Aerie Pharmaceuticals (AERI) 10-Q 7 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Oct. 31, 2018
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Trading Symbol	AERI
Entity Registrant Name	AERIE PHARMACEUTICALS INC
Entity CIK	1,337,553
Current Fiscal Year End Date	--12-31
Emerging Growth Company	false
Smaller Reporting Company	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		45,453,615

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 234,954	$ 197,569
Short-term investments	1,000	52,086
Accounts receivable, net	1,961	0
Inventory	5,612	0
Prepaid expenses and other current assets	3,290	4,487
Total current assets	246,817	254,142
Property, plant and equipment, net	58,360	31,932
Other assets	4,017	4,202
Total assets	309,194	290,276
Current liabilities
Accounts payable	7,066	6,245
Accrued expenses and other current liabilities	27,948	18,939
Total current liabilities	35,014	25,184
Convertible notes, net	0	123,845
Other non-current liabilities	5,598	5,648
Total liabilities	40,612	154,677
Commitments and contingencies (Note 12)
Stockholders’ equity
Preferred stock, $0.001 par value; 15,000,000 shares authorized as of September 30, 2018 and December 31, 2017; None issued and outstanding	0	0
Common stock, $0.001 par value; 150,000,000 shares authorized as of September 30, 2018 and December 31, 2017; 45,451,227 and 36,947,637 shares issued and outstanding as of September 30, 2018 and December 31, 2017, respectively	45	37
Additional paid-in capital	913,499	597,318
Accumulated other comprehensive loss	(1)	(28)
Accumulated deficit	(644,961)	(461,728)
Total stockholders’ equity	268,582	135,599
Total liabilities and stockholders’ equity	$ 309,194	$ 290,276

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	15,000,000	15,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	45,451,227	36,947,637
Common stock, shares outstanding (in shares)	45,451,227	36,947,637

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues	$ 7,302	$ 0	$ 9,725	$ 0
Costs and expenses:
Cost of goods sold	205	0	264	0
Selling, general and administrative	39,933	19,774	107,647	51,402
Research and development	28,502	12,408	59,631	33,977
Total costs and expenses	68,640	32,182	167,542	85,379
Loss from operations	(61,338)	(32,182)	(157,817)	(85,379)
Other income (expense), net	(24,050)	(141)	(23,291)	(1,071)
Loss before income taxes	(85,388)	(32,323)	(181,108)	(86,450)
Income tax expense	0	49	3	142
Net loss	$ (85,388)	$ (32,372)	$ (181,111)	$ (86,592)
Net loss per common share—basic and diluted (in dollars per share)	$ (1.96)	$ (0.89)	$ (4.47)	$ (2.48)
Weighted average number of common shares outstanding—basic and diluted (in shares)	43,657,423	36,210,329	40,505,534	34,932,551
Net loss	$ (85,388)	$ (32,372)	$ (181,111)	$ (86,592)
Unrealized gain (loss) on available-for-sale investments	8	(17)	27	(30)
Comprehensive loss	(85,380)	(32,389)	(181,084)	(86,622)
Product revenues, net
Revenues	$ 7,302	$ 0	$ 9,725	$ 0

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (181,111,000)	$ (86,592,000)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	1,730,000	916,000
Amortization of debt issuance costs and fees	779,000	230,000
Amortization and accretion of premium or discount on investments, net	54,000	52,000
Stock-based compensation	29,015,000	18,072,000
Induced conversion of convertible notes	24,059,000	0
Unrealized foreign exchange (gain) loss	(207,000)	522,000
Changes in operating assets and liabilities
Accounts receivable, net	(1,961,000)	0
Inventory	(5,299,000)	0
Prepaid, current and other assets	955,000	1,718,000
Accounts payable, accrued expenses and other current liabilities	10,924,000	(1,981,000)
Net cash used in operating activities	(121,062,000)	(67,063,000)
Cash flows from investing activities
Purchase of available-for-sale investments	(56,195,000)	(101,217,000)
Proceeds from sales and maturities of investments	107,297,000	48,696,000
Purchase of property, plant and equipment	(29,404,000)	(7,073,000)
Net cash provided by (used in) investing activities	21,698,000	(59,594,000)
Cash flows from financing activities
Proceeds from sale of common stock, net	135,972,000	122,046,000
Proceeds related to issuance of stock for stock-based compensation arrangements, net	2,933,000	744,000
Payment of debt issuance costs	(1,621,000)	0
Other financing	(535,000)	0
Net cash provided by financing activities	136,749,000	122,790,000
Net change in cash and cash equivalents	37,385,000	(3,867,000)
Cash and cash equivalents, at beginning of period	197,569,000	197,945,000
Cash and cash equivalents, at end of period	234,954,000	194,078,000
Non-cash financing activities
Conversion of convertible notes to common stock	$ 148,078,000	$ 0

