Energous (WATT) 10-K 16 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Mar. 02, 2018	Jun. 30, 2017
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Trading Symbol	WATT
Entity Registrant Name	Energous Corp
Entity Central Index Key	1,575,793
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		25,155,547
Entity Public Float			$ 288,974,313

Balance Sheets

Balance Sheets - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 12,795,254	$ 31,258,637
Accounts receivable		149,500
Prepaid expenses and other current assets	1,026,310	1,374,585
Prepaid rent, current	80,784	80,784
Total current assets	13,902,348	32,863,506
Property and equipment, net	1,413,917	2,209,475
Prepaid rent, non-current	56,668	137,452
Other assets	32,512	48,507
Total assets	15,405,445	35,258,940
Current liabilities:
Accounts payable	2,024,690	4,707,763
Accrued expenses	1,622,025	1,867,995
Deferred revenue		131,959
Total current liabilities	3,646,715	6,707,717
Commitments and contingencies
Stockholders' equity:
Preferred Stock, $0.00001 par value, 10,000,000 shares authorized at December 31, 2017 and December 31, 2016; no shares issued or outstanding
Common Stock, $0.00001 par value, 50,000,000 shares authorized at December 31, 2017 and December 31, 2016; 22,584,588 and 20,367,929 shares issued and outstanding at December 31, 2017 and December 31, 2016, respectively.	225	202
Additional paid-in capital	185,659,954	153,075,595
Accumulated deficit	(173,901,449)	(124,524,574)
Total stockholders' equity	11,758,730	28,551,223
Total liabilities and stockholders' equity	$ 15,405,445	$ 35,258,940

Balance Sheets (Parenthetical)

Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
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	22,584,588	20,367,929
Common stock, shares outstanding	22,584,588	20,367,929

Statements of Operations

Statements of Operations - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenue	$ 1,154,009	$ 1,451,941	$ 2,500,000
Operating expenses:
Research and development	33,230,668	32,832,677	18,825,041
Sales and marketing	5,207,746	3,201,549	3,221,303
General and administrative	12,103,423	11,248,435	8,030,995
Total operating expenses	50,541,837	47,282,661	30,077,339
Loss from operations	(49,387,828)	(45,830,720)	(27,577,339)
Other income (expense):
Interest income, net	11,679	13,326	15,637
Loss on sale of property and equipment	(726)
Total	10,953	13,326	15,637
Net loss	$ (49,376,875)	$ (45,817,394)	$ (27,561,702)
Basic and diluted loss per common share	$ (2.31)	$ (2.60)	$ (2.07)
Weighted average shares outstanding, basic and diluted	21,343,001	17,649,013	13,303,715

Statement of Changes in Stockho

Statement of Changes in Stockholder's Equity - USD ($)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]
Beginning balance at Dec. 31, 2014	$ 31,320,563	$ 127	$ 82,465,914	$ (51,145,478)
Beginning balance (in shares) at Dec. 31, 2014		12,781,502
Issuance of shares for services	147,900		147,900
Issuance of shares for services (in shares)		15,000
Stock-based compensation - stock options	1,037,399		1,037,399
Stock-based compensation - IR warrants	85,831		85,831
Stock-based compensation - restricted stock units ("RSUs")	4,225,728		4,225,728
Stock-based compensation - employee stock purchase plan ("ESPP")	113,217		113,217
Stock-based compensation - performance share units ("PSUs")	489,239		489,239
Issuance of shares for RSUs		$ 3	(3)
Issuance of shares for RSUs (in shares)		304,340
Issuance of shares for PSUs (in shares)		1,072
Exercise of stock options	65,647		65,647
Exercise of stock options (in shares)		21,786
Disgorgement on account of short swing profit	12,611		12,611
Cashless exercise of warrants		$ 1	(1)
Cashless exercise of warrants (in shares)		128,480
Shares purchased from contributions to the ESPP	289,787		289,787
Shares purchased from contributions to the ESPP (in shares)		46,023
Secondary offering net of underwriter's discount and offering costs	19,048,456	$ 30	19,048,426
Secondary offering net of underwriter's discount and offering costs (in shares)		3,000,005
Net loss	(27,561,702)			(27,561,702)
Ending balance at Dec. 31, 2015	29,274,676	$ 161	107,981,695	(78,707,180)
Ending balance (in shares) at Dec. 31, 2015		16,298,208
Stock-based compensation - stock options	1,045,081		1,045,081
Stock-based compensation - restricted stock units ("RSUs")	5,735,032		5,735,032
Stock based compensation - deferred stock units ("DSUs")	123,644		123,644
Stock-based compensation - employee stock purchase plan ("ESPP")	318,735		318,735
Stock-based compensation - performance share units ("PSUs")	2,285,683		2,285,683
Issuance of shares for RSUs		$ 5	(5)
Issuance of shares for RSUs (in shares)		519,200
Shares repurchased for tax withholdings on vesting of RSUs	(266,217)		(266,217)
Shares repurchased for tax withholdings on vesting of RSUs (in shares)		(20,669)
Issuance of shares for PSUs		$ 2	(2)
Issuance of shares for PSUs (in shares)		209,673
Shares repurchased for tax withholdings on vesting of PSUs	(46,463)		(46,463)
Shares repurchased for tax withholdings on vesting of PSUs (in shares)		(3,607)
Exercise of stock options	382,351	$ 1	382,350
Exercise of stock options (in shares)		130,354
Cashless exercise of warrants		$ 5	(5)
Cashless exercise of warrants (in shares)		475,683
Shares purchased from contributions to the ESPP	727,784	$ 1	727,783
Shares purchased from contributions to the ESPP (in shares)		85,356
Issuance of shares and warrants in private placements, net of issuance costs	34,788,311	$ 27	34,788,284
Issuance of shares and warrants in private placements, net of issuance costs (in shares)		2,673,731
Net loss	(45,817,394)			(45,817,394)
Ending balance at Dec. 31, 2016	28,551,223	$ 202	153,075,595	(124,524,574)
Ending balance (in shares) at Dec. 31, 2016		20,367,929
Stock-based compensation - stock options	764,723		764,723
Stock-based compensation - restricted stock units ("RSUs")	13,043,171		13,043,171
Stock based compensation - deferred stock units ("DSUs")	1,362		1,362
Stock-based compensation - employee stock purchase plan ("ESPP")	331,913		331,913
Stock-based compensation - performance share units ("PSUs")	1,661,650		1,661,650
Issuance of shares for RSUs		$ 8	(8)
Issuance of shares for RSUs (in shares)		781,051
Issuance of shares for DSUs	0	$ 0	0	0
Issuance of shares for DSUs (in shares)		14,953
Issuance of shares for PSUs		$ 1	(1)
Issuance of shares for PSUs (in shares)		90,000
Exercise of stock options	979,950	$ 3	979,947
Exercise of stock options (in shares)		272,205
Cashless exercise of warrants (in shares)		19,611
Shares purchased from contributions to the ESPP	869,066	$ 1	869,065
Shares purchased from contributions to the ESPP (in shares)		62,700
Issuance of shares and warrants in private placements, net of issuance costs	14,932,547	$ 10	14,932,537
Issuance of shares and warrants in private placements, net of issuance costs (in shares)		976,139
Net loss	(49,376,875)			(49,376,875)
Ending balance at Dec. 31, 2017	$ 11,758,730	$ 225	$ 185,659,954	$ (173,901,449)
Ending balance (in shares) at Dec. 31, 2017		22,584,588

Statement of Changes in Stockh6

Statement of Changes in Stockholder's Equity (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Partners' Capital Account, Public Sale of Units Net of Offering Costs			$ 1,651,578
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs	$ 67,388	$ 211,676

