Energous (WATT) 10-Q 9 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 05, 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	WATT
Entity Registrant Name	Energous Corp
Entity Central Index Key	1,575,793
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		26,094,600

Balance Sheets

Balance Sheets - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 28,551,870	$ 12,795,254
Accounts receivable	208,773	0
Prepaid expenses and other current assets	528,626	1,026,310
Prepaid rent, current	76,864	80,784
Total current assets	29,366,133	13,902,348
Property and equipment, net	1,154,996	1,413,917
Prepaid rent, non-current		56,668
Other assets	125,060	32,512
Total assets	30,646,189	15,405,445
Current liabilities:
Accounts payable	1,819,968	2,024,690
Accrued expenses	1,918,693	1,622,025
Deferred revenue	14,500
Total current liabilities	3,753,161	3,646,715
Commitments and contingencies
Stockholders’ equity:
Preferred Stock, $0.00001 par value, 10,000,000 shares authorized at September 30, 2018 and December 31, 2017; no shares issued or outstanding
Common Stock, $0.00001 par value, 50,000,000 shares authorized at September 30, 2018 and December 31, 2017; 26,059,350 and 22,584,588 shares issued and outstanding at September 30, 2018 and December 31, 2017, respectively.	259	225
Additional paid-in capital	239,181,337	185,659,954
Accumulated deficit	(212,288,568)	(173,901,449)
Total stockholders’ equity	26,893,028	11,758,730
Total liabilities and stockholders’ equity	$ 30,646,189	$ 15,405,445

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2018	Dec. 31, 2017
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	26,059,350	22,584,588
Common stock, shares outstanding	26,059,350	22,584,588

Condensed Statements of Operati

Condensed Statements of Operations - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 228,000	$ 250,000	$ 458,773	$ 1,124,874
Operating expenses:
Research and development	8,442,698	8,743,434	24,804,224	25,788,621
Sales and marketing	1,546,227	1,141,852	4,620,760	3,924,617
General and administrative	2,891,036	3,116,337	9,439,279	9,560,651
Total operating expenses	12,879,961	13,001,623	38,864,263	39,273,889
Loss from operations	(12,651,961)	(12,751,623)	(38,405,490)	(38,149,015)
Other income (expense):
Loss on sales of property and equipment, net				(726)
Interest income	6,670	3,375	18,371	9,343
Total	6,670	3,375	18,371	8,617
Net loss	$ (12,645,291)	$ (12,748,248)	$ (38,387,119)	$ (38,140,398)
Basic and diluted loss per common share	$ (0.49)	$ (0.58)	$ (1.50)	$ (1.81)
Weighted average shares outstanding, basic and diluted	25,742,171	21,958,729	25,519,868	21,034,391

Condensed Statement of Changes

Condensed Statement of Changes in Stockholders' Equity - 9 months ended Sep. 30, 2018 - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2017	$ 11,758,730	$ 225	$ 185,659,954	$ (173,901,449)
Beginning balance (in shares) at Dec. 31, 2017		22,584,588
Stock-based compensation - restricted stock units ("RSUs")	11,714,962		11,714,962
Stock-based compensation - employee stock purchase plan ("ESPP")	474,920		474,920
Stock-based compensation - performance share units ("PSUs")	614,862		614,862
Issuance of shares for RSUs		$ 7	(7)
Issuance of shares for RSUs (in shares)		743,647
Issuance of shares for PSUs		$ 1	(1)
Issuance of shares for PSUs (in shares)		80,098
Exercise of stock options	1,319,461	$ 4	1,319,457
Exercise of stock options (in shares)		380,745
Cashless exercise of warrants (in shares)		19,359
Proceeds from contributions to the ESPP	550,397		550,397
Proceeds from contributions to the ESPP (in shares)		29,458
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs	38,846,815	$ 22	38,846,793
Issuance of shares in an at-the-market ("ATM") offering, net of issuance costs (in shares)		2,221,455
Net loss	(38,387,119)			(38,387,119)
Ending balance at Sep. 30, 2018	$ 26,893,028	$ 259	$ 239,181,337	$ (212,288,568)
Ending balance (in shares) at Sep. 30, 2018		26,059,350

Condensed Statement of Change_2

Condensed Statement of Changes in Stockholders' Equity (Parenthetical)	9 Months Ended
	Sep. 30, 2018USD ($)
Statement Of Stockholders Equity [Abstract]
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 1,153,715

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net loss	$ (38,387,119)	$ (38,140,398)
Adjustments to reconcile net loss to Net cash used in operating activities:
Depreciation and amortization	820,714	999,396
Stock based compensation	12,804,744	12,472,870
Amortization of prepaid rent from stock issuance to landlord	60,588	60,588
Loss on sales of property and equipment, net		726
Changes in operating assets and liabilities:
Accounts receivable	(208,773)	(101,000)
Prepaid expenses and other current assets	497,684	654,654
Other assets	(92,548)	15,995
Accounts payable	(204,722)	(2,537,833)
Accrued expenses	296,668	(209,179)
Deferred revenue	14,500	(102,823)
Net cash used in operating activities	(24,398,264)	(26,887,004)
Cash flows from investing activities:
Purchases of property and equipment	(561,793)	(517,947)
Proceeds from sales of property and equipment		2,800
Net cash used in investing activities	(561,793)	(515,147)
Cash flows from financing activities:
Net proceeds from the sales of common stock	38,846,815	14,932,547
Proceeds from the exercise of stock options	1,319,461	738,552
Proceeds from contributions to employee stock purchase plan	550,397	696,274
Net cash provided by financing activities	40,716,673	16,367,373
Net increase (decrease) in cash and cash equivalents	15,756,616	(11,034,778)
Cash and cash equivalents - beginning	12,795,254	31,258,637
Cash and cash equivalents - ending	28,551,870	20,223,859
Restricted Stock Units (RSUs) [Member]
Supplemental disclosure of non-cash financing activities:
Common stock issued	7	$ 6
Performance Shares [Member]
Supplemental disclosure of non-cash financing activities:
Common stock issued	$ 1

Business Organization, Nature o

Business Organization, Nature of Operations	9 Months Ended
	Sep. 30, 2018
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Business Organization, Nature of Operations	Note 1 - Business Organization, Nature of Operations Energous Corporation (the “Company”) was incorporated in Delaware on October 30, 2012. The Company has developed its WattUp® technology, consisting of proprietary semiconductor chipsets, software, hardware designs and antennas, that enables radio frequency (“RF”) based charging for electronic devices, providing wire-free contact and non-contact charging solutions, with the potential to enable charging with mobility. Dialog Semiconductor plc (“Dialog”) manufactures and distributes integrated circuit (“IC”) products incorporating the Company’s charging technology, p Strategic Alliance Agreement with the Company. Dialog is the exclusive supplier of these IC products for the general market.

