AtriCure (ATRC) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Feb. 22, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
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 Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Common Stock, Shares Outstanding		32,272,648
Entity Public Float			$ 665.2

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 23,764	$ 28,384
Short-term investments	10,814	31,265
Accounts receivable, less allowance for doubtful accounts of $136 and $68, respectively	19,409	17,558
Inventories	17,659	14,257
Other current assets	3,106	2,044
Total current assets	74,752	93,508
Property and equipment, net	31,279	11,552
Long-term investments	7,706	8,894
Intangible assets, net	53,775	8,878
Goodwill	105,257	35,386
Other noncurrent assets	323	186
Total Assets	273,092	158,404
Current liabilities:
Accounts payable	12,744	7,621
Accrued liabilities	18,394	14,041
Other current liabilities and current maturities of capital leases	450	3,981
Total current liabilities	31,588	25,643
Capital leases	13,710	74
Other noncurrent liabilities	41,109	149
Total Liabilities	$ 86,407	$ 25,866
Commitments and contingencies (Note 11)
Stockholders' Equity:
Common stock, $0.001 par value, 90,000 shares authorized and 32,274 and 27,580 issued and outstanding, respectively	$ 32	$ 28
Additional paid-in capital	352,900	271,282
Accumulated other comprehensive loss	(611)	(348)
Accumulated deficit	(165,636)	(138,424)
Total Stockholders' Equity	186,685	132,538
Total Liabilities and Stockholders' Equity	$ 273,092	$ 158,404

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Condensed Consolidated Balance Sheets (Unaudited) [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 136	$ 68
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares issued	32,274,000	27,580,000
Common stock, shares outstanding	32,274,000	27,580,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) [Abstract]
Revenue	$ 129,755	$ 107,454	$ 81,889
Cost of revenue	36,880	31,704	22,326
Gross profit	92,875	75,750	59,563
Operating expenses:
Research and development expenses	25,742	18,600	13,440
Selling, general and administrative expenses	93,853	73,510	57,014
Total operating expenses	119,595	92,110	70,454
Loss from operations	(26,720)	(16,360)	(10,891)
Other income (expense):
Interest expense	(292)	(305)	(566)
Interest income	190	96	16
Other	(354)	391	(3)
Loss before income tax expense	(27,176)	(16,178)	(11,444)
Income tax expense	(36)	(33)	(18)
Net loss	$ (27,212)	$ (16,211)	$ (11,462)
Basic and diluted net loss per share	$ (0.97)	$ (0.61)	$ (0.56)
Weighted average shares outstanding-basic and diluted	28,058	26,374	20,431
Comprehensive loss:
Unrealized gains (losses) on investments	$ 15	$ (48)	$ (7)
Foreign currency translation adjustment	(278)	(161)	(209)
Other comprehensive loss	(263)	(209)	(216)
Net loss	(27,212)	(16,211)	(11,462)
Comprehensive loss	$ (27,475)	$ (16,420)	$ (11,678)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]Estech [Member]	Common Stock [Member]nContact Surgical [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]Estech [Member]	Additional Paid-in Capital [Member]nContact Surgical [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Estech [Member]	nContact Surgical [Member]	Total
Beginning Balance at Dec. 31, 2012			$ 17			$ 123,157	$ (110,751)	$ 77			$ 12,500
Beginning Balance, Shares at Dec. 31, 2012			16,896
Issuance of common stock through public offering			$ 4			26,868					26,872
Issuance of common stock through public offering, Shares			3,996
Issuance of common stock for acquisition	$ 2			$ 39,718					$ 39,720
Issuance of common stock for acquisition, Shares	2,126
Issuance of common stock under equity incentive plans						1,320					1,320
Issuance of common stock under equity incentive plans, Shares			119
Issuance of common stock under employee stock purchase plan						790					790
Issuance of common stock under employee stock purchase plan, Shares			111
Share-based employee compensation expense						3,080					3,080
Other comprehensive loss								(216)			(216)
Net loss							(11,462)				(11,462)
Ending Balance at Dec. 31, 2013			$ 23			194,933	(122,213)	(139)			72,604
Ending Balance, Shares at Dec. 31, 2013			23,248
Issuance of common stock through public offering			$ 4			65,826					65,830
Issuance of common stock through public offering, Shares			3,661
Issuance of common stock under equity incentive plans			$ 1			1,585					1,586
Issuance of common stock under equity incentive plans, Shares			586
Issuance of common stock under employee stock purchase plan						1,320					1,320
Issuance of common stock under employee stock purchase plan, Shares			85
Reclassification of non-employee option liability						47					47
Share-based employee compensation expense						7,571					7,571
Other comprehensive loss								(209)			(209)
Net loss							(16,211)				(16,211)
Ending Balance at Dec. 31, 2014			$ 28			271,282	(138,424)	(348)			132,538
Ending Balance, Shares at Dec. 31, 2014			27,580
Issuance of common stock for acquisition		$ 3			$ 68,985					$ 68,988
Issuance of common stock for acquisition, Shares		3,757
Issuance of common stock under equity incentive plans			$ 1			1,920					1,921
Issuance of common stock under equity incentive plans, Shares			850
Issuance of common stock under employee stock purchase plan						1,539					1,539
Issuance of common stock under employee stock purchase plan, Shares			87
Reclassification of non-employee option liability						177					177
Share-based employee compensation expense						8,997					8,997
Other comprehensive loss								(263)			(263)
Net loss							(27,212)				(27,212)
Ending Balance at Dec. 31, 2015			$ 32			$ 352,900	$ (165,636)	$ (611)			$ 186,685
Ending Balance, Shares at Dec. 31, 2015			32,274

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows from operating activities:
Net loss	$ (27,212)	$ (16,211)	$ (11,462)
Adjustments to reconcile net loss to net cash used in operating activities:
Share-based compensation expense	8,997	7,571	3,080
Depreciation	4,975	3,353	2,008
Amortization of intangible assets	1,303	1,421	12
Amortization of deferred financing costs	61	113	115
Loss (gain) on disposal of property and equipment	276	118	(6)
Realized loss from foreign exchange on intercompany transactions	434	544
Amortization/accretion on investments	577	500	49
Change in allowance for doubtful accounts	144	(34)	(14)
Change in fair value of contingent consideration		(8,032)
Other		95
Changes in operating assets and liabilities, net of amounts acquired:
Accounts receivable	(900)	(4,168)	(1,248)
Inventories	(2,950)	(4,343)	(2,288)
Other current assets	(928)	307	(1,257)
Accounts payable	4,013	(944)	1,445
Accrued liabilities	3,070	(1,847)	4,114
Other noncurrent assets and liabilities	298	(43)	230
Net cash used in operating activities	(7,842)	(21,600)	(5,222)
Cash flows from investing activities:
Purchases of available-for-sale securities	(19,525)	(41,107)	(21,243)
Sales and maturities of available-for-sale securities	40,602	19,614	6,200
Purchases of property and equipment	(13,445)	(5,508)	(2,864)
Increases in property under build-to-suit obligation	(10,552)	(3,699)
Proceeds from sale of property and equipment		77	48
Cash acquired through Estech business combination			3,708
Cash paid for nContact business combination	(7,581)
Net cash used in investing activities	(10,501)	(30,623)	(14,151)
Cash flows from financing activities:
Proceeds from sale of stock, net of offering costs of $0, $257 and $212 respectively		65,830	26,872
Payments on debt and capital leases	(263)	(6,382)	(2,055)
Proceeds from build-to-suit obligation	10,552	3,699
Proceeds from economic incentive loan	340
Payment of debt fees and premium on retirement of debt	(62)	(181)	(99)
Proceeds from stock option exercises	2,703	1,916	1,718
Shares repurchased for payment of taxes on stock awards	(782)	(331)	(398)
Proceeds from issuance of common stock under employee stock purchase plan	1,539	1,320	790
Payment of stock issuance fees	(66)
Net cash provided by financing activities	13,961	65,871	26,828
Effect of exchange rate changes on cash and cash equivalents	(238)	(156)	(316)
Net (decrease) increase in cash and cash equivalents	(4,620)	13,492	7,139
Cash and cash equivalents-beginning of period	28,384	14,892	7,753
Cash and cash equivalents-end of period	23,764	28,384	14,892
Supplemental cash flow information:
Cash paid for interest	232	115	473
Cash paid for taxes	20	146	30
Non-cash investing and financing activities:
Accrued purchases of property and equipment	1,277	547	282
Assets acquired through capital lease	50	47	68
Capital lease asset early termination		$ 38	24
Stock issuance in business combinations	69,054		39,720
Contingent consideration in business combinations	$ 40,207		$ 8,032

Consolidated Statements of Cas7

Consolidated Statements of Cash Flows (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Consolidated Statements of Cash Flows (Unaudited) [Abstract]
Offering cost for sale of stock	$ 0	$ 257	$ 212