The Company

The Company	9 Months Ended
	Sep. 30, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	The Company Aerie Pharmaceuticals, Inc. (“Aerie”), with its wholly-owned subsidiaries, Aerie Distribution, Inc., Aerie Pharmaceuticals Limited and Aerie Pharmaceuticals Ireland Limited (“Aerie Distribution,” “Aerie Limited” and “Aerie Ireland Limited,” respectively, together with Aerie, the “Company”), is an ophthalmic pharmaceutical company focused on the discovery, development and commercialization of first-in-class therapies for the treatment of patients with open-angle glaucoma, retina diseases and other diseases of the eye. The Company has its principal executive offices in Durham, North Carolina, and operates as one business segment. The Company has a U.S. Food and Drug Administration (“FDA”) approved product, Rhopressa ® (netarsudil ophthalmic solution) 0.02% (“Rhopressa ® ”), and an advanced-stage product candidate, Rocklatan TM (netarsudil/latanoprost ophthalmic solution) 0.02% / 0.005% (“Rocklatan TM ”), previously referred to as Roclatan TM , both designed to reduce elevated intraocular pressure (“IOP”) in patients with open-angle glaucoma or ocular hypertension. The Company is commercializing Rhopressa ® and intends to commercialize Rocklatan TM , if approved, on its own in North American markets. The Company’s strategy also includes pursuing regulatory approval for Rhopressa ® (named Rhokiinsa ® in Europe) and Rocklatan TM in Europe and Japan on its own, though the products may be named differently in those respective regions. Rhopressa ® is a once-daily eye drop designed to reduce elevated IOP in patients with open-angle glaucoma or ocular hypertension that received FDA approval on December 18, 2017. The Company launched Rhopressa ® in the United States at the end of April 2018. On October 9, 2018, the Company announced that the European Medicines Agency (“EMA”) accepted for review the marketing authorisation application (“MAA”) for Rhopressa ® , which will be marketed under the name Rhokiinsa ® in Europe, if approved. Additionally, the Company completed a Phase 1 clinical trial and commenced a Phase 2 clinical trial in the United States, which were designed to support meeting the requirements of Japan’s Pharmaceuticals and Medical Devices Agency for potential regulatory submission of Rhopressa ® in Japan. These clinical trials have included Japanese and Japanese-American subjects. The Company is also planning to initiate an additional Phase 2 clinical trial on Japanese patients in Japan to support subsequent Phase 3 registration trials that are expected to be conducted in Japan. The Company’s advanced-stage product candidate, Rocklatan TM , is a once-daily fixed-dose combination of Rhopressa ® and latanoprost. The Company submitted a New Drug Application (“NDA”) to the FDA in May 2018 under Section 505(b)(2) of the Federal Food, Drug and Cosmetic Act, which provides for an abbreviated approval pathway, since Rocklatan TM is a fixed dose combination of two FDA-approved drugs in the United States. In July 2018, the Company announced that the NDA was accepted for review by the FDA and the Prescription Drug User Fee Act goal date was set for March 14, 2019, which represents a ten-month review. In Europe, the Company is currently conducting a Phase 3 trial, named Mercury 3, comparing Rocklatan TM to Ganfort ® , a fixed-dose combination product of bimatoprost (a prostaglandin analog) and timolol marketed in Europe, which if successful, is expected to improve its commercialization prospects in that region. Mercury 3 is not necessary for approval in the United States. The Company plans to submit an MAA for Rocklatan TM in Europe in the second half of 2019, if Rhokiinsa ® is approved by the EMA. On July 31, 2017, the Company entered into a collaborative research, development and licensing agreement with DSM, a global science-based company headquartered in the Netherlands. The research collaboration agreement includes an option to license DSM’s bio-erodible polymer implant technology for sustained delivery of certain Aerie compounds to treat ophthalmic diseases. This technology uses polyesteramide polymers to produce an injectable, thin fiber that is minute in size. Preclinical experiments have demonstrated early success in conjunction with Aerie’s preclinical molecule, AR-13503, including demonstration of linear, sustained elution rates over several months and achievement of target retinal drug concentrations. On August 1, 2018, the Company entered into an Amended and Restated Collaborative Research, Development, and License Agreement with DSM (the “Collaboration Agreement”), which provides for (i) a worldwide exclusive license for all ophthalmic indications to DSM’s polyesteramide polymer technology, (ii) continuation of the collaborative research initiatives through the end of 2020, including the transfer of DSM’s formulation technology to Aerie during that time and (iii) access to a preclinical latanoprost implant. Aerie paid $6.0 million to DSM upon execution of the Collaboration Agreement, with an additional $9.0 million payable to DSM through the end of 2020. As a result, $7.4 million related to our expanded collaboration agreement with DSM was expensed to research and development expense for the three months ended September 30, 2018 , which included the upfront payment of $6.0 million . The Collaboration Agreement also includes contingent payments that may be due to DSM upon the achievement of certain development and regulatory milestones. Aerie would also pay royalties to DSM when products are commercialized under this Collaboration Agreement, if any. On October 4, 2017, the Company entered into an Asset Purchase Agreement (the “Agreement”) with Envisia Therapeutics Inc. (“Envisia”) to acquire the rights to use PRINT ® (Particle Replication in Non-wetting Templates) technology in ophthalmology, as well as rights relating to Envisia’s preclinical dexamethasone steroid implant for the potential treatment of diabetic macular edema that utilizes the PRINT ® technology, referred to as AR-1105. The PRINT ® technology is a proprietary system capable of creating precisely-engineered sustained-release products utilizing fully-scalable manufacturing processes. The Company will also focus on using PRINT ® to manufacture injectable implants containing AR-13503, potentially in conjunction with the bio-erodible polymer from DSM. The Company is also evaluating this technology platform for sustained release of therapies to the front of the eye, including to treat glaucoma or ocular hypertension, as examples. The Company commenced operation of its good manufacturing practices-validated manufacturing facility for production of ophthalmic implants using PRINT ® technology in its Durham, North Carolina, facility in October 2018. Prior to 2018, the Company had not generated any revenue. Aerie commenced generating product revenues related to sales of Rhopressa ® in the second quarter of 2018 following its commercial launch of Rhopressa ® in the United States in late April 2018. The Company’s activities from inception until the commercial launch of Rhopressa ® in the United States had primarily consisted of developing product candidates, raising capital and performing research and development activities. The Company has incurred losses and experienced negative operating cash flows since inception. The Company has funded its operations primarily through the sale of equity securities (see Note 10, “Stockholders’ Equity”) and issuance of convertible notes (see Note 9, “Debt”). On July 23, 2018, the Company’s $125.0 million aggregate principal amount of senior secured convertible notes (the “2014 Convertible Notes”) was converted into shares of Aerie common stock. Aerie issued 329,124 additional shares of common stock in order to induce the conversion for which $24.1 million was expensed to other expense on the condensed consolidated statement of operations and comprehensive loss during the three months ended September 30, 2018. In addition, the Company entered into a $100 million senior secured delayed draw term loan facility (the “credit facility”) that matures on July 23, 2024. See Note 9, “Debt,” for additional information. If the Company does not successfully commercialize Rhopressa ® , Rocklatan TM or any future product candidates, it may be unable to achieve profitability. Accordingly, the Company may be required to draw down on the credit facility it entered into in July 2018, or obtain further funding through public or private offerings, debt financings, collaboration and licensing arrangements or other sources. Adequate additional funding may not be available to the Company on acceptable terms, or at all. If the Company is unable to raise capital when needed or on attractive terms, it may be forced to delay, reduce or eliminate its research and development programs or commercialization and manufacturing efforts.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Basis of Presentation The Company’s interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position and results of operations for the interim periods presented. Certain information and disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on March 1, 2018 (“2017 Form 10-K”). The results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for a full year, any other interim periods or any future year or period. Principles of Consolidation The interim condensed consolidated financial statements include the accounts of Aerie and its wholly-owned subsidiaries. All intercompany accounts, transactions and profits have been eliminated in consolidation. Use of Estimates The preparation of consolidated 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 consolidated financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, the valuation of stock-based awards and operating expense accruals. Actual results could differ from the Company’s estimates. Revenue Recognition Effective January 1, 2018, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). The Company did not generate any revenue prior to the three months ended June 30, 2018, and therefore the adoption of ASC Topic 606 did not have an impact to the Company’s financial statements for any prior periods or upon adoption. In accordance with ASC Topic 606, the Company recognizes revenue when the customer obtains control of a promised good or service, in an amount that reflects the consideration that the Company expects to receive in exchange for the good or service. The reported results for the three and nine months ended September 30, 2018 reflect the application of ASC Topic 606. The Company’s net product revenues are generated through sales of Rhopressa ® , which was approved by the FDA in December 2017 and was commercially launched in the United States on April 30, 2018. See Note 3, “Revenue Recognition,” for more information. Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and investments. The Company’s cash and cash equivalents, which include short-term highly liquid investments with original maturities of three months or less, are held at several financial institutions and at times may exceed insured limits. The Company has placed these funds in high quality institutions to minimize risk relating to exceeding insured limits. The Company’s investment policy permits investments in U.S. federal government and federal agency securities, corporate bonds or commercial paper, money market instruments, and certain qualifying money market mutual funds, and places restrictions on credit ratings, maturities, and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents and investments to the extent recorded on the condensed consolidated balance sheet. The Company depends on single source suppliers for the active pharmaceutical ingredient (“API”) in Rhopressa ® and the manufacture of finished product. The Company is in the process of adding additional contract manufacturers, which are expected to produce API and finished product commercial supply beginning in the first half of 2019. In addition, the Company is building a new manufacturing plant in Athlone, Ireland, which is expected to produce commercial supplies of Rhopressa ® and, if approved, Rocklatan TM and Rhokiinsa ® . Commercial supply from the Ireland manufacturing plant is expected to be available in 2020. Inventories Prior to the date the Company obtains regulatory approval for its product candidates, manufacturing costs related to commercial production for such product candidates are expensed as selling, general and administrative expense. Once regulatory approval is obtained, the Company capitalizes such costs as inventory. Inventories are stated at the lower of cost or estimated realizable value. The Company determines the cost of inventory using the first-in, first-out (“FIFO”) method. Property, Plant and Equipment, Net Property, plant and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets. Construction-in-progress reflects amounts incurred for property, plant or equipment construction or improvements that have not been yet placed in service, which primarily relates to the build-out of the Company’s manufacturing plant in Ireland (see Note 7, “Property, Plant and Equipment, Net”). Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net loss. Estimated useful lives by major asset category are as follows: Manufacturing equipment 10 years Laboratory equipment 7 years Furniture and fixtures 5 years Software and computer equipment 3 years Leasehold improvements Lower of estimated useful life or term of lease Investments The Company determines the appropriate classification of its investments in debt and equity securities at the time of purchase. The Company’s investments are comprised of commercial paper and corporate bonds that are classified as available-for-sale in accordance with ASC Topic 320, Investments—Debt and Equity Securities . The Company classifies investments available to fund current operations as current assets on its consolidated balance sheets. Investments are classified as long-term assets on the consolidated balance sheets if (i) the Company has the intent and ability to hold the investments for a period of at least one year and (ii) the contractual maturity date of the investments is greater than one year. Available-for-sale investments in debt securities are recorded at fair value, with unrealized gains or losses included as other comprehensive loss on the condensed consolidated statements of comprehensive loss and as accumulated other comprehensive loss on the condensed consolidated balance sheets. Realized gains and losses, interest income earned on the Company’s cash, cash equivalents and investments, and amortization or accretion of discounts and premiums on investments are included within other income (expense), net. Interest income was $0.8 million and $2.5 million for the three and nine months ended September 30, 2018 , respectively, and $0.6 million and $1.3 million for the three and nine months ended September 30, 2017 , respectively. Realized losses of $0.2 million were reclassified out of accumulated other comprehensive loss and recognized within other income (expense), net during the nine months ended September 30, 2018 . There were no realized gains or losses recognized during the three months ended September 30, 2018 or during the three or nine months ended September 30, 2017 . Fair Value Measurements The Company records certain financial assets and liabilities at fair value in accordance with the provisions of ASC Topic 820, Fair Value Measurements and Disclosures . As defined in the guidance, fair value, defined as an exit price, represents the amount that would be received to sell an asset or pay to transfer a liability in an orderly transaction between market participants. As a result, fair value is a market-based approach that should be determined based on assumptions that market participants would use in pricing an asset or a liability. As a basis for considering these assumptions, the guidance defines a three-tier value hierarchy that prioritizes the inputs used in the valuation methodologies in measuring fair value. • Level 1—Unadjusted quoted prices in active, accessible markets for identical assets or liabilities. • Level 2—Other inputs that are directly or indirectly observable in the marketplace. • Level 3—Unobservable inputs that are supported by little or no market activity. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. There were no transfers between the different levels of the fair value hierarchy during the three or nine months ended September 30, 2018 . Stock-Based Compensation The estimated fair value of options to purchase common stock is determined on the date of grant using the Black-Scholes option pricing model. Options granted to non-employees are revalued at each financial reporting period until the required service is performed. The fair value of restricted stock awards (“RSAs”) granted is based on the market value of Aerie’s common stock on the date of grant. Compensation expense related to time-based RSAs is expensed on a straight-line basis over the vesting period. For RSAs with non-market performance conditions, the Company evaluates the criteria for each grant to determine the probability that the performance condition will be achieved. Compensation expense for RSAs with non-market performance conditions is recognized over the respective service period when it is deemed probable that the performance condition will be satisfied. Upon issuance and at each reporting period, the fair value of each stock appreciation rights (“SARs”) award is estimated using the Black-Scholes option pricing model and is marked to market through stock-based compensation expense. SARs are liability-based awards as they may only be settled in cash. Adoption of New Accounting Standards In August 2018, the FASB issued Accounting Standards Update (“ASU”) 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which amends ASC 350-40, Internal-Use Software, to include in its scope implementation costs of a cloud computing arrangement that is a service contract. Consequently, the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement, is aligned with the guidance on capitalizing costs associated with developing or obtaining internal-use software. This ASU is effective for the Company beginning January 1, 2019 and early adoption is permitted. The Company elected to early adopt this standard during the third quarter of 2018, which did not have a material impact on its consolidated financial statements and disclosures. In March 2018, the FASB issued ASU 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (“SAB 118”) (“ASU 2018-05”), which adds guidance to clarify the treatment of income taxes based on changes enacted on December 22, 2017 in H.R. 1 (commonly referred to as the “Tax Act”). ASU 2018-05 incorporates references in ASC Topic 740 to SAB 118, which was issued on December 22, 2017, to address the application of U.S. GAAP in situations when a registrant may not have the necessary information available in reasonable detail to complete the accounting for certain income tax effects. The guidance became effective immediately upon the enactment of the Tax Act in accordance with U.S. GAAP which requires deferred tax assets and liabilities to be revalued during the period in which new tax legislation is enacted. The Company’s final impact assessment on the consolidated financial statements will be completed as additional information becomes available, but no later than one year from the enactment of the Tax Act. In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), which clarifies when changes to the terms or conditions of share-based payment awards must be accounted for as modifications. Under ASU 2017-09, an 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. ASU 2017-09 will be applied prospectively to awards modified on or after the adoption date. The guidance became effective for the Company beginning on January 1, 2018. The impact of the adoption of this guidance on its consolidated financial statements would be dependent on future modifications to share-based payment awards, if any. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory , which eliminates the exception to the principle in ASC Topic 740, Income Taxes , that generally requires comprehensive recognition of current and deferred income taxes for all intra-entity sales of assets other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of the asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. This ASU became effective for the Company on January 1, 2018 and was required to be applied on a modified retrospective basis through a cumulative-effect adjustment directly to accumulated deficit as of the beginning of the period of adoption. At December 31, 2017, the Company had $2.1 million of income tax effects deferred from past intercompany transactions that were recorded as prepaid assets within other assets, net, at December 31, 2017 that were adjusted through accumulated deficit as of January 1, 2018. In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which provides guidance related to the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. The guidance became effective for the Company beginning on January 1, 2018 and prescribes different transition methods for the various provisions. The adoption of ASU 2016-01 did not have a material impact on its consolidated financial statements and disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”). The standard states that an entity should recognize revenue based on the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The FASB subsequently issued amendments to ASU 2014-09 that had the same effective date of January 1, 2018. Revenue from sales of Rhopressa ® , as well as any other future revenue arrangements, are and will be recognized under the provisions of ASC Topic 606. Recent Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820-10): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which changes the fair value measurement disclosure requirements of ASC 820. Under this ASU, certain disclosure requirements for fair value measurements are eliminated, amended, or added. These changes aim to improve the overall usefulness of disclosures to financial statement users and reduce unnecessary costs to companies when preparing the disclosures. The guidance is effective for the Company beginning on January 1, 2019 and prescribes different transition methods for the various provisions. The Company does not expect the adoption of ASU 2018-13 to have a material impact on its consolidated financial statements and disclosures. In June 2018, the FASB issued ASU 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”) , which expands the scope of ASC Topic 718, Compensation—Stock Compensation to include share-based payments issued to nonemployees for goods or services. Consequently, the accounting for share-based payments to nonemployees and employees will be substantially aligned. This ASU is effective for the Company beginning January 1, 2019, including interim periods within that fiscal year, but early adoption is permitted. The Company does not expect the adoption of ASU 2018-07 to have a material impact on its consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. Currently, U.S. GAAP delays recognition of the full amount of credit losses until the loss is probable of occurring. Under this ASU, the income statement will reflect an entity’s current estimate of all expected credit losses. The measurement of expected credit losses will be based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down of the security. This ASU is effective for the Company beginning on January 1, 2020, with early adoption permitted beginning on January 1, 2019. The new guidance prescribes different transition methods for the various provisions. The Company does not expect the adoption of ASU 2016-13 to have a material impact on its consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to recognize a right of use asset and related lease liability for those leases classified as operating leases at the commencement date and for those leases that have lease terms of more than 12 months. In July 2018, the FASB issued both ASU 2018-10, Codification Improvements to Topic 842, Leases (“ASU 2018-10”) and ASU 2018-11, Leases (Topic 842)—Targeted Improvements (“ASU 2018-11”), which provides additional guidance or clarifications affecting certain aspects of ASU 2016-02 and certain practical expedients. Further, the updated guidance allows an additional transition method to apply the new leases standard at the adoption date, as compared to the beginning of the earliest period presented, and recognize a cumulative-effect adjustment to the beginning balance of retained earnings in the period of adoption . ASU 2016-02, ASU 2018-10 and ASU 2018-11 are effective for the Company beginning on January 1, 2019, and all annual and interim periods thereafter, with early adoption permitted. The Company expects to elect the transition method described in ASU 2018-11 at the adoption date of January 1, 2019 and recognize a cumulative-effect adjustment to accumulated deficit as of January 1, 2019. The Company is currently evaluating the impact of ASU 2016-02, ASU 2018-10 and ASU 2018-11 on its consolidated financial statements and disclosures , but expects to recognize a right of use asset and corresponding liability related to its operating leases . Net Loss per Common Share Basic net loss per common share (“Basic EPS”) is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for potentially dilutive securities with the exception of warrants for common stock with a $0.05 exercise price, which are exercisable for nominal consideration and are therefore included in the calculation of the weighted average number of shares of common stock as common stock equivalents. Diluted net loss per share (“Diluted EPS”) gives effect to all dilutive potential shares of common stock outstanding during this period. For Diluted EPS, net loss used in calculating Basic EPS is adjusted for certain items related to the dilutive securities. For all periods presented, Aerie’s potential common stock equivalents have been excluded from the computation of Diluted EPS as their inclusion would have had an anti-dilutive effect. The potential common stock equivalents that have been excluded from the computation of Diluted EPS consist of the following: THREE MONTHS ENDED NINE MONTHS ENDED 2018 2017 2018 2017 2014 Convertible Notes — 5,040,323 — 5,040,323 Outstanding stock options 6,951,639 6,237,959 6,951,639 6,237,959 Stock purchase warrants 154,500 157,500 154,500 157,500 Nonvested restricted stock awards 584,124 439,549 584,124 439,549 Total 7,690,263 11,875,331 7,690,263 11,875,331 In July 2018, the entire outstanding principal amount of the 2014 Convertible Notes was converted into shares of Aerie common stock. See Note 9, "Debt," for additional information.