Liquidity and Management Plans

Liquidity and Management Plans	9 Months Ended
	Sep. 30, 2018
Liquidity And Management Plan Disclosure [Abstract]
Liquidity and Management Plans	Note 2 – Liquidity and Management Plans During the three and nine months ended September 30, 2018, the Company recorded revenue of $228,000 and $458,773, respectively, and during the three and nine months ended September 30, 2017, the Company recorded revenue of $250,000 and $1,124,874, respectively. During the three and nine months ended September 30, 2018, the Company recorded a net loss of $12,645,291 and $38,387,119, respectively. During the three and nine months ended September 30, 2017, the Company recorded a net loss of $12,748,248 and $38,140,398, respectively. Net cash used in operating activities was $24,398,264 and $26,887,004 for the nine months ended September 30, 2018 and 2017, respectively. The Company is currently meeting its liquidity requirements through an at-the-market (“ATM”) sale of common stock in January 2018, which raised net proceeds of $38,846,815, the sales of shares to a private investor during July 2017, which raised net proceeds of $14,932,547, and payments received under product development projects. As of September 30, 2018, the Company had cash on hand of $28,551,870. The Company expects that cash on hand as of September 30, 2018, together with anticipated revenues, will be sufficient to fund the Company’s operations into the fourth quarter of 2019. Research and development of new technologies is by its nature unpredictable. Although the Company will undertake development efforts with commercially reasonable diligence, there can be no assurance that its available resources, including the net proceeds from the Company’s financings to date, will be sufficient to enable it to develop and obtain regulatory approval of its technology to the extent needed to create future revenues sufficient to sustain its operations. The Company may pursue additional financing, which could include follow-on equity offerings, debt financing, co-development agreements or other alternatives, depending upon market conditions. Should the Company choose to pursue additional financing, there is no assurance that such financing would be available on terms that it would find acceptable, or at all. The market for products using the Company’s technology is broad, but is nascent and unproven, so the Company’s success is sensitive to many factors, including technological feasibility, regulatory approval, customer acceptance, competition and global market fluctuations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Note 3 – Summary of Significant Accounting Policies Basis of Presentation The accompanying financial statements are presented in U.S. dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”), and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). These unaudited condensed interim financial statements should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2017 included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2017, filed with the SEC on March 16, 2018. The accounting policies used in preparing these unaudited condensed interim financial statements are consistent with those described in the Company’s December 31, 2017 audited financial statements . Note 3 – Summary of Significant Accounting Policies, continued Use of Estimates The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the financial statements as well as the reported expenses during the reporting periods. The Company’s significant estimates and assumptions include the valuation of stock-based compensation instruments, recognition of revenue, the useful lives of long-lived assets, and income tax expense. Some of these judgments can be subjective and complex, and, consequently, actual results may differ from these estimates. Although the Company believes that its estimates and assumptions are reasonable, they are based upon information available at the time the estimates and assumptions were made. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all short-term, highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents. The Company maintains cash balances that may be uninsured or in deposit accounts that exceed Federal Deposit Insurance Corporation limits. The Company maintains its cash deposits with major financial institutions. Revenue Recognition On January 1, 2018, the Company adopted Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers" (Topic 606), which is described below in Recent Accounting Pronouncements. In accordance with Topic 606, the Company recognizes revenue using the following five-step approach: 1. Identify the contract with a customer. 2. Identify the performance obligations in the contract. 3. Determine the transaction price of the contract. 4. Allocate the transaction price to the performance obligations in the contract. 5. Recognize revenue when the performance obligations are met or delivered. The Company records revenue associated with product development projects that it enters into with certain customers. In general, these projects are associated with complex technology development, and as such the Company does not have certainty about its ability to achieve the program milestones. Achievement of the milestone is dependent on the Company’s performance typically requires acceptance by the customer. The payment associated with achieving the milestone is generally commensurate with the Company’s effort or the value of the deliverable and is nonrefundable. The Company records the expenses related to these projects, generally included in research and development expense, in the periods incurred. The Company records royalty revenue from its manufacturing partner, Dialog, based on the number of shipments from Dialog to its customers. Research and Development Research and development expenses are charged to operations as incurred. For internally developed patents, all patent application costs are expensed as incurred as research and development expense. Patent application costs, generally legal costs, are expensed as research and development costs until such time as the future economic benefits of such patents become more certain. The Company incurred research and development costs of $8,442,698 and $8,743,434 for the three months ended September 30, 2018 and 2017, respectively, and the Company incurred research and development cost of $24,804,224 and $25,788,621 for the nine months ended September 30, 2018 and 2017, respectively. Stock-Based Compensation The Company accounts for equity instruments issued to employees in accordance with accounting guidance that requires awards to be recorded at their fair value on the date of grant and are amortized over the vesting period of the award. The Company recognizes compensation costs on a straight-line basis over the requisite service period of the award, which is typically the vesting term of the equity instrument issued. Note 3 – Summary of Significant Accounting Policies, continued Under the Energous Corporation Employee Stock Purchase Plan (“ESPP”), employees may purchase a limited number of shares of the Company’s common stock at a 15% discount from the lower of the closing market prices measured on the first and last days of each half-year period. The Company recognizes compensation expense for the fair value of the purchase options, as measured on the grant date. Income Taxes Tax benefits are recognized only for tax positions that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. A liability for “unrecognized tax benefits” is recorded for any tax benefits claimed in the Company’s tax returns that do not meet these recognition and measurement standards. As of September 30, 2018, no liability for unrecognized tax benefits was required to be reported. The guidance also discusses the Net Loss Per Common Share Basic net loss per share is computed by dividing net loss available to common stockholders by the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share is computed using the weighted average number of common shares and, if dilutive, potential common shares outstanding during the period. Potential common shares consist of the incremental common shares issuable upon the exercise of stock options and warrants (using the treasury stock method), the vesting of restricted stock units (“RSUs”), performance stock units (“PSUs”) and the enrollment of employees in the ESPP. The computation of diluted loss per share excludes potentially dilutive securities of 6,840,737 and 7,862,420 for the three months ended September 30, 2018 and 2017, respectively, and 6,840,737 and 7,862,420 for the nine months ended September 30, 2018 and 2017, respectively, because their inclusion would be anti-dilutive. Potentially dilutive securities outlined in the table below have been excluded from the computation of diluted net loss per share because the effect of their inclusion would have been anti-dilutive. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Financing Warrant to purchase common stock - 13,889 - 13,889 IPO Warrants to purchase common stock - 11,600 - 11,600 Warrant issued to private investors 3,035,688 3,035,688 3,035,688 3,035,688 Options to purchase common stock 656,494 1,149,589 656,494 1,149,589 RSUs 2,276,996 2,498,037 2,276,996 2,498,037 PSUs 871,559 1,153,617 871,559 1,153,617 Total potentially dilutive securities 6,840,737 7,862,420 6,840,737 7,862,420 Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers" (Topic 606) (“ASU 2014-09”), which supersedes the revenue recognition requirements in ASU Topic 605, "Revenue Recognition," and most industry-specific guidance. ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of 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. ASU 2014-09 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. Originally, ASU 2014-09 would be effective Note 3 – Summary of Significant Accounting Policies, continued for the Company starting January 1, 2017 using either of two methods: (i) retrospective to each prior reporting period presented with the option to elect certain practical expedients as defined within ASU 2014-09; or (ii) retrospective with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application and providing certain additional disclosures as defined per ASU 2014-09. In July 2015, FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. The Company used the modified retrospective implementation method for all contracts and did not need to record a cumulative effect adjustment to retained earnings as of the date of initial application. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities”. The standard addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company has adopted ASU 2016-01 and its adoption had no material impact on it financial statements. In January 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. This standard requires that a lessee recognize the assets and liabilities that arise from operating leases. A lessee should recognize in the statement of In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230) – Classification of Certain Cash Receipts and Cash Payments.” ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. It is effective for annual reporting periods beginning after December 15, 2017. The adoption of the new standard did not have a material impact on our financial statements. In November 2016, the FASB issued ASU No. 2016-18, “Statement of Cash Flows (230) – Restricted Cash.” ASU No. 2016-18 requires an entity to include amounts described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. It is effective for annual reporting periods beginning after December 15, 2018. The adoption of this standard is not expected to have a material impact on the Company’s financial position and results of operations. In December 2016, the FASB issued ASU No. 