Document and Entity Information (USD $)	12 Months Ended
Document and Entity Information (USD $)	Dec. 31, 2014	Feb. 20, 2015	Jun. 30, 2014
Document and Entity Information [Abstract]
Entity Registrant Name	VirnetX Holding Corp
Entity Central Index Key	0001082324
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 908,164,887
Entity Common Stock, Shares Outstanding		51,996,701
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2014

CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 18,658	$ 19,173
Investments available for sale	22,571	19,815
Prepaid expenses - current	653	357
Total current assets	41,882	39,345
Prepaid expenses - non-current	3,144	0
Property and equipment, net	64	53
Total assets	45,090	39,398
Current liabilities:
Accounts payable and accrued liabilities	3,554	1,748
Royalty payable	6,100	0
Related-party payable	81	0
Income tax liability	408	395
Deferred revenue, current portion	1,500	667
Derivative liability	320	2,564
Total current liabilities	11,963	5,374
Deferred revenue, non-current portion	500	0
Commitments and contingencies (Note 5)
Stockholders' equity:
Preferred stock, par value $0.0001 per share Authorized: 10,000,000 shares at December 31, 2014 and 2013, Issued and outstanding: 0 shares at December 31, 2014 and 2013	0	0
Common stock, par value $0.0001 per share Authorized: 100,000,000 shares at December 31, 2014 and 2013, Issued and outstanding: 51,996,701 shares and 51,236,141 shares, at December 31, 2014 and 2013, respectively	5	5
Additional paid-in capital	133,072	124,589
Accumulated deficit	(100,435)	(90,533)
Accumulated other comprehensive loss	(15)	(37)
Total stockholders' equity	32,627	34,024
Total liabilities and stockholders' equity	$ 45,090	$ 39,398

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Stockholders' equity:
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	100,000,000	100,000,000
Common stock, issued (in shares)	51,996,701	51,236,141
Common stock, outstanding (in shares)	51,996,701	51,236,141

CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CONSOLIDATED STATEMENTS OF OPERATIONS [Abstract]
Revenue	$ 1,249	$ 2,197	$ 412
Operating expense:
Royalty expense	6,100	0	0
Research and development	2,004	1,782	1,555
General, selling and administrative	28,310	29,002	37,718
Gain on settlement (Note 3)	(23,000)	0	0
Total operating expense	13,414	30,784	39,273
Loss from operations	(12,165)	(28,587)	(38,861)
Gain (loss) on change in value of embedded derivative and warrants	2,238	1,608	(927)
Interest income, net	40	122	329
Loss before taxes	(9,887)	(26,857)	(39,459)
Income tax (expense) benefit	(15)	(751)	12,535
Net loss	$ (9,902)	$ (27,608)	$ (26,924)
Basic and diluted loss per share: (in dollars per share)	$ (0.19)	$ (0.54)	$ (0.53)
Weighted average shares outstanding basic and diluted (in shares)	51,570,472	51,188,006	50,934,266

CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS [Abstract]
Net loss	$ (9,902)	$ (27,608)	$ (26,924)
Other comprehensive income (loss), net of tax:
Change in equity adjustment from foreign currency translation, net of tax	0	(12)	0
Change in unrealized gain (loss) on investments, net of tax	22	(33)	12
Total other comprehensive income(loss), net of tax	22	(45)	12
Comprehensive loss	$ (9,880)	$ (27,653)	$ (26,912)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Amount after tax, before reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Other Comprehensive Income (Expense) [Member]	Total
Balance at Dec. 31, 2011	$ 5	$ 104,277	$ (36,001)	$ (4)	$ 68,277
Balance (in shares) at Dec. 31, 2011	50,619,136
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net		161			161
Stock issued for cash exercise of warrants (in shares)	44,941
Stock-based compensation		6,162			6,162
Deferred tax benefit related to stock based compensation		3,111			3,111
Derivative liability		1,454			1,454
Exercise of options		1,691			1,691
Exercise of options (in shares)	486,165
Comprehensive income:
Net loss			(26,924)		(26,924)
Other comprehensive income net of tax				12	12
Comprehensive loss					(26,912)
Balance at Dec. 31, 2012	5	116,856	(62,925)	8	53,944
Balance (in shares) at Dec. 31, 2012	51,150,242
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		7,563			7,563
Exercise of options		170			170
Exercise of options (in shares)	39,833
Vested RSUs (in shares)	46,066
Comprehensive income:
Net loss			(27,608)		(27,608)
Other comprehensive income net of tax				(45)	(45)
Comprehensive loss					(27,653)
Balance at Dec. 31, 2013	5	124,589	(90,533)	(37)	34,024
Balance (in shares) at Dec. 31, 2013	51,236,141
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net		9			9
Stock issued for cash exercise of warrants (in shares)	2,500
Stock-based compensation		8,189			8,189
Derivative liability		7			7
Exercise of options		278			278
Exercise of options (in shares)	679,321
Vested RSUs (in shares)	78,739
Comprehensive income:
Net loss			(9,902)		(9,902)
Other comprehensive income net of tax				22	22
Comprehensive loss					(9,880)
Balance at Dec. 31, 2014	$ 5	$ 133,072	$ (100,435)	$ (15)	$ 32,627
Balance (in shares) at Dec. 31, 2014	51,996,701

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net (loss)	$ (9,902)	$ (27,608)	$ (26,924)
Adjustments to reconcile net (loss) to net cash used in operating activities:
Depreciation and amortization	25	36	71
Stock-based compensation	8,189	7,563	6,162
Net change in deferred taxes	0	0	3,158
Change in value of derivative liability	(2,238)	(1,608)	927
Changes in assets and liabilities:
Prepaid expenses and other current assets	(296)	(243)	(23)
Prepaid expenses - Non-current	(3,144)	0	0
Prepaid taxes	0	14,963	(4,934)
Deferred revenue	1,333	667	0
Accounts payable and accrued liabilities	1,806	(1,449)	1,970
Royalty payable	6,100	0	0
Related-party payable	81	0	0
Income tax liability	13	395	0
Net cash provided by (used in) operating activities	1,967	(7,284)	(19,593)
Cash flows from investing activities:
Purchase of property and equipment	(35)	(7)	(37)
Purchase of investments	(45,500)	(92,729)	(59,342)
Proceeds from sale or maturity of investments	42,766	99,362	47,299
Net cash provided by (used in) investing activities	(2,769)	6,626	(12,080)
Cash flows from financing activities:
Proceeds from exercise of options	278	170	1,691
Proceeds from exercise of warrants	9	0	161
Net cash provided by financing activities	287	170	1,852
Net decrease in cash and cash equivalents	(515)	(488)	(29,821)
Cash and cash equivalents, beginning of year	19,173	19,661	49,482
Cash and cash equivalents, end of year	18,658	19,173	19,661
Supplemental disclosure of cash flow information:
Cash paid during the year for taxes	2	0	0
Cash paid during the year for interest	$ 0	$ 0	$ 0

Formation and Business of the Company	12 Months Ended
Formation and Business of the Company	Dec. 31, 2014
Formation and Business of the Company [Abstract]
Formation and Business of the Company	Note 1 - Formation and Business of the Company VirnetX Holding Corporation, which we refer to as” we”, “us”, “our”, “the Company” or “VirnetX”, is engaged in the business of commercializing a portfolio of patents. We seek to license our technology, including GABRIEL Connection Technology™, to various original equipment manufacturers, or OEMs, that use our technologies in the development and manufacturing of their own products within the IP-telephony, mobility, fixed-mobile convergence and unified communications markets. Prior to 2012 our revenue was limited to an insignificant amount of software royalties pursuant to the terms of a single license agreement. During 2013 and 2012 we had revenues from settlements of patent infringement disputes whereby we received consideration for past sales of licensees that utilized our technology, where there was no prior patent license agreement (see “Revenue Recognition”). Our portfolio of intellectual property is the foundation of our business model. We currently own approximately 39 U.S. and 66 foreign patents with approximately 75 pending patent applications worldwide. Our patent portfolio is primarily focused on securing real-time communications over the Internet, as well as related services such as the establishment and maintenance of a secure domain name registry. Our patented methods also have additional applications in the key areas of device operating systems and network security for Cloud services, M2M communications in areas of Smart City, Connected Car and Connected Home. The subject matter of all our U.S. and foreign patents and pending applications relates generally to securing communication over the internet and as such covers all our technology and other products. Our issued U.S. and foreign patents expire at various times during the period from 2019 to 2024. Some of our issued patents and pending patent applications were acquired by our principal operating subsidiary; VirnetX, Inc., from Leidos (f/k/a Science Applications International Corporation or SAIC) in 2006 and we are required to make payments to Leidos based on cash or certain other values generated from those patents. The amount of such payments depends upon the type of value generated, and certain categories are subject to maximums and other limitations.

- Definition

The entire disclosure for organization, consolidation and basis of presentation of financial statements disclosure.

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Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2014

Summary of Significant Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Note 2 - Summary of Significant Accounting Policies

The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reported period. The critical accounting policies we employ in the preparation of our consolidated financial statements are those which involve impairment of long-lived assets, income taxes, fair value of financial instruments and stock-based compensation.

Use of Estimates

We prepare our consolidated financial statements in accordance with accounting principles generally accepted in the U.S. ("U.S. GAAP"). In doing so, we have to make estimates and assumptions that affect our reported amounts of assets, liabilities, revenues, and expenses, as well as related disclosure of contingent assets and liabilities. In some cases, we could reasonably have used different accounting policies and estimates. In some cases, changes in the accounting estimates are reasonably likely to occur from period to period. Accordingly, actual results could differ materially from our estimates. To the extent that there are material differences between these estimates and actual results, our financial condition or results of operations will be affected. We base our estimates on past experience and other assumptions that we believe are reasonable under the circumstances, and we evaluate these estimates on an ongoing basis. We refer to accounting estimates of this type as critical accounting policies and estimates, which we discuss further below. We have reviewed our critical accounting policies and estimates with the audit committee of our board of directors.

Basis of Consolidation

The consolidated financial statements include the accounts of VirnetX Holding Corporation and our wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated.

Revenue Recognition

We derive our revenue from patent licensing. The timing and amount of revenue recognized from each licensee depends upon a variety of factors, including the specific terms of each agreement and the nature of the deliverables and obligations. Such agreements may be complex and include multiple elements. These agreements may include, without limitation, elements related to the settlement of past patent infringement liabilities, up-front and non-refundable license fees for the use of patents, patent licensing royalties on covered products sold by licensees, and the compensation structure and ownership of intellectual property rights associated with contractual technology development arrangements. Licensing agreements are accounted for under the Financial Accounting Standards Board (“FASB”) revenue recognition guidance, "Revenue Arrangements with Multiple Deliverables." This guidance requires consideration to be allocated to each element of an agreement that has stand-alone value using the relative fair value method. In other circumstances, such as those agreements involving consideration for past and expected future patent royalty obligations, after consideration of the particular facts and circumstances, the appropriate recording of revenue between periods may require the use of judgment. In all cases, revenue is only recognized after all of the following criteria are met: (1) written agreements have been executed; (2) delivery of technology or intellectual property rights has occurred or services have been rendered; (3) fees are fixed or determinable; and (4) collectability of fees is reasonably assured.