Revenue Recognition

Revenue Recognition	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition In accordance with ASC Topic 606, the Company recognizes revenues when its customers obtain control of its product in an amount that reflects the consideration it expects to receive from its customers in exchange for that product. To determine revenue recognition for contracts that are determined to be in scope of ASC Topic 606, the Company performs the following five steps: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the Company satisfies the performance obligation. The Company only applies the five-step model to contracts when it is probable that the Company will collect the consideration it is entitled to in exchange for the goods or services it transfers to the customer. Once the contract is determined to be within the scope of ASC Topic 606, the Company assesses the goods or services promised within each contract and determines those that are performance obligations and assesses whether each promised good or service is distinct. The Company then recognizes as revenue the amount of the transaction price that is allocated to the respective performance obligation when such performance obligation is satisfied. Shipping and handling costs related to the Company’s product sales are included in selling, general and administrative expenses. Net product revenues for the three and nine months ended September 30, 2018 were derived from sales of Rhopressa ® in the United States to customers, which include a limited number of national and select regional wholesalers (the “Distributors”). These Distributors subsequently resell the product, primarily to retail pharmacies that dispense the product to patients. The Company expenses incremental costs of obtaining a contract as and when incurred if the expected amortization period of the asset that would have been recognized is one year or less or the amount is immaterial. The product that is ultimately used by patients is generally covered by third-party payers, such as government or private healthcare insurers and pharmacy benefit managers (“Third-party Payers”) and may be subject to rebates and discounts payable directly to those Third-party Payers. The Company has already obtained formulary coverage for approximately 85% of lives covered under commercial plans and approximately 40% of lives covered under Medicare Part D plans and is in the process of increasing those levels of coverage. In the glaucoma market in the United States, approximately half of the volumes are covered under commercial plans and half under Medicare Part D. Medicare Part D coverage would normally commence for Rhopressa ® , as with other new products, on or about January 1, 2019. However, there have been early acceptances of Rhopressa ® onto certain Medicare Part D plans, commencing as early as June 1, 2018. Product revenue is recorded net of trade discounts, allowances, rebates, chargebacks, estimated returns and other incentives, discussed below. These reserves are classified as either reductions of accounts receivable or as current liabilities. Amounts billed or invoiced are included in accounts receivable, net on the condensed consolidated balance sheet. The Company did not have any contract assets (unbilled receivables) at September 30, 2018 , as customer invoicing generally occurs before or at the time of revenue recognition. The Company did not have any contract liabilities at September 30, 2018 , as the Company did not receive payments in advance of fulfilling its performance obligations to its customers. Net product revenue is typically recognized when Distributors obtain control of the Company’s product, which occurs at a point in time, typically upon delivery of Rhopressa ® to the Distributors. For both the three and nine months ended September 30, 2018 , three Distributors accounted for 34% , 32% and 31% of total revenues, respectively. The Company evaluates the creditworthiness of each of its Distributors to determine whether it is probable that a significant reversal in the amount of the cumulative revenue recognized will not occur. We do not assess whether a contract has a significant financing component if the expectation is such that the period between the transfer of the promised goods to the customer and the receipt of payment will be less than one year. Standard credit terms do not exceed 75 days. The Company calculates its net product revenue based on the wholesale acquisition cost that the Company charges its Distributors for Rhopressa ® less variable consideration. Variable consideration consists of estimates relating to (i) trade discounts and allowances, such as discounts for prompt payment and Distributor fees, (ii) estimated rebates to Third-party Payers, estimated payments for Medicare Part D prescription drug program coverage gap (commonly called the “donut hole”), patient co-pay program coupon utilization, chargebacks and other discount programs and (iii) reserves for expected product returns. The estimates of reserves established for variable consideration reflect current contractual and statutory requirements, known market events and trends, industry data and forecasted customer mix. The transaction price, which includes variable consideration reflecting the impact of discounts and allowances, may be subject to constraint and is included in the net product revenues only to the extent that it is probable that a significant reversal of the amount of the cumulative revenues recognized will not occur in a future period. Actual amounts may ultimately differ from these estimates. If actual results vary, estimates may be adjusted in the period such change in estimate becomes known, which could have an impact on earnings in the period of adjustment. Trade Discounts and Allowances : The Company generally provides discounts on sales of Rhopressa ® to its Distributors for prompt payment and pays fees for distribution services and for certain data that Distributors provide to the Company. The Company expects its Distributors to earn these discounts and fees, and accordingly deducts the full amount of these discounts and fees from its gross product revenues at the time such revenues are recognized. Rebates, Chargebacks and Other Discounts : The Company contracts with Third-party Payers for coverage and reimbursement of Rhopressa ® . The Company estimates the rebates and chargebacks it expects to be obligated to provide to Third-party Payers and deducts these estimated amounts from its gross product revenue at the time the revenue is recognized. The Company estimates the rebates and chargebacks that it expects to be obligated to provide to Third-party Payers based upon (i) the Company's contracts and negotiations with these Third-party Payers, (ii) estimates regarding the payer mix for Rhopressa ® and (iii) historical industry information regarding the payer mix for comparable pharmaceutical products and product portfolios. Other discounts include the Company’s co-pay assistance coupon programs for commercially-insured patients meeting certain eligibility requirements. The calculation of the accrual for co-pay assistance is based on an estimate of claims and the cost per claim that the Company expects to pay associated with product that has been recognized as revenue. Product Returns : The Company estimates the amount of Rhopressa ® that will be returned and deducts these estimated amounts from its gross revenue at the time the revenue is recognized. The Company currently estimates product returns based on historical industry information regarding rates for comparable pharmaceutical products and product portfolios, the estimated remaining shelf life of Rhopressa ® shipped to Distributors, and contractual agreements with the Company's Distributors intended to limit the amount of inventory they maintain. Reporting from the Distributors includes Distributor sales and inventory held by Distributors, which provides the Company with visibility into the distribution channel to determine when product would be eligible to be returned.

