Entellus Medical (ENTL) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 01, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	ENTL
Entity Registrant Name	ENTELLUS MEDICAL INC
Entity Central Index Key	1,374,128
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,474,059

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2017	Dec. 31, 2016
CURRENT ASSETS
Cash and cash equivalents	$ 51,452,000	$ 21,417,000
Short-term investments	0	10,845,000
Accounts receivable, net of allowance for doubtful accounts and sales returns of $649 and $308, respectively	18,320,000	13,556,000
Inventories	8,618,000	7,226,000
Prepaid expenses and other current assets	2,300,000	1,862,000
Total current assets	80,690,000	54,906,000
Property and equipment, net	8,317,000	6,487,000
Intangible assets, net	89,630,000	9,840,000
Goodwill	62,772,000	477,000
Other non-current assets	427,000	379,000
Total assets	241,836,000	72,089,000
CURRENT LIABILITIES
Accounts payable	3,821,000	2,796,000
Accrued expenses	12,929,000	13,005,000
Current portion of contingent consideration	17,426,000
Revolving credit facility	7,943,000
Current portion of long-term debt		9,118,000
Total current liabilities	42,119,000	24,919,000
LONG-TERM LIABILITIES
Long-term debt, less current portion, net of debt issuance costs of $329 and $116, respectively	39,671,000	10,766,000
Contingent consideration, less current portion	35,493,000
Other non-current liabilities	273,000	959,000
Total liabilities	117,556,000	36,644,000
COMMITMENTS AND CONTINGENCIES (See Note N)
STOCKHOLDERS' EQUITY (see Note J)
Preferred stock, $0.001 par value per share: Authorized shares: 10,000 at September 30, 2017 and December 31, 2016 Issued and outstanding shares: none
Common stock, $0.001 par value per share: Authorized shares: 200,000 at September 30, 2017 and December 31, 2016; Issued and outstanding shares: 25,448 and 18,908 at September 30, 2017 and December 31, 2016, respectively	25,000	19,000
Additional paid-in capital	294,740,000	186,370,000
Accumulated other comprehensive loss	(76,000)	(156,000)
Accumulated deficit	(170,409,000)	(150,788,000)
Total stockholders' equity	124,280,000	35,445,000
Total liabilities and stockholders' equity	$ 241,836,000	$ 72,089,000

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts and sales returns	$ 649	$ 308
Debt issuance costs	$ 329	$ 116
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares Issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	25,448,000	18,908,000
Common stock, shares outstanding	25,448,000	18,908,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Revenue	$ 23,329	$ 17,880	$ 64,575	$ 53,512
Cost of goods sold	6,555	4,648	17,287	13,107
Gross profit	16,774	13,232	47,288	40,405
Operating expenses
Selling and marketing	18,457	15,364	49,743	41,857
Research and development	4,653	2,047	8,881	5,832
General and administrative	5,043	4,698	13,964	12,183
Amortization of intangible assets	1,957	109	2,313	111
Acquisition-related expenses	3,865		5,059	300
Total operating expenses	33,975	22,218	79,960	60,283
Loss from operations	(17,201)	(8,986)	(32,672)	(19,878)
Other income (expense)
Interest income	117	75	286	228
Interest expense	(1,018)	(562)	(2,029)	(1,686)
Other non-operating expense	(20)	(12)	(82)	(42)
Loss before income tax expense	(18,122)	(9,485)	(34,497)	(21,378)
Income tax benefit (expense)	14,882	(34)	14,876	(34)
Net loss	(3,240)	(9,519)	(19,621)	(21,412)
Other comprehensive loss
Unrealized (loss) gain on short-term investments, net of tax		(39)	(1)	26
Foreign currency translation gain (loss)	34	(28)	81	(123)
Comprehensive loss	$ (3,206)	$ (9,586)	$ (19,541)	$ (21,509)
Net loss per share, basic and diluted	$ (0.13)	$ (0.50)	$ (0.87)	$ (1.14)
Weighted average common shares outstanding, basic and diluted	24,944	18,855	22,595	18,827

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net loss	$ (19,621)	$ (21,412)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	1,800	1,201
Amortization of intangible assets	2,313	111
Amortization, other	88	158
Fair value adjustment to contingent consideration	2,329
Deferred taxes, net	(14,876)	34
Acquired inventory fair value adjustment recognized	326	53
Stock-based compensation	5,892	4,060
Other	601	423
Changes in operating assets and liabilities, net of acquired assets and liabilities:
Accounts receivables	(3,448)	(1,454)
Inventories	(924)	(2,057)
Prepaid expenses and other current assets	493	656
Other non-current assets	297	(283)
Accounts payable	(235)	1,834
Accrued expenses	(1,936)	3,393
Net cash used in operating activities	(26,901)	(13,283)
Cash flows from investing activities:
Purchase of property and equipment	(2,603)	(3,469)
Purchase of investments		(32,182)
Proceeds from maturities of short-term investments	10,837	46,339
Net cash used in investing activities	(16,544)	(312)
Cash flows from financing activities:
Proceeds from revolving credit facility	48,145
Payments on revolving credit facility	(40,202)
Proceeds from long-term debt	40,000
Payments of term debt	(20,000)
Payment of debt fees	(1,206)
Payment of debt issuance costs	(132)
Proceeds from stock plans	1,622	372
Proceeds from public offering, net of issuance costs	45,361
Net cash provided by financing activities	73,588	372
Effect of exchange rate changes on cash and cash equivalents	(108)	(89)
Net increase (decrease) in cash and cash equivalents	30,035	(13,312)
Cash and cash equivalents - beginning of period	21,417	28,548
Cash and cash equivalents - end of period	51,452	15,236
Supplemental cash flow information:
Cash paid for interest	1,549	1,410
Non-cash transactions related to investing and financing activities:
Issuance of stock related to acquisition	55,502
Contingent consideration for acquisition	50,590
Spirox [Member]
Adjustments to reconcile net loss to net cash used in operating activities:
Amortization of intangible assets	6,000	6,100
Cash flows from investing activities:
Acquisition of business	$ (24,778)
XeroGel [Member]
Cash flows from investing activities:
Acquisition of business		$ (11,000)

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	NOTE A. BASIS OF PRESENTATION Financial Statement Preparation The financial statements of Entellus Medical, Inc. and its subsidiaries (collectively, the “Company” or “Entellus”) have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). The interim financial data as of September 30, 2017 is unaudited and is not necessarily indicative of the results for a full year. In the opinion of the Company’s management, the interim data includes only normal and recurring adjustments necessary for a fair statement of the Company’s financial results for the three and nine months ended September 30, 2017 and 2016. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to SEC rules and regulations relating to interim financial statements. Certain amounts reported in the condensed consolidated financial statements for the previous reporting periods have been reclassified to conform to the current period presentation. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 that has been filed with the SEC. Spirox Acquisition On July 13, 2017, the Company completed its previously announced acquisition of Spirox, Inc (“Spirox”). Spirox was a privately held medical device company that develops, manufactures and markets the Latera Absorbable Nasal Implant which is a minimally invasive option to treat nasal airway obstruction. Pursuant to the terms of the Agreement and Plan of Merger (the “Merger Agreement”), dated as of July 6, 2017, Stinger Merger Sub Inc., an indirect wholly-owned subsidiary of the Company (“Merger Sub”), merged with and into Spirox, with Spirox continuing as the surviving entity and an indirect wholly-owned subsidiary of the Company (the “Spirox Acquisition”). In the transaction, the Company paid $24.8 million in cash and issued approximately 3.4 million in shares of its common stock with an approximate combined fair value of $80.3 million, subject to certain adjustments and as calculated pursuant to the calculation methodology set forth in the Merger Agreement. The Company common stock issued in connection with the Spirox Acquisition is subject to a lock-up agreement for a period of (i) three months from the date of closing of the Spirox Acquisition in the case of 25% of the shares, (ii) six months from the date of closing of the Spirox Acquisition in the case of an additional 25% of the shares and (iii) 12 months in the case of the remaining shares. Of the $24.8 million cash consideration, $7.5 million was deposited with an escrow agent to fund payment obligations with respect to the working capital adjustment and post-closing indemnification obligations of Spirox’s former equity holders. Under the terms of the Merger Agreement, the Company has agreed to pay additional contingent consideration to Spirox’s former equity holders based on the Company’s annual revenue growth from sales of Spirox’s Latera device and related products during the four-year period following the Spirox Acquisition. Related products include subsequent versions of the Latera device and any other device that treats nasal valve collapse or nasal lateral wall insufficiency by increasing the mechanical strength of the nasal lateral wall using a synthetic graft. The Company has the discretion to pay the contingent consideration in shares of its common stock or cash, subject to compliance with applicable law and the Listing Rules of the NASDAQ Stock Market. A portion of the contingent consideration will be subject to certain rights of set-off for any post-closing indemnification obligations of Spirox’s equity holders. Because the contingent consideration arrangement (a) embodies a conditional obligation and is not an outstanding share, (b) may be settled by delivering a variable number of common shares, and (c) has a monetary value, at inception, that is based on variations in something other than the Company’s stock price, the obligation is classified as a liability under the classification guidance in Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity All options and warrants to acquire shares of Spirox stock were terminated in connection with the Spirox Acquisition and the holders thereof have been entitled to receive the merger consideration that would have been payable to such holders had they exercised their vested options and warrants in full immediately prior to the effective time of the Spirox Acquisition, less the applicable exercise price of such vested options and warrants. See Note C. Business Acquisition. Valuation adjustments to future contingent consideration due to the former equity holders of Spirox along with transaction and integration costs related to the Company’s 2017 acquisition of Spirox and 2016 acquisition of XeroGel are presented as “Acquisition-related expenses” on the condensed consolidated statements of operations. Following the Spirox Acquisition, Company management evaluated the combined operations in light of the guidance provided by ASC 280 Segment Reporting Public Offering In February 2017, the Company completed a public offering of shares of its common stock, issuing a total of 2.9 million shares of common stock (including 0.5 million shares issued after exercise by the underwriters of their option to purchase additional shares) at an offering price of $17.00 per share. Certain existing stockholders of the Company also sold approximately 1.2 million shares of common stock in the offering. The Company received net proceeds of approximately $45.4 million, after deducting underwriting discounts and commissions of $2.9 million and offering expenses of $0.7 million payable by the Company. The Company did not receive any proceeds from the sale of shares by the selling stockholders. Use of Estimates The preparation of financial statements in conformity with U.S. 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 expenses during the reported period. Actual results could differ from those estimates. Significant Accounting Policies There have been no changes in the Company’s significant accounting policies for the three and nine months ended September 30, 2017, as compared to the significant accounting policies described in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2016. In addition to those policies, the following significant accounting policy was adopted in connection with the Spirox Acquisition: Valuation of Business Combinations The fair value of consideration, including contingent consideration, transferred in acquisitions accounted for as business combinations is first allocated to the identifiable tangible and intangible assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Any excess purchase consideration is allocated to goodwill. Further, for those arrangements that involve liability classified contingent consideration, the Company records a liability equal to the fair value of the estimated additional consideration we may be obligated to make in the future on the date of acquisition. Liability classified contingent consideration is adjusted to its fair value each reporting period through earnings. Acquisition transaction costs are expensed as incurred. The fair value of identifiable intangible assets requires management estimates and judgments based on market participant assumptions. Using alternative valuation assumptions, including estimated revenue projections, growth rates, cash flows, discount rates, estimated useful lives, and probabilities surrounding the achievement of milestones could result in different fair value estimates of our net tangible and intangible assets and related amortization expense in current and future periods. Contingent consideration is remeasured to fair value each reporting period using projected revenues, discount rates, and projected payment dates. Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. Increases or decreases in the fair value of the contingent consideration can result from changes in the timing and amount of revenue estimates as well as changes in discount periods and rates. Because the fair value of contingent consideration is based on management assumptions and not observable market inputs, it is considered a Level 3 measurement. Contingent consideration valuation adjustments are recorded as operating expenses or income in the period in which the change is determined. The Company’s accounting policy is to utilize deferred tax liabilities created through purchase accounting to first offset acquired deferred tax assets. The Company then utilizes any residual net deferred tax liability as a source of taxable income that can be used to support an equivalent amount of the Company’s existing deferred tax assets.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Recent Accounting Pronouncements	NOTE B. RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers Technical Corrections and Improvements to Topic 606 – Revenue from Contracts with Customers In March 2016, the FASB issued ASU 2016-08, Principal versus Agent Considerations – Reporting Revenue Gross versus Net . This ASU clarifies the revenue recognition implementation guidance for preparers on certain aspects of principal versus agent consideration. The amendments in this ASU are effective for private companies and emerging growth companies beginning after December 15, 2018. The Company has performed a review of the requirements of the new guidance and has identified which of its revenue streams will be within the scope of ASU 2014-09. The Company is working through an adoption plan which includes a review of customer contracts, applying the five-step model of the new standard to each revenue stream and comparing the results to its current accounting; an evaluation of the method of adoption; and assessing changes that might be necessary to information technology systems, processes, and internal controls to capture new data and address changes in financial reporting. Because of the nature of the work that remains, at this time the Company is unable to reasonably estimate the impact of adoption of ASU 2016-08 and ASU 2014-09 on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities The updated guidance in this ASU is effective for private companies and emerging growth companies beginning after December 15, 2018. In February 2016, the FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In August 2016, the FASB issued ASU 2016-15, Statements of Cash Flows – Classifications of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-01, Business Combinations – Clarifying the Definition of a Business , to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or dispositions) of assets or businesses. This ASU is effective for private companies and emerging growth companies beginning after December 15, 2018; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-01 will have a significant impact on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment This ASU is effective for private companies and emerging growth companies beginning after December 15, 2020; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-04 will have a significant impact on its consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Scope of Modification Accounting entity will not apply modification accounting to a share-based payment award if the award’s fair value, vesting conditions and classification as an equity or liability instrument are the same immediately before and after the change This ASU is effective for private companies and emerging growth companies beginning after December 15, 2017; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-09 will have a significant impact on its consolidated financial statements.