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Description of Business and Summary of Significant Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	1. DE SCRIPTION OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Nature of the Business — AtriCure, Inc. was incorporated in the State of Delaware on October 31, 2000. The “Company” or “AtriCure” consists of AtriCure, Inc. and its wholly owned subsidiaries. The Company is an innovator in surgical treatments for atrial fibrillation (Afib) and left atrial appendage management (LAAM). The Company sells its products to medical centers globally through a direct sales force and distributors. Principles of Consolidation— The Consolidated Financial Statements include the accounts of the Company, AtriCure, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware, Endoscopic Technologies, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware, nContact Surgical, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware and AtriCure Europe, B.V. (AtriCure Europe), the Company’s wholly-owned subsidiary incorporated in the Netherlands. All intercompany accounts and transactions have been eliminated in consolidation. Cash and Cash Equivalents— The Company considers highly liquid investments with maturities of three months or less at the date of acquisition as cash equivalents in the accompanying Consolidated Financial Statements . Investments— The Company places its investments primarily in U.S. Government agencies and securities, corporate bonds and commercial paper. The Company classifies all investments as available-for-sale. Investments with maturities of less than one year are classified as short-term investments. Investments are recorded at fair value, with unrealized gains and losses recorded as accumulated other comprehensive income (loss). The Company recognizes gains and losses when these securities are sold using the specific identification method and includes them in interest income or expense in the Consolidated Statements of Operations and Comprehensive Loss. Revenue Recognition— The Company accounts for revenue in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605, “Revenue Recognition” (ASC 605). The Company recognizes revenue when all of the following criteria are met: (i) there is persuasive evidence that an arrangement exists; (ii) delivery of the products and/or services has occurred; (iii) the selling price is fixed or determinable; and (iv) collectability is reasonably assured. 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 products is performed by the Company subsequent to shipment to the customer in order to render it operational. Revenue includes shipping and handling revenue of $1,056 , $952 and $786 in 2015, 2014 and 2013, 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 with limited exceptions. Sales Returns and Allowances — T he Company maintains a provision for sales returns and allowances to account for potential returns of defective or damaged products, products shipped in error and invoice adjustments. The Company estimates such provision on a quarterly basis based primarily on a specific identification basis, in addition to estimating a general reserve based on historical experience. Increases to the provision result in a reduction of revenue. The provision is included in accrued liabilities in the Consolidated Balance Sheets. Allowance for Doubtful Accounts Receivable— The Company evaluates the collectability of accounts receivable to determine the appropriate reserve for doubtful accounts. In determining the amount of the reserve, the Company considers aging of account balances, historical credit losses, customer-specific information and other relevant factors. An increase to the allowance for doubtful accounts results in a corresponding increase in selling, general and administrative expense. The Company reviews accounts receivable and adjusts the allowance based on current circumstances and charges off uncollectible receivables against the allowance when all attempts to collect the receivable have failed. The Company’s history of write-offs against the allowance has not been significant. Inventories— Inventories are stated at the lower of cost or market using approximate costs based on the first-in, first-out cost method (FIFO) and consist of raw materials, work in process and finished goods. The Company’s industry is characterized by rapid product development and frequent new product introductions. Uncertain timing of product approvals, variability in product launch strategies and variation in product utilization all impact excess and obsolete inventory. An inventory allowance based on product usage is estimated and recorded quarterly for excess, slow moving and obsolete inventory, as well as for inventory with a carrying value in excess of its net realizable value. An increase to the inventory reserve allowance results in a corresponding increase in cost of revenue. Write-offs are recorded when a product is destroyed. The Company’s history of write-offs against the reserve has not been significant. Property and Equipment— Property and equipment is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method of depreciation for financial reporting purposes and applied over the estimated useful lives of the assets. The estimated useful life by major asset category is the following: generators and other capital equipment, machinery, equipment and vehicles is three to seven years, computer and other office equipment is three years, furniture and fixtures is three to seven years and leasehold improvements and equipment under capital leases are the shorter of their useful life or remaining lease term. The Company reassesses the useful lives of property and equipment annually, and assets are retired if they are no longer in service. Maintenance and repair costs are expensed as incurred. Generators and other capital equipment (such as the Company’s switchbox units and cryosurgical consoles) are placed with 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. The Company reviews property and equipment for impairment using its best estimates based on reasonable and supportable assumptions and projections. Intangible Assets— Intangible assets with determinable useful lives are amortized on a straight-line basis over the estimated periods benefited. Included in intangible assets is In Process Research and Development (IPR&D). The Company defines IPR&D as the value of acquired technology which has not yet reached technological feasibility. The primary basis for determining the technological feasibility is obtaining specific regulatory approvals. The estimated fair value of IPR&D acquired in a business combination is capitalized as an indefinite-lived intangible asset until completion or abandonment of the IPR&D project. Upon completion of the development project, the IPR&D is amortized over its estimated useful life. If the IPR&D project is abandoned, the related IPR&D asset would be written off. The estimated fair value of IPR&D was determined using an income approach model. At December 31, 2015, IPR&D represented an estimate of the fair value of the PMA approval that could result from the CONVERGE IDE clinical trial (see Note 5 – Business Combinations). The Company reviews intangible assets for impairment using its best estimates based on reasonable and supportable assumptions and projections. Goodwill— Goodwill represents the excess of purchase price over the fair value of the net assets acquired in business combinations. The Company tests goodwill for impairment annually on November 30, or more often if impairment indicators are present. The Company’s goodwill is accounted for in a single reporting unit representing the Company as a whole. Other Current Liabilities and Current Maturities of Capital Leases— As of December 31, 2014, o ther current liabilities consisted of a financing obligation related to the construction of the Company’s new headquarters. Current maturities of capital leases consist of capital lease obligations with maturities of less than one year (see Note 10 – Indebtedness). Other Noncurrent Liabilities— Other noncurrent liabilities include contingent consideration recorded in business combinations (see Note 5 – Business Combinations), as well as long-term deferred revenues and other contractual obligations. Other Income (Loss)— Other income (loss) consists primarily of foreign currency transaction gains and losses, grant income and non- employee option gains and losses related to the fair market value change for fully vested options outstanding for consultants which are accounted for as free-standing derivatives. The Company recorded foreign currency transaction (losses) gains of ( $339 ), ( $523 ) and $269 for the years ended December 31, 2015, 2014 and 2013, respectively, primarily in connection with settlements of its intercompany balances with AtriCure Europe and invoices transacted in British Pounds. 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 $35 , $731 and $0 during 2015, 2014 and 2013, 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. All vested non-employee options have been exercised as of December 31, 2015. During the years ended December 31, 2015, 2014 and 2013, $57 , $183 and ($272) , respectively, of (expense) income was recorded as a result of the remeasurement of the fair value of these fully vested stock options. Taxes — Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rates is recognized in the period that includes the enactment date. 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 (Patient 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 $667 , $592 and $417 for the years ended December 31, 2015, 2014 and 2013, respectively. In December 2015, the U.S. government approved the suspension of the excise tax on medical device sales beginning January 1, 2016 through December 31, 2017. Net Loss Per Share— Basic and diluted net loss per share is computed in accordance with FASB ASC 260 “Earnings Per Share” (ASC 260) by dividing the net loss by the weighted average number of common shares outstanding during the period. Since the Company has experienced net losses for all periods presented, net loss per share excludes the effect of 4,255 , 3,772 and 2,721 stock options and restricted stock shares as of December 31, 2015, 2014, and 2013, respectively, because they are anti-dilutive. Therefore, the number of shares calculated for basic net loss per share is also used for the diluted net loss per share calculation. Comprehensive Loss and Accumulated Other Comprehensive Loss— In addition to net losses, the comprehensive loss includes foreign currency translation adjustments and unrealized gains and losses on investments. Accumulated o ther comprehensive loss consisted of the following: 2015 2014 2013 Total accumulated other comprehensive (loss) income at beginning of period $ (348) $ (139) $ 77 Unrealized (losses) gains on investments Balance at beginning of period $ (54) $ (6) $ 1 Other comprehensive income (loss) before reclassifications 15 (48) (7) Amounts reclassified from accumulated other comprehensive income (loss) to other income — — — Balance at end of period $ (39) $ (54) $ (6) Foreign currency translation adjustment Balance at beginning of period $ (294) $ (133) $ 76 Other comprehensive income (loss) before reclassifications 156 362 (478) Amounts reclassified from accumulated other comprehensive income (loss) to other income (434) (523) 269 Balance at end of period $ (572) $ (294) $ (133) Total accumulated other comprehensive loss at end of period $ (611) $ (348) $ (139) Research and Development Costs — Research and development costs are expensed as incurred. These costs include compensation and other internal and external costs associated with the development and research related to new and existing products or concepts, preclinical studies, clinical trials, healthcare compliance and regulatory affairs. Advertising Costs — The Company expenses advertising costs as incurred. Advertising costs were not significant during the years ended December 31, 2015, 2014 and 2013, respectively. Share-Based Compensation— The Company follows FASB ASC 718 “Compensation-Stock Compensation” (ASC 718) to record share-based compensation for all employee share-based payment awards, including stock options, restricted stock and stock purchases related to an employee stock purchase plan, based on estimated fair values. The Company’s share-based compensation expense recognized under ASC 718 for the years ended December 31, 2015, 2014 and 2013 was $8,997 , $7,571 and $3,080 , respectively, on a before and after tax basis. 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 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 Consolidated Statement 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) which is available to all eligible employees as defined by the plan document. 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 ESPP 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— The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Actual results could differ from those estimates. Fair Value Disclosures — The Company classifies and records cash and investments in U.S. government agencies and securities as Level 1 within the fair value hierarchy. Accounts receivable, short-term other assets, accounts payable and accrued liabilities are also classified as Level 1. The carrying amounts of these assets and liabilities approximate their fair value due to their relatively short-term nature. Cash equivalents and investments in commercial paper are classified as Level 2 within the fair value hierarchy (see Note 3 – Fair Value for further information). Significant unobservable inputs with respect to the fair value measurement of the Level 3 non-employee stock options and contingent consideration liabilities are developed using Company data. When an input is changed, the corresponding valuation models are updated and the results are analyzed for reasonableness.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
	Dec. 31, 2015
Recent Accounting Pronouncements [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 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. The amendments in ASU 2015-10 that require transition guidance are effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2015. Early adoption is permitted, including adoption in an interim period. All other amendments are effective upon the issuance of ASU 2015-10. The Company has reviewed the amendments in ASU 2015-10 and has determined that the new guidance does 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. In August 2015 the FASB issued ASU 2015-15, “Interest – Imputation of Interest” (ASU 2015-15), which clarifies the Security and Exchange Commission staff’s position on presenting and measuring debt issuance costs incurred in connection with line-of-credit arrangements given the lack of guidance on this topic in ASU 2015-03. ASU 2015-15 was effective upon issuance. The Company has determined that the new guidance does not have a material impact on its financial reporting. In September 2015 the FASB issued ASU 2015-16, “Business Combinations (Topic 805): Simplifying the Accounting for Measurement-Period Adjustments” (ASU 2015-16), which simplifies the accounting for measurement-period adjustments. Under ASU 2015-16, an acquirer must recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. ASU 2015-16 also requires acquirers to present separately on the face of the income statement, or disclose in the notes, the portion of the amount recorded in current-period earnings by line item that would have been recorded in previous reporting periods if the adjustment to the provisional amounts had been recognized as of the acquisition date. ASU 2015-16 is effective for fiscal years beginning after December 15, 2015, including interim periods within those fiscal years, and must be applied prospectively to adjustments to provisional amounts that occur after the effective date. Early adoption is permitted for financial statements that have not been issued. The Company will consider the new guidance in its accounting and financial reporting for acquisitions. In November 2015 the FASB issued ASU 2015-17, “Income Taxes (Topic 740), Balance Sheet Classification of Deferred Taxes” (ASU 2015-17), which requires companies to classify all deferred tax assets and liabilities as noncurrent on the balance sheet instead of separating deferred taxes into current and noncurrent amounts. Also, companies will no longer allocate valuation allowances between current and noncurrent deferred tax assets because those allowances also will be classified as noncurrent. ASU 2015-17 is effective for financial statements issued for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted for financial statements that have not been issued. The Company is evaluating the impact of the provisions of ASU 2015-17 on its consolidated financial position and related disclosures. In January 2016 the FASB issued ASU 2016-01, “Financial Instruments — Overall — Recognition and Measurement of Financial Assets and Financial Liabilities” (ASU 2016-01), which amends the guidance in U.S. GAAP on the classification and measurement of financial instruments. Although the ASU retains many current requirements, it significantly revises an entity’s accounting related to (1) the classification and measurement of investments in equity securities and (2) the presentation of certain fair value changes for financial liabilities measured at fair value. The ASU also amends certain disclosure requirements associated with the fair value of financial instruments. The Company is evaluating the impact of ASU 2016-01 on its consolidated financial position and related disclosures. In February 2016 the FASB issued ASU 2016-02, “ Leases ” (ASU 2016-02) which requires lessees to put most leases on their balance sheets but recognize expenses on their income statements in a manner similar to today’s accounting. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. Entities are required to use a modified retrospective approach for leases that exist or are entered into after the beginning of the earliest comparative period in the fi nancial statements. Full retrospective application is prohibited. The Company will review the provisions of ASU 2016-02 to determine the impact on its consolidated financial position and related disclosures.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2015
Fair Value [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 derivative instruments (non-employee stock options) 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 liabilities was estimated on the respective acquisition dates of Endoscopic Technologies, Inc. (Estech) and nContact Surgical, Inc. (nContact), and is revalued at the end of each subsequent reporting period (see Note 5 – Business Combinations for further information). 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, 2015: Quoted Prices in Active Significant Significant Markets for Other Other Identical Observable Unobservable Assets Inputs Inputs (Level 1) (Level 2) (Level 3) Total Assets: Money market funds $ — $ 18,572 $ — $ 18,572 U.S. government agencies and securities 1,590 — — 1,590 Corporate bonds — 16,930 — 16,930 Total assets $ 1,590 $ 35,502 $ — $ 37,092 Liabilities: Acquisition-related contingent consideration $ — $ — $ 40,207 $ 40,207 Total liabilities $ — $ — $ 40,207 $ 40,207 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 Active Significant Significant Markets for Other Other Identical Observable Unobservable Assets Inputs Inputs (Level 1) (Level 2) (Level 3) 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 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, 2015 and 2014. Derivative Instruments. Vested non-employee options historically issued by the Company are accounted for as derivative liabilities and remeasured at fair value through earnings at each reporting period until exercised or forfeited. All vested non-employee options have been exercised as of December 31, 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: 2015 2014 2013 Beginning Balance – January 1 $ 120 $ 350 $ 78 Total (gains) losses included in earnings 57 (183) 272 Exercises (177) (47) — Reclassification from equity to liability when fully vested — — — Ending Balance – December 31 $ — $ 120 $ 350 Acquisition-Related Contingent Consideration. Contingent consideration arrangements obligate the Company to pay former shareholders of an acquired entity if specified future events occur or conditions are met, such as the achievement of certain technological milestones or the achievement of targeted revenue milestones. The Company measures such liabilities using unobservable inputs, applying the income approach, such as the discounted cash flow technique or the probability-weighted scenario method. Various key assumptions, such as the probability of achievement of the agreed milestones, projected revenues from acquisitions and the discount rate, are used in the determination of fair value of contingent consideration arrangements and are not observable in the market, thus representing a Level 3 measurement within the fair value hierarchy. Subsequent revisions to key assumptions, which impact the estimated fair value of contingent consideration liabilities, are reflected in the Consolidated Statements of Operations and Comprehensive Loss. The Company acquired Estech on December 31, 2013. The aggregate consideration paid to Estech shareholders included up to $26,000 of contingent consideration to be paid based on the achievement of certain performance-based milestones in 2014 and 2015. The fair value of the Estech contingent consideration was determined to be $0 , $0 and $8,032 as of December 31, 2015, 2014 and 2013, respectively. The Company acquired nContact on October 13, 2015. The aggregate consideration paid to nContact shareholders includes up to $50,000 in contingent consideration based on completion of enrollment of the CONVERGE IDE trial and corresponding PMA approval by December 31, 2020. nContact shareholders are entitled to additional sales-based contingent consideration on revenue in excess of an annual growth rate of more than 25% through 2019. The total fair value of the nContact contingent consideration was determined to be $40,207 as of both the acquisition date and December 31, 2015. 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: 2015 2014 2013 Beginning Balance – January 1 $ — $ 8,032 $ — Amounts acquired 40,207 — 8,032 Transfers in (out) of Level 3 — — — Changes in fair value included in earnings — (8,032) — Ending Balance – December 31 $ 40,207 $ — $ 8,032

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Investments	4. INVESTMENTS Investments as of December 31, 2015 consisted of the following: Unrealized Gains Cost Basis (Losses) Fair Value Corporate bonds $ 16,963 $ (33) $ 16,930 U.S. government agencies and securities 1,596 (6) 1,590 Total $ 18,559 $ (39) $ 18,520 Investments as of December 31, 2014 consisted of the following: Unrealized Gains Cost Basis (Losses) Fair Value Corporate bonds $ 35,389 $ (52) $ 35,337 U.S. government agencies and securities 3,024 (2) 3,022 Commercial paper 1,800 — 1,800 Total $ 40,213 $ (54) $ 40,159 The Company has not experienced any significant realized gains or losses on its investments in the periods presented in the Consolidated Statements of Operations and Comprehensive Loss. Long term investments held by the Company have maturities between one and two years at both December 31, 2015 and 2014.

Business Combination

Business Combination	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Combination	5. BUSINESS COMBINATIONS nContact Surgical, Inc. (nContact). On October 13, 2015 the Company completed its acquisition of nContact, pursuant to a merger agreement (Agreement) under which the Company acquired 100% of the outstanding equity interests of nContact. Incorporated in 2004 and based in Morrisville, North Carolina, nContact developed and marketed a portfolio of innovative devices that provide for less invasive ablation options for the treatment of cardiac arrhythmias. The company’s technology is used in the Convergent procedure, a multi-disciplinary therapy in which a closed-chest surgical epicardial ablation is performed, and then complemented by an endocardial catheter ablation performed by an electrophysiologist. The CONVERGE IDE clinical trial is currently being conducted and is the first head-to-head study to evaluate the Convergent procedure versus catheter ablation in patients with persistent Afib. AtriCure’s management believes the acquisition of nContact will expand and strengthen the Company’s presence in the Afib market, reinforce the Company’s commitment to clinical science, and provide improved market access and additional collaboration opportunities with cardiac surgeons and electrophysiologists. The combination of the two companies expands AtriCure’s addressable market with the addition of proven technology that treats an under-served population of patients, complements the Company’s current product portfolio and minimally invasive (MIS) intellectual property portfolio, accelerates and sustains the Company’s revenue growth rate, and drives continued margin expansion and worldwide operating leverage opportunities. The total consideration paid to nContact’s former shareholders at acquisition date was 3,757 shares of AtriCure common stock, valued at $69,054 at the closing of the transaction, and $7,581 in cash. Although the cash paid at acquisition was subject to adjustment for net working capital balances outside of a specified range, no such adjustment was made as a result of the final net working capital delivered. In addition, the Agreement provides for the Company to pay contingent consideration, as follows: · Trial Enrollment Milestone— $7,500 upon completion of patient enrollment of the CONVEGE IDE clinical trial. Such payment is due on or before 30 days following enrollment of the final patient. · Regulatory Milestone— up to $42,500 upon the completion of the CONVERGE IDE clinical trial and receiving approval of a premarket approval ( PMA) by the FDA for the EPi-Sense-AF Guided Coagulation System and/or any other nContact product with an indication for symptomatic persistent Afib or a similar or related indication. The full contingent consideration amount of $42,500 is only earned if such regulatory approvals are received on or before January 1, 2020 . The potential contingent consideration is reduced by 8.33% (or one-twelfth) each month following January 2020 , and is reduced to zero if the regulatory milestone is achieved after December 31, 2020 . Any payment of the regulatory contingent consideration is due on or before 30 days following the receipt of the related PMA approval. · Commercial Milestone— for the calendar years 2016 through 2019, nContact revenues in excess of specified target revenue amounts, which approximate 25% annual revenue growth, will result in contingent consideration equal to 1.5 times the revenues in excess of target. Payments of contingent consideration under the annual commercial milestones are due within 65 days of each calendar year end. Subject to the terms and conditions of the Agreement, all contingent consideration can be paid in cash and AtriCure common stock. The Agreement limits the total number of shares of AtriCure common stock issued in connection with the acquisition to 5,660 . The Company accounted for the acquisition in accordance with FASB ASC 805, “Accounting for Business Combinations”. The assets acquired, liabilities assumed and the estimated future contingent consideration obligation were recorded at their respective fair values as of the date of acquisition. The process for estimating fair values of identifiable intangible assets and certain tangible assets and assumed liabilities requires the use of judgment in determining the appropriate assumptions and estimates. The judgments used to determine the estimated fair value assigned to each class of assets acquired and liabilities assumed, as well as asset lives, can materially impact the Company’s results of operations. The components of the aggregate purchase price for the nContact acquisition were as follows: Fair value of AtriCure common stock issued at closing $ 69,054 Cash 7,581 Fair value of contingent consideration liabilities 40,207 Total purchase price $ 116,842 The fair value of contingent consideration liabilities was determined by applying an income valuation approach, including the discounted cash flow technique probability-weighted scenario method. Key assumptions in the valuation of contingent consideration liabilities are based on management’s judgment and estimates, and include the probability of achievement of each of the milestones, projected revenues from the acquisition, and the discount rates, which ranged from 3% to 14% , reflecting the inherent risks of achieving the respective milestones. These assumptions are not observable in the market, thus represent a Level 3 measurement within the fair value hierarchy. As of December 31, 2015, the purchase price allocation has not yet been finalized as the Company evaluates certain tax attributes of nContact. The following table summarizes the preliminary estimated fair values of the assets acquired and liabilities assumed on the acquisition date: October 13, 2015 Accounts receivable $ 1,450 Inventories 682 Other current assets 166 Property and equipment 311 Intangible assets 46,200 Other assets 7 Total identifiable assets $ 48,816 Accounts payable $ 256 Accrued liabilities 1,589 Total liabilities assumed $ 1,845 Net identifiable assets acquired $ 46,971 Goodwill 69,871 Total consideration $ 116,842 The above estimated fair values of assets acquired and liabilities assumed are based on the information that was available as of the acquisition date. Deferred tax assets and liabilities were also recognized at acquisition date for the future tax consequences attributable to differences between the above financial statement carrying amounts of existing assets and liabilities and their respective tax bases and acquired operating loss and tax credit carryforwards of nContact. At acquisition, nContact had approximately $59,000 of net operating loss carryforwards, which begin to expire in 2025 and are subject to certain limitations under Internal Revenue Code Section 382. The Company recorded a full valuation allowance against the net deferred tax assets at acquisition. The valuation of the intangible assets acquired and related amortization periods are as follows: Amortization Term Valuation (in years) SUBTLE access technology $ 2,179 5 IPR&D 44,021 Total $ 46,200 The fair value of the SUBTLE access technology and IPR&D both were estimated using an income approach. Under this method, an intangible asset’s fair value is equal to the present value of the incremental after-tax cash flows (excess earnings) attributable solely to the intangible asset over its remaining useful life. The Company believes that the level and timing of cash flows related to each asset appropriately reflects market participant assumptions, and such cash flows were discounted at rates considered appropriate given the inherent risks associated with each type of intangible asset. The SUBTLE access technology asset is amortized on a straight-line basis over its estimated useful life. The IPR&D asset, which is accounted for as an indefinite-lived intangible asset until completion or abandonment of the project, represents an estimate of the fair value of the PMA approval from the in-process CONVERGE IDE clinical trial. Upon completion of this development project, the IPR&D is amortized over its estimated useful life. If the IPR&D project is abandoned, the related IPR&D asset would be written off. The Company recorded the excess of the aggregate purchase price over the estimated fair values of the identifiable net assets acquired as goodwill. Goodwill is primarily attributable to the benefits the Company expects to realize by enhancing its product offering and addressable markets, thereby contributing to an expanded revenue base and improved margins. None of the goodwill recorded in the acquisition is deductible for income tax purposes. As discussed in Note 1, the Company accounts for goodwill in a single reporting unit representing the Company as a whole. The operating results of nContact, including $2,192 of revenue, are included in the Consolidated Statements of Operations and Comprehensive Loss beginning October 14, 2015. The Consolidated Balance Sheet as of December 31, 2015 reflects the acquisition of nContact. The Company recognized approximately $2,489 of acquisition-related costs that were expensed during 2015. The costs consisted of $1,767 for investment bank fees and expenses and $722 for legal, audit, tax and other costs. These costs are included in selling, general and administrative expenses in the accompanying Consolidated Statements of Operations and Comprehensive Loss. The following supplemental pro forma information presents the financial results of the Company for the years ended December 31, 2015 and 2014 as if the acquisition of nContact had occurred on January 1, 2014. Year Ended December 31, (unaudited) 2015 2014 Revenue $ 137,882 $ 115,979 Net loss (30,745) (21,438) Basic and diluted net loss per share (0.99) (0.71) Certain pro forma adjustments have been made when calculating the amounts above to reflect the impact of the purchase transaction, primarily consisting of inclusion of amortization of intangible assets with determinable lives and exclusion of nContact’s interest expense incurred on debt paid off in the acquisition. The Company also eliminated transaction expenses incurred by both AtriCure and nContact. This supplemental pro forma information has been prepared for comparative purposes and does not purport to be indicative of what would have occurred had the acquisition been made on January 1, 2014, nor are they indicative of any future results. The pro forma information does not include any adjustment for potential revenue enhancements, cost synergies or other operating efficiencies that could result from the acquisition. Endoscopic Technologies, Inc. (Estech). On December 31, 2013, the Company completed its acquisition of Estech. The aggregate consideration paid to Estech shareholders included up to $26,000 of contingent consideration to be paid based on the achievement of certain performance-based milestones in 2014 and 2015. The fair value of the contingent consideration was estimated using an expected present value approach to estimate an expected value. The Company recorded $8,032 in contingent consideration at acquisition, and, based on results during 2014, reduced the value of the contingent consideration to $0 at December 31, 2014. The $8,032 adjustment was recorded as a reduction of selling, general and administrative expenses in the accompanying 2014 Consolidated Statement of Operations and Comprehensive Loss. At December 31, 2015, the Company’s liability for the Estech contingent consideration remains at $0 based on the final analysis of actual results against the specified milestones in 2014 and 2015.