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers.” ASU No. 2016-20 amends certain aspects of ASU No. 2014-09 and clarifies, rather than changes, the core revenue recognition principles in ASU No. 2014-09. It is effective for annual reporting periods beginning after December 15, 2018. The adoption of this standard is not expected to have a material impact on the Company’s financial position and results of operations. In May 2017, the FASB issued ASU No. 2017-09, “Compensation – Stock Compensation (Topic 718) – Scope of Modification Accounting.” ASU No. 2017-09 provides clarity and reduces complexity when applying the guidance in Topic 718 for changes in terms or conditions of share-based payment awards. It is effective for annual reporting periods beginning after December 15, 2017. The adoption of the new standard did not have a material impact on our financial statements. In July 2017, the FASB issued a two-part ASU No. 2017-11, I. Accounting for Certain Financial Instruments with Down Round Features and II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception. ASU 2017-11 amends guidance in FASB ASC 260, Earnings Per Share, FASB ASC 480, Distinguishing Liabilities from Equity, and FASB ASC 815, Derivatives and Hedging. The amendments in Part I of ASU 2017-11 change the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments in Part II of ASU 2017-11 re-characterize the indefinite Note 3 – Summary of Significant Accounting Policies, continued deferral of certain provisions of Topic 480 that now are presented as pending content in the Codification, to a scope exception. Those amendments do not have an accounting effect. ASU 2017-11 is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements. In June 2018, the FASB issued ASU No. 2018-07, “Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-based Payment Accounting.” ASU 2018-07 aligns accounting for share-based payments issued to nonemployees to that of employees under the existing guidance of Topic 718, with certain exceptions. This update supersedes previous guidance for equity-based payments to nonemployees under Subtopic 505-50, “Equity – Equity-based Payments to Nonemployees.” It is effective for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements. Management’s Evaluation of Subsequent Events The Company evaluates events that have occurred after the balance sheet date of September 30, 2018, through the date which the financial statements are issued. Based upon the review, the Company did not identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 4 – Commitments and Contingencies Operating Leases On September 10, 2014, the Company entered into a Lease Agreement with Balzer Family Investments, L.P. (the “Landlord”) related to space located at Northpointe Business Center, 3590 North First Street, San Jose, California. The initial term of the lease is 60 months, with initial monthly base rent of $36,720 and the lease is subject to certain annual escalations as defined in the agreement. On October 1, 2014, the Company relocated its headquarters to this new location. The Company issued to the Landlord 41,563 shares of the Company’s common stock valued at $500,000, of which $400,000 will be applied to reduce the Company’s monthly base rent obligation by $6,732 per month and of which $100,000 was for certain tenant improvements. The Company recorded $400,000 as prepaid rent on its balance sheet, which is being amortized over the term of the lease and recorded $100,000 as leasehold improvements. On February 26, 2015, the Company entered into a sub-lease agreement for additional space in the San Jose area. The agreement has a term which expires on June 30, 2019 and a current monthly rent of $6,668 per month. On August 25, 2015, the Company entered into an additional amended sub-lease agreement for additional space in San Jose, California. The agreement has a term which expires on June 30, 2019 and a current monthly rent of $4,578 per month. These leases are subject to certain annual escalations as defined in the agreements. On May 31, 2017, the Company renewed a lease agreement for the Company’s space in Costa Mesa, California. The agreement has a term that expires on September 30, 2019 with initial monthly rent of $9,040, and is subject to certain annual escalations as defined in the agreement. The future minimum lease payments for leased locations are as follows: For the Years Ended December 31, Amount 2018 (Three Months) $ 163,303 2019 457,585 Total $ 620,888 Hosted Design Solution Agreement In June 2015, the Company entered into a three-year agreement to license electronic design automation software in a hosted environment. Pursuant to the agreement, under which services began in July 2015, the Company is required to remit quarterly payments in the amount of approximately $101,000 with the last payment due in March 2018. In December 2015, the agreement was amended to redefine the hardware and software configuration and the quarterly payments increased to approximately $198,000. In July 2018, the Company renewed the three-year agreement, and Note 4 – Commitments and Contingencies, continued the Company is required to remit quarterly payments in the amount of approximately $218,000, with the last payment due in March 2021. Employee Agreement – Stephen Rizzone On April 3, 2015, the Company entered into an Amended and Restated Executive Employment Agreement with Stephen R. Rizzone, the Company’s President and Chief Executive Officer (“Employment Agreement”). The Employment Agreement has an effective date of January 1, 2015 and an initial term of four years (“Initial Employment Period”). The Employment Agreement provides for an annual base salary of $365,000, and Mr. Rizzone is eligible to receive quarterly cash bonuses with a total target amount equal to 100% of his base salary based upon achievement of performance-based objectives established by the Company’s board of directors (“Board”). Pursuant to Mr. Rizzone’s prior employment agreement, on December 12, 2013, Mr. Rizzone was granted a 10-year option to purchase 275,689 shares of common stock at an exercise price of $1.68 vesting over four years in 48 monthly installments beginning October 1, 2013 (“First Option”). Mr. Rizzone was also granted a second option award to purchase 496,546 shares of common stock at an exercise price of $6.00 (“Second Option”). The Second Option vests over the same vesting schedule as the First Option. Effective May 21, 2015, with the approval by the Company’s stockholders of its new performance-based equity plan, the Employment Agreement provided and Mr. Rizzone received, a grant of 639,075 PSUs. The PSUs, which represent the right to receive shares of common stock, shall be earned based on the Company’s achievement of market capitalization growth between the effective date of the Employment Agreement and the end of the Initial Employment Period. If the Company’s market capitalization is $100 million or less, no PSUs will be earned. If the Company reaches a market capitalization of $1.1 billion or more, 100% of the PSUs will be earned. For market capitalization between $100 million and $1.1 billion, the percentage of PSUs earned will be determined on a quarterly basis based on straight line interpolation. PSUs earned as of the end of a calendar quarter will be paid 50% immediately and 50% will be deferred until the end of the Initial Employment Period subject to Mr. Rizzone’s continued employment with the Company (See Note 6). Mr. Rizzone is also eligible to receive all customary and usual benefits generally available to senior executives of the Company. The Employment Agreement provides that if Mr. Rizzone’s employment is terminated due to his death or disability, if Mr. Rizzone’s employment is terminated by the Company without cause or if he resigns for good reason, 25% of the shares subject to the First Option and the Second Option shall immediately vest and become exercisable, he will have a period of one year post-termination to exercise the First Option and the Second Option, and if a Liquidation Event (as defined in the Employment Agreement) shall occur prior to the termination of the First Option and the Second Option, 100% of the shares subject to the First Option and Second Option shall immediately vest and become exercisable effective immediately prior to the consummation of the Liquidation Event. In addition, any outstanding deferred PSUs shall be immediately vested and paid, but any remaining unearned portion of the PSUs shall immediately be canceled and forfeited. Strategic Alliance Agreement In November 2016, the Company and Dialog entered into a Strategic Alliance Agreement (“Alliance Agreement”) for the manufacture, distribution and commercialization of products incorporating the Company’s wire-free charging technology (“Licensed Products”). Pursuant to the terms of the Strategic Alliance Agreement, the Company agreed to engage Dialog as the exclusive supplier of the Licensed Products for specified fields of use, subject to certain exceptions (“Company Exclusivity Requirement”). Dialog agreed to not distribute, sell or work with any third party to develop any competing products without the Company’s approval (“Dialog Exclusivity Requirement”). In addition, both parties agreed on a revenue sharing arrangement and will collaborate on the commercialization of Licensed Products based on a mutually-agreed upon plan. Each party will retain all of its intellectual property. The Alliance Agreement has an initial term of seven years and will automatically renew annually thereafter unless terminated by either party upon 180 days’ prior written notice. The Company may terminate the Alliance Agreement at any time after the third anniversary of the Agreement upon 180 days’ prior written notice to Dialog, or if Dialog breaches certain exclusivity obligations. Dialog may terminate the Alliance Agreement if sales of Licensed Products do not meet specified targets. The Company Exclusivity Requirement will terminate upon the earlier of January 1, 2021 or the Note 4 – Commitments and Contingencies, continued occurrence of certain events relating to the Company’s pre-existing exclusivity obligations. The Dialog Exclusivity Requirement will terminate if no Licensed Products have received the necessary Federal Communications Commission approvals within specified timeframes.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	Note 5 – Stockholders’ Equity Authorized Capital The holders of the Company’s common stock are entitled to one vote per share. Holders of common stock are entitled to receive ratably such dividends, if any, as may be declared by the Board out of legally available funds. Upon the liquidation, dissolution or winding up of the Company, holders of common stock are entitled to share ratably in all assets of the Company that are legally available for distribution. Filing of registration statement On April 24, 2015, the Company filed a “shelf” registration statement on Form S-3, which became effective on April 30, 2015. Prior to its expiration in April 2018, the shelf registration statement allowed the Company from time to time to sell any combination of debt or equity securities described in the registration statement up to aggregate proceeds of $75,000,000. Pursuant to the shelf registration, in November 2015, the Company consummated an offering of 3,000,005 shares of common stock at $6.90 per share and received from the underwriters’ net proceeds of $19,333,032 (net of underwriters’ discount of $1,242,002 and underwriters’ offering expenses of $125,000). The Company incurred additional offering expenses of $284,576, yielding net proceeds from the offering under shelf registration of $19,048,456. Pursuant to the shelf registration, in January 2018, the Company raised $38,846,815 (net of $1,153,715 in underwriter’s discount and issuance costs) from the sale of stock to the public in an “at-the-market” equity offering of its common stock. On August 9, 2018, the Company filed a shelf registration statement on Form S-3, which became effective on August 17, 2018. This shelf registration statement will allow the Company to sell, from time to time, any combination of debt or equity securities described in the registration statement up to aggregate proceeds of $75,000,000. Private Placements On August 9, 2016, the Company entered into a securities purchase agreement with Ascend Legend Master Fund, Ltd. pursuant to which the Company agreed to sell to Ascend Legend Master Fund, Ltd., and its affiliates, 1,618,123 shares of common stock at a price of $12.36 per share and a warrant to purchase up to 1,618,123 shares of common stock at an exercise price of $23.00 per share. The aggregate proceeds from the sale of these shares was $20,000,000. On November 7, 2016, the Company and Dialog, a related party (see Note 7—Related Party Transactions), entered into a securities purchase agreement pursuant to which the Company agreed to sell to Dialog 763,552 shares of common stock at a price of $13.0967 per share and a warrant to purchase up to 763,552 shares of common stock that may be exercised only on a cashless basis at a price of $17.0257 per share, and may be exercised at any time between the date that is six months and a day after the closing date of the transaction and the three-year anniversary of the closing date. The aggregate proceeds from the sale of these shares was $10,000,011. On December 30, 2016, the Company and JT Group entered into a securities purchase agreement pursuant to which the Company agreed to sell to JT Group 292,056 shares of common stock at a price of $17.12 per share. The aggregate proceeds from the sale of these shares was $4,999,975. On June 28, 2017, the Company and Dialog entered into a securities purchase agreement pursuant to which the Company agreed to sell Dialog 976,139 shares of common stock at a price of $15.3666 per share and a warrant to purchase up to 654,013 shares of common stock that may be exercised only on a cashless basis at a price of $19.9766 per share, and may be exercised at any time between the date that is six months and one day after the closing date of the transaction and the three-year anniversary of the closing date. The aggregate proceeds from the sale of these shares, which were issued on July 5, 2017, was $14,999,935.