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities:
Net loss	$ (49,376,875)	$ (45,817,394)	$ (27,561,702)
Adjustments to reconcile net loss to Net cash used in operating activities:
Depreciation and amortization	1,309,980	957,836	817,729
Stock based compensation	15,802,819	9,508,175	5,951,414
Loss on sale of property and equipment	726
Amortization of prepaid rent from stock issuance to landlord	80,784	80,784	80,784
Changes in operating assets and liabilities:
Accounts receivable	149,500	(149,500)
Prepaid expenses and other current assets	348,275	(652,336)	(157,769)
Other assets	15,995	2,823	(28,682)
Accounts payable	(2,683,073)	2,382,790	608,962
Accrued expenses	53,530	492,616	283,530
Deferred revenue	(131,959)	131,959
Net cash used in operating activities	(34,430,298)	(33,062,247)	(20,005,734)
Cash flows from investing activities:
Purchases of property and equipment	(817,448)	(1,137,446)	(1,032,795)
Proceeds from the sale of property and equipment	2,800
Net cash used in investing activities	(814,648)	(1,137,446)	(1,032,795)
Cash flows from financing activities:
Proceeds from shares issued under shelf registration, net of underwriter's discount and offering expenses			19,048,456
Net proceeds from issuance of shares to private investors	14,932,547	34,788,311
Proceeds from the exercise of stock options	979,950	382,351	65,647
Proceeds from contributions to employee stock purchase plan	869,066	727,784	289,787
Proceeds from the disgorgement of short-swing profit			12,611
Net cash provided by financing activities	16,781,563	35,585,766	19,416,501
Net (decrease) increase in cash and cash equivalents	(18,463,383)	1,386,073	(1,622,028)
Cash and cash equivalents - beginning	31,258,637	29,872,564	31,494,592
Cash and cash equivalents - ending	12,795,254	31,258,637	29,872,564
Supplemental disclosure of non-cash financing activities:
Common stock issued for services			147,900
Cashless exercise of warrants		5	1
Increase in accrued expenses for the purchase of property and equipment		299,500
Restricted Stock Units (RSUs) [Member]
Cash flows from financing activities:
Shares repurchased for tax withholdings on vesting		(266,217)
Supplemental disclosure of non-cash financing activities:
Common stock issued	8	6	$ 3
Performance Shares [Member]
Cash flows from financing activities:
Shares repurchased for tax withholdings on vesting		(46,463)
Supplemental disclosure of non-cash financing activities:
Common stock issued	$ 1	$ 2

Business Organization, Nature o

Business Organization, Nature of Operations	12 Months Ended
	Dec. 31, 2017
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 a technology called WattUp ® RF-based RF-based e-book The Company is using its WattUp technology to develop solutions that charge electronic devices by surrounding them with a contained 3D RF energy pocket. The Company is engineering solutions that are expected to enable the wire-free transmission of energy from multiple WattUp transmitters to multiple WattUp receiving devices within a range of up to 15 feet in radius or in a circular charging envelope of up to 30 feet. The Company is also developing a transmitter technology to seamlessly mesh, like a network of Wi-Fi room-to-room The market for products using the Company’s technology 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.

Liquidity and Management Plans

Liquidity and Management Plans	12 Months Ended
	Dec. 31, 2017
Text Block [Abstract]
Liquidity and Management Plans	Note 2 – Liquidity and Management Plans During the year ended December 31, 2017, the Company has recorded revenue of $1,154,009. The Company incurred a net loss of $49,376,875, $45,817,394 and $27,561,702 for the years ended December 31, 2017, 2016 and 2015, respectively. Net cash used in operating activities was $34,430,298, $33,062,247 and $20,005,734 for the years ended December 31, 2017, 2016 and 2015, respectively. The Company is currently meeting its liquidity requirements principally through sales of shares to three different private investors during August 2016, November 2016, December 2016 and July 2017, raising net proceeds of $49,720,858, and payments received under product development projects. As of December 31, 2017, the Company had cash on hand of $12,795,254. The Company expects that cash on hand as of December 31, 2017, together with anticipated payments to be received under current product development projects and anticipated royalties from chip revenue, together with potential new financing activities including potential sales of stock, will be sufficient to fund the Company’s operations into the first quarter of 2019. As noted in Note 12—Subsequent Events, the Company raised $38,999,989 (net of underwriters’ discount of $1,000,000) from the sales of stock in January 2018. Research and development of new technologies is, by its nature, unpredictable. Although the Company intends to undertake development efforts with commercially reasonable diligence, there can be no assurance that its available resources 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 expects to pursue additional financing, which could include follow-on co-development

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
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 (“U.S. GAAP”), and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”). Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and 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 The Company recognizes revenue when all of the following criteria have been met: persuasive evidence of an arrangement exists, services have been rendered, collection of the revenue is reasonably assured, and the fees are fixed or determinable. 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 our performance and the milestone typically needs to be accepted 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 also receives nonrefundable payments, typically at the beginning of a customer relationship, for which there are no milestones. The Company recognizes this revenue ratably over the initial engineering product development period. The Company records the expenses related to these projects, generally included in research and development expense, in the periods incurred. 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 $33,230,668, $32,832,677 and $18,825,041 for the years ended December 31, 2017, 2016 and 2015, 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. On April 10, 2015, the Company’s board of directors approved the Energous Corporation Employee Stock Purchase Plan (the “ESPP”), under which 600,000 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. Under the plan, 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 December 31, 2017, no liability for unrecognized tax benefits was required to be reported. The guidance also discusses the classification of related interest and penalties on income taxes. The Company’s policy is to record interest and penalties on uncertain tax positions as a component of income tax expense. No interest or penalties were recorded during the years ended December 31, 2017, 2016 and 2015. The Company files income tax returns with the United States and California governments. 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”) and performance stock units (“PSUs”) and the enrollment of employees in the ESPP. The computation of diluted loss per share excludes potentially dilutive securities of 7,324,400, 6,975,651 and 4,994,425 for the years ended December 31, 2017, 2016 and 2015, respectively, because their inclusion would be antidilutive. 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 Years Ended December 31, 2017 2016 2015 Consulting Warrant to purchase common stock — — 146,252 Financing Warrant to purchase common stock 13,889 13,889 152,778 IPO Warrants to purchase common stock 11,600 11,600 460,000 IR Consulting Warrant — 23,250 36,000 IR Incentive Warrant — 15,000 15,000 Warrants issued to private investors 3,035,688 2,381,675 — Options to purchase common stock 1,037,239 1,309,444 1,487,785 RSUs 2,274,327 2,052,223 1,560,996 PSUs 951,657 1,153,617 1,135,614 DSUs — 14,953 — Total potentially dilutive securities 7,324,400 6,975,651 4,994,425 Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, 2014-09”), 2014-09 2014-09 2014-09 2014-09; 2014-09 2014-09. 2014-09 one-year In August 2014, FASB issued ASU No. 2014-15, 205-40): 2014-15 In April 2015, the FASB issued ASU No. 2015-03, 2015-03, In August 2015, the FASB issued ASU No. 2015-15, Line-of-Credit line-of-credit 2015-15 2015-03. 2015-15, In November 2015, the FASB issued ASU No. 2015-17, 2015-17”). 2015-17 2015-17 2015-17 In January 2016, the FASB issued ASU No. 2016-01, 825-10): 2016-01”). 2016-01 In January 2016, the FASB issued ASU No. 2016-02, 2016-02”). right-of-use 2016-02 In March 2016, the FASB issued ASU No. 2016-09, No. 2016-09 No. 2016-09 2016-09 In June 2016, the FASB issued ASU No. 2016-13, No. 2016-13 In August 2016, the FASB issued ASU No. 2016-15, No. 2016-15 In November 2016, the FASB issued ASU No. 2016-18, No. 2016-18 beginning-of-period end-of-period In December 2016, the FASB issued ASU No. 2016-20, No. 2016-20 No. 2014-09 No. 2014-09. In May 2017, the FASB issued ASU No. 2017-09, No. 2017-09 In July 2017, the Financial Accounting Standards Board (“FASB”) issued a two-part No. 2017-11, 2017-11”). 2017-11 2017-11 2017-11 re-characterize 2017-11 Management’s Evaluation of Subsequent Events The Company evaluates events that have occurred after the balance sheet date of December 31, 2017, through the date which the financial statements are issued. Based upon the review, other than the event disclosed in Note 12 – Subsequent Events, the Company did not identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	Note 4 – Property and Equipment Property and equipment are as follows: As of December 31, 2017 2016 Computer software $ 1,418,457 $ 1,085,258 Computer hardware 2,289,687 2,109,983 Furniture and fixtures 529,287 533,175 Leasehold improvements 613,111 613,111 4,850,542 4,341,527 Less – accumulated depreciation (3,436,625 ) (2,132,052 ) Total property and equipment, net $ 1,413,917 $ 2,209,475 The Company currently uses the following expected life terms for depreciating property and equipment: computer software – 1-2 Total depreciation and amortization expense of the Company’s property and equipment was $1,309,980, $957,836 and $817,729 for the years ended December 31, 2017, 2016 and 2015, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued Expenses	Note 5 – Accrued Expenses Accrued expenses consist of the following: As of December 31, 2017 2016 Accrued compensation $ 948,935 $ 997,908 Accrued legal expenses 445,684 283,160 Accrued equipment cost — 299,500 Other accrued expenses 227,406 287,427 Total $ 1,622,025 $ 1,867,995