Intangible Assets And Goodwill

Intangible Assets And Goodwill	12 Months Ended
	Dec. 31, 2015
Intangible Assets And Goodwill [Abstract]
Intangible Assets And Goodwill	6. INTANGIBLE ASSETS AND GOODWILL The following table provides a summary of the Company’s intangible assets at December 31: 2015 2014 Accumulated Accumulated Cost Amortization Cost Amortization Non-compete agreement $ 100 $ 100 $ 100 $ 93 Fusion technology 9,242 1,848 9,242 924 Clamp & probe technology 829 552 829 276 Estech trade name 208 208 208 208 SUBTLE access technology 2,179 96 — — IPR&D 44,021 — — — Total $ 56,579 $ 2,804 $ 10,379 $ 1,501 For the years ended December 31, 2015, 2014 and 2013, amortization expense related to intangible assets with definite lives was $1,303 , $1,421 and $12 , respectively. The IPR&D asset is not amortized until the completion of the project. Future amortization expense related to intangible assets with definite lives is projected as follows: 2016 $ 1,644 2017 1,367 2018 1,367 2019 1,367 2020 1,235 2021 and thereafter 2,774 Total $ 9,754 The following table provides a summary of the Company’s goodwill, which is not amortized, but rather tested annually for impairment: Net carrying amount as of December 31, 2013 $ 35,386 Additions — Net carrying amount as of December 31, 2014 35,386 Additions 69,871 Net carrying amount as of December 31, 2015 $ 105,257

Inventories

Inventories	12 Months Ended
	Dec. 31, 2015
Inventories [Abstract]
Inventories	7. INVENTORIES Inventories consisted of the following at December 31: 2015 2014 Raw materials $ 6,159 $ 4,429 Work in process 974 1,397 Finished goods 10,526 8,431 Inventories $ 17,659 $ 14,257

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property and Equipment [Abstract]
Property and Equipment	8. PROPERTY AND EQUIPMENT Property and equipment consisted of the following at December 31: 2015 2014 Building under capital lease $ 14,250 $ — Generators and other capital equipment 10,041 8,578 Computer and other office equipment 4,303 2,436 Furniture and fixtures 3,211 488 Machinery, equipment and vehicles 2,551 2,604 Leasehold improvements 2,151 329 Construction in progress 1,978 4,642 Equipment under capital leases 212 162 Total 38,697 19,239 Less accumulated depreciation (7,418) (7,687) Property and equipment, net $ 31,279 $ 11,552 Property and equipment depreciation expense was $4,975 , $3,353 and $2,008 for the years ended December 31, 2015, 2014 and 2013, respectively. Depreciation related to generators and other capital equipment was $2,944 , $2,172 and $1,251 in 2015, 2014 and 2013, respectively. As of December 31, 2015 and 2014, the net carrying amount of generators and other capital equipment was $5,447 and $4,141 , respectively. Included in construction in progress as of December 31, 2014 are $4,234 of costs related to the construction of the Company’s new headquarters building, which were placed in service and transferred to Building under capital lease in 2015 (see Note 10 – Indebtedness).

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2015
Accrued Liabilities [Abstract]
Accrued Liabilities	9. ACCRUED LIABILITIES Accrued liabilities consisted of the following at December 31: 2015 2014 Accrued bonus $ 6,088 $ 4,915 Accrued commissions 6,061 4,477 Accrued payroll and employee-related expenses 4,021 2,281 Accrued taxes and value-added taxes payable 912 1,272 Other accrued liabilities 723 399 Accrued royalties 382 442 Sales returns allowance 207 135 Accrued non-employee stock options — 120 Total $ 18,394 $ 14,041

Indebtedness

Indebtedness	12 Months Ended
	Dec. 31, 2015
Indebtedness [Abstract]
Indebtedness	10. INDEBTEDNESS Bank Credit Facility. The Company has a debt agreement (Loan Agreement) with Silicon Valley Bank (SVB). The Loan 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 Loan Agreement. As of December 31, 2015, the Company had no borrowings under the revolving credit facility and had borrowing availability of $14,559 . The applicable interest rate is 3. 5% . 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 Loan Agreement. The Loan Agreement, as amended restated and modified, contains covenants that include, among others, covenants that limit the Company’s ability to dispose of assets, enter into mergers or acquisitions, incur indebtedness, incur liens, pay dividends or make distributions on the Company’s capital stock, make investments or loans, and enter into certain affiliate transactions, in each case subject to customary exceptions for a credit facility of this size and type. Additional covenants apply when the Company has outstanding borrowings under the revolving credit facility or when the Company holds less than $20,000 in cash and investments with SVB. Financial covenants under the credit facility include a minimum EBITDA and a minimum liquidity ratio. Further, a minimum fixed charge ratio applies when the Company achieves specific covenant milestones. None of the covenants must be applied as of December 31, 2015. The occurrence of an event of default could result in an increase to the applicable interest rate by 3.0% , an acceleration of all obligations under the Loan Agreement, an obligation of the Company to repay all obligations in full and a right by SVB to exercise all remedies available to it under the Loan Agreement and related agreements including any Guaranty or Guarantor Security Agreement. Specified assets have been pledged as collateral. As of December 31, 2015, the Company has an outstanding letter of credit of $1,250 related to the Company’s new headquarters lease in Mason, Ohio. The letter of credit may be reduced or removed entirely based on the Company’s future financial performance, as specified in the lease 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. Capital Lease Obligations. As of December 31, 201 5 the Company had capital leases for its corporate headquarters building and computer equipment that expire at various terms through 2030 . 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 to a building constructed on Innovation Way in Mason, Ohio and occupied exclusively by the Company. Construction of the approximately 92 square-foot building was substantially completed and the lease term began in October 2015 . The term of the Mason Lease is fifteen years with three separate five -year renewal options, at the Company’s option. The amount of initial annual base rent of $1,353 is payable in monthly installments and is subject to a 2% increase each year during the initial term of the agreement. 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. 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 was 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. The Company was deemed the owner of the project during the construction period. As a result, project costs incurred during construction the building were included in property and equipment and the corresponding financing obligation was included in other current liabilities in the Consolidated Balance Sheet as of December 31, 2014. An increase in purchases of building under construction and proceeds from the construction financing obligation are also included in the Consolidated Statement of Cash Flows. At the completion of construction, the Company evaluated the lease agreement under guidance in FASB ASC 840, “Leases”, and included the current and noncurrent portions of the Mason Lease obligation within capital leases and the value of the underlying asset in Property and Equipment in the Consolidated Balance Sheet as of December 31, 2015. The cost of the leased assets, both building and computer equipment, under lease at December 31, 2015 was $14,462 . The assets are depreciated over their estimated useful lives, which equal the terms of the respective leases. Accumulated amortization on the capital leases was $349 at December 31, 2015. Future maturities on capital lease obligations are projected as follows: 2016 $ 1,417 2017 1,425 2018 1,439 2019 1,457 2020 1,478 2021 and thereafter 15,894 Total payments $ 23,110 Imputed interest (8,950) Net capital lease obligations, of which $450 is current and $13,710 is noncurrent $ 14,160

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies [Abstract]
Commitments and Contingencies	11. COMMITMENTS AND CONTINGENCIES Lease Commitments. The Company leases certain office, manufacturing and warehouse facilities and equipment under noncancelable operating leases that expire at various terms through 2021 . Future minimum lease payments under non-cancelable operating leases are projected as follows: 2016 $ 934 2017 663 2018 724 2019 737 2020 556 2021 and thereafter 251 Total $ 3,865 Rent expense was approximately $1,515 , $1,331 and $870 in 2015, 2014, and 2013, respectively. 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 $1,799 , $1,322 and $962 was recorded as part of cost of revenue for the years ended December 31, 2015, 2014 and 2013, respectively. Purchase Agreements. The Company enters into standard purchase agreements with certain vendors in the ordinary course of business. Outstanding commitments at December 31, 2015 were not significant. Legal. The Company is not party to any material pending or threatened litigation, except for the matter described below. The Company may, from time to time, become a party to additional legal proceedings. Department of Justice Investigation In October 2008 the Company received a letter from the Department of Justice (DOJ) informing the Company that it was conducting an investigation for potential False Claims Act (FCA) and common law violations relating to its surgical ablation devices. The Company cooperated with the investigation and operated its business in the ordinary course during the investigation. In December 2009 the Company reached a tentative settlement with the DOJ to resolve the investigation and recorded a liability. The settlement was finalized pursuant to the preliminary terms in February 2010, and the resulting settlement agreement definitively resolved all claims related to the DOJ investigation. The Company did not admit nor will it admit to any wrongdoing in connection with the settlement. The Company completed making payments totaling $4,350 (including interest) in 2014 and has no remaining financial liability. In June 2015 the Company received confirmation from the Office of Inspector General that the Company had satisfactorily completed all obligations under the five -year Corporate Integrity Agreement entered into in 2010.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes [Abstract]
Income Taxes	12. INCOME TAXES 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 detail of deferred tax assets and liabilities at December 31 is as follows: 2015 2014 Deferred tax assets (liabilities): Net operating loss carryforward $ 78,178 $ 49,921 Research and development and AMT credit carryforwards, net 5,677 4,799 Equity compensation 6,618 4,497 Accruals and reserves 539 536 Inventories 1,310 669 Intangible assets (16,953) (149) Property and equipment, net (1,740) (760) Other, net 53 41 Subtotal 73,682 59,554 Less valuation allowance (73,682) (59,554) Total $ — $ — The Company’s provision for income taxes is as follows: 2015 2014 2013 Current income tax expense $ 36 $ 33 $ 18 Deferred tax benefit (8,507) (5,306) (3,728) Increase in valuation allowance 8,507 5,306 3,728 Total income tax expense $ 36 $ 33 $ 18 The Company has a federal net operating loss carryforward of $205,278 which will begin to expire in 20 2 1 and state net operating loss carryforwards of $136,323 which have varying expirations ranging from five years to twenty years. At December 31, 2015 there were $5, 790 of unrecognized deferred tax assets that arose from tax deductions for equity compensation in excess of compensation recognized for financial reporting during years when net operating losses were created. Additional paid in capital will be increased if such deferred tax assets are realized and reduce current tax payable. A portion of the Company’s federal and state net operating loss carryforwards are subject to certain limitations under Internal Revenue Code Sections 382 and 383. The Company also has a foreign net operating loss carryforward of approximately $17,919 of which $970 expires in 2016 . Additionally, the Company has a federal research and development credit carryforward of $5,575 which will begin to expire in 2022 . The Company’s 2015, 2014 and 2013 effective income tax rates differ from the federal statutory rate as follows: 2015 2014 2013 Federal tax at statutory rate 34.00 % $ (9,240) 34.00 % $ (5,501) 34.00 % $ (3,891) Federal R&D credit 3.23 (878) 2.32 (374) 3.35 (383) Valuation allowance (31.30) 8,507 (32.80) 5,306 (29.63) 3,391 State income taxes 1.38 (375) 2.68 (433) 0.04 (5) Foreign NOL rate change (2.02) 549 (4.29) 694 2.47 (283) Foreign tax rate differential (1.99) 542 (2.83) 458 (1.60) 183 Other (3.43) 931 0.72 (117) (8.79) 1,006 Effective tax rate (0.13) % $ 36 (0.20) % $ 33 (0.16) % $ 18 The Company’s pre-tax book loss for domestic and international operations was ( $21,157 ) and ( $6,019 ), respectively, for 2015, ( $11,085 ) and ( $5,093 ), respectively, for 2014 and ( $9,409 ) and ( $2,035 ), respectively, for 2013. The Company has not had to accrue any interest and penalties related to unrecognized income tax benefits as a result of offsetting of net operating losses. However, if the situation occurs, the Company will recognize interest and penalties within the income tax expense line in the Consolidated Statements of Operations and Comprehensive Loss and within the related tax liability line in the Consolidated Balance Sheets. Federal, state, and local tax returns of the Company are routinely subject to examination by various taxing authorities. Federal and foreign income tax returns for periods beginning in 2012 are open for examination. However, taxing authorities have the ability to adjust net operating loss and tax credit carryforwards from years prior to these periods. The Company has not recognized certain tax benefits because of the uncertainty of realizing the entire value of the of the tax position taken on income tax returns upon review by the taxing authorities. A reconciliation of the change in federal and state unrecognized tax benefits for 2015, 2014 and 2013 is presented below: 2015 2014 2013 Balance at the beginning of the year $ 1,982 $ 1,982 $ — Increases (decreases) for prior year tax positions — — 1,982 Increases (decreases) for current year tax positions — — — Increases (decreases) related to settlements — — — Decreases related to statute lapse — — — Balance at the end of the year $ 1,982 $ 1,982 $ 1,982 There are no amounts included in the balance of unrecognized tax benefits at December 31, 2015, 2014 and 2013 that, if recognized, would affect the effective tax rate. Included in the balance of unrecognized tax benefits at December 31, 2015 are $1,982 of tax benefits that, if recognized, would result in adjustments to other tax accounts, primarily deferred taxes and valuation allowance. There are no accrued interest and penalties associated with the unrecognized tax benefit. The Company does not anticipate that there will be any significant adjustments to its recorded unrecognized tax benefits in the next twelve months.

