133)
Other comprehensive income (loss) before reclassifications	392	(44)	68	(47)
Amounts reclassified from accumulated other comprehensive income to other income on the statement of operations	(139)	16	(302)	21
Ending Balance	$ (528)	$ (159)	$ (528)	$ (159)

Fair Value - Financial Assets a

Fair Value - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Significant Other Unobservable Inputs (Level 3) [Member]
Liabilities:
Acquisition-related contingent consideration	$ 0	$ 0
Fair Value, Measurements, Recurring [Member]
Assets:
Total assets	52,938	63,851
Liabilities:
Derivative instruments		120
Acquisition-related contingent consideration		0
Total liabilities		120
Fair Value, Measurements, Recurring [Member] | Money Market Funds [Member]
Assets:
Total assets	23,237	23,692
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Assets:
Total assets		1,800
Fair Value, Measurements, Recurring [Member] | U.S. Government Agencies and Securities [Member]
Assets:
Total assets	1,016	3,022
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Assets:
Total assets	28,685	35,337
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Total assets	1,016	3,022
Liabilities:
Acquisition-related contingent consideration		0
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Government Agencies and Securities [Member]
Assets:
Total assets	1,016	3,022
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Assets:
Total assets	51,922	60,829
Liabilities:
Acquisition-related contingent consideration		0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]
Assets:
Total assets	23,237	23,692
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Assets:
Total assets		1,800
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Assets:
Total assets	$ 28,685	35,337
Fair Value, Measurements, Recurring [Member] | Significant Other Unobservable Inputs (Level 3) [Member]
Liabilities:
Derivative instruments		120
Acquisition-related contingent consideration		0
Total liabilities		$ 120

Fair Value - Level 3 Fair Value

Fair Value - Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Derivative Instruments (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Beginning Balance	$ 120	$ 350
Total (gains) losses included in earnings	57	(183)
Exercises	(177)	(47)
Reclassification from equity to liability when fully vested	$ 0	0
Ending Balance		$ 120

Fair Value - Additional Informa

Fair Value - Additional Information (Detail) - USD ($)	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Significant Other Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	$ 0	$ 0
Maximum [Member] | Estech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration			$ 26,000,000

Fair Value - Level 3 Fair Val32

Fair Value - Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Acquisition Related Contingent Consideration (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2014USD ($)
Debt Instrument Fair Value Carrying Value [Abstract]
Beginning Balance	$ 8,032
Amounts acquired	0
Transfers in (out) of Level 3	0
Changes in fair value included in earnings	(8,032)
Ending Balance	$ 0

Intangible Assets - Summary of

Intangible Assets - Summary of Company's Intangible Assets with Definite Lives (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Cost	$ 10,379	$ 10,379
Accumulated Amortization	2,107	1,501
Non-Compete Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	100	100
Accumulated Amortization	99	93
Fusion Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	9,242	9,242
Accumulated Amortization	1,386	924
Clamp and Probe Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	829	829
Accumulated Amortization	414	276
Estech Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	208	208
Accumulated Amortization	$ 208	$ 208

Intangible Assets - Additional

Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of intangible assets	$ 303	$ 356	$ 606	$ 711

Intangible Assets - Future Amor

Intangible Assets - Future Amortization Expense Related to Intangible Assets with Definite Lives (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Expected amortization expense July 1, 2015 through December 31, 2015	$ 602
Expected amortization expense in 2016	1,201
Expected amortization expense in 2017	924
Expected amortization expense in 2018	924
Expected amortization expense in 2019	924
Expected amortization expense in 2020 and thereafter	3,697
Total	$ 8,272	$ 8,878

Accrued Liabilities - Accrued L

Accrued Liabilities - Accrued Liabilities (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Payables and Accruals [Abstract]
Accrued commissions	$ 4,025	$ 4,477
Accrued bonus	3,374	4,915
Accrued payroll and employee-related expenses	2,381	2,281
Accrued taxes and value-added taxes payable	735	1,272
Other accrued liabilities	535	399
Accrued royalties	377	442
Sales returns allowance	133	135
Accrued non-employee stock options		120
Total	$ 11,560	$ 14,041