Business Acquisition

Business Acquisition	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Business Acquisition	NOTE C. BUSINESS ACQUISITION On July 13, 2017, Entellus completed the Spirox Acquisition. See Note A. Basis of Presentation - Spirox Acquisition The Spirox Acquisition has been accounted for as a business combination, and assets acquired and liabilities assumed were recorded at their estimated fair values as of July 13, 2017, the date of the acquisition. Goodwill as of the acquisition date is measured as the excess of consideration transferred, which is also generally measured at fair value or the net acquisition date fair values of the assets acquired and the liabilities assumed. Total consideration transferred was $130.9 million and consisted of the preliminary purchase price of $80.3 million, consisting of $24.8 million cash and approximately 3.4 million shares of Entellus common stock (at a closing stock price on July 13, 2017 of $17.69 subject to certain discounts for the lock-up period resulting in an implied price of $16.27), and $50.6 million related to the fair value of potential additional earn-out payments based on Entellus’s net revenue from sales of Spirox’s Latera™ device, subsequent versions thereof and any other device that treats nasal valve collapse or nasal lateral wall insufficiency by increasing the mechanical strength of the nasal lateral wall through the use of a synthetic graft, evaluated annually during the four-year period following the Spirox Acquisition. The acquisition has been accounted for in accordance with ASC 805, Business Combinations, (in thousands) Purchase Price Allocation Accounts and other receivables $ 1,440 Prepaid expenses and other current assets 925 Inventory 647 Property and equipment 1,257 Intangible assets 82,103 Other non-current assets 219 Total assets acquired 86,591 Accounts payable 1,297 Accrued expenses and other current liabilities 1,835 Deferred tax liabilities 14,884 Total liabilities assumed 18,016 Identifiable net assets acquired 68,575 Goodwill 62,295 Net assets acquired and purchase price consideration $ 130,870 As a result of recording the assets and liabilities at fair market value for GAAP purposes, but receiving primarily carryover basis for tax purposes in the acquisition, the Company recorded a deferred tax liability of $14.9 million. The goodwill of $62.3 million resulting from the acquisition is the excess of the purchase price over the fair value of the net assets acquired. The goodwill recorded as part of the acquisition primarily reflects the value of strengthening the Company’s strategy of offering less invasive treatment options to ENT physicians while driving procedure volumes to more cost-effective sites of care, thus meaningfully enhancing the Company’s market opportunity and growth potential. Goodwill also reflects the value of the assembled workforce as well as the value to be realized through cost synergies and integration of product lines. None of the goodwill recognized is deductible for income tax purposes as it was a stock acquisition, and as such, no deferred taxes have been recorded related to goodwill. Revenue of $3.1 million and a net operating loss of $6.1 million attributable to the acquisition is included in the Company’s consolidated statement of operations for the three and nine months ended September 30, 2017. Included in the operating loss for the three and nine months ended September 30, 2017 is amortization expenses of $1.8 million related to identifiable intangible assets acquired in the transaction and the full recognition of the $0.3 million of fair value adjustment of acquired inventory. The following summarizes the intangible assets acquired, excluding goodwill. Intangible assets are amortized using methods that approximate the pattern of economic benefit provided by the utilization of the assets. Gross Carrying Value Amortization Term (in thousands) (in years) Developed technology $ 73,930 10.4 Trade names and trademarks 4,630 10.4 Customer relationships 3,500 12.0 Non-competition arrangements 43 3.0 Total $ 82,103 Contingent consideration is a Level 3 fair value measurement, remeasured to fair value each reporting period using projected revenues, discount rates, and projected payment dates. The Company recorded a $2.3 million valuation adjustment to the contingent consideration liability for the three and nine months ended September 30, 2017 due to the passage of time (i.e., accretion) as shown on the following Level 3 rollforward: (in thousands) Contingent Consideration Fair value on July 13, 2017 (acquisition date) 50,590 Valuation adjustment 2,329 Fair value on September 30, 2017 $ 52,919 The following supplemental pro forma information presents the financial results of the Company for the three and nine months ended September 30, 2017 and 2016, as if the acquisition of Spirox had occurred on January 1, 2016. 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, 2016, nor are they indicative of any future results. The fiscal 2016 three and nine month pro forma financial information includes adjustments for additional amortization expense on intangible assets of $2.0 million and $6.1 million and additional interest expense on debt used to finance the transaction of $0.7 million and $2.0 million, respectively. The fiscal 2017 three and nine month pro forma information includes adjustments for the removal of transaction costs of $11.4 million and $12.6 million and net severance and other compensation costs of $1.3 million and $2.0 million, partially offset by additional amortization expense on intangible assets of $1.7 million and $6.0 million and additional interest expense of $0.1 million and $1.4 million, respectively. Three Months Ended September 30, Nine Months Ended September 30, (in millions except per share data) 2017 2016 2017 2016 (Unaudited) (Unaudited) Revenue $ 23.7 $ 18.6 $ 69.8 $ 54.3 Net loss (3.9 ) (15.7 ) (33.4 ) (39.5 ) Net loss per share, basic and diluted $ (0.15 ) $ (0.71 ) $ (1.34 ) $ (1.78 ) Total acquisition-related expenses associated with the Spirox Acquisition aggregated $3.9 million and $5.1 million for the three and nine months ended September 30, 2017, respectively.

Composition of Certain Financia

Composition of Certain Financial Statement Items	9 Months Ended
	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Composition of Certain Financial Statement Items	NOTE D. COMPOSITION OF CERTAIN FINANCIAL STATEMENT ITEMS Inventories September 30, December 31, (in thousands) 2017 2016 Finished goods $ 4,256 $ 3,562 Work-in-process 1,260 536 Raw materials 3,102 3,128 Total $ 8,618 $ 7,226 Property and Equipment September 30, December 31, (in thousands) 2017 2016 Furniture and office equipment $ 992 $ 873 Computer hardware and software 3,717 2,831 Laboratory equipment 6,348 4,336 Tooling and molds 1,525 1,512 Leasehold improvements 2,488 2,006 $ 15,070 $ 11,558 Less accumulated depreciation (7,122 ) (5,465 ) Property and equipment in progress 369 394 Total $ 8,317 $ 6,487 Depreciation expense on property and equipment was $0.8 million and $0.5 million during the three months ended September 30, 2017 and 2016, respectively, and $1.8 million and $1.2 million during the nine months ended September 30, 2017 and 2016, respectively. Accrued Expenses September 30, December 31, (in thousands) 2017 2016 Compensation and commissions payable $ 8,214 $ 8,674 Royalty payable 1,795 1,851 Other accrued expenses 2,920 2,480 Total $ 12,929 $ 13,005

Liquidity and Business Risks

Liquidity and Business Risks	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Liquidity and Business Risks	NOTE E. LIQUIDITY AND BUSINESS RISKS As of September 30, 2017, the Company had cash and cash equivalents of $51.5 million and an accumulated deficit of $170.4 million. In the first quarter of 2017, the Company completed a public offering of shares of its common stock, issuing a total of 2.9 million shares of common stock (including 0.5 million shares issued after exercise by the underwriters of their option to purchase additional shares) at an offering price of $17.00 per share. Certain existing stockholders of the Company also sold approximately 1.2 million shares of common stock in the offering. The Company received net proceeds of $45.4 million, after deducting underwriting discounts and commissions of $2.9 million and offering expenses of $0.7 million payable by the Company. The Company did not receive any proceeds from the sale of shares by the selling stockholders. On March 31, 2017, the Company entered into a loan and security agreement with Oxford Financial, LLC providing for a new credit facility. Under this credit facility, the Company may borrow up to $40.0 million in term loans in three tranches , subject to a borrowing base requirement. The Company immediately borrowed $13.5 million under the first term loan and approximately $20.0 million in pre-existing outstanding indebtedness. Prior to its February 2015 initial public offering (“IPO”), the Company financed its operations with a combination of revenue, private placements of convertible preferred securities and amounts borrowed under its credit facility. Although it is difficult to predict its future liquidity requirements, the Company expects that its existing cash and cash equivalents, anticipated revenue and remaining amounts available under its line of credit will be sufficient to meet its anticipated capital requirements, and fund its operations beyond 2018. Further capital requirements may be necessary to fund any contingent consideration due to the former Spirox equity holders. See Note C. Business Acquisitions.