Concentrations

Concentrations	12 Months Ended
	Dec. 31, 2015
Concentrations [Abstract]
Concentrations	13. CONCENTRATIONS During fiscal 2015, 2014 and 2013 approximately 12.9% , 13.6% and 20.4% , respectively, of the Company’s total net revenue was derived from its top ten customers. During 2015, 2014 and 2013 no individual customer accounted for more than 10% of the Company’s revenue. No individual customer accounted for more than 10% of the Company’s accounts receivable as of December 31, 2015 and 2014. The Company maintains cash and cash equivalents balances at financial institutions which at times exceed FDIC limits. As of December 31, 2015, $23,608 of the cash and cash equivalents balance was in excess of the FDIC limits.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2015
Employee Benefit Plans [Abstract]
Employee Benefit Plans	14. EMPLOYEE BENEFIT PLANS The Company sponsors the AtriCure, Inc. 401(k) Plan (401(k) Plan), a defined contribution plan covering substantially all U.S. employees of the Company. Eligible employees may contribute pre-tax annual compensation up to specified maximums under the Internal Revenue Code. During 2015, 2014 and 2013 the Company made matching contributions of 50% of the first 6% of employee contributions to the 401(k) Plan. The Company’s matching contributions expensed during 2015, 2014 and 2013 were $1,007 , $807 and $606 , respectively. Additional amounts may be contributed to the 401(k) Plan at the discretion of the Company’s board of directors. No such discretionary contributions were made during 2015, 2014 or 2013. The Estech 401(k) plan acquired by the Company through its acquisition of Estech was rolled into the 401(k) Plan during 2014. The Company also provides retirement benefits for AtriCure Europe employees. Total contributions to retirement plans for AtriCure Europe employees were $133 , $176 and $176 in 2015, 2014 and 2013, respectively.

Equity Compensation Plans

Equity Compensation Plans	12 Months Ended
	Dec. 31, 2015
Equity Compensation Plans [Abstract]
Equity Compensation Plans	15. EQUITY COMPENSATION PLANS The Company has several share-based incentive plans: 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). 2005 Plan and 2014 Plan 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. 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 the date of grant. As of December 31, 2015, 8,949 shares of common stock had been reserved for issuance under the 2014 Plan. The shares authorized for issuance under the 2014 Plan include (a) shares reserved but unissued under the 2001 Plan as of August 10, 2005, (b) shares returned to the 2001 Plan as the result of the termination of options or the repurchase of shares issued under such plan, (c) shares reserved but unissued under the 2005 Plan as of May 14, 2014 and (d) 1,300 additional shares authorized under the 2014 Plan. As of December 31, 2015 there were 1,372 shares available for future grants under the plans. Activity under the plans during 2015 was as follows: Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Time-Based Stock Options Outstanding Price Term Value Outstanding at January 1, 2015 2,762 $ 10.93 Granted 228 21.10 Cancelled or forfeited (13) 15.17 Exercised (243) 11.10 Outstanding at December 31, 2015 2,734 $ 11.75 6.15 $ 29,331 Vested and expected to vest 2,660 $ 11.57 6.09 $ 28,974 Exercisable at December 31, 2015 1,862 $ 9.94 5.28 $ 23,263 Weighted Number of Average Shares Grant Date Restricted Stock Outstanding Fair Value Outstanding at January 1, 2015 560 $ 16.33 Awarded 648 17.82 Forfeited (2) 17.76 Released (135) 15.78 Outstanding at December 31, 2015 1,071 $ 17.30 Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Performance Stock Options Outstanding Price Term Value Outstanding at January 1, 2015 450 $ 13.48 Granted — — Cancelled or forfeited — — Exercised — — Outstanding at December 31, 2015 450 $ 13.48 7.46 $ 4,034 Exercisable at December 31, 2015 250 $ 13.48 7.46 $ 2,241 Activity under the plans during 2014 was as follows: Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Time-Based Stock Options Outstanding Price Term Value Outstanding at January 1, 2014 2,423 $ 8.61 Granted 603 19.54 Cancelled or forfeited (49) 10.65 Exercised (215) 8.94 Outstanding at December 31, 2014 2,762 $ 10.93 6.54 $ 25,335 Vested and expected to vest 2,660 $ 10.81 6.46 $ 24,697 Exercisable at December 31, 2014 1,516 $ 8.85 4.86 $ 16,836 Weighted Number of Average Shares Grant Date Restricted Stock Outstanding Fair Value Outstanding at January 1, 2014 248 $ 7.75 Awarded 391 20.25 Forfeited (1) 9.15 Released (78) 8.79 Outstanding at December 31, 2014 560 $ 16.33 Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Performance Stock Options Outstanding Price Term Value Outstanding at January 1, 2014 225 $ 5.91 Granted 225 21.04 Cancelled or forfeited — — Exercised — — Outstanding at December 31, 2014 450 $ 13.48 8.50 $ 3,161 Exercisable at December 31, 2014 250 $ 13.48 8.50 $ 1,756 The total intrinsic value of options exercised during the years ended December 31, 2015, 2014 and 2013 was $2,740 , $2,311 and $951 , respectively. As a result of the Company’s tax position, no tax benefit was recognized related to the stock option exercises. For 2015, 2014 and 2013, $2,703 , $1,916 and $1,718 , respectively, in cash proceeds were included in the Company’s Consolidated Statements of Cash Flows as a result of the exercise of stock options. The total fair value of restricted stock vested during 2015, 2014 and 2013 was $2,767 , $1,434 and $1,442 , respectively. The exercise price per share of each option is equal to the fair market value of the underlying share on the date of grant. The Company issues registered shares of common stock to satisfy stock option exercises and restricted stock grants. The Company recognized expense related to time-based stock options and restricted stock for 2015, 2014, and 2013 of $8,072 , $5,383 and $2,489 , respectively. As of December 31, 2015 there was $21,181 of unrecognized compensation costs related to non-vested stock option and restricted stock arrangements ( $7,375 relating to stock options and $13,806 relating to restricted stock). This cost is expected to be recognized over a weighted-average period of 2.0 years for stock options and 2.6 years for restricted stock. The Company awarded 225 performance options to its new President and Chief Executive Officer (CEO) when he joined the Company in November 2012, and an additional 225 performance options were awarded to the CEO in January 2014. The options expire ten years from the date of grant and vest in increments of 25 shares when the volume adjusted weighted average closing price of the common stock of the Company as reported by NASDAQ (or any other exchange on which the common stock of the Company is listed) for 30 consecutive days equals or exceeds each of $10.00 per share, $12.50 per share, $15.00 per share, $17.50 per share, $20.00 per share, $25.00 per share, $30.00 per share, $35.00 per share and $40.00 per share. In accordance with FASB ASC 718, a Monte Carlo simulation was performed for both grants to estimate the fair values, vesting terms and vesting probabilities for each tranche of options. Expense calculated using these estimates is being recorded over the estimated vesting terms. The Company recognized expense related to the performance options during 2015, 2014 and 2013 of $546 , $1,767 and $272 , respectively. As of December 31, 2015 there was $313 of unrecognized compensation costs related to non-vested performance options. This cost is expected to be recognized over a weighted-average period of 0.25 to 2.05 years. 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 a value of 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 December 31, 2015 there were 491 shares available for future issuance under the ESPP. Share-based compensation expense with respect to the ESPP was $379 , $421 and $319 for 2015, 2014 and 2013, respectively. 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 2015, 2014 and 2013. This expense was allocated as follows: 2015 2014 2013 Cost of revenue $ 416 $ 335 $ 246 Research and development expenses 1,373 937 230 Selling, general and administrative expenses 7,208 6,299 2,604 Total $ 8,997 $ 7,571 $ 3,080 In calculating compensation expense, the fair value of the options is estimated on the grant date using the Black-Scholes model including the following assumptions: 2015 2014 2013 Risk-free interest rate 1.30 - 1.96 % 1.56 - 2.12 % 0.75 - 2.29 % Expected life of option (years) 5.20 to 6.89 5.31 to 6.72 5.38 to 7.14 Expected volatility of stock 46.00 - 67.00 % 47.00 - 70.00 % 69.00 % Weighted-average volatility 54.75 % 69.19 % 69.00 % Dividend yield 0.00 % 0.00 % 0.00 % The Company’s estimate of volatility is based solely on the Company’s trading history. The risk-free interest rate assumption is based upon the U.S. treasury yield curve at the time of grant for the expected option life. The Company estimates the expected terms of options using historical employee exercise behavior. The fair value of restricted stock awards is based on the market value of the Company’s stock on the date of the awards. Based on the assumptions noted above, the weighted average estimated grant date fair value per share of the stock options and restricted stock granted for 2015, 2014 and 2013 was as follows: 2015 2014 2013 Stock options $ 11.12 $ 12.33 $ 5.70 Restricted stock 17.82 20.25 9.35 In calculating compensation expense for performance options, the fair value of the options is estimated on the grant date using a Monte Carlo simulation including the following assumptions: 2015 2014 2013 Strike price $ 5.91 - 21.04 $ 5.91 - 21.04 $ 5.91 Contractual term (years) 10.00 10.00 10.00 Expected volatility of stock 60.50 - 69.60 % 60.50 - 69.60 % 69.60 % Interest rate 1.75 - 2.73 % 1.75 - 2.73 % 1.75 % Dividend yield 0.00 % 0.00 % 0.00 % The contractual term assumes that the performance options issued to the CEO of the Company in 2012 and 2014 will be held until expiration. Expected volatility is estimated based on the Company’s trading history. The expected rate of return assumption is based upon the U.S. treasury yield curve at the time of grant for the expected option life. Based on the assumptions noted above, the estimated grant date fair value per share of the performance options granted were as follows: Price Fair Value of Fair Value of Target 2012 Grant 2014 Grant Tranche 1 $ 10.00 $ 4.32 $ 14.74 Tranche 2 12.50 4.30 14.74 Tranche 3 15.00 4.27 14.74 Tranche 4 17.50 4.23 14.74 Tranche 5 20.00 4.19 14.73 Tranche 6 25.00 4.10 14.73 Tranche 7 30.00 4.01 14.71 Tranche 8 35.00 3.92 14.67 Tranche 9 40.00 3.83 14.61

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2015
Segment and Geographic Information [Abstract]
Segment and Geographic Information	16. 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: 2015 2014 2013 Revenue: United States $ 102,212 $ 80,203 $ 62,311 Europe 17,180 18,163 11,384 Asia 9,510 8,552 7,665 Other international 853 536 529 Total international 27,543 27,251 19,578 Total revenue $ 129,755 $ 107,454 $ 81,889 Domestic revenue by product type was as follows: 2015 2014 2013 Revenue: Open-heart ablation $ 53,541 $ 44,662 $ 37,843 Minimally invasive ablation 21,564 16,050 13,648 AtriClip 24,377 16,675 10,820 Total ablation and AtriClip 99,482 77,387 62,311 Valve tools 2,730 2,816 — Total domestic $ 102,212 $ 80,203 $ 62,311 International revenue by product type was as follows: 2015 2014 2013 Revenue: Open-heart ablation $ 16,287 $ 16,445 $ 13,064 Minimally invasive ablation 7,964 7,881 5,354 AtriClip 2,868 2,158 1,160 Total ablation and AtriClip 27,119 26,484 19,578 Valve tools 424 767 — Total international $ 27,543 $ 27,251 $ 19,578 The majority of the Company’s long-lived assets are located in the United States.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Data [Abstract]
Selected Quarterly Financial Data (Unaudited)	17. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) For the Three Months Ended March 31, June 30, September 30, December 31, 2015 2014 2015 2014 2015 2014 2015 2014 Operating Results: Revenue $ 29,886 $ 24,847 $ 32,583 $ 26,514 $ 31,423 $ 26,678 $ 35,863 $ 29,415 Gross profit 21,735 17,657 23,117 18,781 22,478 18,892 25,545 20,420 Loss from operations (5,144) (7,925) (4,819) (2,853) (6,127) (803) (10,630) (4,779) Net loss (5,266) (7,709) (4,891) (2,692) (6,141) (466) (10,914) (5,344) Net loss per share (basic and diluted) $ (0.19) $ (0.31) $ (0.18) $ (0.10) $ (0.22) $ (0.02) $ (0.36) $ (0.20) Amounts may not sum to consolidated totals for the full year due to rounding. Basic and diluted net loss per share is computed independently for each of the quarters presented. Therefore, the sum of the quarterly per share amounts will not necessarily equal the total for the year.