Investments

Investments	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Cash, cash equivalents and investments as of September 30, 2018 included the following: (in thousands) AMORTIZED COST GROSS UNREALIZED GAINS GROSS UNREALIZED LOSSES FAIR VALUE Cash and cash equivalents: Cash and money market funds $ 234,954 $ — $ — $ 234,954 Total cash and cash equivalents $ 234,954 $ — $ — $ 234,954 Investments: Corporate bonds (due within 1 year) 1,001 — (1 ) 1,000 Total investments $ 1,001 $ — $ (1 ) $ 1,000 Total cash, cash equivalents and investments $ 235,955 $ — $ (1 ) $ 235,954 Cash, cash equivalents and investments as of December 31, 2017 included the following: (in thousands) AMORTIZED COST GROSS UNREALIZED GAINS GROSS UNREALIZED LOSSES FAIR VALUE Cash and cash equivalents: Cash and money market funds $ 197,569 $ — $ — $ 197,569 Total cash and cash equivalents $ 197,569 $ — $ — $ 197,569 Investments: Commercial paper (due within 1 year) $ 30,883 $ — $ — $ 30,883 Corporate bonds (due within 1 year) 21,231 — (28 ) 21,203 Total investments $ 52,114 $ — $ (28 ) $ 52,086 Total cash, cash equivalents and investments $ 249,683 $ — $ (28 ) $ 249,655

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy: FAIR VALUE MEASUREMENTS AS OF SEPTEMBER 30, 2018 (in thousands) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 234,954 $ — $ — $ 234,954 Total cash and cash equivalents $ 234,954 $ — $ — $ 234,954 Investments: Corporate bonds $ — $ 1,000 $ — $ 1,000 Total investments $ — $ 1,000 $ — $ 1,000 Total cash, cash equivalents and investments $ 234,954 $ 1,000 $ — $ 235,954 FAIR VALUE MEASUREMENTS AS OF DECEMBER 31, 2017 (in thousands) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 197,569 $ — $ — $ 197,569 Total cash and cash equivalents $ 197,569 $ — $ — $ 197,569 Investments: Commercial paper $ — $ 30,883 $ — $ 30,883 Corporate bonds — 21,203 — 21,203 Total investments $ — $ 52,086 $ — $ 52,086 Total cash, cash equivalents and investments $ 197,569 $ 52,086 $ — $ 249,655 Convertible Notes As of December 31, 2017 , the estimated fair value of the $125.0 million aggregate principal amount of the 2014 Convertible Notes was $327.6 million . The estimated fair value of the 2014 Convertible Notes required the use of Level 3 unobservable inputs and subjective assumptions. In July 2018, the entire outstanding principal amount of the 2014 Convertible Notes was converted into shares of Aerie common stock. See Note 9, “Debt,” for additional information.

Inventory

Inventory	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Inventory	Inventory Inventory consists of the following: (in thousands) SEPTEMBER 30, 2018 Raw materials $ 559 Work-in-process 2,478 Finished goods 2,575 Total inventory $ 5,612 The Company commenced capitalizing inventory for Rhopressa ® upon FDA approval of Rhopressa ® on December 18, 2017. No inventory was produced from the FDA approval date through the end of 2017; therefore, no inventory was capitalized on the consolidated balance sheet as of December 31, 2017 .

Property, Plant and Equipment,

Property, Plant and Equipment, Net	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment, net consists of the following: (in thousands) SEPTEMBER 30, 2018 DECEMBER 31, 2017 Manufacturing equipment $ 2,307 $ 2,082 Laboratory equipment 4,915 3,602 Furniture and fixtures 1,536 1,209 Software and computer equipment 2,321 1,932 Leasehold improvements 3,685 1,887 Construction-in-progress 48,416 24,228 63,180 34,940 Less: Accumulated depreciation (4,820 ) (3,008 ) Total property, plant and equipment, net $ 58,360 $ 31,932 Manufacturing Plant Build-Out In January 2017, the Company entered into a Euro-denominated lease agreement, expiring in September 2037, for a new manufacturing plant in Athlone, Ireland, under which the Company is leasing approximately 30,000 square feet of interior floor space for build-out. The Company is permitted to terminate the lease beginning in September 2027. The Company is not the legal owner of the leased space. However, in accordance with ASC Topic 840, Leases , the Company is deemed to be the owner of the leased space, including the building shell, during the construction period because of the Company’s expected level of direct financial and operational involvement in the substantial tenant improvements required. As a result, the Company capitalized approximately $4.2 million as a build-to-suit asset within property, plant and equipment, net and recognized a corresponding build-to-suit facility lease obligation as a liability on its condensed consolidated balance sheets equal to the estimated replacement cost of the building at the inception of the lease. Additionally, equipment and construction costs incurred as part of the build-out are also capitalized within property, plant and equipment, net, as construction-in-progress. Capital expenditures related to the manufacturing plant totaled approximately $24.2 million during the nine months ended September 30, 2018 . Rental payments made under the lease will be allocated to interest expense and the build-to-suit facility lease obligation based on the implicit rate of the build-to-suit facility lease obligation. The build-to-suit facility lease obligation was approximately $4.6 million as of September 30, 2018 , of which $0.3 million was classified as other current liabilities. The build-to-suit facility lease obligation was approximately $4.9 million as of December 31, 2017 . The lease obligation is denominated in Euros and is remeasured to U.S. dollars at the balance sheet date with any foreign exchange gain or loss recognized within other income (expense), net on the condensed consolidated statements of operations and comprehensive loss. Unrealized foreign currency gain related to the remeasurement of the lease obligation was zero and $0.2 million for the three and nine months ended September 30, 2018 , respectively. The Company had unrealized foreign currency losses related to the remeasurement of the lease obligation of $0.2 million and $0.5 million for the three and nine months ended September 30, 2017 , respectively.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consist of the following: (in thousands) SEPTEMBER 30, 2018 DECEMBER 31, 2017 Accrued compensation and benefits $ 9,465 $ 7,886 Accrued consulting and professional fees 3,955 3,841 Accrued research and development expenses (1) 4,297 1,855 Accrued revenue reserves 4,819 — Accrued other (2) 5,412 5,357 Total accrued expenses and other current liabilities $ 27,948 $ 18,939 (1) Comprised of accruals related to fees for investigative sites, contract research organizations, contract manufacturing organizations and other service providers that assist in conducting preclinical research studies and clinical trials. (2) Comprised of accruals related to commercial manufacturing activities prior to FDA approval of Rhopressa ® and Rocklatan TM as well as other business-related expenses.