Short-Term Investments

Short-Term Investments	9 Months Ended
	Sep. 30, 2017
Investments Debt And Equity Securities [Abstract]
SHORT-TERM INVESTMENTS	NOTE F. SHORT-TERM INVESTMENTS The Company determines the appropriate classification of its investments at the time of purchase and revaluates such determinations at each balance sheet date. Marketable securities are classified as held-to-maturity when the Company has the intent and ability to hold the securities to maturity. Marketable securities for which the Company does not have the intent or ability to hold to maturity are classified as available-for-sale. Marketable securities classified as available-for-sale are carried at fair market value, with the unrealized gains and losses included in the determination of comprehensive income and reported in stockholders’ equity. The following is a summary of the available-for-sale investments by type of instrument, which are included in short-term investments in the consolidated balance sheet as of December 31, 2016. There were no available-for-sale investments as of September 30, 2017. Unrealized Unrealized Gain in Losses in Accumulated Accumulated Other Other Amortized Comprehensive Comprehensive Estimated December 31, 2016 (in thousands) Cost Income (Loss) Income Fair Value Commercial paper $ 2,495 $ 2 $ — $ 2,497 Corporate bonds 4,099 — (2 ) 4,097 Foreign assets 4,250 1 — 4,251 Total available-for-sale securities $ 10,844 $ 3 $ (2 ) $ 10,845 Based on an evaluation of securities that have been in a loss position, the Company did not recognize any other-than-temporary impairment charges during the nine months ended September 30, 2017. The Company considered various factors, including a credit and liquidity assessment of the underlying securities and the Company’s intent and ability to hold the underlying securities until the estimated date of recovery of its amortized cost. As of December 31, 2016, available-for-sale maturities as noted in the table above mature in one year or less.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	NOTE G. FAIR VALUE MEASUREMENTS As of September 30, 2017 and December 31, 2016, the carrying amounts of cash and cash equivalents, receivables, accounts payable and accrued expenses approximated their estimated fair values because of the short-term nature of these financial instruments. Goodwill and intangible assets acquired are stated at fair value based upon the acquisition valuation. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three categories: • Level 1: Quoted market prices in active markets for identical assets or liabilities. • Level 2: Includes other than Level 1 inputs 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 for which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the asset or liabilities. • Level 3: Unobservable inputs that are supported by little or no market activities, which would require the Company to develop its own assumptions. Short-term Investments The following is a summary of available-for-sale investments by type of instrument measured at fair value on a recurring basis at December 31, 2016. There were no available-for-sale investments as of September 30, 2017. December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Total Commercial paper $ — $ 2,497 $ — $ 2,497 Corporate bonds — 4,097 — 4,097 Foreign assets — 4,251 — 4,251 Total $ — $ 10,845 $ — $ 10,845 Liabilities The following is a summary of liabilities measured at fair value on a recurring basis at September 30, 2017. There were no such liabilities as of December 31, 2016. September 30, 2017 (in thousands) Level 1 Level 2 Level 3 Total Contingent consideration $ — $ — $ 52,919 $ 52,919 The contingent consideration was determined based on discounted cash flow analyses that included projected net revenue assumptions and a discount rate as of September 30, 2017, which are considered significant unobservable inputs. These inputs were used in an option pricing approach in a risk-neutralized framework, using a risk-adjusted discount rate of 12% and a volatility factor of 35% based on the Company’s historical volatility. Projected net revenues developed for each contingent payment period, multiplied by their respective earnout multiples, were discounted to the valuation date using a discount rate of 8% based on the Company’s cost of debt. To the extent these assumptions were to change, the fair value of the contingent consideration could change significantly. Included in acquisition-related expenses in the condensed consolidated statements of operations for both the three and nine months ended September 30, 2017 is $2.3 million of contingent consideration valuation accretion due to the passage of time. There were no transfers in or out of Level 1, Level 2 or Level 3 fair value measurement categories during the three and nine months ended September 30, 2017. 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.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	NOTE H. GOODWILL AND INTANGIBLE ASSETS The change in the carrying amount of goodwill is as follows: (in thousands) Carrying Value December 31, 2016 $ 477 Spirox Acquisition, at acquisition date 62,295 September 30, 2017 $ 62,772 Other intangible assets are as follows: September 30, 2017 December 31, 2016 (in thousands) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Developed technology $ 83,630 $ (2,402 ) $ 9,700 $ (342 ) Trade name 5,130 (141 ) 500 (18 ) Customer relationships 3,500 (127 ) — — Noncompetition arrangements 43 (3 ) — — $ 92,303 $ (2,673 ) $ 10,200 $ (360 ) The weighted average useful lives of each class of intangible assets are as follows: Useful Life (Years) Developed technology 10.9 Trade name 10.8 Customer relationships 12.0 Noncompetition arrangements 3.0 Amortization expense on intangible assets was $2.0 million and $0.1 million during the three months ended September 30, 2017 and 2016, respectively, and $2.3 million and $0.1 million during the nine months ended September 30, 2017 and 2016, respectively. Estimated aggregate amortization expense for the next five fiscal years based on the current carrying value of definite-lived intangible assets at September 30, 2017, is as follows: (in thousands) Remaining 2017 $ 2,216 2018 8,818 2019 8,728 2020 8,647 2021 8,577 2022 8,525

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	NOTE I. DEBT In December 2013, the Company entered into an amended and restated credit facility with Oxford Finance LLC (“Oxford”) under which the Company borrowed $20.0 million at a fixed rate of 9.40%. The facility was scheduled to mature and all amounts borrowed thereunder were due on December 1, 2018. In February 2017, the Company entered into an amendment to the amended and restated loan and security agreement to allow principal payments due on February 1, 2017 and March 1, 2017 to be deferred until March 15, 2017. In March 2017, the principal payments were deferred again during renegotiations with Oxford. In March 2017, the Company entered into a loan and security agreement (the “Loan Agreement”) with Oxford providing for a new credit facility. The key terms of the new credit facility are summarized in the table below: Origination date: March 31, 2017 Maturity date: March 1, 2022 Funding tranches: First term loan $13.5 million Second term loan (1) $10.0 million Third term loan (1) $16.5 million Revolving line of credit: (2) $10.0 million Outstanding as of September 30, 2017: Term loans $40.0 million Revolving line of credit $7.9 million Term loan interest rate: Floating per annum rate equal to the greater of (1) 7.95% and (2) the sum of (i) the greater of (A) the 30-day U.S. LIBOR rate reported in The Wall Street Journal plus Revolving line of credit interest rate: Floating per annum rate of interest is equal to the greater of (1) 4.95% and (2) the sum of (i) the greater of (A) 30-day U.S. LIBOR rate reported in The Wall Street Journal plus Final payment fee as a percentage of term loans outstanding: 4.95% Prepayment fees: 1.00% to 3.00% of the principal amount of such Term Loan prepaid, depending upon the timing of the prepayment. Other fees: Customary commitment fees and unused fees and certain other customary fees related to the Oxford’s administration of the credit facility. Security interest: A first priority security interest in substantially all of the Company’s assets, other than its intellectual property and, under certain circumstances more than 65% of its shares in any foreign subsidiary. The Company has agreed not to pledge or otherwise encumber its intellectual property assets, except for permitted liens, as such terms are defined in the Loan Agreement and except as otherwise provided for in the Loan Agreement. _____________________ (1) Became available and was borrowed to fund the July 13, 2017 Spirox Acquisition (2) Subject to a borrowing base requirement The first term loan of $13.5 million and $8.0 million of the revolving line of credit were borrowed immediately and used to repay approximately $20.0 million of then outstanding indebtedness, which constituted all amounts outstanding related to the prior credit facility, together with the final payment fee of $1.2 million. The new The Loan Agreement contains affirmative and negative covenants applicable to the Company and any subsidiaries and events of default, in each case subject to grace periods, thresholds and materiality qualifiers, as more fully described in the Loan Agreement. The affirmative covenants include, among others, covenants requiring the Company to maintain its legal existence and material governmental approvals, deliver certain financial reports and maintain insurance coverage. The negative covenants include, among others, restrictions on the Company incurring additional indebtedness, engaging in mergers, consolidations or acquisitions, paying dividends or making other distributions, making investments, creating liens, selling assets, and suffering a change in control. The events of default include, among other things, the Company’s failure to pay any amounts due under the credit facility, a breach of covenants under the Loan Agreement, the Company’s insolvency, a material adverse change, the occurrence of a default under certain other indebtedness and the entry of final judgments against the Company in excess of a specified amount. If an event of default occurs, Oxford is entitled to take various actions, including the acceleration of amounts due under the credit facility credit facility The Company was in compliance with all required covenants as of September 30, 2017 and December 31, 2016. As of September 30, 2017 and the carrying amount of debt approximated fair value because the interest rate approximates current market rates of interest available in the market. The fair value of the Company’s debt is considered a Level 3 measurement. Assuming a 60-month amortization period as stated in the Loan Agreement Fiscal Year Principal Payments (in thousands) 2017 $ — 2018 — 2019 10,000 2020 13,333 2021 13,333 2022 3,334 Total $ 40,000

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stockholders' Equity	NOTE J. STOCKHOLDERS’ EQUITY Common Stock The Company’s amended and restated certificate of incorporation authorizes 200.0 million shares of common stock. As of September 30, 2017, 25.4 million shares of common stock were outstanding. On July 13, 2017, the Company issued approximately 3.4 million shares of common stock in connection with the Spirox Acquisition. See Note C. Business Acquisitions. 2015 Incentive Award Plan In December 2014, the Company’s Board of Directors adopted, and in January 2015 the Company’s stockholders approved, the Entellus Medical, Inc. 2015 Incentive Award Plan (the “2015 Plan”). The 2015 Plan became effective in connection with the IPO, at which time the Company ceased making awards under the Entellus Medical, Inc. 2006 Stock Incentive Plan (the “2006 Plan”). Under the 2015 Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and certain other awards to individuals who are employees, officers, directors or consultants of the Company. A total of 1,345,570 shares of common stock were initially reserved for issuance under the 2015 Plan. In addition, the number of shares available for issuance under the 2015 Plan is annually increased by an amount equal to the lesser of (A) 875,000 shares, (B) 4% of the outstanding shares of the Company’s common stock as of the last day of the Company’s immediately preceding fiscal year or an amount determined by the Company’s Board of Directors. Furthermore, any shares subject to awards granted under the 2006 Plan which terminate, expire or lapse without the delivery of shares to the holder thereof become available under the 2015 Plan. In the first quarter of 2017 and 2016, in accordance with this “evergreen” provision, the number of shares available under the 2015 Plan was increased in the amount of 756,339 shares and 751,750 shares, respectively. As of September 30, 2017, 320,865 shares of common stock were available for issuance under the 2015 Plan. 2017 Employee Inducement Incentive Award Plan In connection with the Spirox Acquisition, the Board of Directors of the Company adopted the Entellus Medical, Inc. 2017 Employment Inducement Incentive Award Plan (the “Inducement Plan”), which is a non-stockholder approved plan, to facilitate the granting of equity awards as an inducement to new employees joining the Company. Under the Inducement Plan, the Company may grant stock options, stock appreciation rights, restricted stock, restricted stock units and certain other awards to new employees of the Company. A total of 450,000 shares of common stock were initially reserved for issuance under the Inducement Plan. Stock Options and RSUs Granted in Connection with the Spirox Acquisition The Compensation Committee of the Board of Directors granted the following stock options and restricted stock units (“RSUs”) under the Inducement Plan and the 2015 Plan in connection with the Spirox Acquisition: (shares in thousands) Employee Options Employee RSUs Director & Non-employee Options Director & Non-employee RSUs Inducement Plan 323 - - - 2015 Plan 93 90 23 11 Total 416 90 23 11 The employee stock options and RSUs were effective as of August 4, 2017. The stock options have a ten-year term, a per share exercise price equal to the closing price of the Company’s common stock on August 4, 2017, and will vest as to one-fourth of the underlying shares on the one-year anniversary of the Spirox Acquisition closing date, and monthly thereafter over the subsequent three years, subject to the recipient’s continued service. The RSU awards will vest annually over a four-year period. The director stock options and RSUs were effective as of July 14, 2017 and non-employee stock options and RSUs were effective as of August 4, 2017. The stock options have a ten-year term and a per share exercise price equal to the closing price of the Company’s common stock on their respective effective dates. The stock options vest quarterly over a three-year period and the RSUs vest annually over a three-year period. Stock Options A summary of the Company’s stock option activity and related information is as follows: September 30, 2017 Weighted Average Aggregate Weighted Remaining Intrinsic Options Average Contractual Value (in thousands) Exercise Price Term (in thousands) Outstanding, beginning of period 3,349 $ 13.06 7.6 years $ 21,863 Granted 1,479 15.30 — — Exercised (213 ) 5.68 — — Cancelled — - — — Forfeited (407 ) 16.68 — — Outstanding, end of period 4,208 $ 13.87 8.1 years $ 21,369 Exercisable, end of period 1,850 $ 11.92 7.0 years 13,279 The aggregate pre-tax intrinsic value of options exercised was $2.4 million and $0.8 million for the nine months ended September 30, 2017 and 2016, respectively. The aggregate pre-tax intrinsic value was calculated as the difference between the exercise prices of the underlying options and the estimated fair value of the common stock on the date of exercise on September 30, 2017 and 2016, as applicable. During the nine months ended September 30, 2017 and 2016, the fair value of shares vested was $5.7 million and $3.4 million, respectively. The total cash received by the Company upon the exercise of options was $1.2 million and $0.1 million during the nine months ended September 30, 2017 and 2016, respectively. Restricted Stock Units The Company grants time-based RSUs to directors, executive officers and certain other employees. Employee RSUs generally vest over a four-year period and director RSUs vest over a three-year period. In addition, certain key management members typically receive RSUs upon commencement of employment and may receive them annually in conjunction with their performance review. The grant date fair value of the RSU awards is determined using the closing sale price of the Company’s common stock on the date of the grant. Restricted stock unit activity during the nine months ended September 30, 2017 is summarized below: September 30, 2017 Weighted Average RSUs Grant Date (in thousands) Fair Value Outstanding, beginning of period 12 $ 16.99 Granted 282 — Released (3 ) — Forfeited/expired (28 ) — Outstanding, end of period 263 $ 16.90 Employee Stock Purchase Plan In December 2014, the Company’s Board of Directors adopted, and in January 2015 the Company’s stockholders approved, the Entellus Medical, Inc. 2015 Employee Stock Purchase Plan (“ESPP”). Under the ESPP, the Company has set two six-month offering periods during each calendar year, one beginning January 1 and ending on June 30, and the other beginning July 1 and ending on December 31, during which employees can choose to have up to 20% of their eligible compensation withheld to purchase less than 2,000 shares of the Company’s common stock during each offering period. The purchase price of the shares is 85% of the market price on the first or last trading day of the offering period, whichever is lower. A total of 200,000 shares of common stock were initially reserved for issuance under the ESPP. In addition, the number of shares of common stock available for issuance under the ESPP will be annually increased on the first day of each fiscal year during the term of the ESPP, beginning with the 2016 fiscal year, by an amount equal to the lesser of (A) 1% of the shares of the Company’s common stock outstanding on the date of the adoption of the plan or (B) a lesser amount determined by the Company’s Board of Directors. In accordance with the “evergreen” provision, the number of shares available for grant in the first quarter of 2017 and 2016 increased by 16,488 shares each year, resulting in a total of 232,976 shares reserved for issuance under the ESPP as of March 31, 2017. As of September 30, 2017, 166,523 shares of common stock remained available for issuance under the ESPP.

