Senseonics (SENS) 10-K 19 Feb 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 18, 2016	Jun. 30, 2015
Document and Entity Information
Entity Registrant Name	Senseonics Holdings, Inc.
Entity Central Index Key	1,616,543
Entity Current Reporting Status	No
Entity Voluntary Filers	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 0
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Entity Common Stock, Shares Outstanding		75,760,061

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 3,939	$ 18,923
Prepaid expenses and other current assets	1,025	711
Total current assets	4,964	19,634
Deposits and other assets	217	134
Property and equipment, net	311	227
Total assets	5,492	19,995
Current liabilities:
Accounts payable	1,252	880
Accrued expenses and other current liabilities	3,694	1,161
Note payable, current portion	2,389
Total current liabilities	7,335	2,041
Notes payable, net of discount	7,499	9,815
Accrued interest	327
Warrant liability		197
Deferred rent	28	29
Total liabilities	$ 15,189	$ 12,082
Commitments and contingencies (Note 6)
Stockholders' equity (deficit):
Common stock, $0.001 par value per share; 250,000,000 and 65,679,406 authorized, 75,760,061, shares issued and outstanding, and 1,962,486 shares issued and 1,918,579 shares outstanding, as of December 31, 2015 and 2014, respectively	$ 76	$ 2
Additional paid-in capital	151,019	138,673
Accumulated deficit	(160,792)	(130,915)
Total stockholders' equity (deficit)	(9,697)	7,913
Total liabilities and stockholders' equity (deficit)	$ 5,492	19,995
Series B Preferred Stock
Stockholders' equity (deficit):
Convertible preferred stock		12
Series C Preferred Stock
Stockholders' equity (deficit):
Convertible preferred stock		21
Series D Preferred Stock
Stockholders' equity (deficit):
Convertible preferred stock		198
Common Shares
Stockholders' equity (deficit):
Treasury stock, at cost; 43,907 shares of common stock		$ (84)

Balance Sheet (Parentheticals)

Balance Sheet (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity, par value and other disclosures
Treasury stock, at cost; shares held	0	43,907
Common stock, par value per share (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	250,000,000	65,679,406
Common stock, shares issued	75,760,061	1,962,486
Common stock, shares outstanding	75,760,061	1,918,579
Series A Preferred Stock
Stockholders' Equity, par value and other disclosures
Convertible preferred stock, par value per share (in dollars per share)		$ 0.01
Convertible preferred stock, shares authorized	0	599,997
Convertible preferred stock, shares issued	0	599,997
Convertible preferred stock, shares outstanding	0	599,997
Convertible preferred stock, liquidation preference (in USD)		$ 3,000
Series B Preferred Stock
Stockholders' Equity, par value and other disclosures
Convertible preferred stock, par value per share (in dollars per share)		$ 0.01
Convertible preferred stock, shares authorized	0	1,202,497
Convertible preferred stock, shares issued	0	1,202,497
Convertible preferred stock, shares outstanding	0	1,202,497
Convertible preferred stock, liquidation preference (in USD)		$ 12,025
Series C Preferred Stock
Stockholders' Equity, par value and other disclosures
Convertible preferred stock, par value per share (in dollars per share)		$ 0.01
Convertible preferred stock, shares authorized	0	2,073,749
Convertible preferred stock, shares issued	0	2,073,749
Convertible preferred stock, shares outstanding	0	2,073,749
Convertible preferred stock, liquidation preference (in USD)		$ 41,475
Series D Preferred Stock
Stockholders' Equity, par value and other disclosures
Convertible preferred stock, par value per share (in dollars per share)		$ 0.01
Convertible preferred stock, shares authorized	22,995,265	22,995,265
Convertible preferred stock, shares issued	0	19,777,349
Convertible preferred stock, shares outstanding	0	14,403,015
Convertible preferred stock, liquidation preference (in USD)		$ 74,165
Common Shares
Stockholders' Equity, par value and other disclosures
Treasury stock, at cost; shares held	0	43,907