Schedule II - Valuation And Qua

Schedule II - Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2015
Valuation and Qualifying Accounts [Abstract]
Schedule of Valuation and Qualifying Accounts Disclosure	SCH EDULE II VALUATION AND QUALIFYING ACCOUNTS Beginning Ending Balance Additions Deductions Balance Reserve for sales returns and allowances Year ended December 31, 2015 $ 135 $ 78 $ 6 $ 207 Year ended December 31, 2014 105 34 4 135 Year ended December 31, 2013 105 — — 105 Allowance for inventory valuation Year ended December 31, 2015 $ 522 $ 720 $ 399 $ 843 Year ended December 31, 2014 782 441 701 522 Year ended December 31, 2013 267 921 406 782 Valuation allowance for deferred tax assets Year ended December 31, 2015 $ 59,554 $ 14,128 $ — $ 73,682 Year ended December 31, 2014 54,211 5,343 — 59,554 Year ended December 31, 2013 31,685 22,526 — 54,211

Description of Business and S26

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Description of Business and Summary of Significant Accounting Policies [Abstract]
Nature of the Business	Nature of the Business — AtriCure, Inc. was incorporated in the State of Delaware on October 31, 2000. The “Company” or “AtriCure” consists of AtriCure, Inc. and its wholly owned subsidiaries. The Company is an innovator in surgical treatments for atrial fibrillation (Afib) and left atrial appendage management (LAAM). The Company sells its products to medical centers globally through a direct sales force and distributors.
Principles of Consolidation	Principles of Consolidation— The Consolidated Financial Statements include the accounts of the Company, AtriCure, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware, Endoscopic Technologies, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware, nContact Surgical, LLC, the Company’s wholly-owned subsidiary organized in the State of Delaware and AtriCure Europe, B.V. (AtriCure Europe), the Company’s wholly-owned subsidiary incorporated in the Netherlands. All intercompany accounts and transactions have been eliminated in consolidation.
Cash and Cash Equivalents	Cash and Cash Equivalents— The Company considers highly liquid investments with maturities of three months or less at the date of acquisition as cash equivalents in the accompanying Consolidated Financial Statements
Investments	Investments— The Company places its investments primarily in U.S. Government agencies and securities, corporate bonds and commercial paper. The Company classifies all investments as available-for-sale. Investments with maturities of less than one year are classified as short-term investments. Investments are recorded at fair value, with unrealized gains and losses recorded as accumulated other comprehensive income (loss). The Company recognizes gains and losses when these securities are sold using the specific identification method and includes them in interest income or expense in the Consolidated Statements of Operations and Comprehensive Loss.
Revenue Recognition	Revenue Recognition— The Company accounts for revenue in accordance with Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 605, “Revenue Recognition” (ASC 605). The Company recognizes revenue when all of the following criteria are met: (i) there is persuasive evidence that an arrangement exists; (ii) delivery of the products and/or services has occurred; (iii) the selling price is fixed or determinable; and (iv) collectability is reasonably assured. 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 products is performed by the Company subsequent to shipment to the customer in order to render it operational. Revenue includes shipping and handling revenue of $1,056 , $952 and $786 in 2015, 2014 and 2013, 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 with limited exceptions.
Sales Returns and Allowances	Sales Returns and Allowances — T he Company maintains a provision for sales returns and allowances to account for potential returns of defective or damaged products, products shipped in error and invoice adjustments. The Company estimates such provision on a quarterly basis based primarily on a specific identification basis, in addition to estimating a general reserve based on historical experience. Increases to the provision result in a reduction of revenue. The provision is included in accrued liabilities in the Consolidated Balance Sheets.
Allowance for Doubtful Accounts Receivable	Allowance for Doubtful Accounts Receivable— The Company evaluates the collectability of accounts receivable to determine the appropriate reserve for doubtful accounts. In determining the amount of the reserve, the Company considers aging of account balances, historical credit losses, customer-specific information and other relevant factors. An increase to the allowance for doubtful accounts results in a corresponding increase in selling, general and administrative expense. The Company reviews accounts receivable and adjusts the allowance based on current circumstances and charges off uncollectible receivables against the allowance when all attempts to collect the receivable have failed. The Company’s history of write-offs against the allowance has not been significant.
Inventories	Inventories— Inventories are stated at the lower of cost or market using approximate costs based on the first-in, first-out cost method (FIFO) and consist of raw materials, work in process and finished goods. The Company’s industry is characterized by rapid product development and frequent new product introductions. Uncertain timing of product approvals, variability in product launch strategies and variation in product utilization all impact excess and obsolete inventory. An inventory allowance based on product usage is estimated and recorded quarterly for excess, slow moving and obsolete inventory, as well as for inventory with a carrying value in excess of its net realizable value. An increase to the inventory reserve allowance results in a corresponding increase in cost of revenue. Write-offs are recorded when a product is destroyed. The Company’s history of write-offs against the reserve has not been significant.
Property and Equipment	Property and Equipment— Property and equipment is stated at cost less accumulated depreciation. Depreciation is computed using the straight-line method of depreciation for financial reporting purposes and applied over the estimated useful lives of the assets. The estimated useful life by major asset category is the following: generators and other capital equipment, machinery, equipment and vehicles is three to seven years, computer and other office equipment is three years, furniture and fixtures is three to seven years and leasehold improvements and equipment under capital leases are the shorter of their useful life or remaining lease term. The Company reassesses the useful lives of property and equipment annually, and assets are retired if they are no longer in service. Maintenance and repair costs are expensed as incurred. Generators and other capital equipment (such as the Company’s switchbox units and cryosurgical consoles) are placed with 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. The Company reviews property and equipment for impairment using its best estimates based on reasonable and supportable assumptions and projections.
Intangible Assets	Intangible Assets— Intangible assets with determinable useful lives are amortized on a straight-line basis over the estimated periods benefited. Included in intangible assets is In Process Research and Development (IPR&D). The Company defines IPR&D as the value of acquired technology which has not yet reached technological feasibility. The primary basis for determining the technological feasibility is obtaining specific regulatory approvals. The estimated fair value of IPR&D acquired in a business combination is capitalized as an indefinite-lived intangible asset until completion or abandonment of the IPR&D project. Upon completion of the development project, the IPR&D is amortized over its estimated useful life. If the IPR&D project is abandoned, the related IPR&D asset would be written off. The estimated fair value of IPR&D was determined using an income approach model. At December 31, 2015, IPR&D represented an estimate of the fair value of the PMA approval that could result from the CONVERGE IDE clinical trial (see Note 5 – Business Combinations). The Company reviews intangible assets for impairment using its best estimates based on reasonable and supportable assumptions and projections.
Goodwill	Goodwill— Goodwill represents the excess of purchase price over the fair value of the net assets acquired in business combinations. The Company tests goodwill for impairment annually on November 30, or more often if impairment indicators are present. The Company’s goodwill is accounted for in a single reporting unit representing the Company as a whole.
Other Current Liabilities and Current Maturities of Capital Leases	Other Current Liabilities and Current Maturities of Capital Leases— As of December 31, 2014, o ther current liabilities consisted of a financing obligation related to the construction of the Company’s new headquarters. Current maturities of capital leases consist of capital lease obligations with maturities of less than one year (see Note 10 – Indebtedness).
Other Noncurrent Liabilities	Other Noncurrent Liabilities— Other noncurrent liabilities include contingent consideration recorded in business combinations (see Note 5 – Business Combinations), as well as long-term deferred revenues and other contractual obligations.
Other Income	Other Income (Loss)— Other income (loss) consists primarily of foreign currency transaction gains and losses, grant income and non- employee option gains and losses related to the fair market value change for fully vested options outstanding for consultants which are accounted for as free-standing derivatives. The Company recorded foreign currency transaction (losses) gains of ( $339 ), ( $523 ) and $269 for the years ended December 31, 2015, 2014 and 2013, respectively, primarily in connection with settlements of its intercompany balances with AtriCure Europe and invoices transacted in British Pounds. 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 $35 , $731 and $0 during 2015, 2014 and 2013, 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. All vested non-employee options have been exercised as of December 31, 2015. During the years ended December 31, 2015, 2014 and 2013, $57 , $183 and ($272) , respectively, of (expense) income was recorded as a result of the remeasurement of the fair value of these fully vested stock options.
Taxes	Taxes — Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities from a change in tax rates is recognized in the period that includes the enactment date. 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 (Patient 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 $667 , $592 and $417 for the years ended December 31, 2015, 2014 and 2013, respectively. In December 2015, the U.S. government approved the suspension of the excise tax on medical device sales beginning January 1, 2016 through December 31, 2017.
Net Loss Per Share	Net Loss Per Share— Basic and diluted net loss per share is computed in accordance with FASB ASC 260 “Earnings Per Share” (ASC 260) by dividing the net loss by the weighted average number of common shares outstanding during the period. Since the Company has experienced net losses for all periods presented, net loss per share excludes the effect of 4,255 , 3,772 and 2,721 stock options and restricted stock shares as of December 31, 2015, 2014, and 2013, respectively, because they are anti-dilutive. Therefore, the number of shares calculated for basic net loss per share is also used for the diluted net loss per share calculation.
Comprehensive Loss and Accumulated Other Comprehensive Loss	Comprehensive Loss and Accumulated Other Comprehensive Loss— In addition to net losses, the comprehensive loss includes foreign currency translation adjustments and unrealized gains and losses on investments. Accumulated o ther comprehensive loss consisted of the following: 2015 2014 2013 Total accumulated other comprehensive (loss) income at beginning of period $ (348) $ (139) $ 77 Unrealized (losses) gains on investments Balance at beginning of period $ (54) $ (6) $ 1 Other comprehensive income (loss) before reclassifications 15 (48) (7) Amounts reclassified from accumulated other comprehensive income (loss) to other income — — — Balance at end of period $ (39) $ (54) $ (6) Foreign currency translation adjustment Balance at beginning of period $ (294) $ (133) $ 76 Other comprehensive income (loss) before reclassifications 156 362 (478) Amounts reclassified from accumulated other comprehensive income (loss) to other income (434) (523) 269 Balance at end of period $ (572) $ (294) $ (133) Total accumulated other comprehensive loss at end of period $ (611) $ (348) $ (139)
Research and Development Costs	Research and Development Costs — Research and development costs are expensed as incurred. These costs include compensation and other internal and external costs associated with the development and research related to new and existing products or concepts, preclinical studies, clinical trials, healthcare compliance and regulatory affairs.
Advertising Costs	Advertising Costs — The Company expenses advertising costs as incurred. Advertising costs were not significant during the years ended December 31, 2015, 2014 and 2013, respectively.
Share-Based Compensation	Share-Based Compensation— The Company follows FASB ASC 718 “Compensation-Stock Compensation” (ASC 718) to record share-based compensation for all employee share-based payment awards, including stock options, restricted stock and stock purchases related to an employee stock purchase plan, based on estimated fair values. The Company’s share-based compensation expense recognized under ASC 718 for the years ended December 31, 2015, 2014 and 2013 was $8,997 , $7,571 and $3,080 , respectively, on a before and after tax basis. 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 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 Consolidated Statement 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) which is available to all eligible employees as defined by the plan document. 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 ESPP 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— The preparation of the financial statements in conformity with accounting principles generally accepted in the United States of America (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expense during the reporting period. Actual results could differ from those estimates.
Fair Value Disclosures	Fair Value Disclosures — The Company classifies and records cash and investments in U.S. government agencies and securities as Level 1 within the fair value hierarchy. Accounts receivable, short-term other assets, accounts payable and accrued liabilities are also classified as Level 1. The carrying amounts of these assets and liabilities approximate their fair value due to their relatively short-term nature. Cash equivalents and investments in commercial paper are classified as Level 2 within the fair value hierarchy (see Note 3 – Fair Value for further information). Significant unobservable inputs with respect to the fair value measurement of the Level 3 non-employee stock options and contingent consideration liabilities are developed using Company data. When an input is changed, the corresponding valuation models are updated and the results are analyzed for reasonableness.

Description of Business and S27

Description of Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Description of Business and Summary of Significant Accounting Policies [Abstract]
Accumulated Other Comprehensive Income (Loss)	2015 2014 2013 Total accumulated other comprehensive (loss) income at beginning of period $ (348) $ (139) $ 77 Unrealized (losses) gains on investments Balance at beginning of period $ (54) $ (6) $ 1 Other comprehensive income (loss) before reclassifications 15 (48) (7) Amounts reclassified from accumulated other comprehensive income (loss) to other income — — — Balance at end of period $ (39) $ (54) $ (6) Foreign currency translation adjustment Balance at beginning of period $ (294) $ (133) $ 76 Other comprehensive income (loss) before reclassifications 156 362 (478) Amounts reclassified from accumulated other comprehensive income (loss) to other income (434) (523) 269 Balance at end of period $ (572) $ (294) $ (133) Total accumulated other comprehensive loss at end of period $ (611) $ (348) $ (139)

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value [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 December 31, 2015: Quoted Prices in Active Significant Significant Markets for Other Other Identical Observable Unobservable Assets Inputs Inputs (Level 1) (Level 2) (Level 3) Total Assets: Money market funds $ — $ 18,572 $ — $ 18,572 U.S. government agencies and securities 1,590 — — 1,590 Corporate bonds — 16,930 — 16,930 Total assets $ 1,590 $ 35,502 $ — $ 37,092 Liabilities: Acquisition-related contingent consideration $ — $ — $ 40,207 $ 40,207 Total liabilities $ — $ — $ 40,207 $ 40,207 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 Active Significant Significant Markets for Other Other Identical Observable Unobservable Assets Inputs Inputs (Level 1) (Level 2) (Level 3) 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 Total liabilities $ — $ — $ 120 $ 120
Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Derivative Instruments	2015 2014 2013 Beginning Balance – January 1 $ 120 $ 350 $ 78 Total (gains) losses included in earnings 57 (183) 272 Exercises (177) (47) — Reclassification from equity to liability when fully vested — — — Ending Balance – December 31 $ — $ 120 $ 350
Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Acquisition-Related Contingent Consideration	2015 2014 2013 Beginning Balance – January 1 $ — $ 8,032 $ — Amounts acquired 40,207 — 8,032 Transfers in (out) of Level 3 — — — Changes in fair value included in earnings — (8,032) — Ending Balance – December 31 $ 40,207 $ — $ 8,032

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Investments [Abstract]
Summary of Short-term Investments	Investments as of December 31, 2015 consisted of the following: Unrealized Gains Cost Basis (Losses) Fair Value Corporate bonds $ 16,963 $ (33) $ 16,930 U.S. government agencies and securities 1,596 (6) 1,590 Total $ 18,559 $ (39) $ 18,520 Investments as of December 31, 2014 consisted of the following: Unrealized Gains Cost Basis (Losses) Fair Value Corporate bonds $ 35,389 $ (52) $ 35,337 U.S. government agencies and securities 3,024 (2) 3,022 Commercial paper 1,800 — 1,800 Total $ 40,213 $ (54) $ 40,159

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Schedule of Components of Aggregate Purchase Price	Fair value of AtriCure common stock issued at closing $ 69,054 Cash 7,581 Fair value of contingent consideration liabilities 40,207 Total purchase price $ 116,842
Summary of Estimated Fair Values of Assets Acquired and Liabilities Assumed	October 13, 2015 Accounts receivable $ 1,450 Inventories 682 Other current assets 166 Property and equipment 311 Intangible assets 46,200 Other assets 7 Total identifiable assets $ 48,816 Accounts payable $ 256 Accrued liabilities 1,589 Total liabilities assumed $ 1,845 Net identifiable assets acquired $ 46,971 Goodwill 69,871 Total consideration $ 116,842
Valuation of Intangible Assets Acquired and Related Amortization Periods	Amortization Term Valuation (in years) SUBTLE access technology $ 2,179 5 IPR&D 44,021 Total $ 46,200
Pro-forma Acquisition Information	Year Ended December 31, (unaudited) 2015 2014 Revenue $ 137,882 $ 115,979 Net loss (30,745) (21,438) Basic and diluted net loss per share (0.99) (0.71)

Intangible Assets And Goodwill

Intangible Assets And Goodwill (Tables)	12 Months Ended
	Dec. 31, 2015
Intangible Assets And Goodwill [Abstract]
Company's Intangible Assets with Definite Lives	2015 2014 Accumulated Accumulated Cost Amortization Cost Amortization Non-compete agreement $ 100 $ 100 $ 100 $ 93 Fusion technology 9,242 1,848 9,242 924 Clamp & probe technology 829 552 829 276 Estech trade name 208 208 208 208 SUBTLE access technology 2,179 96 — — IPR&D 44,021 — — — Total $ 56,579 $ 2,804 $ 10,379 $ 1,501
Future Amortization Expense Related to Intangible Assets with Definite Lives	2016 $ 1,644 2017 1,367 2018 1,367 2019 1,367 2020 1,235 2021 and thereafter 2,774 Total $ 9,754
Summary of Company's Goodwill	Net carrying amount as of December 31, 2013 $ 35,386 Additions — Net carrying amount as of December 31, 2014 35,386 Additions 69,871 Net carrying amount as of December 31, 2015 $ 105,257