Stock Based Compensation

Stock Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock Based Compensation	Note 6 – Stock Based Compensation Equity Incentive Plans 2013 Equity Incentive Plan In December 2013, the Company’s Board and stockholders approved the 2013 Equity Incentive Plan, providing for the issuance of equity-based instruments covering up to an initial total of 1,042,167 shares of common stock. Effective on March 10, 2014, the Company’s Board and stockholders approved the First Amendment to the 2013 Equity Incentive Plan which provided for an increase in the aggregate number of shares of common stock that may be issued pursuant to the 2013 Equity Incentive Plan to equal 18% of the total number of shares of common stock outstanding immediately following the completion of the IPO (assuming for this purpose the issuance of all shares issuable under the Company’s equity plans, the conversion into common stock of all outstanding securities that are convertible by their terms into common stock and the exercise of all options and warrants exercisable for shares of common stock and including shares and warrants issued to the underwriters for such IPO upon exercise of its over-allotment options). Effective March 27, 2014, the aggregate total number of shares which may be issued under the 2013 Equity Incentive Plan was increased to 2,335,967. Effective on May 19, 2016, the Company’s stockholders approved the amendment and restatement of the 2013 Equity Incentive Plan to increase the number of shares reserved for issuance thereunder by 2,150,000 shares, bringing the total number of approved shares to 4,485,967 under the 2013 Equity Incentive Plan. Effective on May 16, 2018, the Company’s stockholders approved the amendment and restatement of the 2013 Equity Incentive Plan to increase the number of shares reserved for issuance thereunder by 1,600,000 shares, bringing the total number of approved shares to 6,085,967 under the 2013 Equity Incentive Plan. As of September 30, 2018, 2,079,035 shares of common stock remain available to be issued through equity-based instruments under the 2013 Equity Incentive Plan. 2014 Non-Employee Equity Compensation Plan On March 6, 2014, the Company’s Board and stockholders approved the 2014 Non-Employee Equity Compensation Plan for the issuance of equity-based instruments covering up to 250,000 shares of common stock to directors and other non-employees. Effective on May 19, 2016, the Company’s stockholders approved the amendment and restatement of the 2014 Equity Incentive Plan to increase the number of shares reserved for issuance thereunder by 350,000 shares, bringing the total number of approved shares to 600,000 under the 2014 Non-Employee Equity Compensation Plan. Effective on May 16, 2018, the Company’s stockholders approved the amendment and restatement of the 2014 Equity Incentive Plan to increase the number of shares reserved for issuance thereunder by 250,000 shares, bringing the total number of approved shares to 850,000 under the 2014 Non-Employee Equity Compensation Plan. As of September 30, 2018, 366,829 shares of common stock remain available to be issued through equity-based instruments under the 2014 Non-Employee Equity Compensation Plan. 2015 Performance Share Unit Plan On April 10, 2015, the Company’s Board approved the Energous Corporation 2015 Performance Share Unit Plan (“Performance Share Plan”), under which 1,310,104 shares of common stock became available for issuance as PSUs to a select group of employees and directors, subject to approval by the stockholders. On May 21, 2015, the Company’s stockholders approved the Performance Share Plan. Note 6 – Stock Based Compensation, continued Effective on May 16, 2018, the Company’s stockholders approved the amendment and restatement of the 2014 Non-employee Compensation Plan to increase the number of shares reserved for issuance thereunder by 1,400,000 shares, bringing the total number of approved shares to 2,710,104 under the 2015 Performance Share Unit Plan. As of September 30, 2018, 1,431,951 shares of common stock remain available to be issued through equity-based instruments under the Performance Share Unit Plan. Note 6 – Stock Based Compensation, continued 2017 Equity Inducement Plan On December 28, 2017, the Board approved the 2017 Equity Inducement Plan. Under the plan, the Board reserved 600,000 shares of common stock for the grant of RSUs. These grants will be administered by a committee of the Board or the Board acting as a committee. These awards will be granted to individuals who (a) are being hired as an employee by the Company or any subsidiary and such award is a material inducement to such person being hired; (b) are being rehired as an employee following a bona fide period of interruption of employment with the Company or any subsidiary; or (c) will become an employee of the Company or any subsidiary in connection with a merger or acquisition. As of September 30, 2018, 311,000 shares of common stock remain available to be issued through equity-based instruments under the 2017 Equity Inducement Plan. Employee Stock Purchase Plan On April 10, 2015, the Company’s Board approved the ESPP, under which shares of common stock were reserved for purchase by the Company’s employees, subject to approval by the stockholders. On May 21, 2015, the Company’s stockholders approved the ESPP. Employees may designate an amount not less than 1% but not more than 10% of their annual compensation, but for not more than 7,500 shares during an offering period. An offering period shall be six months in duration commencing on or about January 1 and July 1 of each year. The exercise price of the option will be the lesser of 85% of the fair market of the common stock on the first business day of the offering period and 85% of the fair market value of the common stock on the applicable exercise date. As of September 30, 2018, 376,463 shares of common stock remain available to be issued under the ESPP. As of September 30, 2018, employees have contributed $179,583 through payroll withholdings to the ESPP for the current eligibility period. Shares will be deemed delivered on December 31, 2018 for the current eligibility period. Stock Option Activity The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2018: Number of Options Weighted Average Exercise Price Weighted Average Remaining Life In Years Intrinsic Value Outstanding at January 1, 2018 1,037,239 $ 4.80 6.4 $ 15,198,044 Granted – – – – Exercised (380,745 ) 3.47 – – Forfeited – – – – Outstanding at September 30, 2018 656,494 $ 5.57 4.9 $ 2,986,926 Exercisable at January 1, 2018 1,037,239 $ 4.80 6.4 $ 15,198,044 Vested – – – – Exercised (380,745 ) 3.47 – – Forfeited – – – – Exercisable at September 30, 2018 656,494 $ 5.57 4.9 $ 2,986,926 As of September 30, 2018, the unamortized value of options was $0. Restricted Stock Units (“RSUs”) During the nine months ended September 30, 2018, the Compensation Committee of the Board (“Compensation Committee”) granted various directors and consultants RSUs under which the holders have the right to receive an aggregate 175,826 shares of common stock. These awards were granted under the 2014 Non-Employee Equity Compensation Plan. The awards granted vest over terms from one to four years. Note 6 – Stock Based Compensation, continued During the nine months ended September 30, 2018, the Compensation Committee granted various employees RSU awards under the 2013 Equity Incentive Plan under which the holders have the right to receive an aggregate 459,550 shares of common stock. The majority of these awards granted vest over terms ranging from one to four years. During the nine months ended September 30, 2018, the Compensation Committee granted employees RSU awards under the 2017 Equity Inducement Plan under which the holders have the right to receive 289,000 shares of common stock. The awards vest over four years beginning on the anniversary of the grant date. T h Co p n oun t fo R SU gr n t t on s u lt n t u s i n t h oun ti n gu i d n i n l ud i AS 505-5 qu it y-B s P y n t t N on- p l oy s I ord n w it AS 505-50 t h Co p n s ti t t h f i v l u o t h unv s t por ti o o t h R S w r r por ti n p r i o u s i n t h l o s i n pr i o o o s t o k As of 2018 t h un am or ti ze v a l u o t h R a $ T h un am or ti ze am oun il b e xp e n e ov e weighted average p e r i o o 2.5 y ea r Total Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 2,274,325 $ 13.75 RSUs granted 924,376 $ 19.54 RSUs forfeited (178,058 ) $ 14.10 RSUs vested (743,647 ) $ 13.80 Outstanding at September 30, 2018 2,276,996 $ 16.02 Performance Share Units (“PSUs”) Performance share units (“PSUs”) are grants that vest upon the achievement of certain performance goals. The goals are related to the Company’s market capitalization or market share price of the common stock. The Company determined that the PSUs were equity awards with both market and service conditions. The Company utilized a Monte Carlo simulation to determine the fair value of the market condition, as described below. Grantees of PSUs are required to be employed through December 31, 2018 in order to earn the entire award, if and when vested. No PSUs were granted during the nine months ended September 30, 2018. The fair value of the grants of PSUs to purchase a total of 1,342,061 shares of common stock (including 1,278,153 PSUs granted under the 2015 Performance Share Unit Plan and 63,908 granted as an inducement) was determined to be approximately $3,218,000, and is amortized over the service period of May 21, 2015 through December 31, 2018, on a straight-line basis. On October 24, 2016, the Compensation Committee granted Mr. Rizzone a PSU award under the 2013 Equity Incentive Plan under which Mr. Rizzone has the right to receive 150,000 shares of common stock. The shares of this award vest upon the Company’s stock price meeting specific targets. For this PSU award, a Monte Carlo simulation was used to determine the fair value at each of the five target prices of the Company’s common stock, using a market capitalization of $298,857,000, dividend yield of 0%, expected volatility of 75% and a risk-free interest rate of 0.66%. The fair value of the PSUs granted to Mr. Rizzone under the 2013 Equity Incentive Plan was determined to be $2,332,000, and was amortized over the estimated service period from October 24, 2016 through October 30, 2017. Note 6 – Stock Based Compensation, continued Amortization for all PSU awards was $207,206 and $399,867 for the three months ended September 30, 2018 and 2017, respectively, and $614,862 and $1,601,160 for the nine months ended September 30, 2018 and 2017, respectively. At September 30, 2018, the unamortized value of all PSUs was approximately $204,954. The unamortized amount will be expensed over a weighted average period of 0.3 years. A summary of the activity related to PSUs for the nine months ended September 30, 2018 is presented below: Total Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 951,657 $ 2.65 PSUs granted – - PSUs forfeited – - PSUs vested (80,098 ) 2.65 Outstanding at September 30, 2018 871,559 2.65 Deferred Stock Units (“DSUs”) On January 4, 2016, the Compensation Committee granted to John Gaulding, Director and Chairman of the Board, DSUs under the 2014 Non-Employee Equity Compensation Plan for which Mr. Gaulding has the right to receive 14,953 shares of the Company’s common stock. These shares were issued to Mr. Gaulding in lieu of $125,000 of his anticipated compensation for his services on the Board, including $75,000 worth of DSUs and $50,000 of his regular board stipends. The award granted vests fully on the first anniversary of the grant date. There was no amortization for both the three months ended September 30, 2018 and 2017. Amortization was $0 and $1,362 for the nine months ended September 30, 2018 and 2017, respectively. As of September 30 2018 t h D S were fully amortized Employee Stock Purchase Plan (“ESPP”) The recently completed offering period for the ESPP was January 1, 2018 through June 30, 2018. During the year ended December 31, 2017, there were two offering periods for the ESPP. The first offering period started on January 1, 2017 and concluded on June 30, 2017. The second offering period started on July 1, 2017 and concluded on December 31, 2017. The weighted-average grant-date fair value of the purchase option for each designated share purchased under this plan was approximately $9.72 and $5.88 for the nine months ended September 30, 2018 and 2017, respectively, which represents the fair value of the option, consisting of three main components: (i) the value of the discount on the enrollment date, (ii) the proportionate value of the call option for 85% of the stock and (iii) the proportionate value of the put option for 15% of the stock. The Company recognized compensation expense for the plan of $67,174 and $474,920 for the three and nine months ended September 30, 2018, respectively and $79,046 and $266,398 for the three and nine months ended September 30, 2017, respectively. Note 6 – Stock Based Compensation, continued The Company estimated the fair value of options granted during the nine months ended September 30, 2018 and 2017 using the Black-Scholes option pricing model. The fair values of stock options granted were estimated using the following assumptions: Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Stock price $14.48 - $22.34 $16.08 - $17.59 Dividend yield 0 % 0 % Expected volatility 72% - 177% 56% - 66% Risk-free interest rate 1.61% - 2.14% 0.62% - 1.11% Expected life 6 months 6 months Note 6 – Stock Based Compensation, continued Stock-Based Compensation Expense The following tables summarize total stock-based compensation costs recognized for the three and nine months ended September 30, 2018 and 2017: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Stock options $ - $ 246,617 $ - $ 738,599 RSUs 3,578,276 3,843,186 11,714,962 9,865,351 PSUs 207,206 399,867 614,862 1,601,160 ESPP 67,174 79,046 474,920 266,398 DSU - - - 1,362 Total $ 3,852,656 $ 4,568,716 $ 12,804,744 $ 12,472,870 The total amount of stock-based compensation was reflected within the statements of operations as: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Research and development $ 2,051,986 $ 2,558,472 $ 7,594,209 $ 6,643,094 Sales and marketing 352,941 281,518 1,022,832 782,366 General and administrative 1,447,729 1,728,726 4,187,703 5,047,410 Total $ 3,852,656 $ 4,568,716 $ 12,804,744 $ 12,472,870