Statement of Operations

Statement of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statements of Operations
Revenue	$ 38
Expenses:
Sales and marketing expenses	792	$ 95
Research and development expenses	18,251	12,881
Administrative expenses	9,807	5,726
Operating loss	(28,812)	(18,702)
Interest income	9
Interest expense	(1,100)	(191)
Other income	26	8
Net loss	(29,877)	(18,885)
Deemed dividend as a result of Series E preferred stock beneficial conversion feature	(407)
Net loss available to common shareholders	$ (30,284)	$ (18,885)
Basic and diluted loss per common share (in dollars per share)	$ (4.32)	$ (9.89)
Basic and diluted weighted-average shares outstanding (in shares)	7,002,317	1,908,587

Statements of Changes in Stockh

Statements of Changes in Stockholders' Deficit - USD ($) $ in Thousands	Preferred StockSeries A Preferred Stock	Preferred StockSeries B Preferred Stock	Preferred StockSeries C Preferred Stock	Preferred StockSeries D Preferred Stock	Preferred StockSeries E Preferred Stock	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Total
Balance at Dec. 31, 2013	$ 6	$ 12	$ 21	$ 144		$ 2	$ 118,088	$ (84)	$ (112,030)	$ 6,159
Balance (in shares) at Dec. 31, 2013	600,000	1,202,000	2,074,000	14,403,000		1,943,000		44,000
Changes in Stockholders' Equity (Deficit)
Sale of preferred stock				$ 54			20,036			20,090
Sale of preferred stock (in shares)				5,374,000
Exercise of stock options for cash							10			$ 10
Exercise of stock options for cash (in shares)						19,000				18,664
Stock-based compensation expense							539			$ 539
Net loss									(18,885)	(18,885)
Balance at Dec. 31, 2014	$ 6	$ 12	$ 21	$ 198		$ 2	138,673	$ (84)	(130,915)	7,913
Balance (In shares) at Dec. 31, 2014	600,000	1,202,000	2,074,000	19,777,000		1,962,000		44,000
Changes in Stockholders' Equity (Deficit)
Sale of preferred stock					$ 27		10,606			10,633
Sale of preferred stock (in shares)					2,712,000
Exercise of stock options for cash						$ 1	62			$ 63
Exercise of stock options for cash (in shares)						520,000				121,250
Stock-based compensation expense							1,433			$ 1,433
Reclassification of warrant liability							151			151
Net loss									(29,877)	(29,877)
Effect of reverse merger and conversion of preferred stock to common stock	$ (6)	$ (12)	$ (21)	$ (198)	$ (27)	$ 73	94	$ 84		(13)
Effect of reverse merger and conversion of preferred stock to common stock (in shares)	(600,000)	(1,202,000)	(2,074,000)	(19,777,000)	(2,712,000)	73,278,000		(44,000)
Balance at Dec. 31, 2015						$ 76	$ 151,019		$ (160,792)	$ (9,697)
Balance (In shares) at Dec. 31, 2015						75,760,000

Statements of Cash Flows

Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Cash flows from operating activities
Net loss	$ (29,877,000)	$ (18,885,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	118,174	189,325
Non-cash interest expense (debt discount and deferred costs)	77,000	67,000
Change in fair value of derivative liabilities	(46,000)	(8,000)
Stock-based compensation expense	1,433,000	539,000
Changes in assets and liabilities:
Prepaid expenses and other current assets	(314,000)	(514,000)
Deposits and other assets	(89,000)
Accounts payable, accrued expenses and other current liabilities	3,232,000	(674,000)
Deferred rent (long term)	1,000	16,000
Net cash used in operating activities	(25,465,000)	(19,270,000)
Cash Flows from Investing Activities
Capital expenditures	(202,000)	(29,000)
Net cash used in investing activities	(202,000)	(29,000)
Cash Flows from Financing Activities
Sale of Series D convertible preferred stock, net of costs		20,090,000
Sale of Series E convertible preferred stock, net of costs	10,633,000
Repurchase shares as result of reverse merger	(12,000)
Net proceeds from exercise of stock options	62,000	10,000
Proceeds from notes payable, net		9,879,000
Principal payments under capital lease obligations		(3,000)
Net cash provided by financing activities	10,683,000	29,976,000
Net (decrease) increase in cash and cash equivalents	(14,984,000)	10,677,000
Cash and cash equivalents, at beginning of period	18,923,000	8,246,000
Cash and cash equivalents, at end of period	3,939,000	18,923,000
Supplemental Disclosure of Cash Flow Information
Cash paid during the year for interest	$ 660,000	$ 93,000