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 6 – 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 sub-lease On July 9, 2015, the Company entered into a sub-lease The future minimum lease payments for leased locations are as follows: For the Years Ended December 31, Amount 2018 $ 640,202 2019 457,585 Total $ 1,097,787 Development and Licensing Agreements In 2015, the Company signed a development and licensing agreement with a consumer electronics company to embed WattUp wire-free charging receiver technology in various products including, but not limited to, certain mobile consumer electronics and related accessories. On March 31, 2016, the Company received payment of $500,000 pursuant to the February 15, 2016 commencement of the second phase described in the third amendment of this agreement, of which the Company recorded $108,959 and $391,041 in revenue during the years ended December 31, 2017 and 2016, respectively. During the years ended December 31, 2017 and 2016, the Company also recognized milestone revenue of $1,000,000 for both years related to this agreement. In 2016, the Company entered into a development and license agreement with a commercial and industrial supply company, under which the Company developed wire-free charging solutions. The Company recognized $44,550 and $59,400 of revenue from this agreement during the years ended December 31, 2017 and 2016, respectively. For the years ended December 31, 2017, 2016 and 2015, the customers from the development and license agreement accounted for approximately 100% of the Company’s revenue. As of December 31, 2017, the Company did not have an accounts receivable balance. As of December 31, 2016, the customers from these two agreements accounted for 100% of the accounts receivable balance. Hosted Design Solution Agreement On June 25, 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 July 13, 2015, the Company is required to remit quarterly payments in the amount of $100,568 with the last payment due March 30, 2018. On December 18, 2015, the agreement was amended to redefine the hardware and software configuration and the quarterly payments increased to $198,105. Amended 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 (the “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. Pursuant to Mr. Rizzone’s prior employment agreement, on December 12, 2013 Mr. Rizzone was granted a ten 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 Performance Share Units (the “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 8). 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, twenty-five percent (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, one hundred percent (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, a related party (see Note 10—Related Party Transactions), 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 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 (the “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 (the “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 occurrence of certain events relating to the Company’s pre-existing In addition to the Alliance Agreement, the Company and Dialog entered into two securities purchase agreements (see Note 7 - Stockholders’ Equity).

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Stockholders' Equity	Note 7 – 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 of directors 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, Pursuant to the shelf registration, on November 17, 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. Also, as noted in Note 12—Subsequent Events, the Company raised net proceeds of $38,999,989 (net of underwriters’ discount of $1,000,000) from the sales of 2,221,455 shares of stock in January 2018. 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 10—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 Semiconductor, a related party (see Note 10 – Related Party Transactions), 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	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock Based Compensation	Note 8 – Stock Based Compensation Equity Incentive Plans 2013 Equity Incentive Plan In December 2013, the Company’s board of directors and stockholders approved the Company’s 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 of directors 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 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 shares which may be issued under the 2013 Equity Incentive Plan were 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. As of December 31, 2017, 829,515 shares of common stock remain eligible to be issued through equity-based instruments under the 2013 Equity Incentive Plan. 2014 Non-Employee On March 6, 2014, the Company’s board of directors and stockholders approved the 2014 Non-Employee 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 As of December 31, 2017, 292,655 shares of common stock remain eligible to be issued through equity-based instruments under the 2014 Non-Employee 2015 Performance Share Unit Plan On April 10, 2015, the Company’s board of directors approved the Energous Corporation 2015 Performance Share Unit Plan (the “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. As of December 31, 2017, 31,951 shares of common stock remain eligible to be issued through equity based instruments under the Performance Share Unit Plan. 2017 Equity Inducement Plan On December 28, 2017, the Board of Directors approved the 2017 Equity Inducement Plan. Under the plan, the Board of Directors reserved 600,000 shares for the grant of RSUs. These grants will be administered by a committee of the Board of Directors or the Board of Directors 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. Employee Stock Purchase Plan On April 10, 2015, the Company’s board of directors approved the ESPP, under which 600,000 shares of common stock have been 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 December 31, 2017, 405,921 shares of common stock remain eligible to be issued through equity based instruments under the ESPP. For the year ended December 31, 2017, eligible employees contributed $869,066 through payroll deductions to the ESPP and 64,542 shares were deemed delivered for the year ended December 31, 2017. For the year ended December 31, 2016, eligible employees contributed $727,784 through payroll deductions to the ESPP and 85,356 shares were deemed delivered for the year ended December 31, 2016. Stock Option Award Activity The following is a summary of the Company’s stock option activity during the year ended December 31, 2017: Number of Weighted Weighted Intrinsic Outstanding at January 1, 2017 1,309,444 $ 4.55 7.1 $ 16,107,929 Granted — — — — Exercised (272,205 ) 3.60 — — Forfeited — — — — Outstanding at December 31, 2017 1,037,239 $ 4.80 6.4 $ 15,198,044 Exercisable at December 31, 2017 1,037,239 $ 4.80 6.4 $ 15,198,044 As of December 31, 2017, the unamortized value of options was $0. The aggregate intrinsic value of options exercised was $2,864,845, $984,144 and $92,728 for the years ended December 31, 2017, 2016 and 2015, respectively. No options were granted during the years ended December 31, 2017, 2016 and 2015. Restricted Stock Units (“RSUs”) During the first quarter of 2017, the compensation committee of the board of directors (“Compensation Committee”) granted various directors RSUs under which the holders have the right to receive an aggregate of 48,844 shares of common stock. These awards were granted under the 2014 Non-Employee During the first quarter of 2017, the Compensation Committee granted employees RSU awards under which the holders have the right to receive an aggregate of 246,000 shares of common stock. The awards vest over four years beginning on the anniversary of the employee hire dates. During the first quarter of 2017, 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 of 351,080 shares of common stock. The awards vest over terms from two to four years. During the second quarter of 2017, the Compensation Committee granted various consultants RSUs under which the holders have the right to receive an aggregate of 8,400 shares of common stock. These awards were granted under the 2014 Non-Employee During the second quarter of 2017, the Compensation Committee granted employees RSU awards under which the holders have the right to receive an aggregate of 120,000 shares of common stock. A majority of the awards vest over four years beginning on the anniversary of the employee hire dates. During the second quarter of 2017, the Compensation Committee granted employees RSU awards under the 2013 Equity Incentive Plan under which the holders have the right to receive an aggregate of 308,059 shares of common stock. The awards vest over terms from two to four years. During the third quarter of 2017, the Compensation Committee granted employees RSU awards under the 2013 Equity Incentive Plan under which the holders have the right to receive an aggregate of 117,514 shares of common stock. The awards vest over terms from two to four years. During the fourth quarter of 2017, the Compensation Committee granted employees RSU awards under the 2013 Equity Incentive Plan under which the holders have the right to receive an aggregate of 53,188 shares of common stock. A majority of the awards vest over a four year term. The Company accounts for RSUs granted to consultants using the accounting guidance included in ASC 505-50 Non-Employees” 505-50”). 505-50, At December 31, 2017, the unamortized value of the RSUs was $24,701,605. The unamortized amount will be expensed over a weighted average period of 2.7 years. A summary of the activity related to RSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 2,052,223 $ 11.58 RSUs granted 1,253,085 $ 15.81 RSUs forfeited (249,928 ) $ 12.63 RSUs vested (781,055 ) $ 11.53 Outstanding at December 31, 2017 2,274,325 $ 13.75 Performance Share Units (“PSUs”) Performance share units (“PSUs”) are grants that vest upon the achievement of certain performance goals. The goals are commonly related to the Company’s market capitalization or market share price of the common stock. The PSUs originally issued during 2015 to certain board members and senior management 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. 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 year ended December 31, 2017. Performance Share Market capitalization $ 106,600,000 Dividend yield 0 % Expected volatility 75 % Risk-free interest rate 1.04 % 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 of the board of directors 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 the Company’s common stock. The shares of this award vest upon the Company’s stock price meeting specific targets. For the PSU award grant issued to Mr. Rizzone, 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 is amortized over the estimated service period from October 24, 2016 through October 30, 2017. Amortization for all PSU awards was $1,661,650 and $2,285,683 for the years ended December 31, 2017 and 2016, respectively. At December 31, 2017, the unamortized value of all PSUs was approximately $819,910. The unamortized amount will be expensed over a weighted average period of 1.0 years. A summary of the activity related to PSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 1,153,617 $ 3.66 PSUs granted — $ — PSUs forfeited (111,960 ) $ 2.62 PSUs vested (90,000 ) $ 13.82 Outstanding at December 31, 2017 951,657 $ 2.65 Deferred Stock Units (“DSUs”) On January 4, 2016, the compensation committee of the board of directors granted to John Gaulding, director and chairman of the board, DSUs under the 2014 Non-Employee At December 31, 2017, the unamortized value of the DSUs was $0. A summary of the activity related to DSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 14,953 $ 8.36 DSUs granted — $ — DSUs forfeited — $ — DSUs vested (14,953 ) $ 8.36 Outstanding at December 31, 2017 — $ — Employee Stock Purchase Plan (“ESPP”) 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. During the year ended December 31, 2016, there were also two offering periods for the ESPP. The first offering period started on January 1, 2016 and concluded on June 30, 2016. The second offering period started on July 1, 2016 and concluded on December 31, 2016. During the year ended December 31, 2015, there was one initial offering period for the ESPP which started on July 1, 2015 and concluded on December 31, 2015. The weighted-average grant-date fair value of the purchase option for each designated share purchased under this plan was approximately $5.42, $5.20 and $2.46 during the years ended December 31, 2017, 2016 and 2015, 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 $331,913, $318,735 and $113,217 for the years ended December 31, 2017, 2016 and 2015, respectively. The Company estimated the fair value of the purchase options granted during the years ended December 31, 2017, 2016 and 2015 using the Black-Scholes option pricing model. The fair values of the purchase options granted were estimated using the following assumptions: For the Year Ended Stock price range $ 16.08 -17.59 Dividend yield 0 % Expected volatility range 56 – 66 % Risk-free interest rate range 0.62 – 1.11 % Expected life 6 months For the Year Ended Stock price range $ 8.36 – 12.16 Dividend yield 0 % Expected volatility range 56 – 100 % Risk-free interest rate range 0.37 – 0.49 % Expected life 6 months For the Year Ended Stock price $ 7.41 Dividend yield 0 % Expected volatility 65 % Risk-free interest rate 0.13 % Expected life 6 months Stock-Based Compensation Expense The following tables summarize total stock-based compensation costs recognized for years ended December 31, 2017, 2016 and 2015: For the Years Ended December 31, 2017 2016 2015 Stock options $ 764,723 $ 1,045,081 $ 1,037,399 RSUs 13,043,171 5,735,032 4,225,728 PSUs 1,661,650 2,285,683 489,239 DSUs 1,362 123,644 — ESPP 331,913 318,735 113,217 IR warrants — — 85,831 Total $ 15,802,819 $ 9,508,175 $ 5,951,414 The total amount of stock-based compensation was reflected within the statements of operations as: For the Years Ended December 31, 2017 2016 2015 Research and development $ 8,522,798 $ 4,226,304 $ 2,816,707 Sales and marketing 1,113,120 328,760 729,329 General and administrative 6,166,901 4,953,111 2,405,378 Total $ 15,802,819 $ 9,508,175 $ 5,951,414