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2015
Inventories [Abstract]
Summary Of Inventories	2015 2014 Raw materials $ 6,159 $ 4,429 Work in process 974 1,397 Finished goods 10,526 8,431 Inventories $ 17,659 $ 14,257

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property and Equipment [Abstract]
Summary of Property and Equipment	2015 2014 Building under capital lease $ 14,250 $ — Generators and other capital equipment 10,041 8,578 Computer and other office equipment 4,303 2,436 Furniture and fixtures 3,211 488 Machinery, equipment and vehicles 2,551 2,604 Leasehold improvements 2,151 329 Construction in progress 1,978 4,642 Equipment under capital leases 212 162 Total 38,697 19,239 Less accumulated depreciation (7,418) (7,687) Property and equipment, net $ 31,279 $ 11,552

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2015
Accrued Liabilities [Abstract]
Accrued Liabilities	2015 2014 Accrued bonus $ 6,088 $ 4,915 Accrued commissions 6,061 4,477 Accrued payroll and employee-related expenses 4,021 2,281 Accrued taxes and value-added taxes payable 912 1,272 Other accrued liabilities 723 399 Accrued royalties 382 442 Sales returns allowance 207 135 Accrued non-employee stock options — 120 Total $ 18,394 $ 14,041

Indebtedness (Tables)

Indebtedness (Tables)	12 Months Ended
	Dec. 31, 2015
Indebtedness [Abstract]
Future Maturities on Capital Lease Obligations	2016 $ 1,417 2017 1,425 2018 1,439 2019 1,457 2020 1,478 2021 and thereafter 15,894 Total payments $ 23,110 Imputed interest (8,950) Net capital lease obligations, of which $450 is current and $13,710 is noncurrent $ 14,160

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies [Abstract]
Future Minimum Lease Payments Under Non-cancelable Operating Leases	2016 $ 934 2017 663 2018 724 2019 737 2020 556 2021 and thereafter 251 Total $ 3,865

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes [Abstract]
Detail of Deferred Tax Assets and Liabilities	2015 2014 Deferred tax assets (liabilities): Net operating loss carryforward $ 78,178 $ 49,921 Research and development and AMT credit carryforwards, net 5,677 4,799 Equity compensation 6,618 4,497 Accruals and reserves 539 536 Inventories 1,310 669 Intangible assets (16,953) (149) Property and equipment, net (1,740) (760) Other, net 53 41 Subtotal 73,682 59,554 Less valuation allowance (73,682) (59,554) Total $ — $ —
Company's Provision for Income Taxes	2015 2014 2013 Current income tax expense $ 36 $ 33 $ 18 Deferred tax benefit (8,507) (5,306) (3,728) Increase in valuation allowance 8,507 5,306 3,728 Total income tax expense $ 36 $ 33 $ 18
Difference Between Effective Income Tax Rates and Federal Statutory Rate	2015 2014 2013 Federal tax at statutory rate 34.00 % $ (9,240) 34.00 % $ (5,501) 34.00 % $ (3,891) Federal R&D credit 3.23 (878) 2.32 (374) 3.35 (383) Valuation allowance (31.30) 8,507 (32.80) 5,306 (29.63) 3,391 State income taxes 1.38 (375) 2.68 (433) 0.04 (5) Foreign NOL rate change (2.02) 549 (4.29) 694 2.47 (283) Foreign tax rate differential (1.99) 542 (2.83) 458 (1.60) 183 Other (3.43) 931 0.72 (117) (8.79) 1,006 Effective tax rate (0.13) % $ 36 (0.20) % $ 33 (0.16) % $ 18
Reconciliation of Change in Federal and State Unrecognized Tax Benefits	2015 2014 2013 Balance at the beginning of the year $ 1,982 $ 1,982 $ — Increases (decreases) for prior year tax positions — — 1,982 Increases (decreases) for current year tax positions — — — Increases (decreases) related to settlements — — — Decreases related to statute lapse — — — Balance at the end of the year $ 1,982 $ 1,982 $ 1,982

Equity Compensation Plans (Tabl

Equity Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2015
Activity Under Stock Based Compensation Plans	Activity under the plans during 2015 was as follows: Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Time-Based Stock Options Outstanding Price Term Value Outstanding at January 1, 2015 2,762 $ 10.93 Granted 228 21.10 Cancelled or forfeited (13) 15.17 Exercised (243) 11.10 Outstanding at December 31, 2015 2,734 $ 11.75 6.15 $ 29,331 Vested and expected to vest 2,660 $ 11.57 6.09 $ 28,974 Exercisable at December 31, 2015 1,862 $ 9.94 5.28 $ 23,263 Weighted Number of Average Shares Grant Date Restricted Stock Outstanding Fair Value Outstanding at January 1, 2015 560 $ 16.33 Awarded 648 17.82 Forfeited (2) 17.76 Released (135) 15.78 Outstanding at December 31, 2015 1,071 $ 17.30 Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Performance Stock Options Outstanding Price Term Value Outstanding at January 1, 2015 450 $ 13.48 Granted — — Cancelled or forfeited — — Exercised — — Outstanding at December 31, 2015 450 $ 13.48 7.46 $ 4,034 Exercisable at December 31, 2015 250 $ 13.48 7.46 $ 2,241 Activity under the plans during 2014 was as follows: Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Time-Based Stock Options Outstanding Price Term Value Outstanding at January 1, 2014 2,423 $ 8.61 Granted 603 19.54 Cancelled or forfeited (49) 10.65 Exercised (215) 8.94 Outstanding at December 31, 2014 2,762 $ 10.93 6.54 $ 25,335 Vested and expected to vest 2,660 $ 10.81 6.46 $ 24,697 Exercisable at December 31, 2014 1,516 $ 8.85 4.86 $ 16,836 Weighted Number of Average Shares Grant Date Restricted Stock Outstanding Fair Value Outstanding at January 1, 2014 248 $ 7.75 Awarded 391 20.25 Forfeited (1) 9.15 Released (78) 8.79 Outstanding at December 31, 2014 560 $ 16.33 Weighted Weighted Average Number of Average Remaining Aggregate Shares Exercise Contractual Intrinsic Performance Stock Options Outstanding Price Term Value Outstanding at January 1, 2014 225 $ 5.91 Granted 225 21.04 Cancelled or forfeited — — Exercised — — Outstanding at December 31, 2014 450 $ 13.48 8.50 $ 3,161 Exercisable at December 31, 2014 250 $ 13.48 8.50 $ 1,756
Share-Based Compensation Expense Related to Employee Share-Based Compensation	2015 2014 2013 Cost of revenue $ 416 $ 335 $ 246 Research and development expenses 1,373 937 230 Selling, general and administrative expenses 7,208 6,299 2,604 Total $ 8,997 $ 7,571 $ 3,080
Assumptions Used for Determining Fair Value of Options	2015 2014 2013 Risk-free interest rate 1.30 - 1.96 % 1.56 - 2.12 % 0.75 - 2.29 % Expected life of option (years) 5.20 to 6.89 5.31 to 6.72 5.38 to 7.14 Expected volatility of stock 46.00 - 67.00 % 47.00 - 70.00 % 69.00 % Weighted-average volatility 54.75 % 69.19 % 69.00 % Dividend yield 0.00 % 0.00 % 0.00 %
Weighted Average Estimated Grant Date Fair Value Per Share of Stock Options and Restricted Stock Granted	2015 2014 2013 Stock options $ 11.12 $ 12.33 $ 5.70 Restricted stock 17.82 20.25 9.35
Estimated Grant Date Fair Value Per Share of Performance Options Granted	Price Fair Value of Fair Value of Target 2012 Grant 2014 Grant Tranche 1 $ 10.00 $ 4.32 $ 14.74 Tranche 2 12.50 4.30 14.74 Tranche 3 15.00 4.27 14.74 Tranche 4 17.50 4.23 14.74 Tranche 5 20.00 4.19 14.73 Tranche 6 25.00 4.10 14.73 Tranche 7 30.00 4.01 14.71 Tranche 8 35.00 3.92 14.67 Tranche 9 40.00 3.83 14.61
Performance Shares [Member]
Assumptions Used for Determining Fair Value of Options	2015 2014 2013 Strike price $ 5.91 - 21.04 $ 5.91 - 21.04 $ 5.91 Contractual term (years) 10.00 10.00 10.00 Expected volatility of stock 60.50 - 69.60 % 60.50 - 69.60 % 69.60 % Interest rate 1.75 - 2.73 % 1.75 - 2.73 % 1.75 % Dividend yield 0.00 % 0.00 % 0.00 %

Segment and Geographic Inform39

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment and Geographic Information [Abstract]
Revenue by Geographic Area	2015 2014 2013 Revenue: United States $ 102,212 $ 80,203 $ 62,311 Europe 17,180 18,163 11,384 Asia 9,510 8,552 7,665 Other international 853 536 529 Total international 27,543 27,251 19,578 Total revenue $ 129,755 $ 107,454 $ 81,889
Revenue by Product Type	Domestic revenue by product type was as follows: 2015 2014 2013 Revenue: Open-heart ablation $ 53,541 $ 44,662 $ 37,843 Minimally invasive ablation 21,564 16,050 13,648 AtriClip 24,377 16,675 10,820 Total ablation and AtriClip 99,482 77,387 62,311 Valve tools 2,730 2,816 — Total domestic $ 102,212 $ 80,203 $ 62,311 International revenue by product type was as follows: 2015 2014 2013 Revenue: Open-heart ablation $ 16,287 $ 16,445 $ 13,064 Minimally invasive ablation 7,964 7,881 5,354 AtriClip 2,868 2,158 1,160 Total ablation and AtriClip 27,119 26,484 19,578 Valve tools 424 767 — Total international $ 27,543 $ 27,251 $ 19,578

Selected Quarterly Financial 40

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Selected Quarterly Financial Data [Abstract]
Schedule of Quarterly Financial Information	For the Three Months Ended March 31, June 30, September 30, December 31, 2015 2014 2015 2014 2015 2014 2015 2014 Operating Results: Revenue $ 29,886 $ 24,847 $ 32,583 $ 26,514 $ 31,423 $ 26,678 $ 35,863 $ 29,415 Gross profit 21,735 17,657 23,117 18,781 22,478 18,892 25,545 20,420 Loss from operations (5,144) (7,925) (4,819) (2,853) (6,127) (803) (10,630) (4,779) Net loss (5,266) (7,709) (4,891) (2,692) (6,141) (466) (10,914) (5,344) Net loss per share (basic and diluted) $ (0.19) $ (0.31) $ (0.18) $ (0.10) $ (0.22) $ (0.02) $ (0.36) $ (0.20)

Description of Business and S41

Description of Business and Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Description Of Business And Significant Accounting Policies [Line Items]
Shipping and handling revenue	$ 1,056	$ 952	$ 786
Payment terms for end-users	30 days
Payment terms for distributors	60 days
Grant income	$ 35	731	0
Income (expense) related to remeasurement of fair value of fully vested stock options	57	(183)	(272)
Company's expense related to the medical device excise tax	$ 667	$ 592	$ 417
Options, restricted stock and performance based shares excluded from calculation of net loss per share	4,255	3,772	2,721
Share-based compensation expense recognized	$ 8,997	$ 7,571	$ 3,080
Subsidiaries [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Foreign currency transaction (losses) gains	$ (339)	$ (523)	$ 269
Computer and Other Office Equipment [Member]
Description Of Business And Significant Accounting Policies [Line Items]
Estimated useful life by major asset category	3 years
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]
Description Of Business And Significant Accounting Policies [Line Items]
Maturity period of short term investment	1 year
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 S42

Description of Business and Summary of Significant Accounting Policies (Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive (loss) income, at beginning of period	$ (348)	$ (139)	$ 77
Total accumulated other comprehensive (loss) income, at end of period	(611)	(348)	(139)
Unrealized (Losses) Gains on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive (loss) income, at beginning of period	(54)	(6)	1
Other comprehensive income (loss) before reclassifications	15	(48)	(7)
Total accumulated other comprehensive (loss) income, at end of period	(39)	(54)	(6)
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Total accumulated other comprehensive (loss) income, at beginning of period	(294)	(133)	76
Other comprehensive income (loss) before reclassifications	156	362	(478)
Amounts reclassified from accumulated other comprehensive income (loss) to other income	(434)	(523)	269
Total accumulated other comprehensive (loss) income, at end of period	$ (572)	$ (294)	$ (133)

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Estech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration		$ 8,032
Significant Other Unobservable Inputs (Level 3) [Member] | Estech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	$ 0	0	$ 8,032
Significant Other Unobservable Inputs (Level 3) [Member] | nContact Surgical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	$ 40,207
Minimum [Member] | nContact Surgical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Entitled sales-based contingent consideration on revenue in excess of annual growth through 2019	25.00%
Maximum [Member] | Estech [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	$ 26,000	$ 26,000
Maximum [Member] | nContact Surgical [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition-related contingent consideration	$ 50,000

Fair Value (Financial Assets an

Fair Value (Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Assets:
Total assets	$ 37,092	$ 63,851
Liabilities:
Derivative instruments		120
Acquisition-related contingent consideration	40,207
Total liabilities	40,207	120
Money Market Funds [Member]
Assets:
Total assets	18,572	23,692
Commercial Paper [Member]
Assets:
Total assets		1,800
U.S. Government Agencies and Securities [Member]
Assets:
Total assets	1,590	3,022
Corporate Bonds [Member]
Assets:
Total assets	16,930	35,337
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets:
Total assets	1,590	3,022
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Government Agencies and Securities [Member]
Assets:
Total assets	1,590	3,022
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Total assets	35,502	60,829
Significant Other Observable Inputs (Level 2) [Member] | Money Market Funds [Member]
Assets:
Total assets	18,572	23,692
Significant Other Observable Inputs (Level 2) [Member] | Commercial Paper [Member]
Assets:
Total assets		1,800
Significant Other Observable Inputs (Level 2) [Member] | Corporate Bonds [Member]
Assets:
Total assets	16,930	35,337
Significant Other Unobservable Inputs (Level 3) [Member]
Liabilities:
Derivative instruments		120
Acquisition-related contingent consideration	40,207
Total liabilities	$ 40,207	$ 120

Fair Value (Level 3 Fair Value

Fair Value (Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Derivative Instruments) (Details) - Significant Other Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance – January 1	$ 120	$ 350	$ 78
Total (gains) losses included in earnings	57	(183)	$ 272
Exercises	$ (177)	$ (47)
Reclassification from equity to liability when fully vested
Ending Balance – December 31		$ 120	$ 350

Fair Value (Level 3 Fair Valu46

Fair Value (Level 3 Fair Value Measurements Using Significant Other Unobservable Inputs for Acquisition-Related Contingent Consideration) (Details) - Significant Other Unobservable Inputs (Level 3) [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance – January 1		$ 8,032
Amounts acquired	$ 40,207		$ 8,032
Changes in fair value included in earnings		$ (8,032)
Ending Balance – December 31	$ 40,207		$ 8,032

Investments (Narrative) (Detail

Investments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Minimum [Member]
Investment [Line Items]
Long term marketable debt securities maturity period	1 year	1 year
Maximum [Member]
Investment [Line Items]
Long term marketable debt securities maturity period	2 years	2 years