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Note 7 – Related Party Transactions In November 2016, the Company and Dialog entered into an alliance agreement for the manufacture, distribution and commercialization of products incorporating the Company’s wire-free charging technology (See Note 4 – Commitments and Contingencies, Strategic Alliance Agreement). On November 7, 2016 and June 28, 2017, the Company and Dialog entered into securities purchase agreements under which Dialog acquired a total of 1,739,691 shares and received warrants to purchase up to 1,417,565 shares (See Note 5 – Stockholders’ Equity, Private Placements). Dialog presently owns approximately 6.8% of the Company’s outstanding common shares and could potentially own 11.7% of the Company’s outstanding common shares if it exercised all of its warrants for common shares. For the nine months ended September 30, 2018, the Company paid $43,700 to Dialog for chip development costs incurred, which is recorded under research and development expense. Pursuant to the Strategic Alliance Agreement in Note 4 – Commitments and Contingencies, we recorded $5,773 in revenue for the nine months ended September 30, 2018.

Customer Concentration

Customer Concentration	9 Months Ended
	Sep. 30, 2018
Risks And Uncertainties [Abstract]
Customer Concentration	Note 8 – Customer Concentration One customer accounted for approximately 99% and 100% of the Company’s revenue for the three months ended September 30, 2018 and 2017, respectively. The same customer accounted for approximately 98% and 100% of the Company’s revenue for the nine months ended September 30, 2018 and 2017. The same customer accounted for 96% of the accounts receivable balance as of September 30, 2018. As of December 31, 2017, the Company did not have an accounts receivable balance.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying financial statements are presented in U.S. dollars and have been prepared in accordance with accounting principles generally accepted in the United States of America (“US GAAP”), and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). These unaudited condensed interim financial statements should be read in conjunction with the audited financial statements and notes thereto for the fiscal year ended December 31, 2017 included in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2017, filed with the SEC on March 16, 2018. The accounting policies used in preparing these unaudited condensed interim financial statements are consistent with those described in the Company’s December 31, 2017 audited financial statements .
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent liabilities at the date of the financial statements as well as the reported expenses during the reporting periods. The Company’s significant estimates and assumptions include the valuation of stock-based compensation instruments, recognition of revenue, the useful lives of long-lived assets, and income tax expense. Some of these judgments can be subjective and complex, and, consequently, actual results may differ from these estimates. Although the Company believes that its estimates and assumptions are reasonable, they are based upon information available at the time the estimates and assumptions were made. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all short-term, highly liquid investments with an original maturity at the date of purchase of three months or less to be cash equivalents. The Company maintains cash balances that may be uninsured or in deposit accounts that exceed Federal Deposit Insurance Corporation limits. The Company maintains its cash deposits with major financial institutions.
Revenue Recognition	Revenue Recognition On January 1, 2018, the Company adopted Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers" (Topic 606), which is described below in Recent Accounting Pronouncements. In accordance with Topic 606, the Company recognizes revenue using the following five-step approach: 1. Identify the contract with a customer. 2. Identify the performance obligations in the contract. 3. Determine the transaction price of the contract. 4. Allocate the transaction price to the performance obligations in the contract. 5. Recognize revenue when the performance obligations are met or delivered. The Company records revenue associated with product development projects that it enters into with certain customers. In general, these projects are associated with complex technology development, and as such the Company does not have certainty about its ability to achieve the program milestones. Achievement of the milestone is dependent on the Company’s performance typically requires acceptance by the customer. The payment associated with achieving the milestone is generally commensurate with the Company’s effort or the value of the deliverable and is nonrefundable. The Company records the expenses related to these projects, generally included in research and development expense, in the periods incurred. The Company records royalty revenue from its manufacturing partner, Dialog, based on the number of shipments from Dialog to its customers.
Research and Development	Research and Development Research and development expenses are charged to operations as incurred. For internally developed patents, all patent application costs are expensed as incurred as research and development expense. Patent application costs, generally legal costs, are expensed as research and development costs until such time as the future economic benefits of such patents become more certain. The Company incurred research and development costs of $8,442,698 and $8,743,434 for the three months ended September 30, 2018 and 2017, respectively, and the Company incurred research and development cost of $24,804,224 and $25,788,621 for the nine months ended September 30, 2018 and 2017, respectively.
Stock-Based Compensation	Stock-Based Compensation The Company accounts for equity instruments issued to employees in accordance with accounting guidance that requires awards to be recorded at their fair value on the date of grant and are amortized over the vesting period of the award. The Company recognizes compensation costs on a straight-line basis over the requisite service period of the award, which is typically the vesting term of the equity instrument issued. Note 3 – Summary of Significant Accounting Policies, continued Under the Energous Corporation Employee Stock Purchase Plan (“ESPP”), employees may purchase a limited number of shares of the Company’s common stock at a 15% discount from the lower of the closing market prices measured on the first and last days of each half-year period. The Company recognizes compensation expense for the fair value of the purchase options, as measured on the grant date.
Income Taxes	Income Taxes Tax benefits are recognized only for tax positions that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50 percent likely to be realized upon settlement. A liability for “unrecognized tax benefits” is recorded for any tax benefits claimed in the Company’s tax returns that do not meet these recognition and measurement standards. As of September 30, 2018, no liability for unrecognized tax benefits was required to be reported. The guidance also discusses the
Net Loss Per Common Share	Net Loss Per Common Share Basic net loss per share is computed by dividing net loss available to common stockholders by the weighted average number of shares of common stock outstanding during the period. Diluted earnings per share is computed using the weighted average number of common shares and, if dilutive, potential common shares outstanding during the period. Potential common shares consist of the incremental common shares issuable upon the exercise of stock options and warrants (using the treasury stock method), the vesting of restricted stock units (“RSUs”), performance stock units (“PSUs”) and the enrollment of employees in the ESPP. The computation of diluted loss per share excludes potentially dilutive securities of 6,840,737 and 7,862,420 for the three months ended September 30, 2018 and 2017, respectively, and 6,840,737 and 7,862,420 for the nine months ended September 30, 2018 and 2017, respectively, because their inclusion would be anti-dilutive. Potentially dilutive securities outlined in the table below have been excluded from the computation of diluted net loss per share because the effect of their inclusion would have been anti-dilutive. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Financing Warrant to purchase common stock - 13,889 - 13,889 IPO Warrants to purchase common stock - 11,600 - 11,600 Warrant issued to private investors 3,035,688 3,035,688 3,035,688 3,035,688 Options to purchase common stock 656,494 1,149,589 656,494 1,149,589 RSUs 2,276,996 2,498,037 2,276,996 2,498,037 PSUs 871,559 1,153,617 871,559 1,153,617 Total potentially dilutive securities 6,840,737 7,862,420 6,840,737 7,862,420
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, "Revenue from Contracts with Customers" (Topic 606) (“ASU 2014-09”), which supersedes the revenue recognition requirements in ASU Topic 605, "Revenue Recognition," and most industry-specific guidance. ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of 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. ASU 2014-09 also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments, and assets recognized from costs incurred to obtain or fulfill a contract. Originally, ASU 2014-09 would be effective Note 3 – Summary of Significant Accounting Policies, continued for the Company starting January 1, 2017 using either of two methods: (i) retrospective to each prior reporting period presented with the option to elect certain practical expedients as defined within ASU 2014-09; or (ii) retrospective with the cumulative effect of initially applying ASU 2014-09 recognized at the date of initial application and providing certain additional disclosures as defined per ASU 2014-09. In July 2015, FASB voted to amend ASU 2014-09 by approving a one-year deferral of the effective date as well as providing the option to early adopt the standard on the original effective date. The Company used the modified retrospective implementation method for all contracts and did not need to record a cumulative effect adjustment to retained earnings as of the date of initial application. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments – Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities”. The standard addresses certain aspects of recognition, measurement, presentation, and disclosure of financial instruments. ASU 2016-01 is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company has adopted ASU 2016-01 and its adoption had no material impact on it financial statements. In January 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842)”. This standard requires that a lessee recognize the assets and liabilities that arise from operating leases. A lessee should recognize in the statement of In August 2016, the FASB issued ASU No. 2016-15, “Statement of Cash Flows (Topic 230) – Classification of Certain Cash Receipts and Cash Payments.” ASU No. 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. It is effective for annual reporting periods beginning after December 15, 2017. The adoption of the new standard did not have a material impact on our financial statements. In November 2016, the FASB issued ASU No. 2016-18, “Statement of Cash Flows (230) – Restricted Cash.” ASU No. 2016-18 requires an entity to include amounts described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning-of-period and end-of-period total amounts shown on the statement of cash flows. It is effective for annual reporting periods beginning after December 15, 2018. The adoption of this standard is not expected to have a material impact on the Company’s financial position and results of operations. In December 2016, the FASB issued ASU No. 2016-20, “Technical Corrections and Improvements to Topic 606, Revenue from Contracts with Customers.” ASU No. 2016-20 amends certain aspects of ASU No. 2014-09 and clarifies, rather than changes, the core revenue recognition principles in ASU No. 2014-09. It is effective for annual reporting periods beginning after December 15, 2018. The adoption of this standard is not expected to have a material impact on the Company’s financial position and results of operations. In May 2017, the FASB issued ASU No. 2017-09, “Compensation – Stock Compensation (Topic 718) – Scope of Modification Accounting.” ASU No. 2017-09 provides clarity and reduces complexity when applying the guidance in Topic 718 for changes in terms or conditions of share-based payment awards. It is effective for annual reporting periods beginning after December 15, 2017. The adoption of the new standard did not have a material impact on our financial statements. In July 2017, the FASB issued a two-part ASU No. 2017-11, I. Accounting for Certain Financial Instruments with Down Round Features and II. Replacement of the Indefinite Deferral for Mandatorily Redeemable Financial Instruments of Certain Nonpublic Entities and Certain Mandatorily Redeemable Noncontrolling Interests with a Scope Exception. ASU 2017-11 amends guidance in FASB ASC 260, Earnings Per Share, FASB ASC 480, Distinguishing Liabilities from Equity, and FASB ASC 815, Derivatives and Hedging. The amendments in Part I of ASU 2017-11 change the classification analysis of certain equity-linked financial instruments (or embedded features) with down round features. The amendments in Part II of ASU 2017-11 re-characterize the indefinite Note 3 – Summary of Significant Accounting Policies, continued deferral of certain provisions of Topic 480 that now are presented as pending content in the Codification, to a scope exception. Those amendments do not have an accounting effect. ASU 2017-11 is effective for public business entities for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018. Early adoption is permitted. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements. In June 2018, the FASB issued ASU No. 2018-07, “Compensation – Stock Compensation (Topic 718): Improvements to Nonemployee Share-based Payment Accounting.” ASU 2018-07 aligns accounting for share-based payments issued to nonemployees to that of employees under the existing guidance of Topic 718, with certain exceptions. This update supersedes previous guidance for equity-based payments to nonemployees under Subtopic 505-50, “Equity – Equity-based Payments to Nonemployees.” It is effective for annual reporting periods beginning after December 15, 2018. The Company is currently evaluating the impact the adoption of this new standard will have on its financial statements.
Management's Evaluation of Subsequent Events	Management’s Evaluation of Subsequent Events The Company evaluates events that have occurred after the balance sheet date of September 30, 2018, through the date which the financial statements are issued. Based upon the review, the Company did not identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	Potentially dilutive securities outlined in the table below have been excluded from the computation of diluted net loss per share because the effect of their inclusion would have been anti-dilutive. For the Three Months Ended September 30, For the Nine Months Ended September 30, 2018 2017 2018 2017 Financing Warrant to purchase common stock - 13,889 - 13,889 IPO Warrants to purchase common stock - 11,600 - 11,600 Warrant issued to private investors 3,035,688 3,035,688 3,035,688 3,035,688 Options to purchase common stock 656,494 1,149,589 656,494 1,149,589 RSUs 2,276,996 2,498,037 2,276,996 2,498,037 PSUs 871,559 1,153,617 871,559 1,153,617 Total potentially dilutive securities 6,840,737 7,862,420 6,840,737 7,862,420