Patent License Agreements: Upon signing a patent license agreement, including licenses entered into upon settlement of litigation, we provide the licensee permission to use our patented technology in specific applications. We account for patent license agreements in accordance with the guidance for revenue recognition for arrangements with multiple deliverables, with amounts allocated to each element based on their fair values. We have elected to utilize the leased-based model for revenue recognition with revenue being recognized over the expected period of benefit to the licensee. Under our patent license agreements, we do or expect to typically receive one or a combination of the following forms of payment as consideration for permitting our licensees to use our patented inventions in specific applications and products:

Consideration for Past Sales: Consideration related to a licensee’s product sales from prior periods may result from a negotiated agreement with a licensee that utilized our patented technology prior to signing a patent license agreement with us or from the resolution of a litigation, disagreement or arbitration with a licensee over the specific terms of an existing license agreement. We may also receive royalty for past sales in connection with the settlement of patent litigation where there was no prior patent license agreement. These amounts are negotiated, typically based upon application of a royalty rate to historical sales prior to the execution of the license agreement. In each of these cases, since delivery has occurred, we record the consideration as revenue when we have obtained a signed agreement, identified a fixed or determinable price, and determined that collectability is reasonably assured.

Current Royalty Payments: Ongoing royalty payments cover a licensee’s obligations to us related to its sales of covered products in the current contractual reporting period. Licensees that owe these current royalty payments are obligated to provide us with quarterly or semi-annual royalty reports that summarize their sales of covered products and their related royalty obligations to us. We expect to receive these royalty reports subsequent to the period in which our licensees’ underlying sales occurred. As a result, it is impractical for us to recognize revenue in the period in which the underlying sales occur, and, in most cases, we will recognize revenue in the period in which the royalty report is received and other revenue recognition criteria are met due to the fact that without royalty reports from our licensees, our visibility into our licensees’ sales is limited.

Non-Refundable Up-Front Fees and Minimum Fee Contracts: For licenses that provide for non-refundable up-front or fixed minimum fees over their term, for which we have no future obligations or performance requirements, revenue is generally recognized over the license term. For licenses that provide for fees that are not fixed or determinable, including licenses that provide for extended payment terms and/or payment of a significant portion of the fee after expiration of the license or more than 12 months after delivery, the fees are generally presumed not to be fixed or determinable, and revenue is deferred and recognized as earned, but generally not in advance of collection.

Non-Royalty Elements: Elements that are not related to royalty revenue in nature, such as settlement fees, expense reimbursement, and damages, if any, are recorded as gain from settlement which is reflected as a separate line item within the operating expenses section in the consolidated statements of operations.

Deferred revenue

In August 2013 we began receiving annual payments on a contract that requires payment to us over 4 years of $10,000 ("August 2013 Contract Settlement"). From the inception of that license to December 31, 2014, we received cash totaling $5,000, all of which is non-refundable. We recognized $1,167 and $1,833 of revenue related from the August 2013 Contract Settlement during the years ended December 31, 2014 and 2013.

Activity under the August 2013 Contract Settlement was as follows:

	2014		2013
Deferred Revenue, beginning of year	$	667	$	-
Payment received		2,500		2,500
Less: Amount amortized as revenue		1,167		1,833
Deferred Revenue, end of year	$	2,000	$	667

Cash and Cash Equivalents

We consider all highly liquid investments purchased with original maturities of three months or less at the date of purchase to be cash equivalents. Our cash and cash equivalents are not subject to significant interest rate risk due to the short maturities of these investments.

Prepaid Expenses and Other Current Assets

Prepaid Expense and Other Current Assets at December 31, 2014 includes the current portion of prepaid rent for a facility lease for corporate promotional and marketing purposes. Beginning March 2014, the prepayment totaling $4,000 is being amortized over the 10 year term of the lease. The unamortized non-current portion of the prepayment is included in Prepaid expenses-Non-current on the consolidated balance sheet..

Investments

Investments are classified as available-for-sale and are recorded at fair market value. Unrealized gains and losses are reported as other comprehensive income. Realized gains and losses are recorded in income in the period they are realized. We invest our excess cash primarily in highly liquid debt instruments including municipal and federal agency securities, with contractual maturities less than two years. By policy, we limit the amount of credit exposure to any one issuer.

Property and Equipment

Property and equipment are stated at historical cost, less accumulated depreciation and amortization. Depreciation and amortization are computed using the accelerated and straight line methods over the estimated useful lives of the assets, which range from five to seven years. Repair and maintenance costs are charged to expense as incurred.

Concentration of Credit Risk and Other Risks and Uncertainties

Our cash and cash equivalents are primarily maintained at two major financial institutions in the United States. Deposits held with these financial institutions may exceed the amount of insurance provided on such deposits. A portion of those balances are insured by the Federal Deposit Insurance Corporation, or FDIC. During the year ended December 31, 2014 and 2013, we had, at times, funds that were uninsured. We do not believe that we are subject to any unusual financial risk beyond the normal risk associated with commercial banking relationships. We have not experienced any losses on our deposits of cash and cash equivalents.

Fair Value

The carrying amounts of our financial instruments, including cash equivalents, accounts payable, and accrued liabilities, approximate fair value because of their generally short maturities.

Intangible Assets

We record intangible assets at cost, less accumulated amortization. Amortization of intangible assets is provided over their estimated useful lives, which can range from 3 to 15 years, on either a straight-line basis or as revenue is generated by the assets.

Impairment of Long-Lived Assets

We identify and record impairment losses on long-lived assets used in operations when events and changes in circumstances indicate that the carrying amount of an asset might not be recoverable, but not less than annually. Recoverability is measured by comparison of the anticipated future net undiscounted cash flows to the related assets’ carrying value. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the projected discounted future net cash flows arising from the asset.

Research and Development

Research and development costs include expenses paid to outside development consultants and compensation related expenses for our engineering staff. Research and development costs are expensed as incurred.

Income Taxes

We account for income taxes using the asset and liability method. The asset and liability method requires the recognition of deferred tax assets and liabilities for expected future tax consequences of temporary differences that currently exist between the tax basis and financial reporting basis of our assets and liabilities. We calculate current and deferred tax provisions based on estimates and assumptions that could differ from actual results reflected on the income tax returns filed during the following years. Adjustments based on filed returns are recorded when identified in the subsequent years. The effect on deferred taxes for a change in tax rates is recognized in income in the period that the tax rate change is enacted. In assessing if we will realize our deferred tax assets, we consider whether it is more likely than not that some portion of the deferred tax assets will not be realized.

A valuation allowance is provided for deferred income tax assets when, in our judgment, based upon currently available information and other factors, it is more likely than not that all or a portion of such deferred income tax assets will not be realized. The determination of the need for a valuation allowance is based on an on-going evaluation of current information including, among other things, historical operating results, estimates of future earnings in different taxing jurisdictions and the expected timing of the reversals of temporary differences. We believe the determination to record a valuation allowance to reduce a deferred income tax asset is a significant accounting estimate because it is based, among other things, on an estimate of future taxable income in the United States and certain other jurisdictions, which is susceptible to change and may or may not occur, and because the impact of adjusting a valuation allowance may be material. In determining when to release the valuation allowance established against our net deferred income tax assets, we consider all available evidence, both positive and negative. Consistent with our policy, and because of our history of operating losses, we do not currently recognize the benefit of all of our deferred tax assets, including tax loss carry forwards, that may be used to offset future taxable income. We continually assess our ability to generate sufficient taxable income during future periods in which our deferred tax assets may be realized. If and when we believe it is more likely than not that we will recover our deferred tax assets, we will reverse the valuation allowance as an income tax benefit in our statements of operations.

We account for our uncertain tax positions in accordance with U.S. GAAP. The purpose of this method is to clarify accounting for uncertain tax positions recognized. The U.S. GAAP method of accounting for uncertain tax positions utilizes a two-step approach to evaluate tax positions. Step one, recognition, requires evaluation of the tax position to determine if based solely on technical merits it is more likely than not to be sustained upon examination. Step two, measurement, is addressed only if a position is more likely than not to be sustained. In step two, the tax benefit is measured as the largest amount of benefit, determined on a cumulative probability basis, which is more likely than not to be realized upon ultimate settlement with tax authorities. If a position does not meet the more likely than not threshold for recognition in step one, no benefit is recorded until the first subsequent period in which the more likely than not standard is met, the issue is resolved with the taxing authority, or the statute of limitations expires. Positions previously recognized are derecognized when we subsequently determine the position no longer is more likely than not to be sustained. Evaluation of tax positions, their technical merits, and measurements using cumulative probability are highly subjective management estimates. Actual results could differ materially from these estimates.

Derivative Instruments

Our Series I Warrants are accounted for as derivative instruments as a result of an anti-dilution provision which, in accordance with U.S. GAAP, prevents them from being considered indexed to our stock and qualified for an exception to derivative accounting.

We recognize derivative instruments as either assets or liabilities on the accompanying Consolidated Balance Sheets at fair value. We record changes in the fair value (i.e., gains or losses) of the derivatives in the accompanying Consolidated Statements of Operations.

Stock-Based Compensation

We account for stock-based compensation using the fair value recognition method in accordance with U.S. GAAP. We recognize these compensation costs net of the applicable forfeiture rate and recognize the compensation costs for only those shares expected to vest on a straight-line basis over the requisite service period of the award, which is generally the vesting term of 4 years. We estimate the forfeiture rate based on our historical experience if any. See Note 7 - Stock-Based Compensation for additional information concerning our share-based compensation awards.

In addition, as required we record stock and options granted to non-employees at fair value of the consideration received or the fair value of the equity instruments issued as they vest over the performance period.

Earnings per Share

Basic earnings per share are computed by dividing earnings available to common stockholders by the weighted average number of outstanding common shares during the period. Diluted earnings per share is computed by dividing net income by the weighted average number of shares outstanding during the period increased to include the number of additional shares of common stock that would have been outstanding if the potentially dilutive securities had been issued. During 2014, 2013 and 2012 we incurred losses; therefore the effect of any common stock equivalent would be anti-dilutive during these periods.

New Accounting Pronouncements

In August 2014, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") No. 2014-15, “Presentation of Financial Statements – Going Concern”, Subtopic 205-40, “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern.” The amendments in this ASU apply to all entities and require management to assess an entity’s ability to continue as a going concern by incorporating and expanding upon certain principles that are currently in U.S. auditing standards. Specifically, the amendments (1) provide a definition of the term substantial doubt, (2) require an evaluation every reporting period including interim periods, (3) provide principles for considering the mitigating effect of management’s plans, (4) require certain disclosures when substantial doubt is alleviated as a result of consideration of management’s plans, (5) require an express statement and other disclosures when substantial doubt is not alleviated, and (6) require an assessment for a period of one year after the date that the financial statements are issued (or available to be issued). The amendments in this Update are effective for the annual period ending after December 15, 2016, and for annual periods and interim periods thereafter. Early application is permitted. We are currently evaluating the impact this guidance will have on our financial position and results of operations.

In June 2014, the FASB issued ASU No. 2014-12, "Compensation - Stock Compensation (Topic 718)," which makes amendments to the codification topic 718, "Accounting for Share-Based Payments," when the terms of an award provide that a performance target could be achieved after the requisite service period. The new guidance becomes effective for annual reporting periods beginning after December 15, 2015, early adoption is permitted. We are currently evaluating the impact this guidance will have on our financial position and results of operations.

In May 2014, the FASB issued ASU No. 2014-09 "Revenue from Contracts with Customers" (Topic 606). Topic 606 supersedes the revenue recognition requirements in Topic 605, “Revenue Recognition”, including most industry-specific revenue recognition guidance throughout the Industry Topics of the Codification. In addition, the amendments create a new Subtopic 340-40, “Other Assets and Deferred Costs—Contracts with Customers”. In summary, the core principle of Topic 606 is that an entity recognizes revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. For a public entity, the amendments in this Update are effective for annual reporting periods beginning after December 15, 2016, including interim periods within that reporting period. Early application is not permitted. We are currently evaluating the impact this guidance will have on our financial position and statement of operations.