Debt

Debt	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Debt	Debt 2014 Convertible Notes In September 2014, Aerie issued $125.0 million aggregate principal amount of the 2014 Convertible Notes to Deerfield Partners, L.P., Deerfield International Master Fund, L.P., Deerfield Private Design Fund III, L.P., Deerfield Special Situations Fund, L.P. and Deerfield Special Situations International Master Fund, L.P. (collectively with their transferees, “Deerfield”). The 2014 Convertible Notes were issued pursuant to a note purchase agreement (as amended and supplemented from time to time, the “Note Purchase Agreement”), dated as of September 8, 2014, among Aerie and the Deerfield entities party thereto. The 2014 Convertible Notes were scheduled to mature on the seventh anniversary from the date of issuance , unless earlier converted. The 2014 Convertible Notes were convertible at any time at the option of Deerfield, in whole or in part, into shares of common stock. In July 2018, Deerfield converted the entire outstanding principal amount of the 2014 Convertible Notes into shares of Aerie common stock. The 2014 Convertible Notes bore interest at a rate of 1.75% per annum payable quarterly in arrears on the first business day of each January, April, July and October. The Company recorded the 2014 Convertible Notes as long-term debt at face value less $2.1 million in debt discount and issuance costs incurred at the time of the transaction, which were being amortized to interest expense using the effective interest method through the conversion of the 2014 Convertible Notes. The table below summarizes the carrying value of the 2014 Convertible Notes as of December 31, 2017 : (in thousands) DECEMBER 31, 2017 Gross proceeds $ 125,000 Unamortized debt discount and issuance costs (1,155 ) Carrying value $ 123,845 Conversion of 2014 Convertible Notes On July 23, 2018, Aerie entered into an Exchange and Termination Agreement (the “Exchange and Termination Agreement”) with Deerfield Private Design Fund III, L.P., Deerfield Partners, L.P. and Deerfield Special Situations Fund, L.P. (collectively, the “Holders”). Pursuant to the Exchange and Termination Agreement, (i) the Holders converted the entire outstanding principal amount of the 2014 Convertible Notes into 5,040,323 shares of common stock (the “Conversion Shares”) in accordance with the terms of the 2014 Convertible Notes, which was recognized in stockholders’ equity, (ii) Aerie issued the Conversion Shares, and (iii) Aerie paid accrued and unpaid interest on the Convertible Notes through July 23, 2018. In addition, as mutually agreed to with the Holders in order to complete the conversion on the date of the Exchange and Termination Agreement, Aerie issued an additional 329,124 shares of common stock (the “Additional Shares”) to the Holders. Aerie expensed the value of the Additional Shares in the amount of $24.1 million to other expense during the three months ended September 30, 2018. Entry into Credit Facility On July 23, 2018, Aerie entered into a credit agreement (as amended on August 7, 2018) with certain entities affiliated with Deerfield Management Company L.P. providing for a $100 million credit facility. The credit facility includes fees upon drawdown of 1.75% of amounts drawn, an 8.625% annual interest rate on drawn amounts, and annual fees on undrawn amounts of 1.5% . There is also an exit fee of $1.5 million payable upon termination of the credit facility (whether at maturity or otherwise). The allowable draw period ends two years from the effective date of the credit facility. Fees on undrawn amounts are not payable until July 23, 2020, and no principal payments will be due on drawn amounts, if any, until July 23, 2020. The credit facility matures on July 23, 2024 in respect of any drawn amounts. The credit facility includes affirmative and negative covenants and prepayment terms. No funds were drawn at closing or as of September 30, 2018. Interest expense was $0.8 million and $1.7 million for the three and nine months ended September 30, 2018 , respectively, and included amortization of debt discount and issuance costs related to the 2014 Convertible Notes through the date of conversion as well as issuance costs and fees related to the credit facility. Interest expense, was $0.6 million and $1.8 million for the three and nine months ended September 30, 2017 , respectively, which included amortization of debt discount and issuance costs related to the 2014 Convertible Notes.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders’ Equity During the nine months ended September 30, 2018 , Aerie issued and sold approximately 1.0 million shares of Aerie’s common stock and received net proceeds of approximately $62.3 million , after deducting $0.5 million of fees and expenses, under the “at-the-market” sales agreement that commenced in December 2017. There are no remaining shares available for issuance under the ATM that commenced in December 2017. In addition, the Company entered into an underwriting agreement, dated January 23, 2018, related to the registered public offering of approximately 1.3 million shares of Aerie’s common stock and received net proceeds of approximately $74.1 million , after deducting $0.9 million of underwriting discounts, fees and expenses. The transactions were made pursuant to an automatic shelf registration on Form S-3, filed with the SEC on September 15, 2016, that permits the offering, issuance and sale of an unlimited number of shares of common stock from time to time by Aerie. Warrants As of September 30, 2018 , the following equity-classified warrants to purchase common stock were outstanding: NUMBER OF UNDERLYING SHARES EXERCISE PRICE PER SHARE WARRANT EXPIRATION DATE 75,000 $5.00 February 2019 75,000 $5.00 November 2019 4,500 $5.00 August 2020 223,482 $0.05 December 2019 The warrants outstanding as of September 30, 2018 are all currently exercisable.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense for options granted, RSAs, performance stock awards (“PSAs”), SARs and stock purchase rights is reflected in the condensed consolidated statements of operations and comprehensive loss as follows: THREE MONTHS ENDED NINE MONTHS ENDED (in thousands) 2018 2017 2018 2017 Selling, general and administrative $ 7,382 $ 4,995 $ 21,826 $ 14,032 Research and development 2,596 1,562 7,189 4,040 Total $ 9,978 $ 6,557 $ 29,015 $ 18,072 Equity Plans The Company maintains three equity compensation plans, the 2005 Aerie Pharmaceutical Stock Plan (the “2005 Plan”), the 2013 Omnibus Incentive Plan (the “2013 Equity Plan”), which was amended and restated as the Aerie Pharmaceuticals, Inc. Second Amended and Restated Omnibus Incentive Plan (the “Second Amended and Restated Equity Plan”), as described below, and the Aerie Pharmaceuticals, Inc. Inducement Award Plan (the “Inducement Award Plan”), as described below. The 2005 Plan, the Second Amended and Restated Equity Plan and the Inducement Award Plan are referred to collectively as the “Plans.” On October 30, 2013, the effective date of the 2013 Equity Plan, the 2005 Plan was frozen and no additional awards have been or will be made under the 2005 Plan. Any remaining shares available for future grant under the 2005 Plan were allocated to the 2013 Equity Plan. On April 10, 2015, Aerie’s stockholders approved the adoption of the Aerie Pharmaceuticals, Inc. Amended and Restated Omnibus Incentive Plan (“Amended and Restated Equity Plan”) and no additional awards have been or will be made under the 2013 Equity Plan. Any remaining shares available under the 2013 Equity Plan were allocated to the Amended and Restated Equity Plan. On June 7, 2018, Aerie’s stockholders approved the adoption of the Second Amended and Restated Equity Plan to increase the number of shares issuable under the Plan by 4,500,000 . The Second Amended and Restated Equity Plan provides for the granting of up to 10,229,068 equity awards in respect of Aerie common stock, including equity awards that were previously available for issuance under the 2013 Equity Plan. On December 7, 2016, Aerie’s Board of Directors approved the Inducement Award Plan which provides for the granting of up to 418,000 equity awards in respect of common stock of Aerie and was subsequently amended during the year ended December 31, 2017 to increase the equity awards that may be issued by an additional 874,500 shares. Awards granted under the Inducement Award Plan are intended to qualify as employment inducement awards under NASDAQ Listing Rule 5635(c)(4). Options to Purchase Common Stock The following table summarizes the stock option activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE Options outstanding at December 31, 2017 6,457,343 $ 22.15 Granted 1,207,984 56.81 Exercised (600,690 ) 8.74 Canceled (112,998 ) 46.01 Options outstanding at September 30, 2018 6,951,639 $ 28.92 7.0 $ 227,793 Options exercisable at September 30, 2018 4,440,403 $ 18.39 5.9 $ 191,690 As of September 30, 2018 , the Company had $78.4 million of unrecognized compensation expense related to options granted under its equity plans. This expense is expected to be recognized over a weighted average period of 2.9 years as of September 30, 2018 . Restricted Stock Awards The following table summarizes the RSAs, including PSAs, activity under the Plans: NUMBER OF SHARES WEIGHTED AVERAGE FAIR VALUE PER SHARE Nonvested RSAs at December 31, 2017 447,049 $ 41.08 Granted 264,999 56.00 Vested (122,461 ) 38.47 Canceled (5,463 ) 48.41 Nonvested RSAs at September 30, 2018 584,124 $ 48.32 As of September 30, 2018 , the Company had $20.0 million of unrecognized compensation expense related to unvested RSAs, including PSAs. This expense is expected to be recognized over the weighted average period of 2.9 years as of September 30, 2018 . The vesting of the RSAs is time and service based with terms of one to four years. During the year ended December 31, 2017 , the Company granted 98,817 PSAs with non-market performance conditions that vest upon the satisfaction of certain performance conditions and service conditions. During the nine months ended September 30, 2018 , there were 19,764 PSAs that vested. Stock Appreciation Rights During the nine months ended September 30, 2018 , the Company granted 104,000 SARs awards at a weighted average exercise price of $54.20 . As of September 30, 2018 , 96,000 SARs awards were outstanding and had a weighted average remaining contractual life of 4.5 years . Holders of the SARs are entitled under the terms of the Plans to receive cash payments calculated based on the excess of the Company’s common stock price over the target price in their award; consequently, these awards are accounted for as liability-classified awards and the Company measures compensation cost based on their estimated fair value at each reporting date, net of actual forfeitures, if any.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies The Company may periodically become subject to legal proceedings and claims arising in connection with its business. Except as previously disclosed for matters which have now concluded, the Company is not a party to any known litigation, is not aware of any unasserted claims and does not have contingency reserves established for any litigation liabilities.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s interim condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”). In the opinion of management, the Company has made all necessary adjustments, which include normal recurring adjustments necessary for a fair statement of the Company’s consolidated financial position and results of operations for the interim periods presented. Certain information and disclosures normally included in the annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. These interim condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and accompanying notes for the year ended December 31, 2017 included in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on March 1, 2018 (“2017 Form 10-K”). The results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results to be expected for a full year, any other interim periods or any future year or period.
Principles of Consolidation	Principles of Consolidation The interim condensed consolidated financial statements include the accounts of Aerie and its wholly-owned subsidiaries. All intercompany accounts, transactions and profits have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of consolidated 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 consolidated financial statements and reported amounts of income and expenses during the reporting periods. Significant items subject to such estimates and assumptions include revenue recognition, the valuation of stock-based awards and operating expense accruals. Actual results could differ from the Company’s estimates.
Revenue Recognition	Revenue Recognition Effective January 1, 2018, the Company adopted Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 606, Revenue from Contracts with Customers (“ASC Topic 606”). The Company did not generate any revenue prior to the three months ended June 30, 2018, and therefore the adoption of ASC Topic 606 did not have an impact to the Company’s financial statements for any prior periods or upon adoption. In accordance with ASC Topic 606, the Company recognizes revenue when the customer obtains control of a promised good or service, in an amount that reflects the consideration that the Company expects to receive in exchange for the good or service. The reported results for the three and nine months ended September 30, 2018 reflect the application of ASC Topic 606. The Company’s net product revenues are generated through sales of Rhopressa ® , which was approved by the FDA in December 2017 and was commercially launched in the United States on April 30, 2018. See Note 3, “Revenue Recognition,” for more information.
Concentration of Risk	Concentration of Risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of cash, cash equivalents and investments. The Company’s cash and cash equivalents, which include short-term highly liquid investments with original maturities of three months or less, are held at several financial institutions and at times may exceed insured limits. The Company has placed these funds in high quality institutions to minimize risk relating to exceeding insured limits. The Company’s investment policy permits investments in U.S. federal government and federal agency securities, corporate bonds or commercial paper, money market instruments, and certain qualifying money market mutual funds, and places restrictions on credit ratings, maturities, and concentration by type and issuer. The Company is exposed to credit risk in the event of a default by the financial institutions holding its cash, cash equivalents and investments to the extent recorded on the condensed consolidated balance sheet. The Company depends on single source suppliers for the active pharmaceutical ingredient (“API”) in Rhopressa ® and the manufacture of finished product. The Company is in the process of adding additional contract manufacturers, which are expected to produce API and finished product commercial supply beginning in the first half of 2019. In addition, the Company is building a new manufacturing plant in Athlone, Ireland, which is expected to produce commercial supplies of Rhopressa ® and, if approved, Rocklatan TM and Rhokiinsa ® . Commercial supply from the Ireland manufacturing plant is expected to be available in 2020.
Inventories	Inventories Prior to the date the Company obtains regulatory approval for its product candidates, manufacturing costs related to commercial production for such product candidates are expensed as selling, general and administrative expense. Once regulatory approval is obtained, the Company capitalizes such costs as inventory. Inventories are stated at the lower of cost or estimated realizable value. The Company determines the cost of inventory using the first-in, first-out (“FIFO”) method.
Property, Plant and Equipment, Net	Property, Plant and Equipment, Net Property, plant and equipment is recorded at historical cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets. Construction-in-progress reflects amounts incurred for property, plant or equipment construction or improvements that have not been yet placed in service, which primarily relates to the build-out of the Company’s manufacturing plant in Ireland (see Note 7, “Property, Plant and Equipment, Net”). Repairs and maintenance are expensed when incurred. Upon retirement or sale, the cost of the assets disposed of and the related accumulated depreciation are removed from the accounts, and any resulting gain or loss is included in the determination of net loss.
Investments	Investments The Company determines the appropriate classification of its investments in debt and equity securities at the time of purchase. The Company’s investments are comprised of commercial paper and corporate bonds that are classified as available-for-sale in accordance with ASC Topic 320, Investments—Debt and Equity Securities . The Company classifies investments available to fund current operations as current assets on its consolidated balance sheets. Investments are classified as long-term assets on the consolidated balance sheets if (i) the Company has the intent and ability to hold the investments for a period of at least one year and (ii) the contractual maturity date of the investments is greater than one year. Available-for-sale investments in debt securities are recorded at fair value, with unrealized gains or losses included as other comprehensive loss on the condensed consolidated statements of comprehensive loss and as accumulated other comprehensive loss on the condensed consolidated balance sheets. Realized gains and losses, interest income earned on the Company’s cash, cash equivalents and investments, and amortization or accretion of discounts and premiums on investments are included within other income (expense), net.
Fair Value Measurements	Fair Value Measurements The Company records certain financial assets and liabilities at fair value in accordance with the provisions of ASC Topic 820, Fair Value Measurements and Disclosures . As defined in the guidance, fair value, defined as an exit price, represents the amount that would be received to sell an asset or pay to transfer a liability in an orderly transaction between market participants. As a result, fair value is a market-based approach that should be determined based on assumptions that market participants would use in pricing an asset or a liability. As a basis for considering these assumptions, the guidance defines a three-tier value hierarchy that prioritizes the inputs used in the valuation methodologies in measuring fair value. • Level 1—Unadjusted quoted prices in active, accessible markets for identical assets or liabilities. • Level 2—Other inputs that are directly or indirectly observable in the marketplace. • Level 3—Unobservable inputs that are supported by little or no market activity. The fair value hierarchy also requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value.
Stock-Based Compensation	Stock-Based Compensation The estimated fair value of options to purchase common stock is determined on the date of grant using the Black-Scholes option pricing model. Options granted to non-employees are revalued at each financial reporting period until the required service is performed. The fair value of restricted stock awards (“RSAs”) granted is based on the market value of Aerie’s common stock on the date of grant. Compensation expense related to time-based RSAs is expensed on a straight-line basis over the vesting period. For RSAs with non-market performance conditions, the Company evaluates the criteria for each grant to determine the probability that the performance condition will be achieved. Compensation expense for RSAs with non-market performance conditions is recognized over the respective service period when it is deemed probable that the performance condition will be satisfied. Upon issuance and at each reporting period, the fair value of each stock appreciation rights (“SARs”) award is estimated using the Black-Scholes option pricing model and is marked to market through stock-based compensation expense. SARs are liability-based awards as they may only be settled in cash.
Adoption of New Accounting Standards and Recent Accounting Pronouncements	Adoption of New Accounting Standards In August 2018, the FASB issued Accounting Standards Update (“ASU”) 2018-15, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract, which amends ASC 350-40, Internal-Use Software, to include in its scope implementation costs of a cloud computing arrangement that is a service contract. Consequently, the accounting for costs incurred to implement a cloud computing arrangement that is a service arrangement, is aligned with the guidance on capitalizing costs associated with developing or obtaining internal-use software. This ASU is effective for the Company beginning January 1, 2019 and early adoption is permitted. The Company elected to early adopt this standard during the third quarter of 2018, which did not have a material impact on its consolidated financial statements and disclosures. In March 2018, the FASB issued ASU 2018-05, Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118 (“SAB 118”) (“ASU 2018-05”), which adds guidance to clarify the treatment of income taxes based on changes enacted on December 22, 2017 in H.R. 1 (commonly referred to as the “Tax Act”). ASU 2018-05 incorporates references in ASC Topic 740 to SAB 118, which was issued on December 22, 2017, to address the application of U.S. GAAP in situations when a registrant may not have the necessary information available in reasonable detail to complete the accounting for certain income tax effects. The guidance became effective immediately upon the enactment of the Tax Act in accordance with U.S. GAAP which requires deferred tax assets and liabilities to be revalued during the period in which new tax legislation is enacted. The Company’s final impact assessment on the consolidated financial statements will be completed as additional information becomes available, but no later than one year from the enactment of the Tax Act. In May 2017, the FASB issued ASU 2017-09, Compensation—Stock Compensation (Topic 718): Scope of Modification Accounting (“ASU 2017-09”), which clarifies when changes to the terms or conditions of share-based payment awards must be accounted for as modifications. Under ASU 2017-09, an 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. ASU 2017-09 will be applied prospectively to awards modified on or after the adoption date. The guidance became effective for the Company beginning on January 1, 2018. The impact of the adoption of this guidance on its consolidated financial statements would be dependent on future modifications to share-based payment awards, if any. In October 2016, the FASB issued ASU 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory , which eliminates the exception to the principle in ASC Topic 740, Income Taxes , that generally requires comprehensive recognition of current and deferred income taxes for all intra-entity sales of assets other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of the asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. This ASU became effective for the Company on January 1, 2018 and was required to be applied on a modified retrospective basis through a cumulative-effect adjustment directly to accumulated deficit as of the beginning of the period of adoption. At December 31, 2017, the Company had $2.1 million of income tax effects deferred from past intercompany transactions that were recorded as prepaid assets within other assets, net, at December 31, 2017 that were adjusted through accumulated deficit as of January 1, 2018. In January 2016, the FASB issued ASU 2016-01, Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”), which provides guidance related to the accounting for equity investments, financial liabilities under the fair value option and the presentation and disclosure requirements for financial instruments. The guidance became effective for the Company beginning on January 1, 2018 and prescribes different transition methods for the various provisions. The adoption of ASU 2016-01 did not have a material impact on its consolidated financial statements and disclosures. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”). The standard states that an entity should recognize revenue based on the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The FASB subsequently issued amendments to ASU 2014-09 that had the same effective date of January 1, 2018. Revenue from sales of Rhopressa ® , as well as any other future revenue arrangements, are and will be recognized under the provisions of ASC Topic 606. Recent Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820-10): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement (“ASU 2018-13”), which changes the fair value measurement disclosure requirements of ASC 820. Under this ASU, certain disclosure requirements for fair value measurements are eliminated, amended, or added. These changes aim to improve the overall usefulness of disclosures to financial statement users and reduce unnecessary costs to companies when preparing the disclosures. The guidance is effective for the Company beginning on January 1, 2019 and prescribes different transition methods for the various provisions. The Company does not expect the adoption of ASU 2018-13 to have a material impact on its consolidated financial statements and disclosures. In June 2018, the FASB issued ASU 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting (“ASU 2018-07”) , which expands the scope of ASC Topic 718, Compensation—Stock Compensation to include share-based payments issued to nonemployees for goods or services. Consequently, the accounting for share-based payments to nonemployees and employees will be substantially aligned. This ASU is effective for the Company beginning January 1, 2019, including interim periods within that fiscal year, but early adoption is permitted. The Company does not expect the adoption of ASU 2018-07 to have a material impact on its consolidated financial statements and disclosures. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”), which requires that financial assets measured at amortized cost be presented at the net amount expected to be collected. Currently, U.S. GAAP delays recognition of the full amount of credit losses until the loss is probable of occurring. Under this ASU, the income statement will reflect an entity’s current estimate of all expected credit losses. The measurement of expected credit losses will be based upon historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported amount. Credit losses relating to available-for-sale debt securities will be recorded through an allowance for credit losses rather than as a direct write-down of the security. This ASU is effective for the Company beginning on January 1, 2020, with early adoption permitted beginning on January 1, 2019. The new guidance prescribes different transition methods for the various provisions. The Company does not expect the adoption of ASU 2016-13 to have a material impact on its consolidated financial statements and disclosures. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) (“ASU 2016-02”), which requires lessees to recognize a right of use asset and related lease liability for those leases classified as operating leases at the commencement date and for those leases that have lease terms of more than 12 months. In July 2018, the FASB issued both ASU 2018-10, Codification Improvements to Topic 842, Leases (“ASU 2018-10”) and ASU 2018-11, Leases (Topic 842)—Targeted Improvements (“ASU 2018-11”), which provides additional guidance or clarifications affecting certain aspects of ASU 2016-02 and certain practical expedients. Further, the updated guidance allows an additional transition method to apply the new leases standard at the adoption date, as compared to the beginning of the earliest period presented, and recognize a cumulative-effect adjustment to the beginning balance of retained earnings in the period of adoption . ASU 2016-02, ASU 2018-10 and ASU 2018-11 are effective for the Company beginning on January 1, 2019, and all annual and interim periods thereafter, with early adoption permitted. The Company expects to elect the transition method described in ASU 2018-11 at the adoption date of January 1, 2019 and recognize a cumulative-effect adjustment to accumulated deficit as of January 1, 2019. The Company is currently evaluating the impact of ASU 2016-02, ASU 2018-10 and ASU 2018-11 on its consolidated financial statements and disclosures , but expects to recognize a right of use asset and corresponding liability related to its operating leases .
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share (“Basic EPS”) is calculated by dividing the net loss by the weighted average number of shares of common stock outstanding for the period, without consideration for potentially dilutive securities with the exception of warrants for common stock with a $0.05 exercise price, which are exercisable for nominal consideration and are therefore included in the calculation of the weighted average number of shares of common stock as common stock equivalents. Diluted net loss per share (“Diluted EPS”) gives effect to all dilutive potential shares of common stock outstanding during this period. For Diluted EPS, net loss used in calculating Basic EPS is adjusted for certain items related to the dilutive securities. For all periods presented, Aerie’s potential common stock equivalents have been excluded from the computation of Diluted EPS as their inclusion would have had an anti-dilutive effect.