Stock Based Compensation Expens

Stock Based Compensation Expense	9 Months Ended
	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation Expense	NOTE K. STOCK-BASED COMPENSATION EXPENSE The following table presents the components and classification of stock-based compensation expense for stock options, RSUs and employee stock purchase plan shares recognized for the three and nine months ended September 30, 2017 and 2016: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Cost of goods sold $ 70 $ 30 $ 143 $ 77 Selling and marketing 826 536 2,148 1,470 Research and development 375 149 839 413 General and administrative 900 821 2,762 2,100 Total $ 2,171 $ 1,536 $ 5,892 $ 4,060 At September 30, 2017, there was approximately $17.8 million and $3.8 million of unrecognized stock-based compensation expense related to unvested stock options and RSUs, respectively, which the Company expects to recognize over the remaining weighted-average vesting period of approximately 2.8 years and 3.3 years, respectively. If there are any modifications or cancellations of the underlying unvested securities, the Company may be required to accelerate, increase or cancel any remaining unearned stock-based compensation expense. Future stock-based compensation expense and unearned stock-based compensation will increase to the extent that the Company grants additional stock-based awards. The Company estimates the fair value of stock-based compensation on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model determines the fair value of stock-based payment awards based on the fair market value of the Company’s common stock on the date of grant and is affected by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the fair market value of the Company’s common stock, volatility over the expected term of the awards and actual and projected employee stock option exercise behaviors. The Company has opted to use the “simplified method” for estimating the expected term of options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. Due to the Company’s limited operating history and company-specific historical and implied volatility data, the Company has based its estimate of expected volatility on the blended historical volatility of a group of similar companies that are publicly traded and their historical volatility. The fair value of the options granted to employees or directors during the nine months ended September 30, 2017 and 2016 was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Nine Months Ended September 30, 2017 2016 Expected life in years 6.2 6.0 Risk-free interest rate 2.1 % 1.6 % Expected dividend yield 0 % 0 % Expected volatility 52 % 51 % Weighted average fair value $ 7.90 $ 7.93 The fair value of the ESPP options granted to employees during the nine months ended September 30, 2017 and 2016 was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Nine Months Ended September 30, 2017 2016 Expected life in years 0.5 0.5 Risk-free interest rate 0.8 % 0.4 % Expected dividend yield 0 % 0 % Expected volatility 49 % 49 % Weighted average fair value $ 5.13 $ 5.30

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	NOTE L. INCOME TAXES The Company did not record a federal, state or foreign income tax benefit in any prior periods due to its conclusion that a full valuation allowance is required against its net deferred tax assets, excluding the deferred tax liability related to its tax deductible goodwill acquired in connection with the XeroGel acquisition. In the current period ending September 30, 2017, the Company established a $14.9 million deferred tax liability through purchase accounting related to the acquisition of Spirox. The deferred tax liability is considered a source of taxable income that can be used to support an equivalent amount of the Company’s existing deferred tax assets. Accordingly, the Company recognized a one-time $14.9 million income tax benefit in the current period as a result of reducing the valuation allowance against its deferred tax assets.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings Per Share	NOTE M. EARNINGS PER SHARE Basic net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock outstanding during the period. Diluted net loss per share is computed by dividing the net loss by the weighted average number of shares of common stock and dilutive potential shares of common stock outstanding during the period. In periods in which Company has reported a net loss, diluted net loss per share is the same as basic net loss per share as all potentially dilutive shares consisting of RSUs, stock options and warrants were antidilutive. The following table sets forth the computation of the Company’s net loss per share: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Net loss $ (3,240 ) $ (9,519 ) $ (19,621 ) $ (21,412 ) Weighted average common stock outstanding 24,944 18,855 22,595 18,827 Net loss per share, basic and diluted $ (0.13 ) $ (0.50 ) $ (0.87 ) $ (1.14 ) The following potentially dilutive securities outstanding have been excluded from the computations of diluted earnings per share because such securities have an antidilutive impact due to losses reported: September 30, (in thousands) 2017 2016 Common stock warrants 38 38 Common stock options 4,208 3,375 Restricted stock units 263 12 Common stock ESPP 167 20 Total 4,676 3,445

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	NOTE N. COMMITMENTS AND CONTINGENCIES Operating Leases As of September 30, 2017, the Company had three leased facilities under operating lease agreements. The Company entered into a 41-month lease in February 2012, effective April 1, 2012, for its corporate headquarters. The Company entered into a 50-month lease on June 30, 2014, effective July 1, 2014, for additional distribution space in a second facility. On February 26, 2015, the Company exercised its right to extend the lease term of its manufacturing and corporate facility for an additional three years through August 2018. On June 30, 2015, the Company entered into amendments to each of these two lease agreements, among other things, to expand the space occupied by the Company at the property at which the Company’s corporate headquarters are located, and to extend the term of each lease agreement through June 2021, with an option to extend for an additional term through June 2024. In connection with the Spirox Acquisition, the Company assumed a lease for a facility which expires in October 2021, in Redwood City, California. Rental payments on operating leases are charged to expense on a straight-line basis over the period of the lease. These lease agreements require the Company to pay executory costs such as real estate taxes, insurance and repairs, and include renewal and escalation clauses. Total lease expense was approximately $0.2 million for each of the three months ended September 30, 2017 and 2016 and $0.7 million and $0.5 million for the nine months ended September 30, 2017 and 2016, respectively. Other Commitment In June 2016, the Company entered into an Amended and Restated Fiagon NA Distribution Agreement (the “Distribution Agreement”) with Fiagon NA Corporation in which the Company was granted exclusive distribution rights in the United States and Canada for Fiagon Image Guidance Systems (“IGS”) and certain components, parts and related ancillary products i) to hospitals, ii) to ENT physicians in the office, clinic, and surgery centers, and iii) under ENT healthcare system contracts. The terms of the Distribution Agreement require the Company to purchase minimum quantities of Fiagon IGS units and certain other disposable products through August 9, 2020 for the Company to retain exclusive distribution rights .