Organization

Organization	12 Months Ended
	Dec. 31, 2015
Organization
Organization	1. Organization Senseonics, Incorporated, (“Senseonics”), subsequent to the Acquisition described as a wholly-owned subsidiary of Senseonics Holdings, Inc. (“Senseonics Holdings or the “Company”), a Delaware corporation, is a medical technology company focused on the design, development and commercialization of glucose monitoring systems to improve the lives of people with diabetes by enhancing their ability to manage their disease with relative ease and accuracy. Senseonics was originally incorporated on October 30, 1996 and commenced operations on January 15, 1997. ASN Technologies, Inc. (“ASN”) was incorporated in Nevada on June 26, 2014. O n December 4, 2015, ASN reincorporated in Delaware and changed its name to Senseonics Holdings, Inc.. On December 7, 2015, the Company acquired 100% of the outstanding capital stock of Senseonics (the "Acquisition"). While the Company was the legal acquirer of Senseonics in the transaction, since (i) former Senseonics' stockholders owned 80% of the combined company on a fully diluted basis immediately following the transaction, and (ii) all members of the combined company's executive management and Board of Directors were from Senseonics, Senseonics was deemed to be the acquiring company for accounting purposes. As such, the transaction was accounted for as a reverse recapitalization in accordance with U.S. GAAP and, in the accompanying consolidated financial statements, ASN's historical consolidated financial statements have been replaced with Senseonics' historical consolidated financial statements. Pursuant to the terms of the Acquisition (i) all outstanding shares of common stock of Senseonics, $0.01 par value per share, were exchanged for 1,955,929 shares of the Company's common stock, $0.001 par value per share (reflecting an exchange ratio of 2.0975) , (ii) all outstanding shares of preferred stock were converted into shares of common stock of Senseonics, and exchanged into 55,301,674 shares of the Company’s common stock, $0.001 par value per share, and (iii) all outstanding options and warrants to purchase shares of common stock of Senseonics were exchanged for or replaced with options and warrants to acquire shares of the Company’s common stock using the same exchange ratio. In connection with the reverse recapitalization, the Company transferred its former operations to a former officer, director and stockholder in exchange for the (i) satisfaction of a promissory note issued to the Company's former officer, director and stockholder in the principal amount of $9,000 and (ii) assumption of liabilities related to the former operations. No gain or loss was recorded as a result of the transfer. Senseonics Holdings and its wholly-owned subsidiary Senseonics are hereinafter referred to as the “Company” unless stated otherwise.