Indebtedness - Additional Infor

Indebtedness - Additional Information (Detail) € in Thousands	Mar. 31, 2015USD ($)	Mar. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Jun. 30, 2015USD ($)	Dec. 31, 2014EUR (€)
Credit Facilities [Line Items]
Capital lease expiration period				2,020
Cost of assets under lease			$ 197,000	$ 197,000
Accumulated amortization on the capital leases			84,000	84,000
Silicon Valley Bank Agreement [Member] | Revolving Credit Facility [Member]
Credit Facilities [Line Items]
Credit facility			$ 15,000,000	15,000,000
Letter of credit maturity date	Apr. 30, 2018	Apr. 30, 2016	Apr. 30, 2018
Borrowings under the revolving credit facility, availability			$ 0
Borrowings under the revolving credit facility, outstanding			$ 13,872,000	$ 13,872,000
Outstanding letters of credit limit	$ 2,000,000	$ 1,000,000
Corporate Credit Card [Member]
Credit Facilities [Line Items]
Letter of credit outstanding | €					€ 75
Expiry of outstanding letter of credit				Jun. 30, 2015

Indebtedness - Future Maturitie

Indebtedness - Future Maturities on Debt, Including Capital Lease Obligations (Detail) $ in Thousands	Jun. 30, 2015USD ($)
Debt Disclosure [Abstract]
Capital lease obligations due July 1, 2015 through December 31, 2015	$ 27
Capital lease obligations due 2016	52
Capital lease obligations due 2017	32
Capital lease obligations due 2018	18
Capital lease obligations due 2019	8
Capital lease obligations due thereafter	2
Capital lease obligations total payments	139
Imputed interest	(10)
Net capital lease obligations	$ 129

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015USD ($)ft²	Jun. 30, 2014USD ($)	Jun. 30, 2015USD ($)ft²Lease	Jun. 30, 2014USD ($)	Dec. 31, 2014USD ($)
Commitments and Contingencies [Line Items]
Operating leases expire at various terms			2,021
Letter of credit to be issued to landlord, amount			$ 1,250,000
Royalty expense	$ 471,000	$ 262,000	$ 898,000	$ 569,000
Minimum [Member]
Commitments and Contingencies [Line Items]
Royalty rates			0.75%
Royalty payments	50,000		$ 50,000
Royalty agreement term			3 years
Maximum [Member]
Commitments and Contingencies [Line Items]
Royalty rates			5.00%
Royalty payments	$ 2,000,000		$ 2,000,000
Royalty agreement term			20 years
Mason Lease [Member]
Commitments and Contingencies [Line Items]
Lease term period			15 years
Number of renewal options | Lease			3
Lease renewal option period			5 years
Initial annual base rent			$ 1,353,000
Lease rate increase, percentage	2.00%		2.00%
Area of lease | ft²	92		92
Project cost included in the construction of building			$ 9,176,000		$ 3,941,000
Mason Lease [Member] | Leasehold Improvements [Member]
Commitments and Contingencies [Line Items]
Leases payable, amount	$ 750,000		$ 750,000

Income Tax Provision - Addition

Income Tax Provision - Additional Information (Detail)	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Income Tax Disclosure [Abstract]
Effective tax rate	0.17%	0.19%	0.14%	0.31%

Equity Compensation Plans - 200

Equity Compensation Plans - 2001 Plan, 2005 Plan and 2014 Plan - Additional Information (Detail) - Jun. 30, 2015 - shares shares in Thousands	Total
2001 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options from the date of grant	10 years
2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options from the date of grant	10 years
2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	8,949
Expiry of options from the date of grant	10 years
Employee Stock Option [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period beginning	3 years
Annual vesting percentage	25.00%
Employee Stock Option [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period beginning	3 years
Annual vesting percentage	25.00%
Restricted Stock [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage	25.00%
Options granted from the 2005 Plan generally vest	4 years
Restricted Stock [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage	25.00%
Options granted from the 2005 Plan generally vest	4 years