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Financial Statement Preparation	Financial Statement Preparation The financial statements of Entellus Medical, Inc. and its subsidiaries (collectively, the “Company” or “Entellus”) have been prepared in accordance with U.S. generally accepted accounting principles (“U.S. GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). The interim financial data as of September 30, 2017 is unaudited and is not necessarily indicative of the results for a full year. In the opinion of the Company’s management, the interim data includes only normal and recurring adjustments necessary for a fair statement of the Company’s financial results for the three and nine months ended September 30, 2017 and 2016. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to SEC rules and regulations relating to interim financial statements. Certain amounts reported in the condensed consolidated financial statements for the previous reporting periods have been reclassified to conform to the current period presentation. The accompanying condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2016 that has been filed with the SEC.
Spirox Acquisition	Spirox Acquisition On July 13, 2017, the Company completed its previously announced acquisition of Spirox, Inc (“Spirox”). Spirox was a privately held medical device company that develops, manufactures and markets the Latera Absorbable Nasal Implant which is a minimally invasive option to treat nasal airway obstruction. Pursuant to the terms of the Agreement and Plan of Merger (the “Merger Agreement”), dated as of July 6, 2017, Stinger Merger Sub Inc., an indirect wholly-owned subsidiary of the Company (“Merger Sub”), merged with and into Spirox, with Spirox continuing as the surviving entity and an indirect wholly-owned subsidiary of the Company (the “Spirox Acquisition”). In the transaction, the Company paid $24.8 million in cash and issued approximately 3.4 million in shares of its common stock with an approximate combined fair value of $80.3 million, subject to certain adjustments and as calculated pursuant to the calculation methodology set forth in the Merger Agreement. The Company common stock issued in connection with the Spirox Acquisition is subject to a lock-up agreement for a period of (i) three months from the date of closing of the Spirox Acquisition in the case of 25% of the shares, (ii) six months from the date of closing of the Spirox Acquisition in the case of an additional 25% of the shares and (iii) 12 months in the case of the remaining shares. Of the $24.8 million cash consideration, $7.5 million was deposited with an escrow agent to fund payment obligations with respect to the working capital adjustment and post-closing indemnification obligations of Spirox’s former equity holders. Under the terms of the Merger Agreement, the Company has agreed to pay additional contingent consideration to Spirox’s former equity holders based on the Company’s annual revenue growth from sales of Spirox’s Latera device and related products during the four-year period following the Spirox Acquisition. Related products include subsequent versions of the Latera device and any other device that treats nasal valve collapse or nasal lateral wall insufficiency by increasing the mechanical strength of the nasal lateral wall using a synthetic graft. The Company has the discretion to pay the contingent consideration in shares of its common stock or cash, subject to compliance with applicable law and the Listing Rules of the NASDAQ Stock Market. A portion of the contingent consideration will be subject to certain rights of set-off for any post-closing indemnification obligations of Spirox’s equity holders. Because the contingent consideration arrangement (a) embodies a conditional obligation and is not an outstanding share, (b) may be settled by delivering a variable number of common shares, and (c) has a monetary value, at inception, that is based on variations in something other than the Company’s stock price, the obligation is classified as a liability under the classification guidance in Accounting Standards Codification (“ASC”) 480, Distinguishing Liabilities from Equity All options and warrants to acquire shares of Spirox stock were terminated in connection with the Spirox Acquisition and the holders thereof have been entitled to receive the merger consideration that would have been payable to such holders had they exercised their vested options and warrants in full immediately prior to the effective time of the Spirox Acquisition, less the applicable exercise price of such vested options and warrants. See Note C. Business Acquisition. Valuation adjustments to future contingent consideration due to the former equity holders of Spirox along with transaction and integration costs related to the Company’s 2017 acquisition of Spirox and 2016 acquisition of XeroGel are presented as “Acquisition-related expenses” on the condensed consolidated statements of operations. Following the Spirox Acquisition, Company management evaluated the combined operations in light of the guidance provided by ASC 280 Segment Reporting
Public Offering	Public Offering In February 2017, the Company completed a public offering of shares of its common stock, issuing a total of 2.9 million shares of common stock (including 0.5 million shares issued after exercise by the underwriters of their option to purchase additional shares) at an offering price of $17.00 per share. Certain existing stockholders of the Company also sold approximately 1.2 million shares of common stock in the offering. The Company received net proceeds of approximately $45.4 million, after deducting underwriting discounts and commissions of $2.9 million and offering expenses of $0.7 million payable by the Company. The Company did not receive any proceeds from the sale of shares by the selling stockholders.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. 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 expenses during the reported period. Actual results could differ from those estimates.
Valuation of Business Combinations	Valuation of Business Combinations The fair value of consideration, including contingent consideration, transferred in acquisitions accounted for as business combinations is first allocated to the identifiable tangible and intangible assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Any excess purchase consideration is allocated to goodwill. Further, for those arrangements that involve liability classified contingent consideration, the Company records a liability equal to the fair value of the estimated additional consideration we may be obligated to make in the future on the date of acquisition. Liability classified contingent consideration is adjusted to its fair value each reporting period through earnings. Acquisition transaction costs are expensed as incurred. The fair value of identifiable intangible assets requires management estimates and judgments based on market participant assumptions. Using alternative valuation assumptions, including estimated revenue projections, growth rates, cash flows, discount rates, estimated useful lives, and probabilities surrounding the achievement of milestones could result in different fair value estimates of our net tangible and intangible assets and related amortization expense in current and future periods. Contingent consideration is remeasured to fair value each reporting period using projected revenues, discount rates, and projected payment dates. Projected contingent payment amounts are discounted back to the current period using a discounted cash flow model. Increases or decreases in the fair value of the contingent consideration can result from changes in the timing and amount of revenue estimates as well as changes in discount periods and rates. Because the fair value of contingent consideration is based on management assumptions and not observable market inputs, it is considered a Level 3 measurement. Contingent consideration valuation adjustments are recorded as operating expenses or income in the period in which the change is determined. The Company’s accounting policy is to utilize deferred tax liabilities created through purchase accounting to first offset acquired deferred tax assets. The Company then utilizes any residual net deferred tax liability as a source of taxable income that can be used to support an equivalent amount of the Company’s existing deferred tax assets.
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2014-09, Revenue from Contracts with Customers Technical Corrections and Improvements to Topic 606 – Revenue from Contracts with Customers In March 2016, the FASB issued ASU 2016-08, Principal versus Agent Considerations – Reporting Revenue Gross versus Net . This ASU clarifies the revenue recognition implementation guidance for preparers on certain aspects of principal versus agent consideration. The amendments in this ASU are effective for private companies and emerging growth companies beginning after December 15, 2018. The Company has performed a review of the requirements of the new guidance and has identified which of its revenue streams will be within the scope of ASU 2014-09. The Company is working through an adoption plan which includes a review of customer contracts, applying the five-step model of the new standard to each revenue stream and comparing the results to its current accounting; an evaluation of the method of adoption; and assessing changes that might be necessary to information technology systems, processes, and internal controls to capture new data and address changes in financial reporting. Because of the nature of the work that remains, at this time the Company is unable to reasonably estimate the impact of adoption of ASU 2016-08 and ASU 2014-09 on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities The updated guidance in this ASU is effective for private companies and emerging growth companies beginning after December 15, 2018. In February 2016, the FASB issued ASU 2016-02, Leases In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses In August 2016, the FASB issued ASU 2016-15, Statements of Cash Flows – Classifications of Certain Cash Receipts and Cash Payments In January 2017, the FASB issued ASU 2017-01, Business Combinations – Clarifying the Definition of a Business , to clarify the definition of a business with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (or dispositions) of assets or businesses. This ASU is effective for private companies and emerging growth companies beginning after December 15, 2018; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-01 will have a significant impact on its consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment This ASU is effective for private companies and emerging growth companies beginning after December 15, 2020; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-04 will have a significant impact on its consolidated financial statements. In May 2017, the FASB issued ASU 2017-09, Scope of Modification Accounting entity will not apply modification accounting to a share-based payment award if the award’s fair value, vesting conditions and classification as an equity or liability instrument are the same immediately before and after the change This ASU is effective for private companies and emerging growth companies beginning after December 15, 2017; the ASU allows for early adoption. The Company does not believe that adoption of ASU 2017-09 will have a significant impact on its consolidated financial statements.
Fair Value Measurements	Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value maximize the use of observable inputs and minimize the use of unobservable inputs. Financial assets and liabilities carried at fair value are to be classified and disclosed in one of the following three categories: • Level 1: Quoted market prices in active markets for identical assets or liabilities. • Level 2: Includes other than Level 1 inputs 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 for which all significant inputs are observable or can be corroborated by observable market data for substantially the full term of the asset or liabilities. • Level 3: Unobservable inputs that are supported by little or no market activities, which would require the Company to develop its own assumptions.
Stock Based Compensation Expense	The Company estimates the fair value of stock-based compensation on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model determines the fair value of stock-based payment awards based on the fair market value of the Company’s common stock on the date of grant and is affected by assumptions regarding a number of highly complex and subjective variables. These variables include, but are not limited to, the fair market value of the Company’s common stock, volatility over the expected term of the awards and actual and projected employee stock option exercise behaviors. The Company has opted to use the “simplified method” for estimating the expected term of options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option. Due to the Company’s limited operating history and company-specific historical and implied volatility data, the Company has based its estimate of expected volatility on the blended historical volatility of a group of similar companies that are publicly traded and their historical volatility.

Business Acquisition (Tables)

Business Acquisition (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Summary of Purchase Price Assigned to Acquired Assets and Assumed Liabilities	As of the acquisition date, the purchase price assigned to the acquired assets and assumed liabilities is summarized as follows: (in thousands) Purchase Price Allocation Accounts and other receivables $ 1,440 Prepaid expenses and other current assets 925 Inventory 647 Property and equipment 1,257 Intangible assets 82,103 Other non-current assets 219 Total assets acquired 86,591 Accounts payable 1,297 Accrued expenses and other current liabilities 1,835 Deferred tax liabilities 14,884 Total liabilities assumed 18,016 Identifiable net assets acquired 68,575 Goodwill 62,295 Net assets acquired and purchase price consideration $ 130,870
Summary of Intangible Assets Acquired Excluding Goodwill	The following summarizes the intangible assets acquired, excluding goodwill. Intangible assets are amortized using methods that approximate the pattern of economic benefit provided by the utilization of the assets. Gross Carrying Value Amortization Term (in thousands) (in years) Developed technology $ 73,930 10.4 Trade names and trademarks 4,630 10.4 Customer relationships 3,500 12.0 Non-competition arrangements 43 3.0 Total $ 82,103
Summary of Valuation Adjustment of Contingent Consideration Liability	The Company recorded a $2.3 million valuation adjustment to the contingent consideration liability for the three and nine months ended September 30, 2017 due to the passage of time (i.e., accretion) as shown on the following Level 3 rollforward: (in thousands) Contingent Consideration Fair value on July 13, 2017 (acquisition date) 50,590 Valuation adjustment 2,329 Fair value on September 30, 2017 $ 52,919
Supplemental Pro Forma Information	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, 2016, nor are they indicative of any future results. Three Months Ended September 30, Nine Months Ended September 30, (in millions except per share data) 2017 2016 2017 2016 (Unaudited) (Unaudited) Revenue $ 23.7 $ 18.6 $ 69.8 $ 54.3 Net loss (3.9 ) (15.7 ) (33.4 ) (39.5 ) Net loss per share, basic and diluted $ (0.15 ) $ (0.71 ) $ (1.34 ) $ (1.78 )

Composition of Certain Financ22

Composition of Certain Financial Statement Items (Tables)	9 Months Ended
	Sep. 30, 2017
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Schedule of Inventories	Inventories September 30, December 31, (in thousands) 2017 2016 Finished goods $ 4,256 $ 3,562 Work-in-process 1,260 536 Raw materials 3,102 3,128 Total $ 8,618 $ 7,226
Schedule of Property and Equipment	Property and Equipment September 30, December 31, (in thousands) 2017 2016 Furniture and office equipment $ 992 $ 873 Computer hardware and software 3,717 2,831 Laboratory equipment 6,348 4,336 Tooling and molds 1,525 1,512 Leasehold improvements 2,488 2,006 $ 15,070 $ 11,558 Less accumulated depreciation (7,122 ) (5,465 ) Property and equipment in progress 369 394 Total $ 8,317 $ 6,487
Schedule of Accrued Expenses	Accrued Expenses September 30, December 31, (in thousands) 2017 2016 Compensation and commissions payable $ 8,214 $ 8,674 Royalty payable 1,795 1,851 Other accrued expenses 2,920 2,480 Total $ 12,929 $ 13,005

Short-Term Investments (Tables)

Short-Term Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments Debt And Equity Securities [Abstract]
Summary of Investments by Type of Instrument	The following is a summary of the available-for-sale investments by type of instrument, which are included in short-term investments in the consolidated balance sheet as of December 31, 2016. There were no available-for-sale investments as of September 30, 2017. Unrealized Unrealized Gain in Losses in Accumulated Accumulated Other Other Amortized Comprehensive Comprehensive Estimated December 31, 2016 (in thousands) Cost Income (Loss) Income Fair Value Commercial paper $ 2,495 $ 2 $ — $ 2,497 Corporate bonds 4,099 — (2 ) 4,097 Foreign assets 4,250 1 — 4,251 Total available-for-sale securities $ 10,844 $ 3 $ (2 ) $ 10,845

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Summary of Available-for-sale Investments at Fair Value on Recurring Basis	The following is a summary of available-for-sale investments by type of instrument measured at fair value on a recurring basis at December 31, 2016. There were no available-for-sale investments as of September 30, 2017. December 31, 2016 (in thousands) Level 1 Level 2 Level 3 Total Commercial paper $ — $ 2,497 $ — $ 2,497 Corporate bonds — 4,097 — 4,097 Foreign assets — 4,251 — 4,251 Total $ — $ 10,845 $ — $ 10,845
Summary of Liabilities Measured at Fair Value on a Recurring Basis	The following is a summary of liabilities measured at fair value on a recurring basis at September 30, 2017. There were no such liabilities as of December 31, 2016. September 30, 2017 (in thousands) Level 1 Level 2 Level 3 Total Contingent consideration $ — $ — $ 52,919 $ 52,919

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Change in Carrying Amount of Goodwill	The change in the carrying amount of goodwill is as follows: (in thousands) Carrying Value December 31, 2016 $ 477 Spirox Acquisition, at acquisition date 62,295 September 30, 2017 $ 62,772
Schedule of Other Intangible Assets	Other intangible assets are as follows: September 30, 2017 December 31, 2016 (in thousands) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Developed technology $ 83,630 $ (2,402 ) $ 9,700 $ (342 ) Trade name 5,130 (141 ) 500 (18 ) Customer relationships 3,500 (127 ) — — Noncompetition arrangements 43 (3 ) — — $ 92,303 $ (2,673 ) $ 10,200 $ (360 )
Schedule of Weighted Average Useful Lives of Each Class of Intangible Assets	The weighted average useful lives of each class of intangible assets are as follows: Useful Life (Years) Developed technology 10.9 Trade name 10.8 Customer relationships 12.0 Noncompetition arrangements 3.0
Schedule of Estimated Aggregate Amortization Expense of Definite-Lived Intangible Assets	Estimated aggregate amortization expense for the next five fiscal years based on the current carrying value of definite-lived intangible assets at September 30, 2017, is as follows: (in thousands) Remaining 2017 $ 2,216 2018 8,818 2019 8,728 2020 8,647 2021 8,577 2022 8,525