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Note 9 – Income Taxes On December 22, 2017, the Tax Cuts and Jobs Act (the “2017 Tax Act”) was enacted. The 2017 Tax Act includes a number of changes to existing U.S. tax laws that impact the company, most notably a reduction of the U.S. corporate income tax rate from 35 percent to 21 percent for tax years beginning after December 31, 2017. The company measures deferred tax assets and liabilities using enacted tax rates that will apply in the years in which the temporary differences are expected to be recovered or paid. Accordingly, the company’s deferred tax assets and liabilities were remeasured to reflect the reduction in the U.S. corporate income tax rate from 35% to 21%, resulting in a $19,432,000 decrease in net deferred tax assets for the year ended December 31, 2017 and a corresponding $19,432,000 decrease in valuation allowance as of December 31, 2017. The SEC staff issued Staff Accounting Bulletin No. 118 (“SAB 118”) to address the application of U.S. GAAP in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the 2017 Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the 2017 Tax Act enactment date for companies to complete the accounting for the income tax effects of certain elements of the 2017 Tax Act. In accordance with SAB 118, we have recognized the provisional tax impacts related to the remeasurement of deferred tax assets and liabilities and included these amounts in our financial statements for the year ended December 31, 2017. The ultimate impact may differ from these provisional amounts, possibly materially, due to, among other things, additional analysis, changes in interpretations and assumptions we have made, additional regulatory guidance that may be issued, and actions we may take as a result of the 2017 Tax Act. As of December 31, 2017, and 2016, the Company’s deferred tax assets (liabilities) consisted of the effects of temporary differences attributable to the following: December 31, 2017 2016 Deferred tax assets (liabilities): Tax credit $ 4,335,394 $ 2,802,573 Net operating loss carryovers 23,630,008 16,174,712 Property and equipment 99,756 (58,747 ) Research and development costs 15,372,328 18,628,913 Start-up 774 1,222 Stock-based compensation 2,473,591 1,829,843 Other accruals 260,113 341,090 Total gross deferred tax assets 46,171,964 39,719,606 Less: valuation allowance (46,171,964 ) (39,719,606 ) Deferred tax assets, net $ — $ — The change in the Company’s valuation allowance is as follows: 2017 2016 January 1, $ 39,719,606 $ 22,085,888 Increase in valuation allowance 6,452,358 17,633,718 December 31, $ 46,171,964 $ 39,719,606 The Company has federal and state net operating loss carryovers of approximately $84,418,000 and $85,515,000, respectively, available to offset future taxable income. The federal and state NOL carryforwards will expire at various dates beginning in 2033. The Company has federal and state research and development tax credit carryovers of approximately $2,686,000 and $2,088,000, respectively. The federal R&D credit carryovers will expire beginning in 2032 and state R&D credit carryovers do not expire. The ultimate realization of the net operating loss is dependent upon future taxable income, if any, of the Company and may be limited in any one period by alternative minimum tax rules. Although management believes that the Company may have sufficient future taxable income to absorb the net operating loss carryovers and research and development tax credit carryovers before the expiration of the carryover period, there may be circumstances beyond the Company’s control that limit such utilization. Accordingly, management has determined that a full valuation allowance of the deferred tax asset is appropriate at December 31, 2017 and 2016. Internal Revenue Code Section 382 imposes limitations on the use of net operating loss carryovers when the stock ownership of one or more 5% shareholders (shareholders owning 5% or more of the Company’s outstanding capital stock) has increased on a cumulative basis by more than 50 percentage points. Management cannot control the ownership changes occurring as a result of public trading of the Company’s Common Stock. Accordingly, there is a risk of an ownership change beyond the control of the Company that could trigger a limitation of the use of the loss carryover. The Company completed a Section 382 analysis as of December 31, 2017 and determined that none of its NOLs or R&D credits would be limited. For the Year Ended December 31, Tax benefit at federal statutory rate (34.0 )% (34.0 )% State income taxes (10.2 ) (5.7 ) Permanent differences: Stock-based compensation (2.5 ) 0.8 Meals and entertainment 0.1 0.1 True-up (2.8 ) 1.7 True-up — 1.2 Change in effective tax rate 39.4 — Research and development tax credit, federal (1.4 ) (1.5 ) Research and development tax credit, state (1.6 ) (1.1 ) Increase in valuation allowance, federal 1.3 32.9 Increase in valuation allowance, state 11.7 5.6 Effective income tax rate 0.0 % 0.0 %

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Note 10 – Related Party Transactions On July 14, 2014, the Company’s Board of Directors appointed Howard Yeaton as the Company’s Interim Chief Financial Officer. On July 13, 2015, the Company appointed Brian Sereda as the Company’s Chief Financial Officer, replacing Interim Chief Financial Officer Howard Yeaton. Howard Yeaton is the Managing Principal of Financial Consulting Strategies LLC (“FCS”). During the years ended December 31, 2017, 2016 and 2015, the Company had incurred fees of $0, $0 and $61,848 in connection with Mr. Yeaton’s services as Interim Chief Financial Officer. During the years ended December 31, 2017, 2016 and 2015, the Company incurred fees of $0, $13,306 and $88,813 for other financial advisory and accounting services provided by FCS. In November 2016, the Company and Dialog Semiconductor plc (“Dialog”) entered into an Alliance Agreement for the manufacture, distribution and commercialization of products incorporating the Company’s wire-free charging technology (See Note 6 - Commitments and Contingencies, Strategic Alliance Agreement Private Placements

Unaudited Quarterly Financial I

Unaudited Quarterly Financial Information	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Financial Information	Note 11 – Unaudited Quarterly Financial Information Summarized quarterly information for the years ended December 31, 2017 and 2016 is listed below: For the quarter ended March 31 June 30 September 30 December 31 2017 Revenue $ 575,368 $ 299,506 $ 250,000 $ 29,135 Operating expenses $ 13,051,387 $ 13,220,879 $ 13,001,623 $ 11,267,948 Net loss $ (12,473,140 ) $ (12,919,010 ) $ (12,748,248 ) $ (11,236,477 ) Loss per share, basic and diluted $ (0.61 ) $ (0.63 ) $ (0.58 ) $ (0.50 ) 2016 Revenue $ 136,364 $ 181,818 $ 1,003,973 $ 129,786 Operating expenses $ 10,936,772 $ 10,468,990 $ 11,131,994 $ 14,744,905 Net loss $ (10,796,542 ) $ (10,284,555 ) $ (10,125,063 ) $ (14,611,234 ) Loss per share, basic and diluted $ (0.66 ) $ (0.62 ) $ (0.57 ) $ (0.75 )