Investments (Summary Of Short-t

Investments (Summary Of Short-term Investments) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Investment [Line Items]
Short-term investments, Cost Basis	$ 18,559	$ 40,213
Short-term investment, Unrealized gains (losses)	(39)	(54)
Short-term investments, Fair value	18,520	40,159
Corporate Bonds [Member]
Investment [Line Items]
Short-term investments, Cost Basis	16,963	35,389
Short-term investment, Unrealized gains (losses)	(33)	(52)
Short-term investments, Fair value	16,930	35,337
U.S. Government Agencies and Securities [Member]
Investment [Line Items]
Short-term investments, Cost Basis	1,596	3,024
Short-term investment, Unrealized gains (losses)	(6)	(2)
Short-term investments, Fair value	$ 1,590	3,022
Commercial Paper [Member]
Investment [Line Items]
Short-term investments, Cost Basis		1,800
Short-term investments, Fair value		$ 1,800

Business Combinations (Narrativ

Business Combinations (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands

Oct. 14, 2015

Dec. 31, 2015

Sep. 30, 2015

Jun. 30, 2015

Mar. 31, 2015

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2015

Dec. 31, 2014

Dec. 31, 2013

Business Combination Transactions [Line Items]

Consideration paid to former shareholders

$ 7,581

Revenues

$ 35,863

$ 31,423

$ 32,583

$ 29,886

$ 29,415

$ 26,678

$ 26,514

$ 24,847

129,755

$ 107,454

$ 81,889

Contingent consideration on acquisition, change in value

(8,032)

nContact Surgical [Member]

Business Combination Transactions [Line Items]

Consideration payment, value

69,054

Consideration paid to former shareholders

7,581

Revenues

$ 2,192

Acquisition related costs

2,489

Business acquisition, net operating loss carryforwards

59,000

$ 59,000

Business acquisition, net operating loss carryforwards, expiration date

2,025

nContact Surgical [Member] | Bank Fees and Expenses [Member]

Business Combination Transactions [Line Items]

Acquisition related costs

$ 1,767

nContact Surgical [Member] | Legal, Audit, Tax and Other Costs [Member]

Business Combination Transactions [Line Items]

Acquisition related costs

$ 722

nContact Surgical [Member] | Minimum [Member]

Business Combination Transactions [Line Items]

Discount rate on probablity of achievement of milestone

3.00%

nContact Surgical [Member] | Maximum [Member]

Business Combination Transactions [Line Items]

Contingent liability consideration

50,000

$ 50,000

Discount rate on probablity of achievement of milestone

14.00%

nContact Surgical [Member] | Common Stock [Member]

Business Combination Transactions [Line Items]

Consideration payment, shares

3,757

nContact Surgical [Member] | Common Stock [Member] | Maximum [Member]

Business Combination Transactions [Line Items]

Consideration payment, shares

5,660

nContact Surgical [Member] | Trial Enrollment Milestone [Member]

Business Combination Transactions [Line Items]

Contingent liability consideration

7,500

$ 7,500

Milestone payment period due, maximum

30 days

nContact Surgical [Member] | Regulatory Milestone [Member]

Business Combination Transactions [Line Items]

Contingent liability consideration

$ 42,500

$ 42,500

Milestone consideration due date

Jan. 1, 2020

Milestone payment period due, maximum

30 days

nContact Surgical [Member] | Regulatory Milestone [Member] | Minimum [Member]

Business Combination Transactions [Line Items]

Potential contingent consideration reduction percentage, monthly

8.33%

Date of potential contingent consideration reduction

Jan. 1, 2020

nContact Surgical [Member] | Regulatory Milestone [Member] | Maximum [Member]

Business Combination Transactions [Line Items]

Potential contingent consideration reduction percentage, monthly

0.00%

Date of potential contingent consideration reduction

Dec. 31, 2020

nContact Surgical [Member] | Commercial Milestone [Member]

Business Combination Transactions [Line Items]

Target revenue percentage, 2016 through 2019

25.00%

Multiplier of contingent consideration of revenues in excess of target percentage

1.5

Milestone payment period due, maximum

65 days

Estech [Member]

Business Combination Transactions [Line Items]

Acquisition of shares and voting interest

100.00%

100.00%

Consideration related to earnout calculation

26,000

Contingent liability consideration

8,032

8,032

Contingent consideration on acquisition, change in value

(8,032)

Estech [Member] | Maximum [Member]

Business Combination Transactions [Line Items]

Contingent liability consideration

$ 26,000

26,000

$ 26,000

26,000

Estech [Member] | Estech Milestones [Member]

Business Combination Transactions [Line Items]

Contingent liability consideration

$ 0

$ 0

$ 0

$ 0

Business Combinations (Schedule

Business Combinations (Schedule of Components of Aggregate Purchase Price) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Business Acquisition [Line Items]
Cash	$ 7,581
nContact Surgical [Member]
Business Acquisition [Line Items]
Fair value of AtriCure common stock issued at closing	69,054
Cash	7,581
Fair value of contingent consideration liabilities	40,207
Total purchase price	$ 116,842

Business Combinations (Summary

Business Combinations (Summary Of Estimated Fair Values Of Assets Acquired And Liabilities Assumed) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 105,257	$ 35,386	$ 35,386
nContact Surgical [Member]
Business Acquisition [Line Items]
Accounts receivable	1,450
Inventories	682
Other current assets	166
Property and equipment, net	311
Intangible assets, net	46,200
Other assets	7
Total identifiable assets	48,816
Accounts payable	256
Accrued liabilities	1,589
Total liabilities assumed	1,845
Net identifiable assets acquired	46,971
Goodwill	69,871
Total purchase price/consideration	$ 116,842

Business Combinations (Summar52

Business Combinations (Summary Of Valuation Of Intangible Assets Acquired And Related Amortization Periods) (Details) - nContact Surgical [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 46,200
SUBTLE Access Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 2,179
Intangible assets amortization period	5 years
IPR&D [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 44,021

Business Combinations (Summar53

Business Combinations (Summary Of Pro Forma Acquisition Information) (Details) - nContact Surgical [Member] - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition Pro Forma Information [Line Items]
Revenue	$ 137,882	$ 115,979
Net loss	$ (30,745)	$ (21,438)
Basic and diluted net loss per share	$ (0.99)	$ (0.71)

Intangible Assets And Goodwil54

Intangible Assets And Goodwill (Narative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Intangible Assets And Goodwill [Abstract]
Amortization of intangible assets	$ 1,303	$ 1,421	$ 12

Intangible Assets And Goodwil55

Intangible Assets And Goodwill (Company's Intangible Assets with Definite Lives) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Cost	$ 56,579	$ 10,379
Accumulated Amortization	2,804	1,501
Non-Compete Agreement [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	100	100
Accumulated Amortization	100	93
Fusion Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	9,242	9,242
Accumulated Amortization	1,848	924
Clamp and Probe Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	829	829
Accumulated Amortization	552	276
Estech Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	208	208
Accumulated Amortization	208	$ 208
SUBTLE Access Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	2,179
Accumulated Amortization	96
IPR&D [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	$ 44,021

Intangible Assets And Goodwil56

Intangible Assets And Goodwill (Future Amortization Expense Related to Intangible Assets with Definite Lives) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Intangible Assets And Goodwill [Abstract]
2,016	$ 1,644
2,017	1,367
2,018	1,367
2,019	1,367
2,020	1,235
2021 and thereafter	2,774
Total	$ 9,754

Intangible Assets And Goodwil57

Intangible Assets And Goodwill (Summary Of Company's Goodwill) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Intangible Assets And Goodwill [Abstract]
Goodwill, Beginning Balance	$ 35,386
Additions	69,871
Goodwill, Ending Balance	$ 105,257

Inventories (Summary Of Invento

Inventories (Summary Of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventories [Abstract]
Raw materials	$ 6,159	$ 4,429
Work in process	974	1,397
Finished goods	10,526	8,431
Inventories	$ 17,659	$ 14,257

Property And Equipment (Narrati

Property And Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Depreciation	$ 4,975	$ 3,353	$ 2,008
Net carrying amount of loaned equipment	31,279	11,552
Generators and Other Capital Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciation	2,944	2,172	$ 1,251
Net carrying amount of loaned equipment	$ 5,447	4,141
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Cost on construction of headquarters building		$ 4,234

Property And Equipment (Summary

Property And Equipment (Summary Of Property And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 38,697	$ 19,239
Less accumulated depreciation	(7,418)	(7,687)
Property, and equipment, net	31,279	11,552
Building under Capital Lease [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	14,250
Generators and Other Capital Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	10,041	8,578
Property, and equipment, net	5,447	4,141
Computer and Other Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,303	2,436
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	3,211	488
Machinery, Equipment and Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,551	2,604
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,151	329
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,978	4,642
Equipment under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 212	$ 162

Accrued Liabilities (Accrued Li

Accrued Liabilities (Accrued Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accrued Liabilities [Abstract]
Accrued bonus	$ 6,088	$ 4,915
Accrued commissions	6,061	4,477
Accrued payroll and employee-related expenses	4,021	2,281
Accrued taxes and value-added taxes payable	912	1,272
Other accrued liabilities	723	399
Accrued royalties	382	442
Sales returns allowance	207	135
Accrued non-employee stock options		120
Total	$ 18,394	$ 14,041

Indebtedness (Narrative) (Detai

Indebtedness (Narrative) (Details) € in Thousands, $ in Thousands	Mar. 31, 2015USD ($)	Mar. 30, 2015USD ($)	Dec. 31, 2015USD ($)ft²loan	Dec. 31, 2014EUR (€)
Line of Credit Facility [Line Items]
Cost of assets under lease			$ 14,462
Accumulated amortization on the capital leases			349
Silicon Valley Bank Agreement [Member]
Line of Credit Facility [Line Items]
Amount required in cash and investments before additional covenants apply, maximum			20,000
Silicon Valley Bank Agreement [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Letters of credit, outstanding maximum limit	$ 2,000	$ 1,000
Silicon Valley Bank Agreement [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit, maximum borrowing capacity			$ 15,000
Credit facility maturity date	Apr. 30, 2018	Apr. 30, 2016	Apr. 30, 2018
Line of credit, outstanding			$ 0
Line of credit, availability			$ 14,559
Applicable interest rate			3.50%
Number of covenants applied | loan			0
In occurence of default resulting increase in applicable interest rate			3.00%
Corporate Credit Card [Member]
Line of Credit Facility [Line Items]
Credit facility maturity date			Jun. 30, 2015
Letter of credit outstanding | €				€ 75
Computer And Office Equipment [Member]
Line of Credit Facility [Line Items]
Capital lease expiration year			2,030
Mason Lease [Member]
Line of Credit Facility [Line Items]
Area of lease | ft²			92
Lease term beginning			2015-10
Lease term period			15 years
Number of renewal options | loan			3
Lease renewal option period			5 years
Initial annual base rent			$ 1,353
Lease rate increase, percentage			2.00%
Mason Lease [Member] | Letter of Credit [Member]
Line of Credit Facility [Line Items]
Letter of credit outstanding			$ 1,250
Mason Lease [Member] | Leasehold Improvements [Member]
Line of Credit Facility [Line Items]
Leases payable, amount			$ 750

Indebtedness (Future Maturities

Indebtedness (Future Maturities on Capital Lease Obligations) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Indebtedness [Abstract]
2,016	$ 1,417
2,017	1,425
2,018	1,439
2,019	1,457
2,020	1,478
2021 and thereafter	15,894
Total payments	23,110
Imputed interest	(8,950)
Net capital lease obligations , of which $450 is current and $13,710 is noncurrent	14,160
Net capital lease obligations, current	450
Net capital lease obligations, noncurrent	$ 13,710

Commitments and Contingencies64

Commitments and Contingencies (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies [Line Items]
Operating lease rent expense	$ 1,515	$ 1,331	$ 870
Royalty expense	1,799	1,322	$ 962
Settlement agreement payments (including interest)		$ 4,350
Liability related settlement current	$ 0
Obligations period under Corporate Integrity Agreement	5 years
Minimum [Member]
Commitments and Contingencies [Line Items]
Royalty rates	0.75%
Royalty payments, quarterly	$ 50
Royalty agreement term	3 years
Maximum [Member]
Commitments and Contingencies [Line Items]
Royalty rates	5.00%
Royalty payments, quarterly	$ 2,000
Royalty agreement term	20 years
Office, Manufacturing, Warehouse Facilities, And Equipment [Member]
Commitments and Contingencies [Line Items]
Operating leases expire at various terms	Dec. 31, 2021

Commitments and Contingencies65

Commitments and Contingencies (Schedule Of Future Minimum Lease Payments Under Non-cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments and Contingencies [Abstract]
2,016	$ 934
2,017	663
2,018	724
2,019	737
2,020	556
2021 and thereafter	251
Total	$ 3,865

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Contingency [Line Items]
Research and development credit carryforward	$ 5,677	$ 4,799
Pre-tax book loss for domestic operations	(21,157)	(11,085)	$ (9,409)
Pre-tax book loss for international operations	(6,019)	(5,093)	(2,035)
Unrecognized deferred tax assets	5,790
Unrecognized tax benefits	$ 0	$ 0	0
Unrecognized tax benefits, increase resulting from prior period tax positions			$ 1,982
Federal [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	$ 205,278
Operating loss carryforward, expiration year	2,021
Research and development credit carryforward	$ 5,575
Federal research and development credit credit carry forward expiry	2,022
State [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	$ 136,323
Foreign [Member]
Income Tax Contingency [Line Items]
Operating loss carryforward	17,919
Operating loss carryforward, amount expiring in 2016	$ 970
Operating loss carryforward, expiration year	2,016
Minimum [Member] | State [Member]
Income Tax Contingency [Line Items]
State Operating loss carryforward expiry date	5 years
Maximum [Member] | State [Member]
Income Tax Contingency [Line Items]
State Operating loss carryforward expiry date	20 years

Income Taxes (Summary Of Detail

Income Taxes (Summary Of Detail Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred tax assets (liabilities):
Net operating loss carryforward	$ 78,178	$ 49,921
Research and development and AMT credit carryforwards, net	5,677	4,799
Equity compensation	6,618	4,497
Accruals and reserves	539	536
Inventories	1,310	669
Intangible assets	(16,953)	(149)
Property and equipment, net	(1,740)	(760)
Other, net	53	41
Subtotal	73,682	59,554
Less valuation allowance	$ (73,682)	$ (59,554)
Total

Income Taxes (Summary Of Compan

Income Taxes (Summary Of Company's Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Current income tax expense	$ 36	$ 33	$ 18
Deferred tax benefit	(8,507)	(5,306)	(3,728)
Increase in valuation allowance	8,507	5,306	3,728
Total income tax expense	$ 36	$ 33	$ 18

Income Taxes (Summary Of Differ

Income Taxes (Summary Of Difference Between Effective Income Tax Rates And Federal Statutory Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Federal tax at statutory rate	34.00%	34.00%	34.00%
Federal R&D credit	3.23%	2.32%	3.35%
Valuation allowance	(31.30%)	(32.80%)	(29.63%)
State income taxes	1.38%	2.68%	0.04%
Foreign NOL rate change	(2.02%)	(4.29%)	2.47%
Foreign tax rate differential	(1.99%)	(2.83%)	(1.60%)
Other	(3.43%)	0.72%	(8.79%)
Effective tax rate, Total	(0.13%)	(0.20%)	(0.16%)
Federal tax at statutory rate	$ (9,240)	$ (5,501)	$ (3,891)
Federal R&D credit	(878)	(374)	(383)
Valuation allowance	8,507	5,306	3,391
State income taxes	(375)	(433)	(5)
Foreign NOL rate change	549	694	(283)
Foreign tax rate differential	542	458	183
Other	931	(117)	1,006
Total income tax expense	$ 36	$ 33	$ 18