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives	Estimated useful lives by major asset category are as follows: Manufacturing equipment 10 years Laboratory equipment 7 years Furniture and fixtures 5 years Software and computer equipment 3 years Leasehold improvements Lower of estimated useful life or term of lease Property, plant and equipment, net consists of the following: (in thousands) SEPTEMBER 30, 2018 DECEMBER 31, 2017 Manufacturing equipment $ 2,307 $ 2,082 Laboratory equipment 4,915 3,602 Furniture and fixtures 1,536 1,209 Software and computer equipment 2,321 1,932 Leasehold improvements 3,685 1,887 Construction-in-progress 48,416 24,228 63,180 34,940 Less: Accumulated depreciation (4,820 ) (3,008 ) Total property, plant and equipment, net $ 58,360 $ 31,932
Schedule of Computation of Diluted EPS	The potential common stock equivalents that have been excluded from the computation of Diluted EPS consist of the following: THREE MONTHS ENDED NINE MONTHS ENDED 2018 2017 2018 2017 2014 Convertible Notes — 5,040,323 — 5,040,323 Outstanding stock options 6,951,639 6,237,959 6,951,639 6,237,959 Stock purchase warrants 154,500 157,500 154,500 157,500 Nonvested restricted stock awards 584,124 439,549 584,124 439,549 Total 7,690,263 11,875,331 7,690,263 11,875,331