Property and Equipment

12 Months Ended

Dec. 31, 2014

Property and Equipment [Abstract]

Property and Equipment

Note 4 - Property and Equipment

Our major classes of property and equipment were as follows:

	December 31
	2014			2013			2012
Office furniture	$	70		$	70		$	70
Computer equipment		157			121			115
Total		227			191			185
Less accumulated depreciation		(163	)		(138	)		(115	)
	$	64		$	53		$	70

Depreciation expense for the years ended December 31, 2014, 2013 and 2012 was $25, $24 and $23 respectively.

- Definition

The entire disclosure for long-lived, physical assets used in the normal conduct of business and not intended for resale. Includes, but is not limited to, accounting policies and methodology, roll forwards, depreciation, depletion and amortization expense, including composite depreciation, accumulated depreciation, depletion and amortization expense, useful lives and method used, income statement disclosures, assets held for sale and public utility disclosures.

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Commitments and Related Party Transactions	12 Months Ended
Commitments and Related Party Transactions	Dec. 31, 2014
Commitments and Related Party Transactions [Abstract]
Commitments and Related Party Transactions	Note 5 – Commitments and Related Party Transactions We lease our offices under an operating lease with a third party expiring in October 2015. We recognize rent expense on a straight-line basis over the term of the lease. Rent expense was $56, $56 and $56 for the years ended December 31, 2014, 2013 and 2012, respectively. During 2014 we leased the use of an aircraft from K2 Investment Fund LLC (“LLC”) for business travel for employees of the Company. We incurred approximately $296 in rental fees (including fees and other reimbursements) to the LLC during the year ended December 31, 2014 for such use of which $81 remains payable at December 31, 2014. Our Chief Executive Officer and Chief Administrative Officer are the managing partners of the LLC and control the equity interests of the LLC. Subsequent to the year ended December 31, 2014, on January 31, 2015 we entered into a 12 month non-exclusive lease with the LLC for use of the plane at a rate of $8 per flight hour, with no minimum usage requirement. The agreement contains other terms and conditions normal in such transactions and can be cancelled by either us or the LLC with 30 days notice.

- Definition

The entire disclosure for significant arrangements with third parties, which includes operating lease arrangements and arrangements in which the entity has agreed to expend funds to procure goods or services, or has agreed to commit resources to supply goods or services, and operating lease arrangements. Descriptions may include identification of the specific goods and services, period of time covered, minimum quantities and amounts, and cancellation rights.

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Stock Plan	12 Months Ended
Stock Plan	Dec. 31, 2014
Stock Plan [Abstract]
Stock Plan	Note 6 - Stock Plan We have a stock incentive plan for employees and others called the VirnetX Holding Corporation 2013 Equity Incentive Plan (the "Plan"), which has been approved by our stockholders. The 2013 Plan provides for the issuance of up to 2,500,000 shares of our common stock. To the extent that any award should expire, become un-exercisable or is otherwise forfeited, the shares subject to such award will again become available for issuance under the 2013 Plan. The 2013 Plan provides for the granting of stock options and restricted stock purchase rights (“RSU”) to our employees and consultants. Stock options granted under the 2013 Plan may be incentive stock options or nonqualified stock options. Incentive stock options ("ISO") may only be granted to our employees (including officers and directors). Nonqualified stock options ("NSO") and stock purchase rights may be granted to our employees and consultants. The 2013 Plan will expire in 2023. Options may be granted under the 2013 Plan with an exercise price determined by our Board of Directors, or a duly appointed committee thereof, provided, however, that the exercise price of an option granted to any employee shall be not less than 100% of the fair market value at the date of grant in the case of ISO or 85% of the fair market value at the date of grant in the case of an NSO. The exercise price of an ISO or NSO granted to one of our Named Executive Officers shall not be less than 100% fair market value of the shares at the date of grant and the exercise price of an ISO granted to a 10% shareholder shall not be less than 110% of the fair market value of the shares on the date of grant. Stock options granted under the 2013 Plan typically vest over four years and have a 10 year term. All RSUs are considered to be granted at the fair value of our stock on the date of grant because they have no exercise price. RSUs typically vest over four years. At December 31, 2014 there were 1,886,217 shares available for grant under the 2013 Plan.

Stock-Based Compensation

12 Months Ended

Dec. 31, 2014

Stock-Based Compensation [Abstract]

Stock-Based Compensation

Note 7 - Stock-Based Compensation

The following tables summarize information about stock-options and RSUs outstanding at December 31, 2014:

Options Outstanding									Options Vested and Exercisable
Date of Option Issue	Range of Exercise Prices		Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price
2006	$	0.24		41,516		1.22	$	0.24		41,516		1.22	$	0.24
2007	$	4.20		1,277,574		2.56		4.20		1,277,574		2.56		4.20
2007	$	5.88-6.47		563,931		2.99		5.88		563,931		2.99		5.88
2008	$	1.74-6.20		129,500		3.40		5.00		129,500		3.40		5.00
2009	$	1.15- 1.58		922,986		4.26		1.16		922,986		4.26		1.16
2010	$	5.48-6.03		259,896		5.17		5.49		259,896		5.17		5.49
2011	$	19.85-23.62		405,000		6.37		23.62		367,499		6.37		23.62
2012	$	23.84 – 35.25		357,500		7.40		27.03		242,083		7.38		27.03
2013	$	23.72 – 35.05		269,625		8.37		25.40		128,717		8.37		25.41
2014	$	14.52-15.40		261,500		9.50		15.21		41,928		9.46		14.97
				4,489,028		4.61	$	9.33		3,975,630		4.11	$	7.79

The following tables summarize activity under the Plan for the indicated periods:

	Options
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2011		4,906,998		$	5.12		—		—
Options granted		367,500			26.97		—		—
Options exercised		(486,165	)		3.48		—		—
Options cancelled		(12,109	)		17.34		—		—
Outstanding at December 31, 2012		4,776,224			6.94		—		—
Options granted		274,625			25.37		—		—
Options exercised		(39,833	)		4.27		—		—
Options cancelled		(34,167	)		20.57		—		—
Outstanding at December 31, 2013		4,976,849			7.86		—		—
Options granted		261,500			15.21		—		—
Options exercised		(679,321	)		0.41		—		—
Options cancelled		(70,000	)		13.38		—		—
Outstanding at December 31, 2014		4,489,028		$	9.33		4.61	$	6,000

	RSUs
	Number of RSUs			Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
Outstanding at December 31, 2011		—			—		—
RSUs granted		151,665			25.60		—
Outstanding at December 31, 2012		151,665		$	25.60	$	—
RSUs granted		156,415			23.72		—
RSUs vested		(55,832	)		27.06		—
RSUs cancelled		(3,333	)		24.75		—
Outstanding at December 31, 2013		248,915		$	24.10	$	—
RSUs granted		154,332			15.30		—
RSUs vested		(88,686	)		24.08		—
RSUs cancelled		(4,167	)		24.13		—
Outstanding at December 31, 2014		310,394		$	19.74	$	—

Intrinsic value is calculated as the difference between the per-share market price of our common stock on the last trading day of 2014, which was $5.49, and the exercise price of the options. For options exercised, the intrinsic value is the difference between market price and the exercise price on the date of exercise. We received cash proceeds of $278, $170 and $1,691 from stock options exercised in 2014, 2013 and 2012 respectively. The total intrinsic value of options exercised was $3,575, $676 and $11,509 during the years ended December 31, 2014, 2013 and 2012, respectively. For RSUs vested, the intrinsic value is the difference between market price and the vested price on the date of vest. The total intrinsic value of the RSUs vested was zero during the year ended December 31, 2014.

Stock-based compensation expense is included in general and administrative expense for each period as follows:

Stock-Based Compensation by Type of Award	Year Ended December 31,2014		Year Ended December 31,2013		Year Ended December 31,2012
Employee stock options	$	5,951	$	6,488	$	5,171
RSUs		2,238		1,075		991
Total stock-based compensation expense	$	8,189	$	7,563	$	6,162

As of December 31, 2014, there was $8,583 of unrecognized stock-based compensation expense expected to be recognized related to unvested employee stock options and $4,814 of unrecognized stock-based compensation expense to be recognized related to unvested RSUs. These costs are expected to be recognized over a weighted-average period of 2.38 and 2.58 years, respectively.

The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model using the following weighted average assumptions:

	Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
Expected stock price volatility		88	%		93	%		111	%
Risk-free interest rate		2.56	%		2.04	%		1.90	%
Expected life term (in years)	6.0 years			6.10 years			6.8 years
Expected dividends		0	%		0	%		0	%

Based on the Black-Scholes option pricing model, the weighted average estimated fair value of employee stock options granted was $11.26, $19.24 and $23.17 per share during the years ended December 31, 2014, 2013 and 2012, respectively.

The expected life was determined using the simplified method outlined in ASC 718 "Compensation - Stock Compensation", taking the average of the vesting term and the contractual term of the option. Expected volatility of the stock options was based upon historical data and other relevant factors, such as the volatility of comparable publicly-traded companies at a similar stage of life cycle. We have not provided an estimate for forfeitures because we have had nominal forfeited options and RSUs and believe that all outstanding options and RSUs at December 31, 2014, will vest. In the future, we may change this estimate based on actual and expected future forfeiture rates.

- Definition

The entire disclosure for compensation-related costs for equity-based compensation, which may include disclosure of policies, compensation plan details, allocation of equity compensation, incentive distributions, equity-based arrangements to obtain goods and services, deferred compensation arrangements, employee stock ownership plan details and employee stock purchase plan details.

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Earnings Per Share

12 Months Ended

Dec. 31, 2014

Earnings Per Share [Abstract]

Earnings Per Share

Note 8 - Earnings Per Share

Basic earnings per share are based on the weighted average number of shares outstanding for a period. Diluted earnings per share are based upon the weighted average number of shares and potentially dilutive common shares outstanding. Potential common shares outstanding principally include stock options, under our stock plan and warrants. During 2014, 2013 and 2012 we incurred losses; therefore the effect of any common stock equivalent would be anti-dilutive during those periods.

The table below sets forth the basic loss per share calculations:

	Year Ended December 31,
	2014			2013			2012
Net loss	$	(9,902	)	$	(27,608	)	$	(26,924	)
Basic weighted average number of shares outstanding		51,570			51,188			50,934
Diluted weighted average number of shares outstanding		51,570			51,188			50,934
Basic and diluted loss per share	$	(0.19	)	$	(0.54	)	$	(0.53	)

- Definition

The entire disclosure for earnings per share.

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Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2014
Employee Benefit Plan [Abstract]
Employee Benefit Plan	Note 11 - Employee Benefit Plan We sponsor a defined contribution, 401k plan, covering substantially all our employees. Our matching contribution to the plan was approximately $45 in 2014, $47 in 2013 and $41 in 2012.

- Definition

The entire disclosure for pension and other postretirement benefits.

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Income Taxes

12 Months Ended

Dec. 31, 2014

Income Taxes [Abstract]

Income Taxes

Note 12 - Income Taxes

The benefit (provision) for income taxes is comprised of the following:

	Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
Current:
Federal	$	(13	)	$	(354	)	$	12,154
State		(2	)		(397	)		428
Foreign		-			-			-
		(15	)		(751	)		12,582
Deferred:
Federal		-			-			(40	)
State		-			-			(7	)
		-			-			(47	)
Total (provision) benefit for income taxes	$	(15	)	$	(751	)	$	12,535

A reconciliation of the United States federal statutory income tax rate to our effective income tax rate is as follows:

	Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012

United States federal statutory rate		35.00%		35.00	%		35.00	%
State taxes, net of federal benefit		(0.02)%		(1.48	)%		1.07	%
Valuation allowance		(41.67)%		(37.11	)%		(4.41	)%
Stock options		0.39%		(0.17	)%		0.14	%
Prior year true-up		(0.13)%		(1.32	)%		1.03	%
Warrants		7.92%		2.10	%		(0.82	)%
Other		(1.64)%		0.18	%		(0.32	)%
Effective income tax rate		(0.15)%		(2.80	)%		31.69	%

In 2014 and 2013, we had taxable losses of $10,000 and $27,000, respectively, which are available for carried forward to offset future taxable income. We made determinations to provide full valuation allowances for our net deferred tax assets at the end of 2014 and 2013, including NOL carryforwards generated during the years, based on our evaluation of positive and negative evidence, including our history of operating losses and the uncertainty of generating future taxable income that would enable us to realize our deferred tax assets. The small provision in 2014 was related to the payment of miscellaneous penalties and minimum taxes. The 2013 tax provision of $750 was due primarily to a change in our estimate of taxable income for the 2012 period and a tax reserve for the California research & development credit utilized in the 2010 tax return.