Income Taxes (Summary Of Reconc

Income Taxes (Summary Of Reconciliation Of Change In Federal And State Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Balance at the beginning of the year	$ 1,982	$ 1,982
Increases (decreases) for prior year tax positions			$ 1,982
Increases (decreases) for current year tax positions
Increases (decreases) related to settlements
Decreases related to statute lapse
Balance at the end of the year	$ 1,982	$ 1,982	$ 1,982

Concentrations (Narrative) (Det

Concentrations (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)customer	Dec. 31, 2014	Dec. 31, 2013
Concentration Risk [Line Items]
Number of customers | customer	10
Cash and cash equivalents balance in excess of FDIC limits | $	$ 23,608
Net Revenue [Member]
Concentration Risk [Line Items]
Percentage representation of significant customer	12.90%	13.60%	20.40%
Customer Concentration Risk [Member] | Net Revenue [Member]
Concentration Risk [Line Items]
Percentage representation of significant customer	10.00%

Employee Benefit Plans (Narrati

Employee Benefit Plans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Benefit Plans [Abstract]
Employee contribution percent	50.00%	50.00%	50.00%
Maximum percentage of employee contribution to the plan	6.00%	6.00%	6.00%
Company's matching contribution	$ 1,007,000	$ 807,000	$ 606,000
Discretionary contributions made	0	0	0
Total contributions to retirement plan	$ 133,000	$ 176,000	$ 176,000

Equity Compensation Plans (Narr

Equity Compensation Plans (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended		12 Months Ended
	Jan. 31, 2014	Nov. 30, 2012	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised			$ 2,740	$ 2,311	$ 951
Tax benefit recognized			0	0	0
Proceeds from stock option exercises			2,703	1,916	1,718
Share-based compensation expense recognized			8,997	7,571	3,080
Unrecognized compensation costs related to non-vested share-based compensation arrangements with performance shares			21,181
Recognized expense related to performance options			$ 8,997	7,571	3,080
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]
Expiry of options from the date of grant			10 years
Common stock reserved for issuance			8,949
Common stock authorized for issuance			1,300
Shares available for future grants under plans			1,372
2008 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized			$ 379	421	319
Company's common stock may be purchased at a discount			15.00%
Participants purchase limit value			$ 25
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 a value of more than 3 shares during an offering period.
Participants purchase limit shares			3
Offering period			6 months
Shares available for sale under the ESPP increased			2.00%
Outstanding shares of common stock exceed			600
Shares available for future issuance under the ESPP			491
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognizing cost			2 years
Stock options compensation costs			$ 7,375
Employee Stock Option [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period beginning			3 years
Employee Stock Option [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercisable period beginning			3 years
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognizing cost			2 years 7 months 6 days
Total fair value of restricted stock vested			$ 2,767	$ 1,434	1,442
Unrecognized compensation costs related to non-vested performance options			$ 13,806
Performance options awarded to President and CEO			648	391
Restricted Stock [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Restricted Stock [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			4 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiry of options from the date of grant			10 years
Recognized expense related to performance options			$ 546	$ 1,767	272
Unrecognized compensation costs related to non-vested performance options			$ 313
Performance options awarded to President and CEO	225	225
Number of shares options vest in			25
Period of considering closing price of common stock			30 days
Time Based Stock Options and Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized			$ 8,072	$ 5,383	$ 2,489
First Anniversary Date Of Grant [Member] | Employee Stock Option [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage			25.00%
First Anniversary Date Of Grant [Member] | Employee Stock Option [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage			25.00%
Four Years From Date Of Grant [Member] | Restricted Stock [Member] | 2005 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage			25.00%
Four Years From Date Of Grant [Member] | Restricted Stock [Member] | 2014 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage			25.00%
Tranche 1 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			$ 10
Tranche 2 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			12.50
Tranche 3 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			15
Tranche 4 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			17.50
Tranche 5 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			20
Tranche 6 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			25
Tranche 7 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			30
Tranche 8 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			35
Tranche 9 [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price by which volume adjusted weighted average closing price exceeds under vesting condition			$ 40
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognizing cost			3 months
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of recognizing cost			2 years 18 days

Equity Compensation Plans (Acti

Equity Compensation Plans (Activity Under Stock Based Compensation Plans) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Number of Shares Outstanding, Stock Options	2,762	2,423
Granted, Number of Shares Outstanding, Stock Options	228	603
Cancelled or forfeited, Number of Shares Outstanding, Stock Options	(13)	(49)
Exercised, Number of Shares Outstanding, Stock Options	(243)	(215)
Ending balance, Number of Shares Outstanding, Stock Options	2,734	2,762	2,423
Vested and expected to vest, Number of Shares Outstanding, Stock Options	2,660	2,660
Exercisable, Ending balance, Number of Shares Outstanding, Stock Options	1,862	1,516
Beginning balance, Weighted Average Exercise Price, Stock Options	$ 10.93	$ 8.61
Granted, Weighted Average Exercise Price, Stock Options	21.10	19.54
Cancelled or forfeited, Weighted Average Exercise Price, Stock Options	15.17	10.65
Exercised, Weighted Average Exercise Price, Stock Options	11.10	8.94
Ending balance, Weighted Average Exercise Price, Stock Options	11.75	10.93	$ 8.61
Vested And expected to vest, Weighted Average Exercise Price, Stock Options	11.57	10.81
Exercisable, Ending balance, Weighted Average Exercise Price, Stock Options	$ 9.94	$ 8.85
Outstanding, Ending balance, Weighted Average Remaining Contractual Term, Stock Options	6 years 1 month 24 days	6 years 6 months 15 days
Vested and expected to vest, Weighted Average Remaining Contractual Term, Stock Options	6 years 1 month 2 days	6 years 5 months 16 days
Exercisable, Ending balance, Weighted Average Remaining Contractual Term, Stock Options	5 years 3 months 11 days	4 years 10 months 10 days
Outstanding, Ending balance, Aggregate Intrinsic Value, Stock Options	$ 29,331	$ 25,335
Vested and expected to vest, Aggregate Intrinsic Value, Stock Options	28,974	24,697
Exercisable, Ending balance, Aggregate Intrinsic Value, Stock Options	$ 23,263	$ 16,836
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Number of Shares Outstanding	560	248
Awarded, Number of Shares Outstanding	648	391
Forfeited, Number of Shares Outstanding	(2)	(1)
Released, Number of Shares Outstanding	(135)	(78)
Ending balance, Number of Shares Outstanding	1,071	560	248
Beginning balance, Weighted Average Grant Date Fair Value	$ 16.33	$ 7.75
Awarded, Weighted Average Grant Date Fair Value	17.82	20.25	$ 9.35
Forfeited, Weighted Average Grant Date Fair Value	17.76	9.15
Released, Weighted Average Grant Date Fair Value	15.78	8.79
Ending balance, Weighted Average Grant Date Fair Value	$ 17.30	$ 16.33	$ 7.75
Performance Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Beginning balance, Number of Shares Outstanding, Stock Options	450	225
Granted, Number of Shares Outstanding, Stock Options		225
Cancelled or forfeited, Number of Shares Outstanding, Stock Options
Exercised, Number of Shares Outstanding, Stock Options
Ending balance, Number of Shares Outstanding, Stock Options	450	450	225
Exercisable, Ending balance, Number of Shares Outstanding, Stock Options	250	250
Beginning balance, Weighted Average Exercise Price, Stock Options	$ 13.48	$ 5.91
Granted, Weighted Average Exercise Price, Stock Options		21.04
Cancelled or forfeited, Weighted Average Exercise Price, Stock Options
Exercised, Weighted Average Exercise Price, Stock Options
Ending balance, Weighted Average Exercise Price, Stock Options	$ 13.48	13.48	$ 5.91
Exercisable, Ending balance, Weighted Average Exercise Price, Stock Options	$ 13.48	$ 13.48
Outstanding, Ending balance, Weighted Average Remaining Contractual Term, Stock Options	7 years 5 months 16 days	8 years 6 months
Exercisable, Ending balance, Weighted Average Remaining Contractual Term, Stock Options	7 years 5 months 16 days	8 years 6 months
Outstanding, Ending balance, Aggregate Intrinsic Value, Stock Options	$ 4,034	$ 3,161
Exercisable, Ending balance, Aggregate Intrinsic Value, Stock Options	$ 2,241	$ 1,756

Equity Compensation Plans (Shar

Equity Compensation Plans (Share-Based Compensation Expense Related to Employee Share-Based Compensation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	$ 8,997	$ 7,571	$ 3,080
Cost of Revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total share-based compensation expense related to employees	416	335	246
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	1,373	937	230
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	$ 7,208	$ 6,299	$ 2,604

Equity Compensation Plans (Assu

Equity Compensation Plans (Assumptions Used for Determining Fair Value of Options) (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility of stock			69.00%
Weighted-average volatility	54.75%	69.19%	69.00%
Dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.30%	1.56%	0.75%
Expected life of option (years)	5 years 2 months 12 days	5 years 3 months 22 days	5 years 4 months 17 days
Expected volatility of stock	46.00%	47.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	1.96%	2.12%	2.29%
Expected life of option (years)	6 years 10 months 21 days	6 years 8 months 19 days	7 years 1 month 21 days
Expected volatility of stock	67.00%	70.00%

Equity Compensation Plans (Weig

Equity Compensation Plans (Weighted Average Estimated Grant Date Fair Value Per Share of Stock Options and Restricted Stock Granted) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average estimated grant date fair value per share of the stock options granted	$ 11.12	$ 12.33	$ 5.70
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average estimated grant date fair value per share of the restricted stock granted	$ 17.82	$ 20.25	$ 9.35

Equity Compensation Plans (As78

Equity Compensation Plans (Assumptions Used for Determining Fair Value of Options) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility of stock			69.00%
Dividend yield	0.00%	0.00%	0.00%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Strike price			$ 5.91
Contractual term (years)	10 years	10 years	10 years
Expected volatility of stock			69.60%
Interest rate			1.75%
Dividend yield	0.00%	0.00%	0.00%
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term (years)	5 years 2 months 12 days	5 years 3 months 22 days	5 years 4 months 17 days
Expected volatility of stock	46.00%	47.00%
Interest rate	1.30%	1.56%	0.75%
Minimum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Strike price	$ 5.91	$ 5.91
Expected volatility of stock	60.50%	60.50%
Interest rate	1.75%	1.75%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term (years)	6 years 10 months 21 days	6 years 8 months 19 days	7 years 1 month 21 days
Expected volatility of stock	67.00%	70.00%
Interest rate	1.96%	2.12%	2.29%
Maximum [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Strike price	$ 21.04	$ 21.04
Expected volatility of stock	69.60%	69.60%
Interest rate	2.73%	2.73%

Equity Compensation Plans (Esti

Equity Compensation Plans (Estimated Grant Date Fair Value Per Share of Performance Options Granted) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	$ 11.12	$ 12.33	$ 5.70
Performance Shares [Member] | Tranche 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	10
Performance Shares [Member] | Tranche 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	12.50
Performance Shares [Member] | Tranche 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	15
Performance Shares [Member] | Tranche 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	17.50
Performance Shares [Member] | Tranche 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	20
Performance Shares [Member] | Tranche 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	25
Performance Shares [Member] | Tranche 7 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	30
Performance Shares [Member] | Tranche 8 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	35
Performance Shares [Member] | Tranche 9 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Price Target	40
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.32
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.30
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.27
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.23
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.19
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.10
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 7 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	4.01
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 8 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	3.92
Fair Value Of 2012 Grant [Member] | Performance Shares [Member] | Tranche 9 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	3.83
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 1 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.74
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 2 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.74
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 3 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.74
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 4 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.74
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 5 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.73
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 6 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.73
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 7 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.71
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 8 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	14.67
Fair Value Of 2014 Grant [Member] | Performance Shares [Member] | Tranche 9 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Fair Value	$ 14.61

Segment and Geographic Inform80

Segment and Geographic Information (Revenue by Geographic Area) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 35,863	$ 31,423	$ 32,583	$ 29,886	$ 29,415	$ 26,678	$ 26,514	$ 24,847	$ 129,755	$ 107,454	$ 81,889
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									102,212	80,203	62,311
Europe [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									17,180	18,163	11,384
Asia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									9,510	8,552	7,665
Other International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									853	536	529
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue									$ 27,543	$ 27,251	$ 19,578

Segment and Geographic Inform81

Segment and Geographic Information (Revenue by Product Type) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue from External Customer [Line Items]
Revenue	$ 35,863	$ 31,423	$ 32,583	$ 29,886	$ 29,415	$ 26,678	$ 26,514	$ 24,847	$ 129,755	$ 107,454	$ 81,889
United States [Member]
Revenue from External Customer [Line Items]
Revenue									102,212	80,203	62,311
United States [Member] | Open-heart Ablation [Member]
Revenue from External Customer [Line Items]
Revenue									53,541	44,662	37,843
United States [Member] | Minimally Invasive Ablation [Member]
Revenue from External Customer [Line Items]
Revenue									21,564	16,050	13,648
United States [Member] | AtriClip [Member]
Revenue from External Customer [Line Items]
Revenue									24,377	16,675	10,820
United States [Member] | Ablation and AtriClip [Member]
Revenue from External Customer [Line Items]
Revenue									99,482	77,387	62,311
United States [Member] | Valve Tools [Member]
Revenue from External Customer [Line Items]
Revenue									2,730	2,816
International [Member]
Revenue from External Customer [Line Items]
Revenue									27,543	27,251	19,578
International [Member] | Open-heart Ablation [Member]
Revenue from External Customer [Line Items]
Revenue									16,287	16,445	13,064
International [Member] | Minimally Invasive Ablation [Member]
Revenue from External Customer [Line Items]
Revenue									7,964	7,881	5,354
International [Member] | AtriClip [Member]
Revenue from External Customer [Line Items]
Revenue									2,868	2,158	1,160
International [Member] | Ablation and AtriClip [Member]
Revenue from External Customer [Line Items]
Revenue									27,119	26,484	$ 19,578
International [Member] | Valve Tools [Member]
Revenue from External Customer [Line Items]
Revenue									$ 424	$ 767

Selected Quarterly Financial 82

Selected Quarterly Financial Data (Schedule Of Quarterly Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating Results:
Revenue	$ 35,863	$ 31,423	$ 32,583	$ 29,886	$ 29,415	$ 26,678	$ 26,514	$ 24,847	$ 129,755	$ 107,454	$ 81,889
Gross profit	25,545	22,478	23,117	21,735	20,420	18,892	18,781	17,657	92,875	75,750	59,563
Loss from operations	(10,630)	(6,127)	(4,819)	(5,144)	(4,779)	(803)	(2,853)	(7,925)	(26,720)	(16,360)	(10,891)
Net loss	$ (10,914)	$ (6,141)	$ (4,891)	$ (5,266)	$ (5,344)	$ (466)	$ (2,692)	$ (7,709)	$ (27,212)	$ (16,211)	$ (11,462)
Net loss per share (basic and diluted)	$ (0.36)	$ (0.22)	$ (0.18)	$ (0.19)	$ (0.20)	$ (0.02)	$ (0.10)	$ (0.31)

Schedule II (Schedule Of Valuat

Schedule II (Schedule Of Valuation And Qualifying Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reserve For Sales Returns And Allowances [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 135	$ 105	$ 105
Additions	78	34
Deductions	6	4
Ending Balance	207	135	$ 105
Allowance For Inventory Valuation [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	522	782	267
Additions	720	441	921
Deductions	399	701	406
Ending Balance	843	522	782
Valuation Allowance For Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	59,554	54,211	31,685
Additions	$ 14,128	$ 5,343	$ 22,526
Deductions
Ending Balance	$ 73,682	$ 59,554	$ 54,211