Liquidity

Liquidity	12 Months Ended
	Dec. 31, 2015
Liquidity
Liquidity	2. Liquidity The Company's operations are subject to certain risks and uncertainties including, among others, current and potential competitors with greater resources, lack of operating history and uncertainty of future profitability. Since inception, the Company has incurred substantial operating losses, principally from expenses associated with the Company’s research and development programs. The Company has not generated significant revenues from the sale of products and its ability to generate revenue and achieve profitability largely depends on the Company’s ability, alone or with others, to complete the development of its products or product candidates, and to obtain necessary regulatory approvals for the manufacture, marketing and sales of those products. These activities, including planned significant research and development efforts, will require significant uses of working capital throughout 2016 and beyond. Based on its current operating plans, the Company believes that its existing cash and cash equivalents will not be sufficient to meet the Company’s anticipated operating needs beyond early 2016. These factors raise substantial doubt about the Company’s ability to continue as a going concern. The consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty. Historically, the Company has financed its operating activities through the sale of equity and equity-linked securities and the issuance of debt. The Company plans to continue financing its operations with external capital. However, the Company may not be able to raise additional funds on acceptable terms, or at all. If the Company is unable to secure sufficient capital to fund its research and development and other operating activities, the Company may be required to delay or suspend operations, enter into collaboration agreements with partners that could require the Company to share commercial rights to its products to a greater extent or at earlier stages in the product development process than is currently intended, merge or consolidate with other entities, or liquidate. The accompanying consolidated financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates continuity of operations, realization of assets, and satisfaction of liabilities in the ordinary course of business. The notes payable are classified as long-term in the accompanying consolidated balance sheet. The terms of the notes include a subjective acceleration clause which management deems as remote. The propriety of using the going-concern basis is dependent upon, among other things, the achievement of future profitable operations, the ability to generate sufficient cash from operations, and potential other funding sources, including cash on hand, to meet the Company’s obligations as they become due.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Basis of Accounting The accompanying consolidated financial statements have been prepared in accordance with the requirements of U.S. generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements reflect the accounts of Senseonics Holdings and its wholly-owned subsidiary Senseonics as of December 31, 2015 . All intercompany transactions and balances have been eliminated in consolidation. Reclassification Sales and marketing expenses of $94,546 included in administrative expenses in 2014 have been reclassified to sales and marketing expenses to conform to 2015 presentation. Segment Information Operating segments are defined as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (CODM), or decision-making group, in deciding how to allocate resources and in accessing performance. The Company views its operations and manages its business in one segment, glucose monitoring systems. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues and expenses during the reporting period. In the accompanying consolidated financial statements, estimates are used for, but not limited to, valuation of common and preferred stock, stock-based compensation, the fair value of warrant liabilities, recoverability of long-lived assets, deferred taxes and valuation allowances, depreciable lives of property and equipment, and estimated accruals for preclinical study costs, which are accrued based on estimates of work performed under contracts. Actual results could differ from those estimates; however management does not believe that such differences would be material. Fair Value Disclosures The carrying amounts of short-term financial instruments, including cash and cash equivalents, prepaid expenses and other current assets, and accounts payable and other current liabilities approximate fair value as of December 31, 2015 and 2014 , because of the relatively short-term maturity of these instruments. The fair value of the note payable approximates its carrying value as of December 31, 2015 and 2014 and is based on the effective interest rate compared to the current market rates, which is a Level 2 fair value measurement as described below. See Note 12 for further discussion of fair value measurements. Cash and Cash Equivalents and Concentration of Credit Risk Cash equivalents are highly-liquid instruments with original maturities of three months or less and consist of U.S. Government and U.S. Government agency securities and money market funds with major commercial banks and financial institutions. Cash equivalents are recorded at cost plus accrued interest. The Company’s cash and cash equivalents potentially subject the Company to credit and liquidity risk. The Company maintains cash deposits at major financial institutions with high credit quality and, at times, the balances of those deposits may exceed the Federal Deposit Insurance Corporation limits of $250,000. The Company has not experienced and does not anticipate any losses on deposits with commercial banks and financial institutions that exceed the federally insured amounts. Property and Equipment Property and equipment are stated at historical cost and depreciated on a straight-line basis over the estimated useful lives, generally five years. Equipment under capital leases is depreciated on a straight-line basis over the lesser of its estimated useful life or the lease term. Leasehold improvements are depreciated over the shorter of the remaining lease term or useful lives of the assets. Upon disposition of the assets, the costs and related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations. Repairs and maintenance costs are included as expense in the accompanying statement of operations. Management reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If the undiscounted cash flows are less than the carrying amount, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. Management did not identify any indicators of impairment in 2015 and 2014. Treasury Stock The Company records purchases of common stock for treasury at cost, and carries the cost of treasury stock as a reduction in stockholder’ equity. The Company maintained 43,907 shares of common stock in treasury as of December 31, 2014; the treasury stock was retired effective with the Acquisition. There is no treasury stock outstanding as of December 31, 2015. Revenue Recognition Product sales revenues are recognized when persuasive evidence of an arrangement exists, delivery has occurred, the price is fixed or determinable and collectability is probable. These criteria are generally anticipated to be met as products are shipped to customers. When revenue arrangements provide the customer with a contractual right of return, revenue is deferred until the right of return lapses or a reasonable estimate of returns can be determined. Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include costs related to employee compensation, preclinical and clinical trials, manufacturing, supplies, outsource testing, consulting and depreciation and other facilities-related expenses. Stock-Based Compensation The Company recognizes the cost of employee services received in exchange for awards of equity instruments, such as stock options, based on the fair value of those awards at the date of grant. The estimated fair value of stock options on the date of grant is amortized on a straight-line basis over the requisite service period for each separately vesting portion of the award for those awards with service conditions only. For awards that also contain performance conditions, expense is recognized beginning at the time the performance condition is considered probable of being met over the remaining vesting period. The Company uses the Black-Scholes-Merton option pricing model (“Black-Scholes Model”) to determine the fair value of stock ‑option awards. Valuation of stock awards requires management to make assumptions and to apply judgment to determine the fair value of the awards. These assumptions and judgments include estimating the fair value of the Company’s common stock, future volatility of the Company’s stock price, dividend yields, future employee turnover rates, and future employee stock option exercise behaviors. Changes in these assumptions can affect the fair value estimate. Under Accounting Standards Codification (“ASC”) 718, the cumulative amount of compensation cost recognized for instruments classified as equity that ordinarily would result in a future tax deduction under existing tax law shall be considered to be a deductible difference in applying ASC 740 , Income Taxes . The deductible temporary difference is based on the compensation cost recognized for financial reporting purposes; however, these provisions currently do not impact the Company, as all the deferred tax assets have a full valuation allowance. Since the Company had net operating loss (“NOL”) carryforwards as of December 31, 2015 and 2014 , no excess tax benefits for the tax deductions related to share-based awards were recognized in the statements of operations. Comprehensive Income ASC 220-10, Reporting Comprehensive Income, requires the presentation of the comprehensive income or loss and its components as part of the financial statements. For the years ended December 31, 2015 and 2014, the Company’s net loss equals comprehensive loss. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that are in effect when the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that such tax rate changes are enacted. The measurement of a deferred tax asset is reduced, if necessary, by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. Management uses a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return, as well as guidance on derecognition, classification, interest and penalties and financial statement reporting disclosures. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities. In the ordinary course of business, transactions occur for which the ultimate outcome may be uncertain. Management does not expect the outcome related to accrued uncertain tax provisions to have a material adverse effect on the Company’s financial position, results of operations or cash flows. The Company recognizes interest and penalties accrued on any unrecognized tax exposures as a component of income tax expense. The Company did not have any amounts accrued relating to interest and penalties as of December 31, 2015 and 2014 . The Company is subject to taxation in various jurisdictions in the United States and remains subject to examination by taxing jurisdictions for the year 1996 and all subsequent periods due to the availability of NOL carryforwards. In addition, all of the net operating losses and research and development credit carryforwards that may be used in future years are still subject to adjustment. Loss per Share Basic loss per share is computed by dividing net loss available to common shareholders by the weighted average number of shares of common stock outstanding during the period. For periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all potential common shares is anti-dilutive. The total number of anti-dilutive shares was 14,261,768 and 34,435,548 at December 31, 2015 and 2014 , consisting of convertible preferred shares, common stock options and stock purchase warrants, which have been excluded from the computation of diluted loss per share, as follows: December 31, 2015 2014 Convertible preferred shares — Common stock options Stock purchase warrants Total anti-dilutive outstanding For periods of net income, and when the effects are not anti-dilutive, diluted earnings per share is computed by dividing net income available to common shareholders by the weighted-average number of shares outstanding plus the impact of all potential dilutive common shares, consisting primarily of common stock options and stock purchase warrants using the treasury stock method. For periods prior to December 7, 2015, common share and per share amounts of Senseonics have been retrospectively adjusted to reflect each historical common share for 2.0975 common shares. Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance for revenue recognition for contracts, superseding the previous revenue recognition requirements, along with most existing industry-specific guidance. The guidance requires an entity to review contracts in five steps: 1) identify the contract, 2) identify performance obligations, 3) determine the transaction price, 4) allocate the transaction price, and 5) recognize revenue. The new standard will result in enhanced disclosures regarding the nature, amount, timing and uncertainty of revenue arising from contracts with customers. The standard is effective for the Company’s reporting year beginning January 1, 2018 and early adoption is permitted starting January 1, 2017. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In August 2014, the FASB issued guidance requiring management to evaluate on a regular basis whether any conditions or events have arisen that could raise substantial doubt about the entity’s ability to continue as a going concern. The guidance 1) provides a definition for the term “substantial doubt,” 2) requires an evaluation every reporting period, interim periods included, 3) provides principles for considering the mitigating effect of management’s plans to alleviate the substantial doubt, 4) requires certain disclosures if the substantial doubt is alleviated as a result of management’s plans, 5) requires an express statement, as well as other disclosures, if the substantial doubt is not alleviated, and 6) requires an assessment period of one year from the date the consolidated financial statements are issued. The standard is effective for the Company’s reporting year beginning January 1, 2017 and early adoption is permitted. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In April 2015, the FASB issued accounting guidance requiring that debt issuance costs related to a recognized liability be presented on the balance sheet as a direct reduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected. The standard is effective for reporting periods beginning after December 15, 2015. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In April 2015, the FASB issued accounting guidance related to Internal-Use Software specifically for the Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. The amendments in this Update provide guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The standard is effective for reporting periods beginning after December 15, 2015. An entity can elect to adopt the amendments either 1) prospectively for all arrangements entered into or materially modified after the effective date or 2) retrospectively. The Company decided to adopt the standards prospectively and will be accounting for the new cloud arrangements in accordance with the new standards. The Company has evaluated all other issued and unadopted Accounting Standards Updates and believes the adoption of these standards will not have a material impact on the results of operations, financial position, or cash flows.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2015
Property and Equipment
Property and Equipment	4. Property and Equipment Property and equipment consisted of the following as of December 31, 2015 and 2014 (in thousands) December 31, 2015 2014 Laboratory equipment $ $ Office furniture and equipment Software — Leasehold improvements Less: Accumulated depreciation Property and equipment, net $ $ Depreciation expense for the years ended December 31, 2015 and 2014 was $118,174 and $189,325 , respectively and is recorded within the administrative expenses in the consolidated statements of operations. The Company disposed of $143,155 and $1,070,595 of fully depreciated property and equipment in 2015 and 2014, respectively.