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2018
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	The future minimum lease payments for leased locations are as follows: For the Years Ended December 31, Amount 2018 (Three Months) $ 163,303 2019 457,585 Total $ 620,888

Stock Based Compensation (Table

Stock Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	The following is a summary of the Company’s stock option activity during the nine months ended September 30, 2018: Number of Options Weighted Average Exercise Price Weighted Average Remaining Life In Years Intrinsic Value Outstanding at January 1, 2018 1,037,239 $ 4.80 6.4 $ 15,198,044 Granted – – – – Exercised (380,745 ) 3.47 – – Forfeited – – – – Outstanding at September 30, 2018 656,494 $ 5.57 4.9 $ 2,986,926 Exercisable at January 1, 2018 1,037,239 $ 4.80 6.4 $ 15,198,044 Vested – – – – Exercised (380,745 ) 3.47 – – Forfeited – – – – Exercisable at September 30, 2018 656,494 $ 5.57 4.9 $ 2,986,926
Schedule of Restricted Stock Units Activity	A summary of the activity related to RSUs for the nine months ended September 30, 2018 is presented below: Total Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 2,274,325 $ 13.75 RSUs granted 924,376 $ 19.54 RSUs forfeited (178,058 ) $ 14.10 RSUs vested (743,647 ) $ 13.80 Outstanding at September 30, 2018 2,276,996 $ 16.02
Summary of Activity Related to PSUs	A summary of the activity related to PSUs for the nine months ended September 30, 2018 is presented below: Total Weighted Average Grant Date Fair Value Outstanding at January 1, 2018 951,657 $ 2.65 PSUs granted – - PSUs forfeited – - PSUs vested (80,098 ) 2.65 Outstanding at September 30, 2018 871,559 2.65
Summary of Fair Values of Stock Options Granted	The fair values of stock options granted were estimated using the following assumptions: Nine Months Ended September 30, 2018 Nine Months Ended September 30, 2017 Stock price $14.48 - $22.34 $16.08 - $17.59 Dividend yield 0 % 0 % Expected volatility 72% - 177% 56% - 66% Risk-free interest rate 1.61% - 2.14% 0.62% - 1.11% Expected life 6 months 6 months
Summary of Stock-based Compensation Costs Recognized	The following tables summarize total stock-based compensation costs recognized for the three and nine months ended September 30, 2018 and 2017: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Stock options $ - $ 246,617 $ - $ 738,599 RSUs 3,578,276 3,843,186 11,714,962 9,865,351 PSUs 207,206 399,867 614,862 1,601,160 ESPP 67,174 79,046 474,920 266,398 DSU - - - 1,362 Total $ 3,852,656 $ 4,568,716 $ 12,804,744 $ 12,472,870
Summary of Stock-based Compensation Reflected within Statements of Operations	The total amount of stock-based compensation was reflected within the statements of operations as: Three Months Ended September 30, Nine Months Ended September 30, 2018 2017 2018 2017 Research and development $ 2,051,986 $ 2,558,472 $ 7,594,209 $ 6,643,094 Sales and marketing 352,941 281,518 1,022,832 782,366 General and administrative 1,447,729 1,728,726 4,187,703 5,047,410 Total $ 3,852,656 $ 4,568,716 $ 12,804,744 $ 12,472,870

Liquidity and Management Plans

Liquidity and Management Plans - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016
Liquidity And Management Plans [Line Items]
Engineering product development		$ 228,000	$ 250,000	$ 458,773	$ 1,124,874
Net income (loss)		(12,645,291)	(12,748,248)	(38,387,119)	(38,140,398)
Net cash provided by (used in) operating activities				(24,398,264)	(26,887,004)
Proceeds from issuance of common stock				38,846,815	14,932,547
Cash and cash equivalents, at carrying value, total		28,551,870	20,223,859	28,551,870	20,223,859	$ 12,795,254	$ 31,258,637
At-the-Market [Member]
Liquidity And Management Plans [Line Items]
Proceeds from issuance of common stock				38,846,815
Private Placements [Member]
Liquidity And Management Plans [Line Items]
Proceeds from issuance of common stock	$ 14,932,547
Technology Service [Member]
Liquidity And Management Plans [Line Items]
Engineering product development		$ 228,000	$ 250,000	$ 458,773	$ 1,124,874

Significant Accounting Policies

Significant Accounting Policies - Additional Information (Detail) - USD ($)	Apr. 10, 2015	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary Of Significant Accounting Policies [Line Items]
Research and development expense, total		$ 8,442,698	$ 8,743,434	$ 24,804,224	$ 25,788,621
Liability for unrecognized tax benefits		0		$ 0
Interest or penalties for uncertian tax positions		$ 0	$ 0
Antidilutive securities excluded from computation of earnings per share, amount		6,840,737	7,862,420	6,840,737	7,862,420
Employee Stock Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Common stock purchase price discount percentage	85.00%			15.00%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	6,840,737	7,862,420	6,840,737	7,862,420
Financing Warrant to Purchase Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		13,889		13,889
IPO Warrants to Purchase Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		11,600		11,600
Warrant Issued to Private Investors [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	3,035,688	3,035,688	3,035,688	3,035,688
Employee Stock Option [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	656,494	1,149,589	656,494	1,149,589
Restricted Stock Units (RSUs) [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	2,276,996	2,498,037	2,276,996	2,498,037
Performance Share Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	871,559	1,153,617	871,559	1,153,617