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Note 12 – Subsequent Events During January 2018, the Company raised $38,999,989 (net of underwriters’ discount of $1,000,000) from the sale of stock to the public in an “at-the-market” In March 2018, the Company’s Board of Directors (“Board”), on the recommendation of the Board’s Compensation Committee (“Compensation Committee”), approved the Energous Corporation MBO Bonus Plan (“Bonus Plan”) for executive officers of the Company. To be eligible to receive a bonus under the Bonus Plan, an executive officer must be continuously employed throughout the applicable performance period, and in good standing, and achieve the performance objectives selected by the Compensation Committee.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
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 (“U.S. GAAP”), and pursuant to the accounting and disclosure rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”).
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and 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 The Company recognizes revenue when all of the following criteria have been met: persuasive evidence of an arrangement exists, services have been rendered, collection of the revenue is reasonably assured, and the fees are fixed or determinable. 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 our performance and the milestone typically needs to be accepted 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 also receives nonrefundable payments, typically at the beginning of a customer relationship, for which there are no milestones. The Company recognizes this revenue ratably over the initial engineering product development period. The Company records the expenses related to these projects, generally included in research and development expense, in the periods incurred.
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 $33,230,668, $32,832,677 and $18,825,041 for the years ended December 31, 2017, 2016 and 2015, 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. On April 10, 2015, the Company’s board of directors approved the Energous Corporation Employee Stock Purchase Plan (the “ESPP”), under which 600,000 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. Under the plan, 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 December 31, 2017, no liability for unrecognized tax benefits was required to be reported. The guidance also discusses the classification of related interest and penalties on income taxes. The Company’s policy is to record interest and penalties on uncertain tax positions as a component of income tax expense. No interest or penalties were recorded during the years ended December 31, 2017, 2016 and 2015. The Company files income tax returns with the United States and California governments.
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”) and performance stock units (“PSUs”) and the enrollment of employees in the ESPP. The computation of diluted loss per share excludes potentially dilutive securities of 7,324,400, 6,975,651 and 4,994,425 for the years ended December 31, 2017, 2016 and 2015, respectively, because their inclusion would be antidilutive. 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 Years Ended December 31, 2017 2016 2015 Consulting Warrant to purchase common stock — — 146,252 Financing Warrant to purchase common stock 13,889 13,889 152,778 IPO Warrants to purchase common stock 11,600 11,600 460,000 IR Consulting Warrant — 23,250 36,000 IR Incentive Warrant — 15,000 15,000 Warrants issued to private investors 3,035,688 2,381,675 — Options to purchase common stock 1,037,239 1,309,444 1,487,785 RSUs 2,274,327 2,052,223 1,560,996 PSUs 951,657 1,153,617 1,135,614 DSUs — 14,953 — Total potentially dilutive securities 7,324,400 6,975,651 4,994,425
Recent Accounting Pronouncements	Recent Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update No. 2014-09, 2014-09”), 2014-09 2014-09 2014-09 2014-09; 2014-09 2014-09. 2014-09 one-year In August 2014, FASB issued ASU No. 2014-15, 205-40): 2014-15 In April 2015, the FASB issued ASU No. 2015-03, 2015-03, In August 2015, the FASB issued ASU No. 2015-15, Line-of-Credit line-of-credit 2015-15 2015-03. 2015-15, In November 2015, the FASB issued ASU No. 2015-17, 2015-17”). 2015-17 2015-17 2015-17 In January 2016, the FASB issued ASU No. 2016-01, 825-10): 2016-01”). 2016-01 In January 2016, the FASB issued ASU No. 2016-02, 2016-02”). right-of-use 2016-02 In March 2016, the FASB issued ASU No. 2016-09, No. 2016-09 No. 2016-09 2016-09 In June 2016, the FASB issued ASU No. 2016-13, No. 2016-13 In August 2016, the FASB issued ASU No. 2016-15, No. 2016-15 In November 2016, the FASB issued ASU No. 2016-18, No. 2016-18 beginning-of-period end-of-period In December 2016, the FASB issued ASU No. 2016-20, No. 2016-20 No. 2014-09 No. 2014-09. In May 2017, the FASB issued ASU No. 2017-09, No. 2017-09 In July 2017, the Financial Accounting Standards Board (“FASB”) issued a two-part No. 2017-11, 2017-11”). 2017-11 2017-11 2017-11 re-characterize 2017-11
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 December 31, 2017, through the date which the financial statements are issued. Based upon the review, other than the event disclosed in Note 12 – Subsequent Events, the Company did not identify any subsequent events that would have required adjustment or disclosure in the financial statements.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
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 Years Ended December 31, 2017 2016 2015 Consulting Warrant to purchase common stock — — 146,252 Financing Warrant to purchase common stock 13,889 13,889 152,778 IPO Warrants to purchase common stock 11,600 11,600 460,000 IR Consulting Warrant — 23,250 36,000 IR Incentive Warrant — 15,000 15,000 Warrants issued to private investors 3,035,688 2,381,675 — Options to purchase common stock 1,037,239 1,309,444 1,487,785 RSUs 2,274,327 2,052,223 1,560,996 PSUs 951,657 1,153,617 1,135,614 DSUs — 14,953 — Total potentially dilutive securities 7,324,400 6,975,651 4,994,425

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment	Property and equipment are as follows: As of December 31, 2017 2016 Computer software $ 1,418,457 $ 1,085,258 Computer hardware 2,289,687 2,109,983 Furniture and fixtures 529,287 533,175 Leasehold improvements 613,111 613,111 4,850,542 4,341,527 Less – accumulated depreciation (3,436,625 ) (2,132,052 ) Total property and equipment, net $ 1,413,917 $ 2,209,475

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Summary of Accrued Expenses	Accrued expenses consist of the following: As of December 31, 2017 2016 Accrued compensation $ 948,935 $ 997,908 Accrued legal expenses 445,684 283,160 Accrued equipment cost — 299,500 Other accrued expenses 227,406 287,427 Total $ 1,622,025 $ 1,867,995

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
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 $ 640,202 2019 457,585 Total $ 1,097,787

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Stock Option Activity	The following is a summary of the Company’s stock option activity during the year ended December 31, 2017: Number of Weighted Weighted Intrinsic Outstanding at January 1, 2017 1,309,444 $ 4.55 7.1 $ 16,107,929 Granted — — — — Exercised (272,205 ) 3.60 — — Forfeited — — — — Outstanding at December 31, 2017 1,037,239 $ 4.80 6.4 $ 15,198,044 Exercisable at December 31, 2017 1,037,239 $ 4.80 6.4 $ 15,198,044
Schedule of Restricted Stock Units Activity	A summary of the activity related to RSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 2,052,223 $ 11.58 RSUs granted 1,253,085 $ 15.81 RSUs forfeited (249,928 ) $ 12.63 RSUs vested (781,055 ) $ 11.53 Outstanding at December 31, 2017 2,274,325 $ 13.75
Summary of Fair Value of Market Condition	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 year ended December 31, 2017. Performance Share Market capitalization $ 106,600,000 Dividend yield 0 % Expected volatility 75 % Risk-free interest rate 1.04 %
Summary of Activity Related to PSUs	A summary of the activity related to PSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 1,153,617 $ 3.66 PSUs granted — $ — PSUs forfeited (111,960 ) $ 2.62 PSUs vested (90,000 ) $ 13.82 Outstanding at December 31, 2017 951,657 $ 2.65
Summary of Activity Related to DSUs	A summary of the activity related to DSUs for the year ended December 31, 2017 is presented below: Total Weighted Outstanding at January 1, 2017 14,953 $ 8.36 DSUs granted — $ — DSUs forfeited — $ — DSUs vested (14,953 ) $ 8.36 Outstanding at December 31, 2017 — $ —
Summary of Fair Values of Purchase Options Granted	The fair values of the purchase options granted were estimated using the following assumptions: For the Year Ended Stock price range $ 16.08 -17.59 Dividend yield 0 % Expected volatility range 56 – 66 % Risk-free interest rate range 0.62 – 1.11 % Expected life 6 months For the Year Ended Stock price range $ 8.36 – 12.16 Dividend yield 0 % Expected volatility range 56 – 100 % Risk-free interest rate range 0.37 – 0.49 % Expected life 6 months For the Year Ended Stock price $ 7.41 Dividend yield 0 % Expected volatility 65 % Risk-free interest rate 0.13 % Expected life 6 months
Summary of Stock-based Compensation Costs Recognized	The following tables summarize total stock-based compensation costs recognized for years ended December 31, 2017, 2016 and 2015: For the Years Ended December 31, 2017 2016 2015 Stock options $ 764,723 $ 1,045,081 $ 1,037,399 RSUs 13,043,171 5,735,032 4,225,728 PSUs 1,661,650 2,285,683 489,239 DSUs 1,362 123,644 — ESPP 331,913 318,735 113,217 IR warrants — — 85,831 Total $ 15,802,819 $ 9,508,175 $ 5,951,414
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: For the Years Ended December 31, 2017 2016 2015 Research and development $ 8,522,798 $ 4,226,304 $ 2,816,707 Sales and marketing 1,113,120 328,760 729,329 General and administrative 6,166,901 4,953,111 2,405,378 Total $ 15,802,819 $ 9,508,175 $ 5,951,414