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Instrument [Line Items]
Summary of Key Terms of New Credit Facility	The key terms of the new credit facility are summarized in the table below: Origination date: March 31, 2017 Maturity date: March 1, 2022 Funding tranches: First term loan $13.5 million Second term loan (1) $10.0 million Third term loan (1) $16.5 million Revolving line of credit: (2) $10.0 million Outstanding as of September 30, 2017: Term loans $40.0 million Revolving line of credit $7.9 million Term loan interest rate: Floating per annum rate equal to the greater of (1) 7.95% and (2) the sum of (i) the greater of (A) the 30-day U.S. LIBOR rate reported in The Wall Street Journal plus Revolving line of credit interest rate: Floating per annum rate of interest is equal to the greater of (1) 4.95% and (2) the sum of (i) the greater of (A) 30-day U.S. LIBOR rate reported in The Wall Street Journal plus Final payment fee as a percentage of term loans outstanding: 4.95% Prepayment fees: 1.00% to 3.00% of the principal amount of such Term Loan prepaid, depending upon the timing of the prepayment. Other fees: Customary commitment fees and unused fees and certain other customary fees related to the Oxford’s administration of the credit facility. Security interest: A first priority security interest in substantially all of the Company’s assets, other than its intellectual property and, under certain circumstances more than 65% of its shares in any foreign subsidiary. The Company has agreed not to pledge or otherwise encumber its intellectual property assets, except for permitted liens, as such terms are defined in the Loan Agreement and except as otherwise provided for in the Loan Agreement. _____________________ (1) Became available and was borrowed to fund the July 13, 2017 Spirox Acquisition (2) Subject to a borrowing base requirement
Loan Agreement [Member]
Debt Instrument [Line Items]
Schedule of Principal Payments on Outstanding Term Loans	Assuming a 60-month amortization period as stated in the Loan Agreement Fiscal Year Principal Payments (in thousands) 2017 $ — 2018 — 2019 10,000 2020 13,333 2021 13,333 2022 3,334 Total $ 40,000

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of Stock Option Activity and Related Information	Stock Options A summary of the Company’s stock option activity and related information is as follows: September 30, 2017 Weighted Average Aggregate Weighted Remaining Intrinsic Options Average Contractual Value (in thousands) Exercise Price Term (in thousands) Outstanding, beginning of period 3,349 $ 13.06 7.6 years $ 21,863 Granted 1,479 15.30 — — Exercised (213 ) 5.68 — — Cancelled — - — — Forfeited (407 ) 16.68 — — Outstanding, end of period 4,208 $ 13.87 8.1 years $ 21,369 Exercisable, end of period 1,850 $ 11.92 7.0 years 13,279
Summary of Restricted Stock Units Activity	Restricted stock unit activity during the nine months ended September 30, 2017 is summarized below: September 30, 2017 Weighted Average RSUs Grant Date (in thousands) Fair Value Outstanding, beginning of period 12 $ 16.99 Granted 282 — Released (3 ) — Forfeited/expired (28 ) — Outstanding, end of period 263 $ 16.90
Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Stock Options and Restricted Stock Units (“RSUs”) Granted under Inducement Plan and 2015 Plan	The Compensation Committee of the Board of Directors granted the following stock options and restricted stock units (“RSUs”) under the Inducement Plan and the 2015 Plan in connection with the Spirox Acquisition: (shares in thousands) Employee Options Employee RSUs Director & Non-employee Options Director & Non-employee RSUs Inducement Plan 323 - - - 2015 Plan 93 90 23 11 Total 416 90 23 11

Stock Based Compensation Expe28

Stock Based Compensation Expense (Tables)	9 Months Ended
	Sep. 30, 2017
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Components and Classification of Stock-based Compensation Expense	The following table presents the components and classification of stock-based compensation expense for stock options, RSUs and employee stock purchase plan shares recognized for the three and nine months ended September 30, 2017 and 2016: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Cost of goods sold $ 70 $ 30 $ 143 $ 77 Selling and marketing 826 536 2,148 1,470 Research and development 375 149 839 413 General and administrative 900 821 2,762 2,100 Total $ 2,171 $ 1,536 $ 5,892 $ 4,060
Summary of Weighted Average Assumptions Used in Black-Scholes Model in Estimating Fair Value of Option Granted	The fair value of the options granted to employees or directors during the nine months ended September 30, 2017 and 2016 was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Nine Months Ended September 30, 2017 2016 Expected life in years 6.2 6.0 Risk-free interest rate 2.1 % 1.6 % Expected dividend yield 0 % 0 % Expected volatility 52 % 51 % Weighted average fair value $ 7.90 $ 7.93
Summary of Weighted Average Assumptions Used in Black-Scholes Model in Estimating Fair Value of ESPP Option Granted	The fair value of the ESPP options granted to employees during the nine months ended September 30, 2017 and 2016 was estimated as of the grant date using the Black-Scholes model assuming the weighted average assumptions listed in the following table: Nine Months Ended September 30, 2017 2016 Expected life in years 0.5 0.5 Risk-free interest rate 0.8 % 0.4 % Expected dividend yield 0 % 0 % Expected volatility 49 % 49 % Weighted average fair value $ 5.13 $ 5.30

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of Net Loss Per Share	The following table sets forth the computation of the Company’s net loss per share: Three Months Ended Nine Months Ended September 30, September 30, (in thousands) 2017 2016 2017 2016 Net loss $ (3,240 ) $ (9,519 ) $ (19,621 ) $ (21,412 ) Weighted average common stock outstanding 24,944 18,855 22,595 18,827 Net loss per share, basic and diluted $ (0.13 ) $ (0.50 ) $ (0.87 ) $ (1.14 )
Schedule of Antidilutive Securities Outstanding Excluded from Computation of Earnings Per Share	The following potentially dilutive securities outstanding have been excluded from the computations of diluted earnings per share because such securities have an antidilutive impact due to losses reported: September 30, (in thousands) 2017 2016 Common stock warrants 38 38 Common stock options 4,208 3,375 Restricted stock units 263 12 Common stock ESPP 167 20 Total 4,676 3,445

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) $ / shares in Units, shares in Millions	Jul. 13, 2017USD ($)shares	Feb. 28, 2017USD ($)$ / sharesshares	Mar. 31, 2017USD ($)$ / sharesshares	Sep. 30, 2017USD ($)Segment
Basis Of Presentation [Line Items]
Number of reportable segments | Segment				1
Proceeds from public offering, net of issuance costs				$ 45,361,000
Secondary Public Offering [Member]
Basis Of Presentation [Line Items]
Common stock, shares issued | shares		2.9	2.9
Common stock offering price per share | $ / shares		$ 17	$ 17
Proceeds from public offering, net of issuance costs		$ 45,400,000	$ 45,400,000
Underwriting discounts and commissions		2,900,000	2,900,000
Public offering expenses		$ 700,000	$ 700,000
Additional Share Purchase by Underwriters [Member]
Basis Of Presentation [Line Items]
Common stock, shares issued | shares		0.5	0.5
Sale by Certain Existing Shareholders [Member]
Basis Of Presentation [Line Items]
Common stock sold by certain existing stockholders | shares		1.2	1.2
Proceeds from sale of shares by existing selling stockholders		$ 0	$ 0
Spirox [Member]
Basis Of Presentation [Line Items]
Business acquisition, date of acquisition	Jul. 13, 2017
Merger agreement date	Jul. 6, 2017
Cash paid for acquisition	$ 24,800,000			$ 24,778,000
Business acquisition, common stock issued | shares	3.4
Lock-up agreement, description	The Company common stock issued in connection with the Spirox Acquisition is subject to a lock-up agreement for a period of (i) three months from the date of closing of the Spirox Acquisition in the case of 25% of the shares, (ii) six months from the date of closing of the Spirox Acquisition in the case of an additional 25% of the shares and (iii) 12 months in the case of the remaining shares.
Percentage of common stock issued under lock-up agreement	25.00%
Percentage of additional common stock issued under lock-up agreement	25.00%
Escrow deposit	$ 7,500,000
Business acquisition, combined fair value of common stock issued	80,300,000
Cumulative undiscounted payments	$ 80,000,000

Business Acquisition - Addition

Business Acquisition - Additional Information (Detail) - USD ($) $ / shares in Units, shares in Millions	Jul. 13, 2017	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 62,772,000	$ 62,772,000		$ 62,772,000		$ 477,000
Revenue attributable to acquisition			23,329,000	$ 17,880,000	64,575,000	$ 53,512,000
Net operating loss attributable to acquisition			(17,201,000)	(8,986,000)	(32,672,000)	(19,878,000)
Amortization expenses related to intangible assets acquired			1,957,000	109,000	2,313,000	111,000
Fair value adjustment to contingent consideration			2,300,000		2,329,000
Business combination, acquisition-related expenses			3,865,000		5,059,000	300,000
Spirox [Member]
Business Acquisition [Line Items]
Business acquisition, date of acquisition	Jul. 13, 2017
Business acquisition, consideration transferred	$ 130,900,000
Business acquisition preliminary purchase price	80,300,000
Cash paid for acquisition	$ 24,800,000				24,778,000
Business acquisition, common stock issued	3.4
Business acquisition, share price	$ 17.69
Business acquisition, per share price implied by lockup period	$ 16.27
Business acquisition, fair value of potential additional earn-out payments	$ 50,600,000
Identifiable net assets	68,575,000
Deferred tax liability	14,884,000
Goodwill	62,295,000
Goodwill recognized for income tax purposes	0
Deferred taxes recorded related to goodwill	0
Revenue attributable to acquisition			3,100,000		3,100,000
Net operating loss attributable to acquisition			(6,100,000)		(6,100,000)
Amortization expenses related to intangible assets acquired			1,700,000	2,000,000	6,000,000	6,100,000
Interest expense on debt			100,000	$ 700,000	1,400,000	$ 2,000,000
Adjustments for removal of transaction costs			11,400,000		12,600,000
Net severance and other compensation costs			1,300,000		2,000,000
Business combination, acquisition-related expenses			3,900,000		5,100,000
Spirox [Member] | Level 3 [Member]
Business Acquisition [Line Items]
Fair value adjustment to contingent consideration		$ 2,329,000	2,300,000		2,300,000
Spirox [Member] | Operating Loss [Member]
Business Acquisition [Line Items]
Amortization expenses related to intangible assets acquired			1,800,000		1,800,000
Business combination fair value adjustment of acquired inventory			$ 300,000		$ 300,000
Spirox [Member] | Assets and Liabilities Valuation [Member]
Business Acquisition [Line Items]
Identifiable net assets	$ 68,600,000

Business Acquisition - Summary

Business Acquisition - Summary of Purchase Price Assigned to Acquired Assets and Assumed Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Jul. 13, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill	$ 62,772		$ 477
Spirox [Member]
Business Acquisition [Line Items]
Accounts and other receivables		$ 1,440
Prepaid expenses and other current assets		925
Inventory		647
Property and equipment		1,257
Intangible assets		82,103
Other non-current assets		219
Total assets acquired		86,591
Accounts payable		1,297
Accrued expenses and other current liabilities		1,835
Deferred tax liabilities		14,884
Total liabilities assumed		18,016
Identifiable net assets acquired		68,575
Goodwill		62,295
Net assets acquired and purchase price consideration		$ 130,870