The income tax benefit for the year ended December 31, 2012 resulted from recognition of net operating losses (“NOLs”) generated during the year that could be carried back to generate refunds of taxes paid in prior years. Generally, NOLs can be carried back to the two years preceding the loss year and then forward for twenty years following the loss year. In 2010, we had a taxable income of $75,000, which allowed us to carry back our 2012 NOL in the amount $42,000 for tax refunds. Due to the tax refunds derived from carrying back the 2012 NOLs, we recognized the tax benefit of $12,000 in 2012. In addition, we made a determination to provide a full valuation allowance for its net deferred tax assets at the end of 2012 based on our evaluation of positive and negative evidence, including our history of operating losses and the uncertainty of generating future taxable income that would enable it to realize its deferred tax assets.

Deferred tax assets (liabilities) consist of the following:

	Year Ended December 31, 2014			Year Ended December 31, 2013
Deferred tax assets:
Reserves and accruals	$	-		$	58
State tax		1			1
Research and development credits and other credits		924			907
Net operating loss carry forward		11,190			8,249
Stock based compensation		8,452			6,600
Other		127			154
Total deferred tax assets		20,694			15,969

Valuation allowance		(20,679	)		(15,955	)
Deferred tax assets after valuation allowance		15			14

Deferred tax liability:
Depreciation and amortization		(15	)		(14	)

Total deferred tax liability		(15	)		(14	)

Net deferred tax assets	$	-		$	-

In assessing the realization of deferred tax assets, management considers whether it is more likely than not that some portion or all of deferred assets will not be realized. The ultimate realization of the deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible.

Based on the available objective evidence, management believes it is more likely than not that the net deferred tax assets at December 31, 2014 will not be fully realizable. Accordingly, management has maintained a full valuation allowance against its net deferred tax assets at December 31, 2014. The net change in the total valuation allowance for the 12 months ended December 31, 2014 was an increase of $4,724. At December 31, 2014, we had federal and state net operating loss carry-forwards of approximately $31,617 and $37,993, respectively, expiring beginning in 2028 and 2017, respectively. At December 31, 2014, we had federal research and development credit carry-forwards of approximately $924 expiring beginning in 2031.

Internal Revenue Code Section 382 places a limitation (the "Section 382 Limitation") on the amount of taxable income that can be offset by net operating loss carry forwards after a change in control (generally greater than 50% change in ownership) of a loss corporation. California has similar rules. Our capitalization described herein may have resulted in such a change. Generally, after a control change, a loss corporation cannot deduct net operating loss carry forwards generated in years prior to the deemed change of control under IRC Section 382 in excess of the Section 382 Limitation.

We are required to recognize the financial statement effects of a tax position when it is more likely than not, based on the technical merits, that the position will be sustained upon examination. As a result, we have provided contingent reserve under ASC 740-10 of $316 and $316 at December 31, 2014 and December 31, 2013, respectively. Our tax returns are subject to review by various tax authorities. The returns are subject to review those from 2008 forward.

Our policy is to recognize interest and penalties accrued on any unrecognized tax benefits as a component of income tax expense. We have accrued interest or penalties during the 12 month period ended December 31, 2014 in the amount of $79.

A reconciliation of beginning and ending amounts of unrecognized tax benefits follows:

	Year Ended December 31, 2014		Year Ended December 31, 2013		Year Ended December 31, 2012

Balance at the beginning of the year	$	316	$	128	$	128
Additions based on tax positions related to the current year		-		-		-
Additions for tax positions of prior years		-		188		-
Settlements		-		-		-
Lapse of applicable statute of limitations		-		-		-
Balance at the end of the year	$	316	$	316	$	128

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

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Fair Value Measurement

12 Months Ended

Dec. 31, 2014

Fair Value Measurement [Abstract]

Fair Value Measurement

Note 13 - Fair Value Measurement

We apply fair value accounting for all financial assets and liabilities and non-financial assets and liabilities that are recognized or disclosed at fair value in the financial statements on a recurring basis. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement:

Level 1 – Quoted prices in active markets for identical assets or liabilities.

Level 2 – Observable inputs other than quoted prices in active markets for identical assets and liabilities, quoted prices for identical or similar assets or liabilities in inactive markets, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 – Inputs that are generally unobservable and typically reflect management’s estimate of assumptions that market participants would use in pricing the asset or liability.

The carrying amounts for cash and cash equivalents, investments in certificates of deposit, accounts payable and accrued expenses approximate their fair values due to the short period of time until maturity.

Mutual Funds: Valued at the quoted net asset value (NAV) of shares held.

Corporate, Municipal and U.S. Agency securities: Fair value measured at the closing price reported on the active market on which the individual securities are traded.

Series I Warrants: Fair value measured by using a Binomial valuation model. As of December 31, 2014, the assumptions used to measure fair value of the liability embedded in our outstanding Series I Warrants included a warrant exercise price of $3.59 per share, a common share price of $5.49, a discount rate of 1.65%, and a volatility of 89.69%. As of December 31, 2013, the assumptions used to measure fair value of the liability embedded in our outstanding Series I Warrants included a warrant exercise price of $3.59 per share, a common share price of $19.41, a discount rate of 1.75%, and a volatility of 91.55%.

The following table shows our cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category recorded as cash and cash equivalents of investments available for sale as of December 31, 2014 and 2013 (in thousands):

	December 31,2014
										Cash		Investments
	Adjusted		Unrealized		Unrealized			Fair		and Cash		Available
	Cost		Gains		Losses			Value		Equivalents		for Sale
Cash	$	1,183	$	-	$	-		$	1,183	$	1,183	$	-

Level 1:
Mutual funds		10,139		-		-			10,139		10,139		-
Corporate securities		9,405		1		(3	)		9,403		1,645		7,758
U.S agency securities		20,504		2		(2	)		20,504		5,691		14,813
		40,048		3		(5	)		40,046		17,475		22,571
Total	$	41,231	$	3	$	(5	)	$	41,229	$	18,658	$	22,571

	December 31,2013
										Cash		Investments
	Adjusted		Unrealized		Unrealized			Fair		and Cash		Available
	Cost		Gains		Losses			Value		Equivalents		for Sale
Cash	$	11,699	$	-	$	-		$	11,699	$	11,699	$	-

Level 1:
Mutual funds		73		-		-			73		73		-
Corporate securities		10,782		-		-			10,782		2,325		8,457
Municipal securities		2,172		-		-			2,172		665		1,507
U.S agency securities		14,287		-		(25	)		14,262		4,411		9,851
		27,314		-		(25	)		27,289		7,474		19,815
Total	$	39,013	$	-	$	(25	)	$	38,988	$	19,173	$	19,815

The maturities of our marketable securities generally range from within one to two years. Actual maturities could differ from contractual maturities due to call or prepayment provisions.

The following table sets forth, by level within the fair value hierarchy, our financial instrument liabilities as of December 31, 2014 (in thousands):

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Series l Warrants	$	—	$	—	$	320	$	320
Total	$	—	$	—	$	320	$	320

The following table sets forth, by level within the fair value hierarchy, our financial instrument liabilities as of December 31, 2013 (in thousands):

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Series l Warrants	$	—	$	—	$	2,564	$	2,564
Total	$	—	$	—	$	2,564	$	2,564

The following table sets forth a summary of changes in the fair value of our Level 3 financial instrument liability for the year ended December 31, 2014, 2013 and 2012 (in thousands):

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Year ended December 31, 2014			Year ended December 31, 2013			Year ended December 31, 2012
Beginning Balance	$	2,564		$	4,172		$	4,699
(Gain) losses included in net losses		(2,237	)		(1,608	)		927
Settlements		(7	)		—			(1,454	)
Ending Balance	$	320		$	2,564		$	4,172