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities	As of December 31, 2017, and 2016, the Company’s deferred tax assets (liabilities) consisted of the effects of temporary differences attributable to the following: December 31, 2017 2016 Deferred tax assets (liabilities): Tax credit $ 4,335,394 $ 2,802,573 Net operating loss carryovers 23,630,008 16,174,712 Property and equipment 99,756 (58,747 ) Research and development costs 15,372,328 18,628,913 Start-up 774 1,222 Stock-based compensation 2,473,591 1,829,843 Other accruals 260,113 341,090 Total gross deferred tax assets 46,171,964 39,719,606 Less: valuation allowance (46,171,964 ) (39,719,606 ) Deferred tax assets, net $ — $ —
Summary of Valuation Allowance	The change in the Company’s valuation allowance is as follows: 2017 2016 January 1, $ 39,719,606 $ 22,085,888 Increase in valuation allowance 6,452,358 17,633,718 December 31, $ 46,171,964 $ 39,719,606
Schedule of Effective Income Tax Rate Reconciliation	For the Year Ended December 31, Tax benefit at federal statutory rate (34.0 )% (34.0 )% State income taxes (10.2 ) (5.7 ) Permanent differences: Stock-based compensation (2.5 ) 0.8 Meals and entertainment 0.1 0.1 True-up (2.8 ) 1.7 True-up — 1.2 Change in effective tax rate 39.4 — Research and development tax credit, federal (1.4 ) (1.5 ) Research and development tax credit, state (1.6 ) (1.1 ) Increase in valuation allowance, federal 1.3 32.9 Increase in valuation allowance, state 11.7 5.6 Effective income tax rate 0.0 % 0.0 %

Unaudited Quarterly Financial27

Unaudited Quarterly Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	Summarized quarterly information for the years ended December 31, 2017 and 2016 is listed below: For the quarter ended March 31 June 30 September 30 December 31 2017 Revenue $ 575,368 $ 299,506 $ 250,000 $ 29,135 Operating expenses $ 13,051,387 $ 13,220,879 $ 13,001,623 $ 11,267,948 Net loss $ (12,473,140 ) $ (12,919,010 ) $ (12,748,248 ) $ (11,236,477 ) Loss per share, basic and diluted $ (0.61 ) $ (0.63 ) $ (0.58 ) $ (0.50 ) 2016 Revenue $ 136,364 $ 181,818 $ 1,003,973 $ 129,786 Operating expenses $ 10,936,772 $ 10,468,990 $ 11,131,994 $ 14,744,905 Net loss $ (10,796,542 ) $ (10,284,555 ) $ (10,125,063 ) $ (14,611,234 ) Loss per share, basic and diluted $ (0.66 ) $ (0.62 ) $ (0.57 ) $ (0.75 )

Liquidity and Management Plans

Liquidity and Management Plans - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended								12 Months Ended
	Jan. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Liquidity And Management Plans [Line Items]
Engineering product development										$ 1,154,009
Net income (loss)		$ (11,236,477)	$ (12,748,248)	$ (12,919,010)	$ (12,473,140)	$ (14,611,234)	$ (10,125,063)	$ (10,284,555)	$ (10,796,542)	(49,376,875)	$ (45,817,394)	$ (27,561,702)
Net cash provided by (used in) operating activities										(34,430,298)	(33,062,247)	(20,005,734)
Proceeds from issuance of common stock										14,932,547	34,788,311
Cash and cash equivalents, at carrying value, total		$ 12,795,254				$ 31,258,637				$ 12,795,254	$ 31,258,637	$ 29,872,564	$ 31,494,592
Subsequent Event [Member]
Liquidity And Management Plans [Line Items]
Stock issued during period, shares, new issues	$ 38,999,989
Common stock, discount on shares	$ 1,000,000

Significant Accounting Policies

Significant Accounting Policies - Additional Information (Detail) - USD ($)	May 21, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 10, 2015
Summary Of Significant Accounting Policies [Line Items]
Research and development expense, total		$ 33,230,668	$ 32,832,677	$ 18,825,041
Antidilutive securities excluded from computation of earnings per share, amount		7,324,400	6,975,651	4,994,425
Employee Stock Purchase Plan [Member]
Summary Of Significant Accounting Policies [Line Items]
Common stock, capital shares reserved for future issuance					600,000
Common stock purchase price discount percentage	15.00%

Summary of Significant Accoun30

Summary of Significant Accounting Policies - Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	7,324,400	6,975,651	4,994,425
Consulting Warrant to Purchase Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities			146,252
Financing Warrant to Purchase Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	13,889	13,889	152,778
IPO Warrants to Purchase Common Stock [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	11,600	11,600	460,000
IR Consulting Warrant [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		23,250	36,000
IR Incentive Warrant [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		15,000	15,000
Warrants Issued to Private Investors [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	3,035,688	2,381,675
Employee Stock Option [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	1,037,239	1,309,444	1,487,785
Restricted Stock Units (RSUs) [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	2,274,327	2,052,223	1,560,996
Performance Share Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities	951,657	1,153,617	1,135,614
Deferred Stock Units [Member]
Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities		14,953

Property and Equipment - Summar

Property and Equipment - Summary of Property and Equipment (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross, Total	$ 4,850,542	$ 4,341,527
Less - accumulated depreciation	(3,436,625)	(2,132,052)
Total property and equipment, net	1,413,917	2,209,475
Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross, Total	1,418,457	1,085,258
Computer Hardware [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross, Total	2,289,687	2,109,983
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross, Total	529,287	533,175
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross, Total	$ 613,111	$ 613,111

Property Plant and Equipment -

Property Plant and Equipment - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation, depletion and amortization, total	$ 1,309,980	$ 957,836	$ 817,729
Computer Hardware [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	7 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	remaining life of the lease.
Minimum [Member] | Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	1 year
Maximum [Member] | Computer Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years

Accrued Expenses - Summary of A

Accrued Expenses - Summary of Accrued Expenses (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Schedule of Accrued Liabilities [Line Items]
Accrued expenses	$ 1,622,025	$ 1,867,995
Accrued Compensation [Member]
Schedule of Accrued Liabilities [Line Items]
Accrued expenses	948,935	997,908
Accrued Legal Expenses [Member]
Schedule of Accrued Liabilities [Line Items]
Accrued expenses	445,684	283,160
Accrued Equipment Cost [Member]
Schedule of Accrued Liabilities [Line Items]
Accrued expenses		299,500
Other Accrued Expenses [Member]
Schedule of Accrued Liabilities [Line Items]
Accrued expenses	$ 227,406	$ 287,427

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases - Additional Information (Detail) - USD ($)	May 31, 2017	Aug. 25, 2015	Jul. 09, 2015	Feb. 26, 2015	Sep. 10, 2014
Commitments And Contingencies [Line Items]
Operating leases, rent expense	$ 9,040
Operating leases, rent expense, net		$ 4,458
Operating leases, rent expense, sublease rentals			$ 6,376	$ 6,493
Sub 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 Contingencies35

Commitments and Contingencies - Schedule of Future Minimum Rental Payments for Operating Leases (Detail)	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,018	$ 640,202
2,019	457,585
Total	$ 1,097,787

Commitments and Contingencies36

Commitments and Contingencies - Development and Licensing Agreement - Additional Information (Detail) - USD ($)	Dec. 31, 2016	Mar. 31, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Commitments And Contingencies [Line Items]
Revenues			$ 29,135	$ 250,000	$ 299,506	$ 575,368	$ 129,786	$ 1,003,973	$ 181,818	$ 136,364	$ 1,154,009	$ 1,451,941	$ 2,500,000
Revenue recognition, milestone method, revenue recognized											44,550	59,400
Development and Licensing Agreements [Member]
Commitments And Contingencies [Line Items]
Licenses revenue		$ 500,000
Revenues											108,959	391,041
Revenue recognition, milestone method, revenue recognized											$ 1,000,000	$ 1,000,000
Development and Licensing Agreements [Member] | Revenues [Member] | Customer Concentration Risk [Member]
Commitments And Contingencies [Line Items]
Concentration percentage											100.00%	100.00%	100.00%
Development and Licensing Agreements [Member] | Accounts Receivable [Member] | Customer Concentration Risk [Member]
Commitments And Contingencies [Line Items]
Concentration percentage	100.00%

Commitments and Contingencies37

Commitments and Contingencies - Hosted Design Solution Agreement - Additional Information (Detail) - Hosted Design Solution Agreement [Member] - USD ($)	Dec. 18, 2015	Dec. 31, 2017
Commitments And Contingencies [Line Items]
Other cost of services		$ 100,568
Hardware and software configuration payments period increase	$ 198,105