Business Acquisition - Summar33

Business Acquisition - Summary of Intangible Assets Acquired Excluding Goodwill (Detail) - Spirox [Member] $ in Thousands	Jul. 13, 2017USD ($)
Business Acquisition [Line Items]
Gross Carrying Value	$ 82,103
Developed Technology [Member]
Business Acquisition [Line Items]
Gross Carrying Value	$ 73,930
Amortization Term	10 years 4 months 25 days
Trade Names and Trademarks [Member]
Business Acquisition [Line Items]
Gross Carrying Value	$ 4,630
Amortization Term	10 years 4 months 25 days
Customer Relationships [Member]
Business Acquisition [Line Items]
Gross Carrying Value	$ 3,500
Amortization Term	12 years
Non-competition Agreement [Member]
Business Acquisition [Line Items]
Gross Carrying Value	$ 43
Amortization Term	3 years

Business Acquisition - Summar34

Business Acquisition - Summary of Valuation Adjustment of Contingent Consideration Liability (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2017
Business Acquisition [Line Items]
Fair value on July 13, 2017 (acquisition date)			$ 0
Valuation adjustment		$ 2,300,000	2,329,000
Spirox [Member] | Level 3 [Member]
Business Acquisition [Line Items]
Fair value on July 13, 2017 (acquisition date)	$ 50,590,000
Valuation adjustment	2,329,000	2,300,000	2,300,000
Fair value on September 30, 2017	$ 52,919,000	$ 52,919,000	$ 52,919,000

Business Acquisition - Suppleme

Business Acquisition - Supplemental Pro Forma Information (Detail) - Spirox [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Business Acquisition [Line Items]
Revenue	$ 23.7	$ 18.6	$ 69.8	$ 54.3
Net loss	$ (3.9)	$ (15.7)	$ (33.4)	$ (39.5)
Net loss per share, basic and diluted	$ (0.15)	$ (0.71)	$ (1.34)	$ (1.78)

Composition of Certain Financ36

Composition of Certain Financial Statement Items - Schedule of Inventories (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Finished goods	$ 4,256	$ 3,562
Work-in-process	1,260	536
Raw materials	3,102	3,128
Total	$ 8,618	$ 7,226

Composition of Certain Financ37

Composition of Certain Financial Statement Items - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	$ 15,070	$ 11,558
Less accumulated depreciation	(7,122)	(5,465)
Property and equipment in progress	369	394
Total	8,317	6,487
Furniture and Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	992	873
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	3,717	2,831
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	6,348	4,336
Tooling and Molds [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	1,525	1,512
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property plant and equipment, Gross	$ 2,488	$ 2,006

Composition of Certain Financ38

Composition of Certain Financial Statement Items - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Property Plant And Equipment [Abstract]
Depreciation expense on property and equipment	$ 800	$ 500	$ 1,800	$ 1,201

Composition of Certain Financ39

Composition of Certain Financial Statement Items - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Payables And Accruals [Abstract]
Compensation and commissions payable	$ 8,214	$ 8,674
Royalty payable	1,795	1,851
Other accrued expenses	2,920	2,480
Total	$ 12,929	$ 13,005

Liquidity and Business Risks -

Liquidity and Business Risks - Additional Information (Detail) $ / shares in Units, shares in Millions	Mar. 31, 2017USD ($)Tranches$ / shares	Feb. 28, 2017USD ($)$ / sharesshares	Mar. 31, 2017USD ($)$ / sharesshares	Sep. 30, 2017USD ($)	Jul. 13, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Dec. 31, 2015USD ($)
Subsidiary, Sale of Stock [Line Items]
Cash and cash equivalents				$ 51,452,000		$ 21,417,000	$ 15,236,000	$ 28,548,000
Accumulated deficit				(170,409,000)		$ (150,788,000)
Proceeds from issuance of common stock, net of issuance costs				45,361,000
Line of credit facility, repayment of amount outstanding	$ 20,000,000			40,202,000
Term Loans [Member] | Spirox [Member]
Subsidiary, Sale of Stock [Line Items]
Amount borrowed under facility					$ 26,500,000
Revolving Line of Credit [Member] | Spirox [Member]
Subsidiary, Sale of Stock [Line Items]
Line of credit facility, amount outstanding				7,900,000
Revolving Line of Credit [Member] | Maximum [Member] | Spirox [Member]
Subsidiary, Sale of Stock [Line Items]
Line of credit facility, additional borrowing capacity on meeting future requirement				2,100,000
New Credit Facility [Member] | Term Loans [Member]
Subsidiary, Sale of Stock [Line Items]
Number of tranches | Tranches	3
New Credit Facility [Member] | Term Loans [Member] | Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Amount borrowed under facility	$ 40,000,000		$ 40,000,000
New Credit Facility [Member] | First Term Loan [Member]
Subsidiary, Sale of Stock [Line Items]
Amount borrowed under facility	13,500,000		13,500,000
New Credit Facility [Member] | Revolving Line of Credit [Member]
Subsidiary, Sale of Stock [Line Items]
Line of credit facility, maximum borrowing capacity	10,000,000		10,000,000
Line of credit facility, amount outstanding	8,000,000		8,000,000	$ 7,900,000
New Credit Facility [Member] | Revolving Line of Credit [Member] | Maximum [Member]
Subsidiary, Sale of Stock [Line Items]
Line of credit facility, maximum borrowing capacity	$ 10,000,000		$ 10,000,000
Secondary Public Offering [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued | shares		2.9	2.9
Common stock offering price per share | $ / shares	$ 17	$ 17	$ 17
Proceeds from issuance of common stock, net of issuance costs		$ 45,400,000	$ 45,400,000
Underwriting discounts and commissions		2,900,000	2,900,000
Public offering expenses		$ 700,000	$ 700,000
Additional Share Purchase by Underwriters [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock, shares issued | shares		0.5	0.5
Sale by Certain Existing Shareholders [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock sold by certain existing stockholders | shares		1.2	1.2
Proceeds from sale of shares by existing selling stockholders		$ 0	$ 0

Short-term Investments - Additi

Short-term Investments - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Investments Debt And Equity Securities [Abstract]
Available-for-sale investments	$ 0	$ 10,845,000
Other-than-temporary impairment charges	$ 0

Short-term Investments - Summar

Short-term Investments - Summary of Investments by Type of Instrument (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		$ 10,844,000
Unrealized Gain in Accumulated Other Comprehensive Income (Loss)		3,000
Unrealized Losses in Accumulated Other Comprehensive Income (Loss)		(2,000)
Estimated Fair Value	$ 0	10,845,000
Short-term Investments [Member] | Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		2,495,000
Unrealized Gain in Accumulated Other Comprehensive Income (Loss)		2,000
Estimated Fair Value		2,497,000
Short-term Investments [Member] | Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		4,099,000
Unrealized Losses in Accumulated Other Comprehensive Income (Loss)		(2,000)
Estimated Fair Value		4,097,000
Short-term Investments [Member] | Foreign Assets [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost		4,250,000
Unrealized Gain in Accumulated Other Comprehensive Income (Loss)		1,000
Estimated Fair Value		$ 4,251,000

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Fair Value Disclosures [Abstract]
Short-term investments	$ 0	$ 0	$ 10,845,000
Contingent purchase price liability			$ 0
Risk-adjusted discount rate		12.00%
Volatility factor		35.00%
Valuation discount rate		8.00%
Fair value adjustment to contingent consideration	2,300,000	$ 2,329,000
Transfer of assets between level 1, level 2 or level 3	$ 0	$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Available-for-sale Investments at Fair Value on Recurring Basis (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments	$ 0	$ 10,845,000
Fair Value, Measurements, Recurring [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		10,845,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		10,845,000
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		2,497,000
Fair Value, Measurements, Recurring [Member] | Commercial Paper [Member] | Level 2 [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		2,497,000
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		4,097,000
Fair Value, Measurements, Recurring [Member] | Corporate Bonds [Member] | Level 2 [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		4,097,000
Fair Value, Measurements, Recurring [Member] | Foreign Assets [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		4,251,000
Fair Value, Measurements, Recurring [Member] | Foreign Assets [Member] | Level 2 [Member]
Schedule Of Available For Sale Securities [Line Items]
Available-for-sale investments		$ 4,251,000

Fair Value Measurements - Sum45

Fair Value Measurements - Summary of Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration		$ 0
Fair Value, Measurements, Recurring [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration	$ 52,919,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration	$ 52,919,000

Goodwill and Intangible Asset46

Goodwill and Intangible Assets - Schedule of Change in Carrying Amount of Goodwill (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2017USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Beginning balance	$ 477
Spirox Acquisition, at acquisition date	62,295
Ending balance	$ 62,772

Goodwill and Intangible Asset47

Goodwill and Intangible Assets - Schedule of Other Intangible Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 92,303	$ 10,200
Accumulated Amortization	(2,673)	(360)
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	83,630	9,700
Accumulated Amortization	(2,402)	(342)
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	5,130	500
Accumulated Amortization	(141)	$ (18)
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	3,500
Accumulated Amortization	(127)
Noncompetition Arrangements [Member]
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	43
Accumulated Amortization	$ (3)

Goodwill and Intangible Asset48

Goodwill and Intangible Assets - Schedule of Weighted Average Useful Lives of Each Class of Intangible Assets (Detail)	9 Months Ended
	Sep. 30, 2017
Developed Technology [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life (Years)	10 years 10 months 25 days
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life (Years)	10 years 9 months 19 days
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life (Years)	12 years
Noncompetition Arrangements [Member]
Finite Lived Intangible Assets [Line Items]
Intangible assets, Useful Life (Years)	3 years

Goodwill and Intangible Asset49

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Goodwill And Intangible Assets Disclosure [Abstract]
Amortization expenses related to intangible assets acquired	$ 1,957	$ 109	$ 2,313	$ 111

Goodwill and Intangible Asset50

Goodwill and Intangible Assets - Schedule of Estimated Aggregate Amortization Expense of Definite-Lived Intangible Assets (Detail) $ in Thousands	Sep. 30, 2017USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
Remaining 2,017	$ 2,216
2,018	8,818
2,019	8,728
2,020	8,647
2,021	8,577
2,022	$ 8,525

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2013
Debt Instrument [Line Items]
Description of deferred principal payment due		In February 2017, the Company entered into an amendment to the amended and restated loan and security agreement to allow principal payments due on February 1, 2017 and March 1, 2017 to be deferred until March 15, 2017. In March 2017, the principal payments were deferred again during renegotiations with Oxford.
Amended and Restated Credit Facility [Member]
Debt Instrument [Line Items]
Amount borrowed under facility			$ 20
Fixed interest floor rate			9.40%
Maturity date of debt instrument		Dec. 1, 2018
New Credit Facility [Member]
Debt Instrument [Line Items]
Maturity date of debt instrument		Mar. 1, 2022
Long term debt, repayment of amount outstanding	$ 20
Payment fee	1.2
New Credit Facility [Member] | First Term Loan [Member]
Debt Instrument [Line Items]
Amount borrowed under facility	13.5
New Credit Facility [Member] | Revolving Line of Credit [Member]
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 8	$ 7.9