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Cash, Cash Equivalents and Investments	Cash, cash equivalents and investments as of September 30, 2018 included the following: (in thousands) AMORTIZED COST GROSS UNREALIZED GAINS GROSS UNREALIZED LOSSES FAIR VALUE Cash and cash equivalents: Cash and money market funds $ 234,954 $ — $ — $ 234,954 Total cash and cash equivalents $ 234,954 $ — $ — $ 234,954 Investments: Corporate bonds (due within 1 year) 1,001 — (1 ) 1,000 Total investments $ 1,001 $ — $ (1 ) $ 1,000 Total cash, cash equivalents and investments $ 235,955 $ — $ (1 ) $ 235,954 Cash, cash equivalents and investments as of December 31, 2017 included the following: (in thousands) AMORTIZED COST GROSS UNREALIZED GAINS GROSS UNREALIZED LOSSES FAIR VALUE Cash and cash equivalents: Cash and money market funds $ 197,569 $ — $ — $ 197,569 Total cash and cash equivalents $ 197,569 $ — $ — $ 197,569 Investments: Commercial paper (due within 1 year) $ 30,883 $ — $ — $ 30,883 Corporate bonds (due within 1 year) 21,231 — (28 ) 21,203 Total investments $ 52,114 $ — $ (28 ) $ 52,086 Total cash, cash equivalents and investments $ 249,683 $ — $ (28 ) $ 249,655

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	The following tables summarize the fair value of financial assets and liabilities that are measured at fair value and the classification by level of input within the fair value hierarchy: FAIR VALUE MEASUREMENTS AS OF SEPTEMBER 30, 2018 (in thousands) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 234,954 $ — $ — $ 234,954 Total cash and cash equivalents $ 234,954 $ — $ — $ 234,954 Investments: Corporate bonds $ — $ 1,000 $ — $ 1,000 Total investments $ — $ 1,000 $ — $ 1,000 Total cash, cash equivalents and investments $ 234,954 $ 1,000 $ — $ 235,954 FAIR VALUE MEASUREMENTS AS OF DECEMBER 31, 2017 (in thousands) Level 1 Level 2 Level 3 Total Cash and cash equivalents: Cash and money market funds $ 197,569 $ — $ — $ 197,569 Total cash and cash equivalents $ 197,569 $ — $ — $ 197,569 Investments: Commercial paper $ — $ 30,883 $ — $ 30,883 Corporate bonds — 21,203 — 21,203 Total investments $ — $ 52,086 $ — $ 52,086 Total cash, cash equivalents and investments $ 197,569 $ 52,086 $ — $ 249,655

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventory consists of the following: (in thousands) SEPTEMBER 30, 2018 Raw materials $ 559 Work-in-process 2,478 Finished goods 2,575 Total inventory $ 5,612

Property, Plant and Equipment_2

Property, Plant and Equipment, Net (Tables)	9 Months Ended
	Sep. 30, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Estimated useful lives by major asset category are as follows: Manufacturing equipment 10 years Laboratory equipment 7 years Furniture and fixtures 5 years Software and computer equipment 3 years Leasehold improvements Lower of estimated useful life or term of lease Property, plant and equipment, net consists of the following: (in thousands) SEPTEMBER 30, 2018 DECEMBER 31, 2017 Manufacturing equipment $ 2,307 $ 2,082 Laboratory equipment 4,915 3,602 Furniture and fixtures 1,536 1,209 Software and computer equipment 2,321 1,932 Leasehold improvements 3,685 1,887 Construction-in-progress 48,416 24,228 63,180 34,940 Less: Accumulated depreciation (4,820 ) (3,008 ) Total property, plant and equipment, net $ 58,360 $ 31,932

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	9 Months Ended
	Sep. 30, 2018
Payables and Accruals [Abstract]
Summary of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consist of the following: (in thousands) SEPTEMBER 30, 2018 DECEMBER 31, 2017 Accrued compensation and benefits $ 9,465 $ 7,886 Accrued consulting and professional fees 3,955 3,841 Accrued research and development expenses (1) 4,297 1,855 Accrued revenue reserves 4,819 — Accrued other (2) 5,412 5,357 Total accrued expenses and other current liabilities $ 27,948 $ 18,939 (1) Comprised of accruals related to fees for investigative sites, contract research organizations, contract manufacturing organizations and other service providers that assist in conducting preclinical research studies and clinical trials. (2) Comprised of accruals related to commercial manufacturing activities prior to FDA approval of Rhopressa ® and Rocklatan TM as well as other business-related expenses.

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Summary of Carrying Value of Convertible Notes	The table below summarizes the carrying value of the 2014 Convertible Notes as of December 31, 2017 : (in thousands) DECEMBER 31, 2017 Gross proceeds $ 125,000 Unamortized debt discount and issuance costs (1,155 ) Carrying value $ 123,845

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Equity Classified Warrants Outstanding	As of September 30, 2018 , the following equity-classified warrants to purchase common stock were outstanding: NUMBER OF UNDERLYING SHARES EXERCISE PRICE PER SHARE WARRANT EXPIRATION DATE 75,000 $5.00 February 2019 75,000 $5.00 November 2019 4,500 $5.00 August 2020 223,482 $0.05 December 2019

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense for Options Granted, Restricted Stock and Stock Purchase Rights as Reflected in Statement of Operations	Stock-based compensation expense for options granted, RSAs, performance stock awards (“PSAs”), SARs and stock purchase rights is reflected in the condensed consolidated statements of operations and comprehensive loss as follows: THREE MONTHS ENDED NINE MONTHS ENDED (in thousands) 2018 2017 2018 2017 Selling, general and administrative $ 7,382 $ 4,995 $ 21,826 $ 14,032 Research and development 2,596 1,562 7,189 4,040 Total $ 9,978 $ 6,557 $ 29,015 $ 18,072
Schedule of Stock Options Activity	The following table summarizes the stock option activity under the Plans: NUMBER OF WEIGHTED AVERAGE WEIGHTED AGGREGATE Options outstanding at December 31, 2017 6,457,343 $ 22.15 Granted 1,207,984 56.81 Exercised (600,690 ) 8.74 Canceled (112,998 ) 46.01 Options outstanding at September 30, 2018 6,951,639 $ 28.92 7.0 $ 227,793 Options exercisable at September 30, 2018 4,440,403 $ 18.39 5.9 $ 191,690
Restricted Stock and Restricted Stock Units Activity	The following table summarizes the RSAs, including PSAs, activity under the Plans: NUMBER OF SHARES WEIGHTED AVERAGE FAIR VALUE PER SHARE Nonvested RSAs at December 31, 2017 447,049 $ 41.08 Granted 264,999 56.00 Vested (122,461 ) 38.47 Canceled (5,463 ) 48.41 Nonvested RSAs at September 30, 2018 584,124 $ 48.32

The Company (Detail)

The Company (Detail)	Dec. 31, 2020USD ($)	Aug. 01, 2018USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)Segment	Sep. 30, 2017USD ($)	Jul. 23, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2014USD ($)
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Number of operating segments | Segment					1
Research and development expense			$ 28,502,000	$ 12,408,000	$ 59,631,000	$ 33,977,000
Aggregate amount of senior notes issued								$ 125,000,000
Induced conversion, expense recognized			24,100,000
2014 Notes | 2014 Convertible Notes
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Aggregate amount of senior notes issued								$ 125,000,000	$ 125,000,000
Revolving Credit Facility | Delayed Draw Term Loan
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Maximum borrowing capacity							$ 100,000,000
Collaborative Arrangement
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Amount paid upon execution of collaboration agreement		$ 6,000,000
Research and development expense			$ 7,400,000
Collaborative Arrangement | Scenario, Forecast
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Amount payable on collaborative arrangement	$ 9,000,000

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest income	$ 800,000	$ 600,000	$ 2,500,000	$ 1,300,000
Gross realized loss	$ 0	$ 0	$ 200,000	$ 0
Warrants exercise price (in dollars per share)	$ 0.05		$ 0.05
Long-term Receivable | Accounting Standards Update 2016-16
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax effects deferred from past intercompany transactions					$ 2,100,000

Significant Accounting Polici_5

Significant Accounting Policies - Schedule of Estimated Useful Lives (Details)	9 Months Ended
	Sep. 30, 2018
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Useful lives	10 years
Laboratory equipment
Property, Plant and Equipment [Line Items]
Useful lives	7 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful lives	5 years
Software and computer equipment
Property, Plant and Equipment [Line Items]
Useful lives	3 years

Significant Accounting Polici_6

Significant Accounting Policies - Antidilutive Securities (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	7,690,263	11,875,331	7,690,263	11,875,331
2014 Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	0	5,040,323	0	5,040,323
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	6,951,639	6,237,959	6,951,639	6,237,959
Stock purchase warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	154,500	157,500	154,500	157,500
Nonvested restricted stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential common stock equivalents excluded from the computation of diluted net loss per share (in shares)	584,124	439,549	584,124	439,549

Revenue Recognition (Details)

Revenue Recognition (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Percentage of coverage for lives obtained under commercial plans		85.00%
Percentage of coverage for lives obtained under medicare plans		40.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor One
Disaggregation of Revenue [Line Items]
Concentration risk percentage	34.00%	34.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor Two
Disaggregation of Revenue [Line Items]
Concentration risk percentage	32.00%	32.00%
Customer Concentration Risk | Sales Revenue, Net | Rhopressa | Distributor Three
Disaggregation of Revenue [Line Items]
Concentration risk percentage	31.00%	31.00%

Investments (Detail)