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases - Additional Information (Detail) - USD ($)	May 31, 2017	Aug. 25, 2015	Feb. 26, 2015	Sep. 10, 2014	Sep. 30, 2018
San Jose, California [Member] | Amended Sub-lease Agreement [Member]
Commitments And Contingencies [Line Items]
Operating leases, rent expense, net					$ 4,578
Lease expiration date		Jun. 30, 2019
San Jose, California [Member] | Sub-lease Agreement [Member]
Commitments And Contingencies [Line Items]
Operating leases, rent expense, sublease rentals					$ 6,668
Lease expiration date			Jun. 30, 2019
Costa Mesa, California [Member]
Commitments And Contingencies [Line Items]
Operating leases, rent expense	$ 9,040
Lease expiration date	Sep. 30, 2019
Balzer Family Investments Lp [Member]
Commitments And Contingencies [Line Items]
Operating leases expiration period				60 months
Operating leases, rent expense				$ 36,720
Number of shares issued to landlord as prepaid rent and tenant improvements				41,563
Payments for rent				$ 400,000
Operating leases, rent expense, net				6,732
Balzer Family Investments Lp [Member] | Term Leases [Member]
Commitments And Contingencies [Line Items]
Payments for tenant improvements				100,000
Balzer Family Investments Lp [Member] | Common Stock [Member]
Commitments And Contingencies [Line Items]
Shares issued to landlord as prepaid rent and tenant improvements value				500,000
Payments for rent				$ 400,000

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Rental Payments for Operating Leases (Detail)	Sep. 30, 2018USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2018 (Three Months)	$ 163,303
2,019	457,585
Total	$ 620,888

Commitments and Contingencies_3

Commitments and Contingencies - Hosted Design Solution Agreement - Additional Information (Detail) - Hosted Design Solution Agreement [Member] - USD ($)	1 Months Ended			3 Months Ended
	Jul. 31, 2018	Dec. 31, 2015	Jun. 30, 2015	Sep. 30, 2018
Commitments And Contingencies [Line Items]
Initial term of agreement	3 years		3 years
Hardware and software configuration payments period increase		$ 198,000
Service, Other [Member]
Commitments And Contingencies [Line Items]
Other cost of services	$ 218,000			$ 101,000

Commitments and Contingencies_4

Commitments and Contingencies - Employee Agreement - Stephen Rizzone - Additional Information (Detail) - USD ($)	May 21, 2015	Jan. 01, 2015	Dec. 12, 2013	Sep. 30, 2018	Dec. 31, 2015
Commitments And Contingencies [Line Items]
Performance based equity plan, market capitalization minimum amount					$ 100,000,000
Performance based equity plan market capitalization maximum amount					$ 1,100,000,000
Performance Based Equity Plan [Member]
Commitments And Contingencies [Line Items]
Performance based equity plan, market capitalization minimum amount	$ 100,000,000
Performance share units to be earned on achievement of market capitalization growth	0
Performance based equity plan market capitalization maximum amount	$ 1,100,000,000
Percentage of performance share units to be earned on achievement of market capitalization growth	100.00%			100.00%	100.00%
Percentage of performance share units to be paid on quarterly basis	50.00%
Percentage of performance share units deferred	50.00%
Percentage of performance share units to be paid on termination of employment agreement				25.00%
Performance Share Units [Member] | Performance Based Equity Plan [Member]
Commitments And Contingencies [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross	639,075
Second Employee Stock Option [Member]
Commitments And Contingencies [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross			496,546
Deferred compensation arrangement with individual, exercise price			$ 6
Employee Stock Option [Member]
Commitments And Contingencies [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross				0
Deferred compensation arrangement with individual, maximum contractual term			48 months
Deferred compensation arrangement with individual, exercise price			$ 1.68
Vesting period			4 years
Mr. Rizzone [Member]
Commitments And Contingencies [Line Items]
Agreement effective date		Jan. 1, 2015
Initial term of agreement		4 years
Officers' compensation				$ 365,000
Employment agreement percentage of base salary				100.00%
Mr. Rizzone [Member] | Employee Stock Option [Member]
Commitments And Contingencies [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross			275,689
Deferred compensation arrangement with individual, maximum contractual term			10 years

Commitments and Contingencies_5

Commitments and Contingencies - Strategic Alliance Agreement - Additional Information (Detail)	1 Months Ended
	Nov. 30, 2016
Strategic Alliance Agreement [Member]
Commitments And Contingencies [Line Items]
Initial term of agreement	7 years

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Detail)

Aug. 17, 2018USD ($)

Jul. 05, 2017USD ($)

Jun. 28, 2017$ / sharesshares

Dec. 30, 2016USD ($)$ / sharesshares

Nov. 07, 2016USD ($)$ / sharesshares

Aug. 09, 2016USD ($)$ / sharesshares

Apr. 24, 2015USD ($)

Jan. 31, 2018USD ($)

Jul. 31, 2017USD ($)

Nov. 30, 2015USD ($)$ / sharesshares

Sep. 30, 2018USD ($)Vote

Sep. 30, 2017USD ($)

Class of Stock [Line Items]

Number of common stock voting entitlement per share | Vote

1

Shelf registration statement expiration date

2018-04

Proceeds from issuance of common stock

$ 38,846,815

$ 14,932,547

Dialog Semiconductor Plc [Member]

Class of Stock [Line Items]

Class of warrant or right, exercise price of warrants or rights | $ / shares

$ 19.9766

$ 17.0257

Dialog Semiconductor Plc [Member] | Common Stock [Member]

Class of Stock [Line Items]

Class of warrant or right, number of securities called by warrants or rights | shares

654,013

763,552

Dialog Semiconductor Plc [Member] | Warrant Issued to Private Investors [Member]

Class of Stock [Line Items]

Stock issued during period, shares, new issues | shares

976,139

763,552

Stock issued during period, value, new issues

$ 14,999,935

$ 10,000,011

Consummation of Offering Under Shelf Registration [Member]

Class of Stock [Line Items]

Proceeds from shelf registration debt or equity securities

$ 75,000,000

$ 75,000,000

Stock issued during period, shares, new issues | shares

3,000,005

Share price | $ / shares

$ 6.90

Proceeds from issuance of common stock

$ 19,333,032

Common stock, discount on shares

1,242,002

Stock offering expenses on issue of common stock

125,000

Additional stock offering expenses on issue of common stock

284,576

Proceeds from issuance of common stock net off offering expenses and discount

$ 19,048,456

At-the-Market [Member]

Class of Stock [Line Items]

Proceeds from issuance of common stock

$ 38,846,815

Stock issued during period, value, new issues

$ 38,846,815

Underwriter’s discount and issuance costs

$ 1,153,715

Private Placements [Member]

Class of Stock [Line Items]

Proceeds from issuance of common stock

$ 14,932,547

Stock issued during period, value, new issues

$ 20,000,000

Class of warrant or right, exercise price of warrants or rights | $ / shares

$ 23

Private Placements [Member] | Ascend Legemd Master Fund

Class of Stock [Line Items]

Stock issued during period, shares, new issues | shares

1,618,123

Share price | $ / shares

$ 12.36

Class of warrant or right, number of securities called by warrants or rights | shares

1,618,123

Private Placements [Member] | Dialog Semiconductor Plc [Member]

Class of Stock [Line Items]

Share price | $ / shares

$ 15.3666

$ 13.0967

Private Placements [Member] | JT Group [Member]

Class of Stock [Line Items]

Stock issued during period, shares, new issues | shares

292,056

Share price | $ / shares

$ 17.12

Stock issued during period, value, new issues

$ 4,999,975

Stock Based Compensation - Equi

Stock Based Compensation - Equity Incentive Plan - Additional Information (Detail) - USD ($)	Apr. 10, 2015	Mar. 27, 2014	Mar. 10, 2014	Sep. 30, 2018	May 16, 2018	Dec. 28, 2017	May 19, 2016	Mar. 06, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee contribution through payroll withholdings				$ 179,583
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized	1,310,104				2,710,104
Common stock, capital shares reserved for future issuance					1,400,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant				1,431,951
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant				376,463
Lowest percentage of annual compensation to be utilized by an employee for the plan	1.00%
Highest percentage of annual compensation to be utilized by an employee for the plan	10.00%
Maximum number of shares permitted to purchase	7,500
Offering period	6 months
Exercise price discount from fair value on offering date	85.00%
Exercise price discount from fair value on exercise date	85.00%			15.00%
Share-based compensation arrangement by share-based payment award, terms of award				On April 10, 2015, the Company’s Board approved the ESPP, under which shares of common stock were reserved for purchase by the Company’s employees, subject to approval by the stockholders. On May 21, 2015, the Company’s stockholders approved the ESPP. Employees may designate an amount not less than 1% but not more than 10% of their annual compensation, but for not more than 7,500 shares during an offering period. An offering period shall be six months in duration commencing on or about January 1 and July 1 of each year. The exercise price of the option will be the lesser of 85% of the fair market of the common stock on the first business day of the offering period and 85% of the fair market value of the common stock on the applicable exercise date.
2013 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized					6,085,967		4,485,967		1,042,167
Percentage of total number of shares to be issued under incentive plan			18.00%
Share-based compensation arrangement by share-based payment award, other share increase (decrease)		2,335,967
Common stock, capital shares reserved for future issuance					1,600,000		2,150,000
Common stock to be issued				2,079,035
Non-Employee Equity Compensation Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares authorized					850,000		600,000	250,000
Common stock, capital shares reserved for future issuance					250,000		350,000
Common stock available to be issued				366,829
2017 Equity Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock available to be issued				311,000
2017 Equity Inducement Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance						600,000