Equity Compensation Plans - Emp

Equity Compensation Plans - Employee Stock Purchase Plan - Additional Information (Detail) - Jun. 30, 2015 - USD ($)	Total
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Description of participants purchase limit	Participants may not purchase more than $25 of the Company's common stock in a calendar year and, effective January 1, 2014, may not purchase more than 3 shares during an offering period.
Participants purchase limit shares	3,000
Offering period	6 months
2008 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Company's common stock may be purchased at a discount	15.00%
Participants purchase limit value	$ 25,000
Shares available for sale under the ESPP increased	2.00%
Outstanding shares of common stock exceed	600,000
Shares available for future issuance under the ESPP	524,000

Equity Compensation Plans - Sum

Equity Compensation Plans - Summary of Share-Based Compensation Expense Related to Employee Share-Based Compensation (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	$ 2,417	$ 1,846	$ 4,141	$ 3,988
Cost of Revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	106	93	196	164
Research and Development Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	347	267	636	399
Selling, General and Administrative Expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	$ 1,964	$ 1,486	$ 3,309	$ 3,425

Segment and Geographic Inform44

Segment and Geographic Information - Summary of Revenue by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Information About Revenue And Geographic Areas [Line Items]
Revenue	$ 32,583	$ 26,514	$ 62,469	$ 51,361
United States [Member]
Information About Revenue And Geographic Areas [Line Items]
Revenue	25,744	19,903	48,667	38,046
Europe [Member]
Information About Revenue And Geographic Areas [Line Items]
Revenue	4,122	4,303	8,538	8,607
Asia [Member]
Information About Revenue And Geographic Areas [Line Items]
Revenue	2,538	2,175	4,838	4,471
Other International [Member]
Information About Revenue And Geographic Areas [Line Items]
Revenue	179	133	426	237
International [Member]
Information About Revenue And Geographic Areas [Line Items]
Revenue	$ 6,839	$ 6,611	$ 13,802	$ 13,315

Segment and Geographic Inform45

Segment and Geographic Information - Revenue by Product (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Product Type Reporting Information [Line Items]
Revenue	$ 32,583	$ 26,514	$ 62,469	$ 51,361
United States [Member]
Product Type Reporting Information [Line Items]
Revenue	25,744	19,903	48,667	38,046
United States [Member] | Open-heart Ablation [Member]
Product Type Reporting Information [Line Items]
Revenue	13,648	10,856	26,002	21,233
United States [Member] | Minimally Invasive Ablation [Member]
Product Type Reporting Information [Line Items]
Revenue	5,057	4,393	9,404	7,841
United States [Member] | AtriClip [Member]
Product Type Reporting Information [Line Items]
Revenue	6,286	3,951	11,789	7,571
United States [Member] | Ablation and AtriClip [Member]
Product Type Reporting Information [Line Items]
Revenue	24,991	19,200	47,195	36,645
United States [Member] | Valve Tools [Member]
Product Type Reporting Information [Line Items]
Revenue	753	703	1,472	1,401
International [Member]
Product Type Reporting Information [Line Items]
Revenue	6,839	6,611	13,802	13,315
International [Member] | Open-heart Ablation [Member]
Product Type Reporting Information [Line Items]
Revenue	4,088	4,054	8,304	8,025
International [Member] | Minimally Invasive Ablation [Member]
Product Type Reporting Information [Line Items]
Revenue	1,858	1,966	3,826	3,969
International [Member] | AtriClip [Member]
Product Type Reporting Information [Line Items]
Revenue	789	404	1,460	847
International [Member] | Ablation and AtriClip [Member]
Product Type Reporting Information [Line Items]
Revenue	6,735	6,424	13,590	12,841
International [Member] | Valve Tools [Member]
Product Type Reporting Information [Line Items]
Revenue	$ 104	$ 187	$ 212	$ 474

Public Offerings of Common St46

Public Offerings of Common Stock - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	6 Months Ended
	Feb. 28, 2014	Jun. 30, 2014	Jun. 30, 2015	Dec. 31, 2014
Equity [Abstract]
Common stock sold	3,661
Common stock, par value	$ 0.001		$ 0.001	$ 0.001
Common stock, price per share	$ 19.25
Proceeds from issuance of common stock	$ 65,830	$ 65,830