Commitments and Contingencies38

Commitments and Contingencies - Amended Employee Agreement - Stephen Rizzone - Additional Information (Detail) - USD ($)	May 21, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Commitments And Contingencies [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross		0	0	0
Performance based equity plan market capitalization maximum amount				$ 1,100,000,000
Performance based equity plan, market capitalization minimum amount				$ 100,000,000
Performance Based Equity Plan [Member]
Commitments And Contingencies [Line Items]
Performance based equity plan market capitalization maximum amount	$ 1,100,000,000
Performance based equity plan, market capitalization minimum amount	$ 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]
Deferred compensation arrangement with individual, exercise price					$ 6
Share-based compensation arrangement by share-based payment award, options, grants in period, gross					496,546
Employee Stock Option [Member]
Commitments And Contingencies [Line Items]
Deferred compensation arrangement with individual, maximum contractual term					48 months
Deferred compensation arrangement with individual, exercise price					$ 1.68
Share-based compensation arrangement by share-based payment award, options, grants in period, gross		0
Mr. Rizzone [Member]
Commitments And Contingencies [Line Items]
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

Stockholders' Equity Note - Add

Stockholders' Equity Note - Additional Information (Detail) - USD ($)	Jul. 05, 2017	Jun. 28, 2017	Nov. 07, 2016	Aug. 09, 2016	Nov. 17, 2015	Apr. 24, 2015	Jan. 31, 2018	Dec. 30, 2016	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Proceeds from issuance of common stock									$ 14,932,547	$ 34,788,311
Dialog Semiconductor Plc [Member]
Class of Stock [Line Items]
Class of warrant or right, exercise price of warrants or rights		$ 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		654,013	763,552
Dialog Semiconductor Plc [Member] | Warrants Issued to Private Investors [Member]
Class of Stock [Line Items]
Stock issued during period, shares, new issues		976,139	763,552
Stock issued during period, value, new issues	$ 14,999,935		$ 10,000,011
Subsequent Event [Member]
Class of Stock [Line Items]
Stock issued during period, shares, new issues							2,221,455
Common stock, discount on shares							$ 1,000,000
Stock issued during period, value, new issues							$ 38,999,989
Private Placement [Member]
Class of Stock [Line Items]
Stock issued during period, value, new issues				$ 20,000,000
Class of warrant or right, exercise price of warrants or rights				$ 23
Private Placement [Member] | Ascend Legemd Master Fund [Member]
Class of Stock [Line Items]
Stock issued during period, shares, new issues				1,618,123
Share price				$ 12.36
Class of warrant or right, number of securities called by warrants or rights				1,618,123
Private Placement [Member] | Dialog Semiconductor Plc [Member]
Class of Stock [Line Items]
Share price		$ 15.3666	$ 13.0967
Private Placement [Member] | JT Group [Member]
Class of Stock [Line Items]
Stock issued during period, shares, new issues								292,056
Share price								$ 17.12
Stock issued during period, value, new issues								$ 4,999,975
Consummation of Offering Under Shelf Registration [Member]
Class of Stock [Line Items]
Proceeds from shelf registration debt or equity securities						$ 75,000,000
Stock issued during period, shares, new issues					3,000,005
Share price					$ 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

Stock Based Compensation - Equi

Stock Based Compensation - Equity Incentive Plan - Additional Information (Detail) - USD ($)	Apr. 10, 2015	Mar. 27, 2014	Mar. 10, 2014	Dec. 31, 2017	Dec. 31, 2016	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				$ 869,066	$ 727,784
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period				1,253,085
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
Share-based compensation arrangement by share-based payment award, number of shares available for grant				0
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance	600,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant				405,921
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%
Share-based compensation arrangement by share-based payment award, terms of award				On April 10, 2015, the Company’s board of directors approved the ESPP, under which 600,000 shares of common stock have been 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.
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period				64,542	85,356
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									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 to be issued				829,515
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							4,485,967
Common stock, capital shares reserved for future issuance							2,150,000
Share-based compensation arrangement by share-based payment award, number of shares available for grant				31,951
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							600,000	250,000
Common stock, capital shares reserved for future issuance							350,000
Common stock available to be issued				292,655
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) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Granted	0	0	0
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding	1,309,444
Number of Options, Granted	0
Number of Options, Exercised	(272,205)
Number of Options, Forfeited	0
Number of Options, Outstanding	1,037,239	1,309,444
Number of Options, Exercisable	1,037,239
Weighted Average Exercise Price, Outstanding	$ 4.55
Weighted Average Exercise Price, Granted	0
Weighted Average Exercise Price, Exercised	3.60
Weighted Average Exercise Price, Forfeited	0
Weighted Average Exercise Price, Outstanding	4.80	$ 4.55
Weighted Average Exercise Price, Exercisable	$ 4.80
Weighted Average Remaining Life In Years, Outstanding	6 years 4 months 14 days	7 years 1 month 6 days
Weighted Average Remaining Life In Years, Exercisable	6 years 4 months 24 days
Intrinsic Value, Outstanding	$ 15,198,044	$ 16,107,929
Intrinsic Value, Exercisable	$ 15,198,044

Stock Based Compensation - Stoc

Stock Based Compensation - Stock Option Award Activity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, options, exercises in period, intrinsic value	$ 2,864,845	$ 984,144	$ 92,728
Options granted	0	0	0
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) - USD ($)	Jan. 04, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 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						1,253,085
Restricted Stock Units (RSUs) [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
Employee service share-based compensation, nonvested awards, compensation not yet recognized, share-based awards other than options		$ 24,701,605				$ 24,701,605
Employee service share-based compensation, nonvested awards, compensation cost not yet recognized, period for recognition						2 years 8 months 12 days
2013 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [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		53,188	117,514	308,059	351,080
Share-based compensation arrangement by share-based payment award, award vesting period		4 years
Non-Employee Equity Compensation Plan 2014 [Member] | Restricted Stock Units (RSUs) [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				8,400	48,844
Inducement RSU 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				120,000
Share-based compensation arrangement by share-based payment award, award vesting period				4 years
Minimum [Member] | 2013 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period			2 years	2 years	2 years
Minimum [Member] | Non-Employee Equity Compensation Plan 2014 [Member] | Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, award vesting period				2 years
Maximum [Member] | 2013 Equity Incentive Plan [Member] | Restricted Stock Units (RSUs) [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	4 years	4 years
Maximum [Member] | Non-Employee Equity Compensation Plan 2014 [Member] | Restricted Stock Units (RSUs) [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
Mr. Gaulding [Member] | 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	14,953
Mr. Gaulding [Member] | Non-Employee Equity Compensation Plan 2014 [Member] | Restricted Stock Units (RSUs) [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					246,000

Stock Based Compensation - Sche

Stock Based Compensation - Schedule of Restricted Stock Units Activity (Detail)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Number of Options, Outstanding | shares	2,052,223
RSUs granted | shares	1,253,085
RSUs forfeited | shares	(249,928)
RSUs vested | shares	(781,055)
Number of Options, Outstanding | shares	2,274,325
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 11.58
Weighted Average Grant Date Fair Value, RSUs granted | $ / shares	15.81
Weighted Average Grant Date Fair Value, RSUs forfeited | $ / shares	12.63
Weighted Average Grant Date Fair Value, RSUs vested | $ / shares	11.53
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 13.75

Stock Based Compensation - Perf

Stock Based Compensation - Performance Share Units - Additional Information (Detail) - USD ($)	Oct. 24, 2016	May 21, 2015	Dec. 31, 2017	Dec. 31, 2016	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
Share-based compensation arrangement by share-based payment award, options, grants in period, gross			0	0	0
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period			1,253,085
Share-based compensation arrangement by share-based payment award, options, vested in period, fair value				$ 106,600,000
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				1.04%
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross			0
Share-based compensation arrangement by share-based payment award, equity instruments other than options, grants in period			63,908
Share based compensation arrangement by share based payment award options grants in period fair value			$ 3,218,000
Share based compensation arrangement by share based payment award unamortized value			$ 819,910
Share based compensation arrangement by share based payment award unamortized weighted average period			1 year
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 available for grant			0
Share-based compensation arrangement by share-based payment award, 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			$ 1,661,650	$ 2,285,683	$ 489,239
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%
Performance Based Equity 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, options, grants in period, gross		639,075
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 available for grant			31,951
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 options grants in period fair value			$ 2,332,000
2015 Performance Share Unit Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, options, grants in period, gross			1,342,061
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, options, grants in period, gross			1,278,153
Mr. Rizzone [Member] | 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	150,000

Stock Based Compensation - Su46

Stock Based Compensation - Summary of Fair Value of Market Condition (Detail)	12 Months Ended
	Dec. 31, 2016USD ($)
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Market capitalization	$ 106,600,000
Dividend yield	0.00%
Expected volatility	75.00%
Risk-free interest rate	1.04%