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

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Litigation	12 Months Ended
Litigation	Dec. 31, 2014
Litigation [Abstract]
Litigation	Note 14 - Litigation We have three intellectual property infringement lawsuits pending against Apple, Inc. in the United States District Court for the Eastern District of Texas, Tyler Division, pursuant to which we allege that these parties infringe on certain of our patents. We seek damages and injunctive relief in all the complaints. VirnetX Inc. et al., v. Microsoft Corporation (Case 6:13-CV-00351-LED) On April 22, 2013, we initiated a lawsuit by filing a complaint against Microsoft Corporation in the United States District Court for the Eastern District of Texas, Tyler Division, pursuant to which we allege that Microsoft has infringed U.S. Patent Nos. 6,502,135, 7,188,180, 7,418,504, 7,490,151, 7,921,211, and 7,987,274. We seek an unspecified amount of damages and injunctive relief. A hearing on claims construction and multiple motions by both parties was held on September 4, 2014. On September 10, 2014, the court issued an order granting in part and denying-in-part our sealed motion to compel interrogatory responses, denying Microsoft’s sealed motion to enter order focusing patent claims and prior art, denying Microsoft’s sealed motion to compel, denying Microsoft’s sealed motion to stay the case and granting our request for leave to file a Motion for Partial Summary Judgment. On December 17, 2014, we entered into an Amended Settlement and License Agreement with Microsoft Corporation. The agreement amends and restates certain terms of the original Settlement and License Agreement, dated May 14, 2010, between VirnetX, Inc. and Microsoft Corporation. As a result of the agreement, both parties have settled their pending patent disputes including the patent infringement case brought by us against Microsoft before the U.S. District Court for the Eastern District of Texas and jointly move to terminate the pending Inter Partes Review (IPR) proceedings between Microsoft and VirnetX as to Microsoft. Under the terms of the amended agreement, Microsoft paid us $23 million to settle the patent dispute and expand Microsoft’s license. Under the amended agreement, Microsoft received a worldwide, irrevocable, nonexclusive, non-sublicensable, royalty-free, fully paid-up license to all our patents. VirnetX Inc. v. Cisco Systems, Inc. et al (13-1489-LP VirnetX, Case 6:10-CV-00417-LED) On August 11, 2010, we initiated a lawsuit by filing a complaint against Aastra, Apple, Cisco, and NEC in the United States District Court for the Eastern District of Texas, Tyler Division, pursuant to which we alleged that these parties infringe on certain of our patents. We sought damages and injunctive relief. Subsequently, on February 4, 2011, we amended our original complaint, filed on August 11, 2010, against Aastra, Apple, Cisco and NEC, to assert U.S. Patent No. 7,418,504 against Apple and Aastra. On April 5, 2011, we further amended our complaint to include Apple’s iPad 2 in the list of Apple products that are accused of infringing our patents and to assert our newly-issued patent, U.S. Patent No. 7,921,211 against all of the defendants in that lawsuit. A claim construction hearing was held on January 5, 2012 and the court issued a Markman ruling on April 25, 2012. Aastra and NEC agreed to sign license agreements with us and we agreed to drop all the accusations of infringement against them. At the pre-trial hearing, the judge decided to conduct separate jury trial for each defendant, and just try the case against Apple on the scheduled trial date. The jury trial against Cisco was held on March 4, 2013. The jury against Cisco came back with a verdict of non-infringement also determined that all our patents-in-suit patents are not invalid. Our motions for a new trial and Cisco’s infringement of certain VirnetX patents was denied and the case against Cisco was closed. The jury trial against Apple was held on October 31, 2012 and on November 6, 2012, a jury in the United States Court for the Eastern District of Texas, Tyler Division, awarded us over $368 million in a verdict against Apple Corporation for infringing four of our patents. On February 26, 2013, the court issued its Memorandum Opinion and Order regarding post-trial motions resulting from the prior jury verdict denying Apple’s motion to reduce the damages awarded by the jury for past infringement. The Court further denied Apple’s request for a new trial on the liability and damages portions of the verdict and granted our motions for pre-judgment interest, post-judgment interest, and post-verdict damages to date. The Court ordered that Apple pay $34 in daily interest up to final judgment and $330 in daily damages for infringement up to final judgment for certain Apple devices included in the verdict. The Court denied our request for a permanent injunction and severed the future infringement portion into its own separate proceedings under Case 6:13-CV-00211-LED. On July 3, 2013, Apple filed an appeal of the judgment dated February 27, 2013 and order dated June 4, 2013 denying Apple’s motion to alter or amend the judgment to the United States Court of Appeals for the Federal Circuit (USCAFC). On October 16, 2013 Apple filed its opening appeal brief to the USCAFC. Our response to the opening brief was filed on December 2, 2013, and on December 19, 2013, Apple filed its final response to complete the briefing of the court. A hearing was held on March 3, 2014 at the USCAFC. On September 16, 2014, USCAFC issued their opinion, affirming the jury’s finding that all 4 of our patents are valid, confirming the jury’s finding of infringement of VPN on Demand under many of the asserted claims of our ‘135 and ‘151 patents, and confirming the district’s court’s decision to allow evidence concerning our licenses and royalty rates in connection with the determination of damages. In its opinion, the USCAFC also vacated the jury’s damages award and the district court’s claim construction with respect to parts of our ‘504 and ‘211 patents and remanded the damages award and determination of infringement with respect to FaceTime –for further proceedings consistent with its opinion. On October 16, 2014, we filed a petition with the USCAFC, requesting a rehearing and rehearing en banc of the Federal Circuit’s September 14, 2014, decision concerning VirnetX’s litigation against Apple Inc. In our petition, we have asked the court to rehear its decision with respect to damages and affirm the district court’s damages award against Apple in full because the Federal Circuit’s decision is contrary to the patent statute and Supreme Court precedent. We are also asking the Federal Circuit to reinstate the jury’s award that Apple infringed the ’504 and ’211 patents on the basis that the district court correctly construed the claim term “secure communication link”. On December 16, 2014, USCAFC denied our petition requesting a rehearing and rehearing en banc of the Federal Circuit's September 14, 2014, decision and remanded the case back to the Eastern District of Texas, Tyler Division, for further proceedings consistent with its opinion. We are currently awaiting a scheduling order from the court. VirnetX, Inc. v. Apple, Inc. (Case 6:13-CV-00211-LED) The Court ordered the parties to mediate over an ongoing license in the following 45 days for Apple’s future infringing use not covered by the Court’s Order, and ordered us to file an appropriate motion with the court if the parties fail to agree to a license. On March 28, 2013, Apple filed a motion to alter or amend the judgment entered by the Court. The mediation was held on April 9, 2013 and the parties did not come to an agreement on an ongoing royalty rate for infringing Apple products. We filed our opposition to this motion on April 10, 2013. As ordered by the Court, we filed a sealed motion with the Court on April 16, 2013, requesting the Court’s assistance in deciding an appropriate royalty rate for all infringing products shipped by Apple that are “not more than colorably different” with regards to the accused functionality. On August 1, 2013, a hearing was held in the United States District Court for the Eastern District of Texas, Tyler Division on our motion for an ongoing royalty. On March 6, 2014, the court issued a public version of the order previously issued under seal on March 3, 2014, awarding us an on-going royalty of 0.98% on adjudicated products and products “not colorably” different from those adjudicated at trial that incorporate any of the FaceTime or VPN on Demand features found to infringe at trial. On March 27, 2014, Apple filed its notice of appeal to the United States Court of Appeals for the Federal Circuit. On March 28, 2014 Apple also filed a motion for Entry of Final Judgment by Apple Inc. with the United States District Court for the Eastern District of Texas, Tyler Division. The Court had stayed the proceedings in this matter while the Court’s ruling in the Case 6:10-CV-00417-LED was pending. With the denial of the rehearing request by USCAFC on December 16, 2014, this case has also been remanded back to the Eastern District of Texas, Tyler Division, for further processing with the Case 6:10-CV-00417-LED. We are currently awaiting a scheduling order from the court. VirnetX Inc. v. Apple, Inc. (Case 6:12-CV-00855-LED) On November 6, 2012, we filed a new complaint against Apple Inc., in the United States District Court for the Eastern District of Texas, Tyler Division for willfully infringing four of our patents, U.S. Patent Nos. 6,502,135, 7,418,504, 7,921,211 and 7,490,151, and seeking both an unspecified amount of damages and injunctive relief. The accused products include the iPhone 5, iPod Touch 5th Generation, iPad 4th Generation, iPad mini, and the latest Macintosh computers. Due to their release dates, these products were not included in the previous lawsuit that concluded with a Jury verdict on November 6, 2012 that was subsequently upheld by the United States District Court for the Eastern District of Texas, Tyler Division, on February 26, 2013. On July 1, 2013, we filed a consolidated and amended complaint to include U.S. Patent No. 8,051,181 and consolidate Civil Action No. 6:11-cv-00563-LED. On August 27, 2013, we filed an amended complaint including allegations of willful infringement related to U.S. Patent No. 8,504,697 seeking both damages and injunctive relief. The Markman hearing in this case was held on May 20, 2014 and on August 8, 2014, issued its Markman Order, denying Apple’s motion for summary judgment of indefiniteness, in which Apple alleged that some of the disputed claims terms in the patents asserted by us were invalid for indefiniteness. In a separate order, the court granted in part and denied in part our motion for partial summary judgment on Apple’s invalidity counterclaims, precluding Apple from asserting invalidity as a defense against infringement of the claims that were tried before a jury in our prior litigation against Apple (VirnetX vs. Cisco et. al., Case 6:10-CV-00417-LED). The jury trial in this case is scheduled for October 13, 2015. One or more potential intellectual property infringement claims may also be available to us against certain other companies who have the resources to defend against any such claims. Although we believe these potential claims are worth pursuing, commencing a lawsuit can be expensive and time-consuming, and there is no assurance that we will prevail on such potential claims. In addition, bringing a lawsuit may lead to potential counterclaims which may preclude our ability to commercialize our initial products, which are currently in development. Currently, we are not a party to any other pending legal proceedings, and are not aware of any proceeding threatened or contemplated against us by any governmental authority or other party.

Quarterly Financial Information (unaudited)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information (unaudited) [Abstract]

Quarterly Financial Information (unaudited)

Note 15 - Quarterly Financial Information (unaudited)

	First			Second			Third			Fourth
	(in thousands except per share)
2014
Revenue	$	250		$	268		$	292		$	439
Gain on settlement		—			—			—			23,000
Income (loss) from operations		(6,953	)		(6,171	)		(6,250	)		6,870
Net Income/ (loss)		(6,087	)		(6,670	)		(4,468	)		7,325
Basic earnings (loss) per common share	$	(0.12	)	$	(0.13	)	$	(0.09	)	$	0.14
Diluted earnings (loss) per common share	$	(0.12	)	$	(0.13	)	$	(0.09	)	$	0.14

	First				Second				Third				Fourth
	(in thousands except per share)
2013
Revenue		$	293			$	6			$	1,612			$	286
Loss from operations			(9,529	)			(6,578	)			(5,133	)			(7,347	)
Net loss			(7,891	)			(7,029	)			(5,134	)			(7,554	)
Basic and diluted loss per common share		$	(0.15	)		$	(0.14	)		$	(0.10	)		$	(0.15	)

- Definition

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Summary of Significant Accounting Policies [Abstract]

Use of Estimates

Basis of Consolidation

The consolidated financial statements include the accounts of VirnetX Holding Corporation and our wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated.

Revenue Recognition

Deferred Revenue

Deferred revenue

Activity under the August 2013 Contract Settlement was as follows:

	2014		2013
Deferred Revenue, beginning of year	$	667	$	-
Payment received		2,500		2,500
Less: Amount amortized as revenue		1,167		1,833
Deferred Revenue, end of year	$	2,000	$	667

Cash and Cash Equivalents

Prepaid Expenses and Other Current Assets

Investments

Property and Equipment

Concentration of Credit Risk and Other Risks and Uncertainties

Fair Value

The carrying amounts of our financial instruments, including cash equivalents, accounts payable, and accrued liabilities, approximate fair value because of their generally short maturities.

Intangible Assets

Impairment of Long-Lived Assets

Research and Development

Income Taxes

Derivative Instruments

Stock-Based Compensation

Earnings Per Share

Earnings per Share

New Accounting Pronouncements

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2014

Summary of Significant Accounting Policies [Abstract]

Activity under August 2013 Contract Settlement

Activity under the August 2013 Contract Settlement was as follows:

	2014		2013
Deferred Revenue, beginning of year	$	667	$	-
Payment received		2,500		2,500
Less: Amount amortized as revenue		1,167		1,833
Deferred Revenue, end of year	$	2,000	$	667

Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2014

Property and Equipment [Abstract]

Classes of Property and Equipment

Our major classes of property and equipment were as follows:

	December 31
	2014			2013			2012
Office furniture	$	70		$	70		$	70
Computer equipment		157			121			115
Total		227			191			185
Less accumulated depreciation		(163	)		(138	)		(115	)
	$	64		$	53		$	70

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2014

Stock-Based Compensation [Abstract]

Information about Stock Options Outstanding

The following tables summarize information about stock-options and RSUs outstanding at December 31, 2014:

Options Outstanding									Options Vested and Exercisable
Date of Option Issue	Range of Exercise Prices		Number Outstanding		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price		Number Exercisable		Weighted Average Remaining Contractual Life (Years)		Weighted Average Exercise Price
2006	$	0.24		41,516		1.22	$	0.24		41,516		1.22	$	0.24
2007	$	4.20		1,277,574		2.56		4.20		1,277,574		2.56		4.20
2007	$	5.88-6.47		563,931		2.99		5.88		563,931		2.99		5.88
2008	$	1.74-6.20		129,500		3.40		5.00		129,500		3.40		5.00
2009	$	1.15- 1.58		922,986		4.26		1.16		922,986		4.26		1.16
2010	$	5.48-6.03		259,896		5.17		5.49		259,896		5.17		5.49
2011	$	19.85-23.62		405,000		6.37		23.62		367,499		6.37		23.62
2012	$	23.84 – 35.25		357,500		7.40		27.03		242,083		7.38		27.03
2013	$	23.72 – 35.05		269,625		8.37		25.40		128,717		8.37		25.41
2014	$	14.52-15.40		261,500		9.50		15.21		41,928		9.46		14.97
				4,489,028		4.61	$	9.33		3,975,630		4.11	$	7.79

Stock Option Activity

The following tables summarize activity under the Plan for the indicated periods:

	Options
	Number of Shares			Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)		Aggregate Intrinsic Value
Outstanding at December 31, 2011		4,906,998		$	5.12		—		—
Options granted		367,500			26.97		—		—
Options exercised		(486,165	)		3.48		—		—
Options cancelled		(12,109	)		17.34		—		—
Outstanding at December 31, 2012		4,776,224			6.94		—		—
Options granted		274,625			25.37		—		—
Options exercised		(39,833	)		4.27		—		—
Options cancelled		(34,167	)		20.57		—		—
Outstanding at December 31, 2013		4,976,849			7.86		—		—
Options granted		261,500			15.21		—		—
Options exercised		(679,321	)		0.41		—		—
Options cancelled		(70,000	)		13.38		—		—
Outstanding at December 31, 2014		4,489,028		$	9.33		4.61	$	6,000

Restricted Stock Units Activity

	RSUs
	Number of RSUs			Weighted Average Grant Date Fair Value		Aggregate Intrinsic Value
Outstanding at December 31, 2011		—			—		—
RSUs granted		151,665			25.60		—
Outstanding at December 31, 2012		151,665		$	25.60	$	—
RSUs granted		156,415			23.72		—
RSUs vested		(55,832	)		27.06		—
RSUs cancelled		(3,333	)		24.75		—
Outstanding at December 31, 2013		248,915		$	24.10	$	—
RSUs granted		154,332			15.30		—
RSUs vested		(88,686	)		24.08		—
RSUs cancelled		(4,167	)		24.13		—
Outstanding at December 31, 2014		310,394		$	19.74	$	—

Stock-Based Compensation by Type of Award

Stock-based compensation expense is included in general and administrative expense for each period as follows:

Stock-Based Compensation by Type of Award	Year Ended December 31,2014		Year Ended December 31,2013		Year Ended December 31,2012
Employee stock options	$	5,951	$	6,488	$	5,171
RSUs		2,238		1,075		991
Total stock-based compensation expense	$	8,189	$	7,563	$	6,162

Fair Value Assumptions

The fair value of each option grant was estimated on the date of grant using the Black-Scholes option pricing model using the following weighted average assumptions:

	Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
Expected stock price volatility		88	%		93	%		111	%
Risk-free interest rate		2.56	%		2.04	%		1.90	%
Expected life term (in years)	6.0 years			6.10 years			6.8 years
Expected dividends		0	%		0	%		0	%

Warrants (Tables)

12 Months Ended

Dec. 31, 2014

Warrants [Abstract]

Information about Warrants Outstanding

Information about warrants outstanding during the twelve months ended December 31, 2014 follows:

Original Number of Warrants Issued	Exercise Price per Common Share		Exercisable at December 31, 2013	Became Exercisable	Exercised	Terminated / Cancelled / Expired	Exercisable at December 31, 2013	Expiration Date

2,619,036(1)	$	3.59	159,967	—	2,500	—	157,467	March 2015
Total			159,967	—	2,500	—	157,467

(1)	Referred to as our Series I Warrants.

- Definition

Tabular disclosure of warrants or rights issued. Warrants and rights outstanding are derivative securities that give the holder the right to purchase securities (usually equity) from the issuer at a specific price within a certain time frame. Warrants are often included in a new debt issue to entice investors by a higher return potential. The main difference between warrants and call options is that warrants are issued and guaranteed by the company, whereas options are exchange instruments and are not issued by the company. Also, the lifetime of a warrant is often measured in years, while the lifetime of a typical option is measured in months. Disclose the title of issue of securities called for by warrants and rights outstanding, the aggregate amount of securities called for by warrants and rights outstanding, the date from which the warrants or rights are exercisable, and the price at which the warrant or right is exercisable.

+ References+ Details

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2014

Income Taxes [Abstract]

Components of Income Tax Expense (Benefit)

The benefit (provision) for income taxes is comprised of the following:

	Year Ended December 31, 2014			Year Ended December 31, 2013			Year Ended December 31, 2012
Current:
Federal	$	(13	)	$	(354	)	$	12,154
State		(2	)		(397	)		428
Foreign		-			-			-
		(15	)		(751	)		12,582
Deferred:
Federal		-			-			(40	)
State		-			-			(7	)
		-			-			(47	)
Total (provision) benefit for income taxes	$	(15	)	$	(751	)	$	12,535

Effective Income Tax Rate Reconciliation

A reconciliation of the United States federal statutory income tax rate to our effective income tax rate is as follows:

	Year Ended December 31, 2014		Year Ended December 31, 2013			Year Ended December 31, 2012

United States federal statutory rate		35.00%		35.00	%		35.00	%
State taxes, net of federal benefit		(0.02)%		(1.48	)%		1.07	%
Valuation allowance		(41.67)%		(37.11	)%		(4.41	)%
Stock options		0.39%		(0.17	)%		0.14	%
Prior year true-up		(0.13)%		(1.32	)%		1.03	%
Warrants		7.92%		2.10	%		(0.82	)%
Other		(1.64)%		0.18	%		(0.32	)%
Effective income tax rate		(0.15)%		(2.80	)%		31.69	%

Deferred Tax Assets and Liabilities

Deferred tax assets (liabilities) consist of the following:

	Year Ended December 31, 2014			Year Ended December 31, 2013
Deferred tax assets:
Reserves and accruals	$	-		$	58
State tax		1			1
Research and development credits and other credits		924			907
Net operating loss carry forward		11,190			8,249
Stock based compensation		8,452			6,600
Other		127			154
Total deferred tax assets		20,694			15,969

Valuation allowance		(20,679	)		(15,955	)
Deferred tax assets after valuation allowance		15			14

Deferred tax liability:
Depreciation and amortization		(15	)		(14	)

Total deferred tax liability		(15	)		(14	)

Net deferred tax assets	$	-		$	-

Unrecognized Tax Benefits Reconciliation

A reconciliation of beginning and ending amounts of unrecognized tax benefits follows:

	Year Ended December 31, 2014		Year Ended December 31, 2013		Year Ended December 31, 2012

Balance at the beginning of the year	$	316	$	128	$	128
Additions based on tax positions related to the current year		-		-		-
Additions for tax positions of prior years		-		188		-
Settlements		-		-		-
Lapse of applicable statute of limitations		-		-		-
Balance at the end of the year	$	316	$	316	$	128

Fair Value Measurement (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Measurement [Abstract]

Cash and Available-for-Sale Securities Adjusted Cost, Gross Unrealized Gains, Gross Unrealized Losses and Fair Value by Significant Investment Category

	December 31,2014
										Cash		Investments
	Adjusted		Unrealized		Unrealized			Fair		and Cash		Available
	Cost		Gains		Losses			Value		Equivalents		for Sale
Cash	$	1,183	$	-	$	-		$	1,183	$	1,183	$	-

Level 1:
Mutual funds		10,139		-		-			10,139		10,139		-
Corporate securities		9,405		1		(3	)		9,403		1,645		7,758
U.S agency securities		20,504		2		(2	)		20,504		5,691		14,813
		40,048		3		(5	)		40,046		17,475		22,571
Total	$	41,231	$	3	$	(5	)	$	41,229	$	18,658	$	22,571

	December 31,2013
										Cash		Investments
	Adjusted		Unrealized		Unrealized			Fair		and Cash		Available
	Cost		Gains		Losses			Value		Equivalents		for Sale
Cash	$	11,699	$	-	$	-		$	11,699	$	11,699	$	-

Level 1:
Mutual funds		73		-		-			73		73		-
Corporate securities		10,782		-		-			10,782		2,325		8,457
Municipal securities		2,172		-		-			2,172		665		1,507
U.S agency securities		14,287		-		(25	)		14,262		4,411		9,851
		27,314		-		(25	)		27,289		7,474		19,815
Total	$	39,013	$	-	$	(25	)	$	38,988	$	19,173	$	19,815

Financial Instrument Liabilities by Level within Fair Value Hierarchy

The following table sets forth, by level within the fair value hierarchy, our financial instrument liabilities as of December 31, 2014 (in thousands):

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Series l Warrants	$	—	$	—	$	320	$	320
Total	$	—	$	—	$	320	$	320

The following table sets forth, by level within the fair value hierarchy, our financial instrument liabilities as of December 31, 2013 (in thousands):

	Quoted Prices in Active Markets for Identical Assets		Significant Other Observable Inputs		Significant Unobservable Inputs
	(Level 1)		(Level 2)		(Level 3)		Total
Series l Warrants	$	—	$	—	$	2,564	$	2,564
Total	$	—	$	—	$	2,564	$	2,564

Summary of Changes in Fair Value of Level 3 Liabilities

The following table sets forth a summary of changes in the fair value of our Level 3 financial instrument liability for the year ended December 31, 2014, 2013 and 2012 (in thousands):

	Fair Value Measurements Using Significant Unobservable Inputs (Level 3)
	Year ended December 31, 2014			Year ended December 31, 2013			Year ended December 31, 2012
Beginning Balance	$	2,564		$	4,172		$	4,699
(Gain) losses included in net losses		(2,237	)		(1,608	)		927
Settlements		(7	)		—			(1,454	)
Ending Balance	$	320		$	2,564		$	4,172

- Definition

Tabular disclosure of liabilities, including [financial] instruments measured at fair value that are classified in stockholders' equity, if any, by class that are measured at fair value on a recurring basis. The disclosures contemplated herein include the fair value measurements at the reporting date by the level within the fair value hierarchy in which the fair value measurements in their entirety fall, segregating fair value measurements using quoted prices in active markets for identical assets (Level 1), significant other observable inputs (Level 2), and significant unobservable inputs (Level 3). Where the quoted price in an active market for the identical liability is not available, the Level 1 input is the quoted price of an identical liability when traded as an asset.

+ References+ Details

- Definition

Tabular disclosure of the fair value measurement of liabilities using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets), and gains or losses recognized in other comprehensive income (loss) and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issues, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs) by class of liability.

+ References+ Details

Quarterly Financial Information (unaudited) (Tables)

12 Months Ended

Dec. 31, 2014

Quarterly Financial Information (unaudited) [Abstract]

Quarterly Financial Information

	First			Second			Third			Fourth
	(in thousands except per share)
2014
Revenue	$	250		$	268		$	292		$	439
Gain on settlement		—			—			—			23,000
Income (loss) from operations		(6,953	)		(6,171	)		(6,250	)		6,870
Net Income/ (loss)		(6,087	)		(6,670	)		(4,468	)		7,325
Basic earnings (loss) per common share	$	(0.12	)	$	(0.13	)	$	(0.09	)	$	0.14
Diluted earnings (loss) per common share	$	(0.12	)	$	(0.13	)	$	(0.09	)	$	0.14

	First				Second				Third				Fourth
	(in thousands except per share)
2013
Revenue		$	293			$	6			$	1,612			$	286
Loss from operations			(9,529	)			(6,578	)			(5,133	)			(7,347	)
Net loss			(7,891	)			(7,029	)			(5,134	)			(7,554	)
Basic and diluted loss per common share		$	(0.15	)		$	(0.14	)		$	(0.10	)		$	(0.15	)

Summary of Significant Accounting Policies (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 Institution	Dec. 31, 2013	Mar. 31, 2014
Patent License Agreements [Abstract]
Minimum period after delivery in which fees are generally presumed not to be fixed or determinable, and revenue is deferred and recognized as earned	12 months
Activity under August 2013 contract settlement [Roll Forward]
Deferred Revenue, beginning of year	$ 667	$ 0
Payment received	2,500	2,500
Less: Amount amortized as revenue	1,167	1,833
Deferred Revenue, end of year	2,000	667
Prepaid Expense and Other Assets, Current [Abstract]
Prepayment of facility lease for corporate promotional and marketing purposes			4,000
Lease term	10 years
Investments [Abstract]
Contractual maturities of highly liquid debt instruments, maximum	2 years
Concentration of Credit Risk and Others Risks and Uncertainties [Abstract]
Number of financial institutions holding company's cash	2
Stock-Based Compensation [Abstract]
Option vesting term	4 years
Minimum [Member]
Property and Equipment [Abstract]
Useful lives	5 years
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	3 years
Maximum [Member]
Property and Equipment [Abstract]
Useful lives	7 years
Finite-Lived Intangible Assets [Line Items]
Estimated useful lives	15 years
August 2013 Contract [Member]
Deferred Revenue [Abstract]
Contract amount	10,000
Term of contract	4 years
Total payment on contract received	$ 5,000

Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property and Equipment [Line Items]
Property and equipment, gross	$ 227	$ 191	$ 185
Less accumulated depreciation	(163)	(138)	(115)
Property and equipment, net	64	53	70
Depreciation expense	25	24	23
Office Furniture [Member]
Property and Equipment [Line Items]
Property and equipment, gross	70	70	70
Computer Equipment [Member]
Property and Equipment [Line Items]
Property and equipment, gross	$ 157	$ 121	$ 115

Commitments and Related Party Transactions (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Operating lease expiring date	Oct. 31, 2015
Rent expense	$ 56	$ 56	$ 56
Rent expense payable to related parties	81	0
Term of lease	10 years
K2 Investment Fund LLC [Member] \| Aircraft [Member]
Operating Leased Assets [Line Items]
Rental fees incurred for use of plane	296
Rent expense payable to related parties	81
Term of lease	12 months
Term of notice for cancellation of lease	30 days
K2 Investment Fund LLC [Member] \| Aircraft [Member] \| Subsequent Event [Member]
Operating Leased Assets [Line Items]
Rate of aircraft lease (in dollars per flight hour)	$ 8

- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References+ Details

Stock Plan (Details)	12 Months Ended
Stock Plan (Details)	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	2,500,000
Shares available for grant (in shares)	1,886,217
2013 Plan [Member] \| Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum exercise price of ISO granted (in hundredths)	100.00%
Minimum exercise price of NSO granted (in hundredths)	85.00%
Minimum exercise price of options granted to named executive officers (in hundredths)	100.00%
Minimum exercise price of options granted to 10% shareholders (in hundredths)	110.00%
Term of award	10 years
Vesting period	4 years
2013 Plan [Member] \| Restricted Stock Purchase Rights ("RSU") [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years

Stock-Based Compensation, Information about Stock Options and RSUs Outstanding (Details) (Stock Options [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, number outstanding (in shares)	4,489,028
Options outstanding, weighted average remaining contractual life	4 years 7 months 10 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 9.33
Options vested and exercisable, number exercisable (in shares)	3,975,630
Options vested and exercisable, weighted average remaining contractual life	4 years 1 month 10 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 7.79
Award Issued in 2006 [Member] \| Exercise Price $0.24 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit (in dollars per share)	$ 0.24
Options outstanding, number outstanding (in shares)	41,516
Options outstanding, weighted average remaining contractual life	1 year 2 months 19 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 0.24
Options vested and exercisable, number exercisable (in shares)	41,516
Options vested and exercisable, weighted average remaining contractual life	1 year 2 months 19 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 0.24
Award Issued in 2007 [Member] \| Exercise Price $4.20 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, upper range limit (in dollars per share)	$ 4.20
Options outstanding, number outstanding (in shares)	1,277,574
Options outstanding, weighted average remaining contractual life	2 years 6 months 22 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 4.20
Options vested and exercisable, number exercisable (in shares)	1,277,574
Options vested and exercisable, weighted average remaining contractual life	2 years 6 months 22 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 4.20
Award Issued in 2007 [Member] \| Exercise Price Range $5.88 - $6.47 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 5.88
Exercise price range, upper range limit (in dollars per share)	$ 6.47
Options outstanding, number outstanding (in shares)	563,931
Options outstanding, weighted average remaining contractual life	2 years 11 months 26 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 5.88
Options vested and exercisable, number exercisable (in shares)	563,931
Options vested and exercisable, weighted average remaining contractual life	2 years 11 months 26 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 5.88
Award Issued in 2008 [Member] \| Exercise Price Range $1.74 - $6.20 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 1.74
Exercise price range, upper range limit (in dollars per share)	$ 6.20
Options outstanding, number outstanding (in shares)	129,500
Options outstanding, weighted average remaining contractual life	3 years 4 months 24 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 5.00
Options vested and exercisable, number exercisable (in shares)	129,500
Options vested and exercisable, weighted average remaining contractual life	3 years 4 months 24 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 5.00
Award Issued in 2009 [Member] \| Exercise Price Range $1.15 - $1.58 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 1.15
Exercise price range, upper range limit (in dollars per share)	$ 1.58
Options outstanding, number outstanding (in shares)	922,986
Options outstanding, weighted average remaining contractual life	4 years 3 months 4 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.16
Options vested and exercisable, number exercisable (in shares)	922,986
Options vested and exercisable, weighted average remaining contractual life	4 years 3 months 4 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 1.16
Award Issued in 2010 [Member] \| Exercise Price Range $5.48 - $6.03 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 5.48
Exercise price range, upper range limit (in dollars per share)	$ 6.03
Options outstanding, number outstanding (in shares)	259,896
Options outstanding, weighted average remaining contractual life	5 years 2 months 1 day
Options outstanding, weighted average exercise price (in dollars per share)	$ 5.49
Options vested and exercisable, number exercisable (in shares)	259,896
Options vested and exercisable, weighted average remaining contractual life	5 years 2 months 1 day
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 5.49
Award Issued in 2011 [Member] \| Exercise Price Range $19.85 - $23.62 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 19.85
Exercise price range, upper range limit (in dollars per share)	$ 23.62
Options outstanding, number outstanding (in shares)	405,000
Options outstanding, weighted average remaining contractual life	6 years 4 months 13 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 23.62
Options vested and exercisable, number exercisable (in shares)	367,499
Options vested and exercisable, weighted average remaining contractual life	6 years 4 months 13 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 23.62
Award Issued in 2012 [Member] \| Exercise Price Range $23.84 - $35.25 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 23.84
Exercise price range, upper range limit (in dollars per share)	$ 35.25
Options outstanding, number outstanding (in shares)	357,500
Options outstanding, weighted average remaining contractual life	7 years 4 months 24 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 27.03
Options vested and exercisable, number exercisable (in shares)	242,083
Options vested and exercisable, weighted average remaining contractual life	7 years 4 months 17 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 27.03
Award Issued in 2013 [Member] \| Exercise Price Range $23.72 - $35.05 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 23.72
Exercise price range, upper range limit (in dollars per share)	$ 35.05
Options outstanding, number outstanding (in shares)	269,625
Options outstanding, weighted average remaining contractual life	8 years 4 months 13 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 25.40
Options vested and exercisable, number exercisable (in shares)	128,717
Options vested and exercisable, weighted average remaining contractual life	8 years 4 months 13 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 25.41
Award Issued in 2014 [Member] \| Exercise Price Range $14.52 - $15.40 [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, lower range limit (in dollars per share)	$ 14.52
Exercise price range, upper range limit (in dollars per share)	$ 15.40
Options outstanding, number outstanding (in shares)	261,500
Options outstanding, weighted average remaining contractual life	9 years 6 months
Options outstanding, weighted average exercise price (in dollars per share)	$ 15.21
Options vested and exercisable, number exercisable (in shares)	41,928
Options vested and exercisable, weighted average remaining contractual life	9 years 5 months 16 days
Options vested and exercisable, weighted average exercise price (in dollars per share)	$ 14.97

Stock-Based Compensation, Summary of Activity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
RSUs, aggregate intrinsic value [Abstract]
Per share market price of common stock on last trading day of year (in dollars per share)	$ 5.49
Proceeds from exercise of options	$ 278	$ 170	$ 1,691
Stock Options [Member]
Options, number of shares [Roll Forward]
Outstanding, beginning of period (in shares)	4,976,849	4,776,224	4,906,998
Options granted (in shares)	261,500	274,625	367,500
Options exercised (in shares)	(679,321)	(39,833)	(486,165)
Options cancelled (in shares)	(70,000)	(34,167)	(12,109)
Outstanding, end of period (in shares)	4,489,028	4,976,849	4,776,224
Options, weighted average exercise price [Roll Forward]
Outstanding, beginning of period (in dollars per share)	$ 7.86	$ 6.94	$ 5.12
Options granted (in dollars per share)	$ 15.21	$ 25.37	$ 26.97
Options exercised (in dollars per share)	$ 0.41	$ 4.27	$ 3.48
Options cancelled (in dollars per share)	$ 13.38	$ 20.57	$ 17.34
Outstanding, end of period (in dollars per share)	$ 9.33	$ 7.86	$ 6.94
Options, additional disclosures [Abstract]
Options outstanding, weighted average remaining contractual life	4 years 7 months 10 days
Options outstanding, aggregate intrinsic value	6,000
RSUs, aggregate intrinsic value [Abstract]
Total intrinsic value of options exercised	3,575	676	11,509
Restricted Stock Units (RSUs) [Member]
RSUs, number of RSUs [Roll Forward]
Outstanding, beginning of period (in shares)	248,915	151,665	0
RSUs granted (in shares)	154,332	156,415	151,665
RSUs vested (in shares)	(88,686)	(55,832)
RSUs cancelled (in shares)	(4,167)	(3,333)
Outstanding, end of period (in shares)	310,394	248,915	151,665
RSUs, weighted average grant date fair value [Abstract]
Outstanding, beginning of period (in dollars per share)	$ 24.10	$ 25.60	$ 0
RSUs granted (in dollars per share)	$ 15.30	$ 23.72	$ 25.60
RSUs vested (in dollars per share)	$ 24.08	$ 27.06
RSUs cancelled (in dollars per share)	$ 24.13	$ 24.75
Outstanding, end of period (in dollars per share)	$ 19.74	$ 24.10	$ 25.60
RSUs, aggregate intrinsic value [Abstract]
Outstanding, end of period	0	0	0	0
Total intrinsic value of RSUs vested	$ 0

Stock-Based Compensation, Stock-Based Compensation by Type of Award (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,189	$ 7,563	$ 6,162
Employee Stock Options [Member]
Compensation cost not yet recognized [Abstract]
Unrecognized stock-based compensation expense expected to be recognized	8,583
Weighted-average period for recognition of unrecognized stock-based compensation expense	2 years 4 months 17 days
Employee Stock Options [Member] \| General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	5,951	6,488	5,171
Restricted Stock Units (RSUs) [Member]
Compensation cost not yet recognized [Abstract]
Unrecognized stock-based compensation expense expected to be recognized	4,814
Weighted-average period for recognition of unrecognized stock-based compensation expense	2 years 6 months 29 days
Restricted Stock Units (RSUs) [Member] \| General and Administrative Expense [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,238	$ 1,075	$ 991

Stock-Based Compensation, Fair Value Assumptions Used (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Fair value assumptions used in estimating fair value of each option grant [Abstract]
Expected stock price volatility (in hundredths)	88.00%	93.00%	111.00%
Risk-free interest rate (in hundredths)	2.56%	2.04%	1.90%
Expected life term	6 years	6 years 1 month 6 days	6 years 9 months 18 days
Expected dividends (in hundredths)	0.00%	0.00%	0.00%
Weighted average estimated fair value of employee stock options granted (in dollars per share)	$ 11.26	$ 19.24	$ 23.17

Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Calculation of basic loss per share [Abstract]
Net loss	$ 7,325	$ (4,468)	$ (6,670)	$ (6,087)	$ (7,554)	$ (5,134)	$ (7,029)	$ (7,891)	$ (9,902)	$ (27,608)	$ (26,924)
Basic weighted average number of shares outstanding (in shares)									51,570	51,188	50,934
Diluted weighted average number of shares outstanding (in shares)									51,570	51,188	50,934
Basic and diluted loss per share (in dollars per share)					$ (0.15)	$ (0.10)	$ (0.14)	$ (0.15)	$ (0.19)	$ (0.54)	$ (0.53)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References+ Details

Common Stock (Details) (USD $)	12 Months Ended
Common Stock (Details) (USD $)	Dec. 31, 2014 Vote	Dec. 31, 2013
Common Stock [Abstract]
Common stock, voting rights	Each share of common stock has the right to one vote
Number of votes entitled to each share of common stock	1
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001

Warrants (Details) (Warrants [Member], USD $)

12 Months Ended

Dec. 31, 2014

Warrants [Line Items]

Exercisable, beginning of period (in shares)

159,967

Became Exercisable (in shares)

Exercised (in shares)

2,500

Terminated/Cancelled/Expired (in shares)

Exercisable, end of period (in shares)

157,467

Series I Warrants [Member]

Warrants [Line Items]

Original Number of Warrants Issued (in shares)

2,619,036

^[1]

Exercise Price per Common Share (in dollars per share)

$ 3.59

Exercisable, beginning of period (in shares)

159,967

Became Exercisable (in shares)

Exercised (in shares)

2,500

Terminated/Cancelled/Expired (in shares)

Exercisable, end of period (in shares)

157,467

Expiration date

March 2015

[1]	Referred to as our Series I Warrants.

Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2010
Current [Abstract]
Federal	$ (13)	$ (354)	$ 12,154
State	(2)	(397)	428
Foreign	0	0	0
Current income taxes	(15)	(751)	12,582
Deferred [Abstract]
Federal	0	0	(40)
State	0	0	(7)
Deferred income taxes	0	0	(47)
Total (provision) benefit for income taxes	(15)	(751)	12,535
Effective Tax Rate Reconciliation [Abstract]
United States federal statutory rate (in hundredths)	35.00%	35.00%	35.00%
State taxes, net of federal benefit (in hundredths)	(0.02%)	(1.48%)	1.07%
Valuation allowance (in hundredths)	(41.67%)	(37.11%)	(4.41%)
Stock options (in hundredths)	0.39%	(0.17%)	0.14%
Prior year true-up (in hundredths)	(0.13%)	(1.32%)	1.03%
Warrants (in hundredths)	7.92%	2.10%	(0.82%)
Other (in hundredths)	(1.64%)	0.18%	(0.32%)
Effective income tax rate (in hundredths)	(0.15%)	(2.80%)	31.69%
Net operating losses available for carry forward/backward	10,000	27,000	42,000
Net operating losses, period allowed to carry backwards	2 years
Net operating losses, period allowed to carryforwards	20 years
Taxable income	(9,887)	(26,857)	(39,459)	75,000
Tax benefit recognized			12,000
Deferred tax assets [Abstract]
Reserves and accruals	0	58
State taxes	1	1
Research and development credits and other credits	924	907
Net operating loss carry forward	11,190	8,249
Stock based compensation	8,452	6,600
Other	127	154
Total deferred tax assets	20,694	15,969
Valuation allowance	(20,679)	(15,955)
Deferred tax assets after valuation allowance	15	14
Deferred tax liability [Abstract]
Depreciation and amortization	(15)	(14)
Total deferred tax liability	(15)	(14)
Net deferred tax assets	0	0
Net change in valuation allowance	4,724
Federal operating loss carryforwards	31,617
State operating loss carryforwards	37,993
Net change in gross deferred tax assets offset by a change in valuation allowance	316	316
Accrued interest and penalties	79
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at the beginning of the year	316	128	128
Additions based on tax positions related to the current year	0	0	0
Additions for tax positions of prior years	0	188	0
Settlements	0	0	0
Lapse of applicable statute of limitations	0	0	0
Balance at the end of the year	$ 316	$ 316	$ 128

Fair Value Measurement (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Fair value assumptions [Abstract]
Common share price (in dollars per share)	$ 5.49
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	$ 18,658	$ 19,173	$ 19,661	$ 49,482
Adjusted Cost	40,048	27,314
Unrealized Gains	3	0
Unrealized Losses	(5)	(25)
Fair Value	40,046	27,289
Adjusted Cost	41,231	39,013
Fair Value	41,229	38,988
Investments Available for Sale	40,046	27,289
Changes in fair value of Level 3 liabilities [Roll Forward]
Beginning Balance	2,564	4,172	4,699
(Gain) losses included in net losses	(2,237)	(1,608)	927
Settlements	(7)	0	(1,454)
Ending Balance	320	2,564	4,172
Minimum [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Maturities of available for sale securities	1 year
Maximum [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Maturities of available for sale securities	2 years
Cash [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	1,183	11,699
Fair Value	1,183	11,699
Cash and Cash Equivalents	1,183	11,699
Mutual Funds [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	10,139	73
Unrealized Gains	0	0
Unrealized Losses	0	0
Fair Value	10,139	73
Investments Available for Sale	10,139	73
Corporate Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	9,405	10,782
Unrealized Gains	1	0
Unrealized Losses	(3)	0
Fair Value	9,403	10,782
Investments Available for Sale	9,403	10,782
Municipal Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost		2,172
Unrealized Gains		0
Unrealized Losses		0
Fair Value		2,172
Investments Available for Sale		2,172
US Agency Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Adjusted Cost	20,504	14,287
Unrealized Gains	2	0
Unrealized Losses	(2)	(25)
Fair Value	20,504	14,262
Investments Available for Sale	20,504	14,262
Series I Warrants [Member]
Fair value assumptions [Abstract]
Warrant exercise price (in dollars per share)	$ 3.59	$ 3.59
Common share price (in dollars per share)	$ 5.49	$ 19.41
Discount rate (in hundredths)	1.65%	1.75%
Expected volatility rate (in hundredths)	89.69%	91.55%
Fair value of liabilities [Abstract]
Series I Warrants	320	2,564
Level 1 [Member] \| Series I Warrants [Member]
Fair value of liabilities [Abstract]
Series I Warrants	0	0
Level 2 [Member] \| Series I Warrants [Member]
Fair value of liabilities [Abstract]
Series I Warrants	0	0
Level 3 [Member] \| Series I Warrants [Member]
Fair value of liabilities [Abstract]
Series I Warrants	320	2,564
Recurring [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	18,658	19,173
Fair Value	22,571	19,815
Cash and Cash Equivalents	18,658	19,173
Investments Available for Sale	22,571	19,815
Recurring [Member] \| Cash [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	1,183	11,699
Cash and Cash Equivalents	1,183	11,699
Recurring [Member] \| Level 1 [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	17,475	7,474
Fair Value	22,571	19,815
Cash and Cash Equivalents	17,475	7,474
Investments Available for Sale	22,571	19,815
Recurring [Member] \| Level 1 [Member] \| Mutual Funds [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	10,139	73
Fair Value	0	0
Cash and Cash Equivalents	10,139	73
Investments Available for Sale	0	0
Recurring [Member] \| Level 1 [Member] \| Corporate Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	1,645	2,325
Fair Value	7,758	8,457
Cash and Cash Equivalents	1,645	2,325
Investments Available for Sale	7,758	8,457
Recurring [Member] \| Level 1 [Member] \| Municipal Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value		665
Fair Value		1,507
Cash and Cash Equivalents		665
Investments Available for Sale		1,507
Recurring [Member] \| Level 1 [Member] \| US Agency Securities [Member]
Cash and available-for-sale securities adjusted cost, gross unrealized gains, gross unrealized losses and fair value by significant investment category [Abstract]
Fair Value	5,691	4,411
Fair Value	14,813	9,851
Cash and Cash Equivalents	5,691	4,411
Investments Available for Sale	$ 14,813	$ 9,851

Litigation (Details) (USD $)	0 Months Ended		12 Months Ended
Litigation (Details) (USD $)	Dec. 16, 2014	Nov. 06, 2012 Patent	Dec. 31, 2014 Lawsuit
Litigation [Abstract]
Number of intellectual property infringement lawsuits pending			3
Amount received for settlement of patent dispute			$ 23,000,000
Amount of damages awarded in patent infringement case			368,000,000
Amount of interest payment awarded up to final judgment, per day			34,000
Amount of damage infringement payment awarded up to final judgment, per day			$ 330,000
Court order mediation interval	45 days
On-going royalty awarded (in hundredths)			0.98%
Number of patents allegedly infringed upon by Apple, Inc.		4

Quarterly Financial Information (unaudited) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	1 Months Ended		3 Months Ended								12 Months Ended			55 Months Ended
	Dec. 31, 2014	Jun. 30, 2010	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2014
Quarterly Financial Information (unaudited) [Abstract]
Revenue			$ 439	$ 292	$ 268	$ 250	$ 286	$ 1,612	$ 6	$ 293	$ 1,249	$ 2,197	$ 412
Gain on settlement	23,000	200,000	23,000	0	0	0					23,000	0	0	223,000
Loss from operations			6,870	(6,250)	(6,171)	(6,953)	(7,347)	(5,133)	(6,578)	(9,529)	(12,165)	(28,587)	(38,861)
Net income/ (loss)			$ 7,325	$ (4,468)	$ (6,670)	$ (6,087)	$ (7,554)	$ (5,134)	$ (7,029)	$ (7,891)	$ (9,902)	$ (27,608)	$ (26,924)
Basic earnings (loss) per common share (in dollars per share)			$ 0.14	$ (0.09)	$ (0.13)	$ (0.12)
Diluted earnings (loss) per common share (in dollars per share)			$ 0.14	$ (0.09)	$ (0.13)	$ (0.12)
Basic and diluted loss per common share (in dollars per share)							$ (0.15)	$ (0.10)	$ (0.14)	$ (0.15)	$ (0.19)	$ (0.54)	$ (0.53)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

+ References+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References+ Details

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) (USD $)	Dec. 31, 2012 Issued at $3.93-3.59 per Share [Member] Minimum [Member]	Dec. 31, 2012 Issued at $3.93-3.59 per Share [Member] Maximum [Member]	Dec. 31, 2014 Issued at $3.59 per Share [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued for cash exercise of warrants, net (in dollars per share)	$ 3.59	$ 3.93	$ 3.59

Gain on Settlement	12 Months Ended
Gain on Settlement	Dec. 31, 2014
Gain on Settlement [Abstract]
Gain on Settlement	Note 3 - Gain on Settlement In December 2014, we received a $23,000 cash settlement resulting from litigation with Microsoft (see Note 14 “Litigation”). In June 2010, we received a $200,000 cash settlement from litigation with Microsoft, in which we agreed to dismiss the pending lawsuits and any damages. The 2010 settlement agreement was amended in December 2014 to settle a subsequent lawsuit with Microsoft, raising the total cash settlement with Microsoft, as amended, to $223,000. In both the original settlement and the December 2014 amendment, we could not practically and objectively separate any settlement portion from the revenue element as discussed under the guidance of Accounting Standards Codification, or ASC 605 "Revenue Recognition", and as a result, the settlement proceeds are classified as a gain on settlement in our consolidated statement of operations.

Formation and Business of the Company (Details)	Dec. 31, 2014 Patent
Formation and Business of the Company [Abstract]
Number of U.S. patents owned	39
Number of foreign patents owned	66
Number of pending patent applications	75

Common Stock	12 Months Ended
Common Stock	Dec. 31, 2014
Common Stock [Abstract]
Common Stock	Note 9 - Common Stock Each share of common stock has the right to one vote. The holders of common stock are entitled to receive dividends whenever funds are legally available and when declared by our Board of Directors, subject to the prior rights of holders of all classes of stock outstanding having priority rights as to dividends. Our restated articles of incorporation authorize us to issue up to 100,000,000 shares of $.0001 par value common stock.