Other Balance Sheet Details

Other Balance Sheet Details	12 Months Ended
	Dec. 31, 2015
Other Balance Sheet Details
Other Balance Sheet Details	5. Other Balance Sheet Details Accrued expenses and other current liabilities consisted of the following as of December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Clinical and preclinical $ $ Compensation and benefits Financing Costs — Contract manufacturing Legal Audit and tax related Other Deferred rent, current portion — Total $ $

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies
Commitments and Contingencies	6. Commitments and Contingencies The Company leases approximately 20,000 square feet of research and office space under a non-cancelable operating lease expiring in 2018. The Company has an option to renew the lease for one additional five -year term. Rent expense is recognized on a straight-line basis and was $386,438 for the years ended December 31, 2015 and 2014 . The contractually required cash payments under this lease at December 31, 2015 are as follows: 2016 $ 2017 2018 Total minimum lease payments $ On May 10, 2012 the Company amended a corporate development agreement with a supplier to include a minimum purchase commitment per year based on the delivery of the current application-specific integrated circuit. Total research and development expense related to the minimum payment was $0 and $289,000 during the years ended December 31, 2015 and 2014 , respectively. There are approximately $820,000 of future minimum payments under this commitment at December 31, 2015 .

401(k) Plan

401(k) Plan	12 Months Ended
	Dec. 31, 2015
401(k) Plan
401(k) Plan	7. 401(k) Plan The Company has a defined contribution 401(k) plan available to all full-time employees. Employee contributions are voluntary and are determined on an individual basis subject to the maximum allowable under federal income tax regulations. Participants are fully vested in their contributions. There have been no employer contributions to this plan. Administrative expenses for the plan, which are paid by the Company, were not material in 2015 and 2014.