Stock Based Compensation - Su47

Stock Based Compensation - Summary of Activity Related to PSUs (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
PSUs granted	0	0	0
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding	1,153,617
PSUs granted	0
PSUs forfeited	(111,960)
PSUs vested	(90,000)
Number of Options, Outstanding	951,657	1,153,617
Weighted Average Grant Date Fair Value, Outstanding	$ 3.66
Weighted Average Grant Date Fair Value, PSUs granted	0
Weighted Average Grant Date Fair Value, PSUs forfeited	2.62
Weighted Average Grant Date Fair Value, PSUs vested	13.82
Weighted Average Grant Date Fair Value, Outstanding	$ 2.65	$ 3.66

Stock Based Compensation - Defe

Stock Based Compensation - Deferred Stock Units - Additional Information (Detail) - USD ($)	Jan. 04, 2016	Dec. 31, 2017	Dec. 31, 2016
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		1,253,085
Deferred Stock 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		0
Allocated share-based compensation expense		$ 1,362	$ 123,644
Share based compensation arrangement by share based payment award unamortized value		$ 0
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 - Su49

Stock Based Compensation - Summary of Activity Related to DSUs (Detail)	12 Months Ended
	Dec. 31, 2017$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding | shares	2,052,223
DSUs granted | shares	1,253,085
DSUs forfeited | shares	249,928
DSUs vested | shares	(781,055)
Number of Options, Outstanding | shares	2,274,325
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 11.58
Weighted Average Grant Date Fair Value, DSUs granted | $ / shares	15.81
Weighted Average Grant Date Fair Value, DSUs forfeited | $ / shares	12.63
Weighted Average Grant Date Fair Value, DSUs vested | $ / shares	11.53
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares	$ 13.75
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Outstanding | shares	14,953
DSUs granted | shares	0
DSUs forfeited | shares	0
DSUs vested | shares	(14,953)
Number of Options, Outstanding | shares
Weighted Average Grant Date Fair Value, Beginning Balance | $ / shares	$ 8.36
Weighted Average Grant Date Fair Value, DSUs granted | $ / shares	0
Weighted Average Grant Date Fair Value, DSUs forfeited | $ / shares	0
Weighted Average Grant Date Fair Value, DSUs vested | $ / shares	$ 8.36
Weighted Average Grant Date Fair Value, Ending Balance | $ / shares

Stock Based Compensation - Empl

Stock Based Compensation - Employee Stock Purchase Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
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	$ 15.81
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, equity instruments other than options, grants in period, weighted average grant date fair value	$ 5.42	$ 5.20	$ 2.46
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	$ 331,913	$ 318,735	$ 113,217

Stock Based Compensation - Su51

Stock Based Compensation - Summary of Fair Values of Purchase Options Granted (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Dividend yield		0.00%
Expected volatility		75.00%
Risk-free interest rate		1.04%
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price			$ 7.41
Dividend yield	0.00%	0.00%	0.00%
Expected volatility			65.00%
Risk-free interest rate			0.13%
Expected life	6 months	6 months	6 months
Minimum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 16.08	$ 8.36
Expected volatility	56.00%	56.00%
Risk-free interest rate	0.62%	0.37%
Maximum [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock price	$ 17.59	$ 12.16
Expected volatility	66.00%	100.00%
Risk-free interest rate	1.11%	0.49%

Stock Based Compensation -Summa

Stock Based Compensation -Summary of Stock-based Compensation Costs Recognized (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total	$ 15,802,819	$ 9,508,175	$ 5,951,414
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	13,043,171	5,735,032	4,225,728
Performance Share Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	1,661,650	2,285,683	489,239
Deferred Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	1,362	123,644
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	331,913	318,735	113,217
Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 764,723	$ 1,045,081	1,037,399
IR Consulting Warrant [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense			$ 85,831

Stock Based Compensation - Su53

Stock Based Compensation - Summary of Stock-based Compensation Reflected within Statements of Operations (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share-based Compensation, Total	$ 15,802,819	$ 9,508,175	$ 5,951,414
Research and Development Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	8,522,798	4,226,304	2,816,707
Selling and Marketing Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	1,113,120	328,760	729,329
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 6,166,901	$ 4,953,111	$ 2,405,378

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Federal statutory income tax rate		34.00%	34.00%
Decrease in net deferred tax assets due to reduction in the U.S. corporate income tax rate		$ 19,432,000
Decrease in valuation allowance due to reduction in the U.S. corporate income tax rate		$ 19,432,000
Tax credit carry forward expiration period		2,033
Operating loss carryforwards, limitations on use		Stock ownership of one or more 5% shareholders (shareholders owning 5% or more of the Company's outstanding capital stock) has increased on a cumulative basis by more than 50 percentage points.
Maximum [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate		35.00%
Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate	21.00%
Domestic Tax Authority [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 84,418,000
Deferred tax assets, tax credit carryforwards, research		$ 2,686,000
Tax credit research and development expiration period		2,032
State and Local Jurisdiction [Member]
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 85,515,000
Deferred tax assets, tax credit carryforwards, research		$ 2,088,000

Income Taxes - Schedule of Defe

Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets (liabilities):
Tax credit	$ 4,335,394	$ 2,802,573
Net operating loss carryovers	23,630,008	16,174,712
Property and equipment	99,756	(58,747)
Research and development costs	15,372,328	18,628,913
Start-up and organizational costs	774	1,222
Stock-based compensation	2,473,591	1,829,843
Other accruals	260,113	341,090
Total gross deferred tax assets	46,171,964	39,719,606
Less: valuation allowance	(46,171,964)	(39,719,606)	$ (22,085,888)
Deferred tax assets, net	$ 0	$ 0

Income Taxes -Summary of Valuat

Income Taxes -Summary of Valuation Allowance (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
January 1	$ 39,719,606	$ 22,085,888
Increase in valuation allowance	6,452,358	17,633,718
December 31	$ 46,171,964	$ 39,719,606

Income Taxes -Schedule of Effec

Income Taxes -Schedule of Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
Tax benefit at federal statutory rate	(34.00%)	(34.00%)
State income taxes	(10.20%)	(5.70%)
Permanent differences:
Stock-based compensation	(2.50%)	0.80%
Meals and entertainment	0.10%	0.10%
Change in effective tax rate	39.40%
Effective income tax rate	0.00%	0.00%
Domestic Tax Authority [Member]
Permanent differences:
Effective income tax rate reconciliation, prior year income taxes, percent	(2.80%)	1.70%
Effective income tax rate reconciliation, tax credit, research, percent	(1.40%)	(1.50%)
Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, percent	1.30%	32.90%
State and Local Jurisdiction [Member]
Permanent differences:
Effective income tax rate reconciliation, prior year income taxes, percent		1.20%
Effective income tax rate reconciliation, tax credit, research, percent	(1.60%)	(1.10%)
Effective income tax rate reconciliation, change in deferred tax assets valuation allowance, percent	11.70%	5.60%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($)	Aug. 09, 2016	Jun. 28, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Howard Yeatons Service [Member]
Related Party Transaction [Line Items]
Payments for fees			$ 0	$ 0	$ 61,848
Other Financial Advisory and Accounting Services [Member]
Related Party Transaction [Line Items]
Payments for fees			$ 0	$ 13,306	$ 88,813
Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Equity method investment, ownership percentage			7.70%
Percentage of common shares potentially own outstanding shares			13.20%
Private Placement [Member]
Related Party Transaction [Line Items]
Stock issued during period, value, new issues	$ 20,000,000
Private Placement [Member] | Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Stock issued during period, value, new issues		$ 1,739,691
Private Placement [Member] | Warrants 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
Research and Development Expense [Member] | Dialog Semiconductor Plc [Member]
Related Party Transaction [Line Items]
Payments for fees			$ 516,725

Unaudited Quarterly Financial59

Unaudited Quarterly Financial Information - Schedule of Quarterly Financial Information (Detail) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 29,135	$ 250,000	$ 299,506	$ 575,368	$ 129,786	$ 1,003,973	$ 181,818	$ 136,364	$ 1,154,009	$ 1,451,941	$ 2,500,000
Operating expenses	11,267,948	13,001,623	13,220,879	13,051,387	14,744,905	11,131,994	10,468,990	10,936,772	50,541,837	47,282,661	30,077,339
Net loss	$ (11,236,477)	$ (12,748,248)	$ (12,919,010)	$ (12,473,140)	$ (14,611,234)	$ (10,125,063)	$ (10,284,555)	$ (10,796,542)	$ (49,376,875)	$ (45,817,394)	$ (27,561,702)
Loss per share, basic and diluted	$ (0.50)	$ (0.58)	$ (0.63)	$ (0.61)	$ (0.75)	$ (0.57)	$ (0.62)	$ (0.66)	$ (2.31)	$ (2.60)	$ (2.07)

Subsequent Events - Additional

Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	1 Months Ended
	Jan. 31, 2018USD ($)
Subsequent Event [Line Items]
Proceeds from sale of stock	$ 38,999,989
Common stock, discount on shares	$ 1,000,000