Investments (Detail) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Cash and cash equivalents:
AMORTIZED COST	$ 234,954	$ 197,569	$ 194,078	$ 197,945
FAIR VALUE	234,954	197,569
Investments:
AMORTIZED COST	1,001	52,114
GROSS UNREALIZED GAINS	0	0
GROSS UNREALIZED LOSSES	(1)	(28)
FAIR VALUE	1,000	52,086
Total cash, cash equivalents and investments, amortized cost	235,955	249,683
Total cash, cash equivalents and investments, fair value	235,954	249,655
Commercial paper
Investments:
AMORTIZED COST		30,883
GROSS UNREALIZED GAINS		0
GROSS UNREALIZED LOSSES		0
FAIR VALUE		30,883
Corporate bonds
Investments:
AMORTIZED COST	1,001	21,231
GROSS UNREALIZED GAINS	0	0
GROSS UNREALIZED LOSSES	(1)	(28)
FAIR VALUE	1,000	21,203
Cash and money market funds
Cash and cash equivalents:
AMORTIZED COST	234,954	197,569
FAIR VALUE	$ 234,954	$ 197,569

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities by Level of Input (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	$ 234,954	$ 197,569
Total investments	1,000	52,086
Total cash, cash equivalents and investments	235,954	249,655
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	234,954	197,569
Total investments	0	0
Total cash, cash equivalents and investments	234,954	197,569
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	0	0
Total investments	1,000	52,086
Total cash, cash equivalents and investments	1,000	52,086
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	0	0
Total investments	0	0
Total cash, cash equivalents and investments	0	0
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		30,883
Commercial paper | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		0
Commercial paper | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		30,883
Commercial paper | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments		0
Corporate bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	1,000	21,203
Corporate bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Corporate bonds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	1,000	21,203
Corporate bonds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total investments	0	0
Cash and money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	234,954	197,569
Cash and money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	234,954	197,569
Cash and money market funds | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	0	0
Cash and money market funds | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash and cash equivalents	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($)	Dec. 31, 2017	Sep. 30, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate amount of senior notes issued	$ 125,000,000
2014 Notes | 2014 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Aggregate amount of senior notes issued	125,000,000	$ 125,000,000
Senior secured convertible notes	$ 327,600,000

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Inventory Disclosure [Abstract]
Raw materials	$ 559
Work-in-process	2,478
Finished goods	2,575
Total inventory	$ 5,612	$ 0

Property, Plant and Equipment_3

Property, Plant and Equipment, Net - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 63,180	$ 34,940
Less: Accumulated depreciation	(4,820)	(3,008)
Total property, plant and equipment, net	58,360	31,932
Manufacturing equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,307	2,082
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,915	3,602
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,536	1,209
Software and computer equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,321	1,932
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,685	1,887
Construction-in-progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 48,416	$ 24,228

Property, Plant and Equipment_4

Property, Plant and Equipment, Net - Additional Information (Details)	1 Months Ended	3 Months Ended		9 Months Ended
	Jan. 31, 2017USD ($)ft²	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)
Property, Plant and Equipment [Line Items]
Area of interior floor space (in sqft) | ft²	30,000
Capital expenditures related to manufacturing plant				$ 24,200,000
Build-to-suit facility lease obligation		$ 4,600,000		4,600,000		$ 4,900,000
Foreign exchange gain (loss)		0	$ (200,000)	200,000	$ (500,000)
Property, Plant and Equipment
Property, Plant and Equipment [Line Items]
Capitalized amount of build-to-suit asset	$ 4,200,000
Other Current Liabilities
Property, Plant and Equipment [Line Items]
Build-to-suit facility lease obligation		$ 300,000		$ 300,000

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Accrued expenses and other liabilities:
Accrued compensation and benefits	$ 9,465	$ 7,886
Accrued consulting and professional fees	3,955	3,841
Accrued research and development	4,297	1,855
Accrued revenue reserves	4,819	0
Accrued other	5,412	5,357
Total accrued expenses and other current liabilities	$ 27,948	$ 18,939

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Jul. 23, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Sep. 30, 2014
Debt Instrument [Line Items]
Aggregate amount of senior notes issued						$ 125,000,000
Induced conversion, expense recognized		$ 24,100,000
Funds withdrawn at closing	$ 0	0		$ 0
Convertible notes
Debt Instrument [Line Items]
Debt instrument, interest rate percentage							1.75%
Interest expense related to convertible notes		800,000	$ 600,000	1,700,000	$ 1,800,000
2014 Notes | Convertible notes
Debt Instrument [Line Items]
Aggregate amount of senior notes issued						$ 125,000,000	$ 125,000,000
Unamortized discount, gross		$ (2,100,000)		$ (2,100,000)
Common stock | 2014 Notes
Debt Instrument [Line Items]
Shares converted (in shares)	5,040,323
Additional shares converted (in shares)	329,124
Revolving Credit Facility | Delayed Draw Term Loan
Debt Instrument [Line Items]
Debt instrument, interest rate percentage	8.625%
Maximum borrowing capacity	$ 100,000,000
Percentage of fees upon drawdown of amounts drawn	1.75%
Percentage of annual fees on undrawn amount	1.50%
One-time termination fee amount	$ 1,500,000

Debt - Summary of Carrying Valu

Debt - Summary of Carrying Value of Convertible Notes (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Gross proceeds		$ 125,000
Unamortized debt discount and issuance costs		(1,155)
Carrying value	$ 0	$ 123,845

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	Jan. 23, 2018	Sep. 30, 2018	Sep. 30, 2017
Class of Stock [Line Items]
Proceeds from sale of common stock, net		$ 135,972	$ 122,046
Common stock
Class of Stock [Line Items]
Common stock issued and sold under sales agreement (in shares)		1
Proceeds from sale of common stock, net		$ 62,300
Underwriting discounts, fees and expenses	$ 900	$ 500
Stock issued during period (in shares)	1.3
Proceeds from issuance of common stock, net of underwriting discounts, fees and expenses	$ 74,100

Stockholders' Equity - Schedule

Stockholders' Equity - Schedule of Warrants Outstanding (Detail)	Sep. 30, 2018$ / sharesshares
Class of Warrant or Right [Line Items]
EXERCISE PRICE PER SHARE (in dollars per share)	$ 0.05
February 2019 | Common stock
Class of Warrant or Right [Line Items]
NUMBER OF UNDERLYING SHARES (in shares) | shares	75,000
EXERCISE PRICE PER SHARE (in dollars per share)	$ 5
November 2019 | Common stock
Class of Warrant or Right [Line Items]
NUMBER OF UNDERLYING SHARES (in shares) | shares	75,000
EXERCISE PRICE PER SHARE (in dollars per share)	$ 5
August 2020 | Common stock
Class of Warrant or Right [Line Items]
NUMBER OF UNDERLYING SHARES (in shares) | shares	4,500
EXERCISE PRICE PER SHARE (in dollars per share)	$ 5
December 2019 | Common stock
Class of Warrant or Right [Line Items]
NUMBER OF UNDERLYING SHARES (in shares) | shares	223,482
EXERCISE PRICE PER SHARE (in dollars per share)	$ 0.05

Stock-Based Compensation - Allo

Stock-Based Compensation - Allocated Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 9,978	$ 6,557	$ 29,015	$ 18,072
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	7,382	4,995	21,826	14,032
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,596	$ 1,562	$ 7,189	$ 4,040

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) $ / shares in Units, $ in Millions	Apr. 10, 2015shares	Oct. 30, 2013shares	Sep. 30, 2018USD ($)plan$ / sharesshares	Dec. 31, 2017shares	Jun. 07, 2018shares	Dec. 07, 2016shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equity compensation plans | plan			3
Additional awards granted (in shares)			1,207,984
Weighted-average exercise price (in dollars per share) | $ / shares			$ 8.74
Options exercisable, weighted average remaining contractual life			5 years 11 months 5 days
2005 Aerie Pharmaceutical Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional awards granted (in shares)		0
2013 Omnibus incentive plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional awards granted (in shares)	0
Equity awards (in shares)			10,229,068		4,500,000
Inducement Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards (in shares)				874,500		418,000
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense | $			$ 78.4
Weighted-average remaining vesting period			2 years 10 months 21 days
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense related to unvested awards | $			$ 20
Weighted-average of remaining vesting period			2 years 10 months 24 days
Granted (in shares)			264,999
Vested (in shares)			122,461
Awards outstanding (in shares)			584,124	447,049
Restricted stock | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based awards, vesting period			1 year
Restricted stock | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based awards, vesting period			4 years
Restricted Stock With Non-Market Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				98,817
Vested (in shares)			19,764
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			104,000
Weighted-average exercise price (in dollars per share) | $ / shares			$ 54.20
Awards outstanding (in shares)			96,000
Options exercisable, weighted average remaining contractual life			4 years 5 months 27 days

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock Options Activity (Detail) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
NUMBER OF SHARES
Beginning balance (in shares) | shares	6,457,343
Granted (in shares) | shares	1,207,984
Exercised (in shares) | shares	(600,690)
Canceled (in shares) | shares	(112,998)
Ending balance (in shares) | shares	6,951,639
Options exercisable (in shares) | shares	4,440,403
WEIGHTED AVERAGE EXERCISE PRICE
Beginning balance (in dollars per share) | $ / shares	$ 22.15
Granted (in dollars per share) | $ / shares	56.81
Exercised (in dollars per share) | $ / shares	8.74
Cancelled (in dollars per share) | $ / shares	46.01
Ending balance (in dollars per share) | $ / shares	28.92
Options exercisable (in dollars per share) | $ / shares	$ 18.39
WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)
Options outstanding, weighted average remaining contractual life	6 years 11 months 15 days
Options exercisable	5 years 11 months 5 days
AGGREGATE INTRINSIC VALUE
Options outstanding | $	$ 227,793
Options exercisable | $	$ 191,690

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock and Restricted Stock Units Activity (Details) - Restricted stock	9 Months Ended
	Sep. 30, 2018$ / sharesshares
NUMBER OF SHARES
Beginning balance (in shares) | shares	447,049
Granted (in shares) | shares	264,999
Vested (in shares) | shares	(122,461)
Canceled (in shares) | shares	(5,463)
Ending balance (in shares) | shares	584,124
WEIGHTED AVERAGE FAIR VALUE PER SHARE
Beginning balance (in dollars per share) | $ / shares	$ 41.08
Granted (in dollars per share) | $ / shares	56
Vested (in dollars per share) | $ / shares	38.47
Canceled (in dollars per share) | $ / shares	48.41
Ending balance (in dollars per share) | $ / shares	$ 48.32