Stock Based Compensation - Summ

Stock Based Compensation - Summary of Stock Option Activity (Detail) - Employee Stock Option [Member] - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding	1,037,239
Number of Options, Granted	0
Number of Options, Exercised	(380,745)
Number of Options, Forfeited	0
Number of Options, Outstanding	656,494	1,037,239
Number of Options, Exercisable	1,037,239
Number of Options, Vested	0
Number of Options, Exercised	(380,745)
Number of Options, Forfeited	0
Number of Options, Exercisable	656,494	1,037,239
Weighted Average Exercise Price, Outstanding	$ 4.80
Weighted Average Exercise Price, Granted	0
Weighted Average Exercise Price, Exercised	3.47
Weighted Average Exercise Price, Forfeited	0
Weighted Average Exercise Price, Outstanding	5.57	$ 4.80
Weighted Average Exercise Price, Exercisable	4.80
Weighted Average Exercise Price, Vested	0
Weighted Average Exercise Price, Exercised	3.47
Weighted Average Exercise Price, Forfeited	0
Weighted Average Exercise Price, Exercisable	$ 5.57	$ 4.80
Weighted Average Remaining Life In Years, Outstanding	4 years 10 months 24 days	6 years 4 months 24 days
Weighted Average Remaining Life In Years, Exercisable	4 years 10 months 24 days	6 years 4 months 24 days
Intrinsic Value, Outstanding	$ 2,986,926	$ 15,198,044
Intrinsic Value, Exercisable	$ 2,986,926	$ 15,198,044

Stock Based Compensation - Stoc

Stock Based Compensation - Stock Option Award Activity - Additional Information (Detail)	Sep. 30, 2018USD ($)
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee service share-based compensation, nonvested awards, compensation not yet recognized, stock options	$ 0

Stock Based Compensation - Rest

Stock Based Compensation - Restricted Stock Units - Additional Information (Detail) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Sep. 30, 2018USD ($)shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee service share-based compensation, nonvested awards, compensation not yet recognized, share-based awards other than options | $	$ 27,341,086
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition	2 years 6 months
Non-Employee Equity Compensation Plan 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	175,826
Non-Employee Equity Compensation Plan 2014 [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period	1 year
Non-Employee Equity Compensation Plan 2014 [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period	4 years
2013 Equity Incentive Plan [Member] | Employee [Member] | Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	459,550
2013 Equity Incentive Plan [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period	1 year
2013 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period	4 years
2017 Equity Inducement Plan [Member] | Employee [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	289,000
Share-based compensation arrangement by share-based payment award, award vesting period	4 years

Stock Based Compensation - Sche

Stock Based Compensation - Schedule of Restricted Stock Units Activity (Detail) - Restricted Stock Units (RSUs) [Member]	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding | shares	2,274,325
RSUs granted | shares	924,376
RSUs forfeited | shares	(178,058)
RSUs vested | shares	(743,647)
Number of Options, Outstanding | shares	2,276,996
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 13.75
Weighted Average Grant Date Fair Value, RSUs granted | $ / shares	19.54
Weighted Average Grant Date Fair Value, RSUs forfeited | $ / shares	14.10
Weighted Average Grant Date Fair Value, RSUs vested | $ / shares	13.80
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 16.02

Stock Based Compensation - Perf

Stock Based Compensation - Performance Share Units - Additional Information (Detail) - USD ($)	Oct. 24, 2016	May 21, 2015	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based equity plan market capitalization minimum amount							$ 100,000,000
Performance based equity plan market capitalization maximum amount							$ 1,100,000,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period					0		0
Share based compensation arrangement by share based payment award equity instruments other than options grants in period fair value					$ 3,218,000
Share based compensation arrangement by share based payment award unamortized value					$ 204,954
Share based compensation arrangement by share based payment award unamortized weighted average period					3 months 18 days
Performance Shares and Inducement Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period					1,342,061
Inducement PSU Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period					63,908
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, vested in period, fair value					$ 298,857,000
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected dividend rate					0.00%
Share-based compensation arrangement by share-based payment award, fair value assumptions, expected volatility rate					75.00%
Share-based compensation arrangement by share-based payment award, fair value assumptions, risk free interest rate					0.66%
Allocated share-based compensation expense			$ 207,206	$ 399,867	$ 614,862	$ 1,601,160
Performance Based Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance based equity plan market capitalization minimum amount		$ 100,000,000
Performance based equity plan market capitalization maximum amount		$ 1,100,000,000
Percentage of performance share units to be earned on achievement of market capitalization growth		100.00%			100.00%		100.00%
2015 Performance Share Unit Plan [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period					1,278,153
2013 Equity Incentive Plan [Member] | Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share based compensation arrangement by share based payment award equity instruments other than options grants in period fair value					$ 2,332,000
2013 Equity Incentive Plan [Member] | Performance Share Units [Member] | Mr. Rizzone [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	150,000

Stock Based Compensation - Su_2

Stock Based Compensation - Summary of Activity Related to PSUs (Detail) - Performance Shares [Member] - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2018	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding	951,657
PSUs granted	0	0
PSUs forfeited	0
PSUs vested	(80,098)
Number of Options, Outstanding	871,559
Weighted Average Grant Date Fair Value, Beginning Balance	$ 2.65
Weighted Average Grant Date Fair Value, PSUs granted	0
Weighted Average Grant Date Fair Value, PSUs forfeited	0
Weighted Average Grant Date Fair Value, PSUs vested	2.65
Weighted Average Grant Date Fair Value, Ending Balance	$ 2.65

Stock Based Compensation - Defe

Stock Based Compensation - Deferred Stock Units - Additional Information (Detail) - USD ($)	Jan. 04, 2016	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense		$ 0	$ 0	$ 0	$ 1,362
Mr. Gaulding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, value, share-based compensation, net of forfeitures	$ 75,000
Mr. Gaulding [Member] | Stipends [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock issued during period, value, share-based compensation, net of forfeitures	$ 50,000
Non-Employee Equity Compensation Plan 2014 [Member] | Mr. Gaulding [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period	14,953
Stock issued during period, value, share-based compensation, net of forfeitures	$ 125,000

Stock Based Compensation - Empl

Stock Based Compensation - Employee Stock Purchase Plan - Additional Information (Detail) - Employee Stock Purchase Plan [Member] - USD ($)	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]
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period, weighted average grant date fair value			$ 9.72	$ 5.88
Percentage of proportionate value of call option of stock			85.00%
Percentage of proportionate value of put option of stock			15.00%
Allocated share-based compensation expense	$ 67,174	$ 79,046	$ 474,920	$ 266,398

Stock Based Compensation - Su_3

Stock Based Compensation - Summary of Fair Values of Stock Options Granted (Detail) - Employee Stock Option [Member] - $ / shares	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility, minimum	72.00%	56.00%
Expected volatility, maximum	177.00%	66.00%
Risk-free interest rate, minimum	1.61%	0.62%
Risk-free interest rate, maximum	2.14%	1.11%
Expected life	6 months	6 months
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 14.48	$ 16.08
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 22.34	$ 17.59

Stock Based Compensation -Summa

Stock Based Compensation -Summary of Stock-based Compensation Costs Recognized (Detail) - USD ($)	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, Compensation Cost [Line Items]
Total	$ 3,852,656	$ 4,568,716	$ 12,804,744	$ 12,472,870
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	3,578,276	3,843,186	11,714,962	9,865,351
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	207,206	399,867	614,862	1,601,160
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	67,174	79,046	474,920	266,398
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	0	0	0	1,362
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 0	$ 246,617	$ 0	$ 738,599

Stock Based Compensation - Su_4

Stock Based Compensation - Summary of Stock-based Compensation Reflected within Statements of Operations (Detail) - USD ($)	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, Compensation Cost [Line Items]
Share-based Compensation, Total	$ 3,852,656	$ 4,568,716	$ 12,804,744	$ 12,472,870
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	2,051,986	2,558,472	7,594,209	6,643,094
Selling and Marketing Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	352,941	281,518	1,022,832	782,366
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 1,447,729	$ 1,728,726	$ 4,187,703	$ 5,047,410

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	8 Months Ended	9 Months Ended
	Jun. 28, 2017	Sep. 30, 2018
Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Equity method investment, ownership percentage		6.80%
Percentage of common shares potentially own outstanding shares		11.70%
Dialog Semiconductor Plc [Member] | Research and Development Expense [Member]
Related Party Transaction [Line Items]
Payments for fees		$ 43,700
Strategic Alliance Agreement [Member]
Related Party Transaction [Line Items]
Revenue		$ 5,773
Private Placements [Member] | Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Stock issued during period, shares, new issues	1,739,691
Private Placements [Member] | Warrant Issued to Private Investors [Member] | Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Class of warrant or right, number of securities called by warrants or rights	1,417,565

Customer Concentration - Additi

Customer Concentration - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)Customer	Sep. 30, 2017Customer	Sep. 30, 2018USD ($)Customer	Sep. 30, 2017Customer	Dec. 31, 2017USD ($)
Concentration Risk [Line Items]
Accounts receivable | $	$ 208,773		$ 208,773		$ 0
Revenues [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customers	1	1	1	1
Concentration percentage	99.00%	100.00%	98.00%	100.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of customers			1
Concentration percentage			96.00%