Debt - Summary of Key Terms of

Debt - Summary of Key Terms of New Credit Facility (Details) - New Credit Facility [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Mar. 31, 2017
Line Of Credit Facility [Line Items]
Origination date:	Mar. 31, 2017
Maturity date:	Mar. 1, 2022
Prepayment fees:	1.00% to 3.00% of the principal amount of such Term Loan prepaid, depending upon the timing of the prepayment.
Other fees:	Customary commitment fees and unused fees and certain other customary fees related to the Oxford’s administration of the credit facility.
Security interest:	A first priority security interest in substantially all of the Company’s assets, other than its intellectual property and, under certain circumstances more than 65% of its shares in any foreign subsidiary. The Company has agreed not to pledge or otherwise encumber its intellectual property assets, except for permitted liens, as such terms are defined in the Loan Agreement and except as otherwise provided for in the Loan Agreement.
First Term Loan [Member]
Line Of Credit Facility [Line Items]
Amount borrowed under facility		$ 13.5
Second Term Loan [Member]
Line Of Credit Facility [Line Items]
Amount borrowed under facility		10
Third Term Loan [Member]
Line Of Credit Facility [Line Items]
Amount borrowed under facility		16.5
Revolving Line of Credit [Member]
Line Of Credit Facility [Line Items]
Revolving line of credit:		10
Revolving line of credit	$ 7.9	$ 8
Debt instrument, description of floating rate terms	Floating per annum rate of interest is equal to the greater of (1) 4.95% and (2) the sum of (i) the greater of (A) 30-day U.S. LIBOR rate reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue and (B) 0.77%, plus (ii) 4.18%. The per annum rate was 5.39% as of September 30, 2017.
Term Loans [Member]
Line Of Credit Facility [Line Items]
Amount borrowed under facility	$ 40
Debt instrument, description of floating rate terms	Floating per annum rate equal to the greater of (1) 7.95% and (2) the sum of (i) the greater of (A) the 30-day U.S. LIBOR rate reported in The Wall Street Journal on the last business day of the month that immediately precedes the month in which the interest will accrue and (B) 0.77%, plus (ii) 7.18%. The per annum rate was 8.39% as of September 30, 2017.
Final payment fee as a percentage of term loans outstanding:	4.95%

Debt - Summary of Key Terms o53

Debt - Summary of Key Terms of New Credit Facility (Parenthetical) (Details) - New Credit Facility [Member]	1 Months Ended	9 Months Ended
	Mar. 31, 2017	Sep. 30, 2017
Minimum [Member]
Line Of Credit Facility [Line Items]
Credit facility secured by shares in foreign subsidiary	65.00%
Term Loans [Member]
Line Of Credit Facility [Line Items]
Debt instrument, interest rate		8.39%
Debt Instrument Description Of Variable Rate Basis		30-day U.S. LIBOR
Term Loans [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, interest rate	7.95%
Term Loans [Member] | LIBOR Rate Added to Base Rate [Member]
Line Of Credit Facility [Line Items]
Debt instrument, basis interest rate	7.18%
Term Loans [Member] | LIBOR Rate Added to Base Rate [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, incremental rate	0.77%
Revolving Line of Credit [Member]
Line Of Credit Facility [Line Items]
Debt instrument, interest rate		5.39%
Debt Instrument Description Of Variable Rate Basis		30-day U.S. LIBOR
Revolving Line of Credit [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, interest rate	4.95%
Revolving Line of Credit [Member] | LIBOR Rate Added to Base Rate [Member]
Line Of Credit Facility [Line Items]
Debt instrument, basis interest rate	4.18%
Revolving Line of Credit [Member] | LIBOR Rate Added to Base Rate [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Debt instrument, incremental rate	0.77%
Prior to First Anniversary [Member] | Minimum [Member]
Line Of Credit Facility [Line Items]
Credit facility prepayment fee	1.00%
Prior to First Anniversary [Member] | Maximum [Member]
Line Of Credit Facility [Line Items]
Credit facility prepayment fee	3.00%

Debt - Schedule of Principal Pa

Debt - Schedule of Principal Payments on Outstanding Term Loans (Detail) - Loan Agreement [Member] $ in Thousands	Sep. 30, 2017USD ($)
Debt Instrument [Line Items]
2,019	$ 10,000
2,020	13,333
2,021	13,333
2,022	3,334
Total	$ 40,000

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Millions	Aug. 04, 2017	Jul. 13, 2017	Jan. 31, 2015	Mar. 31, 2017	Mar. 31, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized						200,000,000		200,000,000
Common stock, shares outstanding						25,448,000		18,908,000
Aggregate pre-tax intrinsic value of options exercised						$ 2.4	$ 0.8
Fair value of options vested						5.7	3.4
Total cash received upon the exercise of options						$ 1.2	$ 0.1
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			200,000	232,976
Annual increase in shares available for grant				16,488	16,488
Increase in share reserve as percentage of shares of Common Stock outstanding on plan adoption date						1.00%
First offering date						Jan. 1, 2016
Maximum number of shares eligible to purchases by employee under employee stock purchase plan						2,000
Maximum percentage of compensation employees can have withheld						20.00%
Purchase price as a percentage of market price						85.00%
Employee Stock Purchase Plan, Plan Description						Under the ESPP, the Company has set two six-month offering periods during each calendar year, one beginning January 1 and ending on June 30, and the other beginning July 1 and ending on December 31, during which employees can choose to have up to 20% of their eligible compensation withheld to purchase less than 2,000 shares of the Company’s common stock during each offering period. The purchase price of the shares is 85% of the market price on the first or last trading day of the offering period, whichever is lower.
Common stock available for issuance						166,523
2015 Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance			1,345,570
Annual maximum increase in shares available for grant			875,000
Annual increase in shares available for grant				756,339	751,750
Annual percentage increase in shares available for grant			4.00%
Common stock available for issuance						320,865
Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in acquisition		3,400,000
Spirox [Member] | 2017 Employment Inducement Incentive Award Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance						450,000
Common Stock [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in acquisition		3,400,000
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term						4 years
Restricted Stock Units [Member] | Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term						3 years
Employee Stock Options and RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options and RSUs effective date	Aug. 4, 2017
Employee Stock Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted, expiration term	10 years
Description of vesting term						will vest as to one-fourth of the underlying shares on the one-year anniversary of the Spirox Acquisition closing date, and monthly thereafter over the subsequent three years, subject to the recipient’s continued service
Vesting remaining term	3 years
Employee Stock Options [Member] | Spirox [Member] | One-Year Anniversary of the Closing Date [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of underlying shares	25.00%
Employee Stock RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting term	4 years
Director Stock Options and RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options and RSUs effective date		Jul. 14, 2017
Stock options granted, expiration term		10 years
Vesting term		3 years
Non-Employee Stock Options and RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options and RSUs effective date	Aug. 4, 2017
Stock options granted, expiration term	10 years
Vesting term	3 years

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Stock Options and Restricted Stock Units ("RSUs") Granted under Inducement Plan and 2015 Plan (Detail) - shares shares in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted		1,479
Employee Stock Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	416
Director & Non-Employee Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	23
Employee RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted	90
Director & Non-Employee RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted	11
Inducement Plan [Member] | Employee Stock Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	323
2015 Plan [Member] | Employee Stock Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	93
2015 Plan [Member] | Director & Non-Employee Options [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted	23
2015 Plan [Member] | Employee RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted	90
2015 Plan [Member] | Director & Non-Employee RSUs [Member] | Spirox [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted	11

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity and Related Information (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, Beginning balance | shares	3,349
Options Granted | shares	1,479
Options Exercised | shares	(213)
Options Forfeited | shares	(407)
Options outstanding, Ending balance | shares	4,208	3,349
Options Exercisable, end of period | shares	1,850
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract]
Weighted Average Exercise Price, Beginning balance | $ / shares	$ 13.06
Weighted Average Exercise Price, Granted | $ / shares	15.30
Weighted Average Exercise Price, Exercised | $ / shares	5.68
Weighted Average Exercise Price, Forfeited | $ / shares	16.68
Weighted Average Exercise Price, Ending balance | $ / shares	13.87	$ 13.06
Weighted Average Exercise Price, Exercisable end of period | $ / shares	$ 11.92
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted Average Remaining Contractual Term	8 years 1 month 7 days	7 years 7 months 7 days
Weighted Average Remaining Contractual Term, Exercisable	7 years
Aggregate Intrinsic Value | $	$ 21,369	$ 21,863
Aggregate Intrinsic Value Exercisable | $	$ 13,279

Stockholders' Equity - Summar58

Stockholders' Equity - Summary of Restricted Stock Units Activity (Detail) - Restricted Stock Units [Member] - 2015 Incentive Award Plan [Member] shares in Thousands	9 Months Ended
	Sep. 30, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
RSUs outstanding, beginning of period	12
RSUs Granted	282
RSUs Released	(3)
RSUs Forfeited/expired	(28)
RSUs outstanding, end of period	263
Share-based Compensation Arrangement by Share-based Payment Award, Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Weighted Average Grant Date Fair Value, Outstanding, beginning of period | $ / shares	$ 16.99
Weighted Average Grant Date Fair Value, Outstanding, end of period | $ / shares	$ 16.90

Stock Based Compensation Expe59

Stock Based Compensation Expense - Summary of Components and Classification of Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 2,171	$ 1,536	$ 5,892	$ 4,060
Cost of Goods Sold [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	70	30	143	77
Selling and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	826	536	2,148	1,470
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	375	149	839	413
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Stock-based compensation expense	$ 900	$ 821	$ 2,762	$ 2,100

Stock Based Compensation Expe60

Stock Based Compensation Expense - Additional Information (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested stock options awards	$ 17.8
Unvested Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Remaining weighted-average vesting period for unrecognized stock-based compensation expense	2 years 9 months 19 days
RSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested other than stock options awards	$ 3.8
Remaining weighted-average vesting period for unrecognized stock-based compensation expense	3 years 3 months 19 days

Stock Based Compensation Expe61

Stock Based Compensation Expense - Summary of Weighted Average Assumptions Used in Black-Scholes Model in Estimating Fair Value of Option Granted (Detail) - $ / shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	6 months	6 months
Risk-free interest rate	0.80%	0.40%
Expected dividend yield	0.00%	0.00%
Expected volatility	49.00%	49.00%
Weighted average fair value	$ 5.13	$ 5.30
Employee Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	6 years 2 months 13 days	6 years
Risk-free interest rate	2.10%	1.60%
Expected dividend yield	0.00%	0.00%
Expected volatility	52.00%	51.00%
Weighted average fair value	$ 7.90	$ 7.93

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Taxes [Line Items]
One-time income tax benefit	$ 14,882	$ (34)	$ 14,876	$ (34)
Spirox [Member]
Income Taxes [Line Items]
Deferred tax liabilities	$ 14,900		$ 14,900

Earnings Per Share - Schedule o

Earnings Per Share - Schedule of Net Loss Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net loss	$ (3,240)	$ (9,519)	$ (19,621)	$ (21,412)
Weighted average common stock outstanding	24,944	18,855	22,595	18,827
Net loss per share, basic and diluted	$ (0.13)	$ (0.50)	$ (0.87)	$ (1.14)

Earnings Per Share - Schedule64

Earnings Per Share - Schedule of Antidilutive Securities Outstanding Excluded from Computation of Earnings Per Share (Detail) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	4,676	3,445
Common Stock Warrants [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	38	38
Common Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	4,208	3,375
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	263	12
Common Stock ESPP [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive potential common shares excluded from computation of diluted earning per share	167	20

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) $ in Millions	Feb. 26, 2015	Jun. 30, 2014	Feb. 29, 2012	Sep. 30, 2017USD ($)Facilities	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Facilities	Sep. 30, 2016USD ($)
Operating Leased Assets [Line Items]
Number of leased facilities under operating lease agreement | Facilities				3		3
Operating leased facility, period		50 months	41 months
Operating leased facility, effective date		Jul. 1, 2014	Apr. 1, 2012
Operating leased facility, additional period	3 years
Operating leased facility, amendment description						On June 30, 2015, the Company entered into amendments to each of these two lease agreements, among other things, to expand the space occupied by the Company at the property at which the Company’s corporate headquarters are located, and to extend the term of each lease agreement through June 2021, with an option to extend for an additional term through June 2024.
Total lease expense | $				$ 0.2	$ 0.2	$ 0.7	$ 0.5
Spirox [Member]
Operating Leased Assets [Line Items]
Leased facility expire date						2021-10