Notes Payable and Stock Purchas

Notes Payable and Stock Purchase Warrants	12 Months Ended
	Dec. 31, 2015
Notes Payable and Stock Purchase Warrants
Notes Payable and Stock Purchase Warrants	8. Notes Payable and Stock Purchase Warrants Term Notes Payable On July 31 and December 23, 2014, the Company issued secured notes (“the Oxford notes”), and detachable stock purchase warrants to Oxford Finance LLC (“Oxford Finance”) in a private placement, for gross proceeds of $4.0 million and $6.0 million respectively. The Oxford notes bear interest at a fixed annual rate of 6.95% , require monthly interest payments, and mature on July 1, 2019. If the Company receives its CE mark by February 1, 2016, the monthly payments will convert to payments of principal and interest , beginning on August 1, 2016 , with the principal amount being amortized over the ensuing 36 months. Alternatively, if the Company has not received its CE mark by February 1, 2016, monthly payments will convert to payments of principal and interest beginning on February 1, 2016 , with the principal amount being amortized over the ensuing 42 months. The Oxford notes are collateralized by all of the Company’s assets other than its intellectual property. The Company incurred issuance costs related to the notes of approximately $121,200 which were initially deferred and are being amortized as additional interest expense over the term of the notes using the effective interest method. The fair value of the warrants was recorded as a discount to the notes, which is also being amortized as additional interest expense over the term of the notes using the effective interest method. In addition, the Company is obligated for a final fee at maturity of $0.9 million; this fee is being accrued as additional interest expense over the term of the note using the effective interest method. For the years ended December 31, 2015 and 2014 , the Company recorded accretion of debt discount of $72,229 and $20,514 , respectively within interest expense in the accompanying consolidated statement of operations. The following are the scheduled maturities of the Oxford notes as of December 31, 2015 , assuming the Company does not receive its CE mark by February 1, 2016, in which case, principal payments will begin on February 1, 2016 (in thousands): 2016 $ 2017 2018 2019 Energy Capital, LLC Borrowing Facility On December 7, 2015, the Company entered into a note purchase agreement (the “Purchase Agreement”) with Energy Capital, LLC (“Energy Capital”) pursuant to which Energy Capital may lend an aggregate principal amount of up to $10.0 million. Under the terms of the agreement, if the Company has not received at least $20.0 million from the sale of the Company’s capital stock in an offering of the Company’s equity prior to February 29, 2016 (the “Triggering Event”), then Energy Capital is obligated to disburse funds on or after March 15, 2016. If the Triggering Event has occurred and the Company provides documentation to Energy Capital that the Company’s available cash is lower than $500,000 , then Energy Capital is obligated to disburse funds any time after March 1, 2016. If after the Triggering Event has occurred and if the Company’s cash on hand is higher than $500,000 the Company will be unable to borrow under the Purchase Agreement until March 15, 2016. In the event that the Triggering Event occurs and the Company is able to incur indebtedness under the terms of the Energy Capital note, the Company is obligated to repay the aggregate principal and accrued interest thereon if the Company issues and sells shares of the Company’s equity securities in an underwritten public offering with total proceeds to the Company exceeding $45.0 million (within ten business days after the closing of such public offering). In the event that the Company is unable to repay such amounts, the Company will be in default under the terms of the Energy Capital note, which may also trigger an event of default under the Oxford notes. Stock Purchase Warrants In 2014, in connection with the issuance of the Oxford notes, the Company issued to Oxford Finance four 10 -year stock purchase warrants to acquire an aggregate of 79,892 shares of the Company’s Series D Convertible Preferred Stock (the “Series D Stock”) or shares issued in a future qualified financing, at an initial exercise price of approximately $3.75 per share. Following the reverse merger the warrants were exchanged for warrants for common stock using the exchange ratio of one share for 2.0975 shares ( 167,573 shares with an exercise price of approximately $1.79 per share). These warrants expire on July 31, 2024. The warrants were initially recorded at their fair value of $205,150 and were classified as a warrant liability on the Company’s balance sheet due to the presence of non-standard anti-dilution provisions. The Company recorded the fair value of the warrants as a discount on debt and is amortizing the discount over the term of the notes using the effective interest method. Prior to the Acquisition, the warrant instruments required liability accounting which was recorded in the balance sheet based on their fair values determined using the Black-Scholes Model and the fair value of underlying preferred stock. The warrant instruments were re-valued for the last time immediately prior to the Acquisition and reclassified into stockholders’ equity in 2015. In connection with the issuance of convertible notes in prior years that were subsequently converted into Series D Stock in 2011 (see Note 9), the Company issued to the investors 10 -year stock purchase warrants to purchase an aggregate of 2,308,972 shares of the Series D Stock with an original exercise price of $3.75 per share. Following the reverse merger the warrants were exchanged for warrants for common stock using the exchange ratio of one share for 2.0975 shares ( 4,843,031 shares with an exercise price of approximately $1.79 per share). These warrants expire on November 2, 2020, July 14, 2021 and August 19, 2021, and are classified as equity.

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity (Deficit)
Stockholders' Equity (Deficit)	9. Stockholders’ Equity (Deficit) Pursuant to the terms of the Acquisition (i) all outstanding shares of common stock of Senseonics, $0.01 par value per share, were exchanged for 1,955,929 shares of the Company's common stock, $0.001 par value per share (reflecting an exchange ratio of 2.0975 ), (ii) all outstanding shares of preferred stock were converted into shares of common stock of Senseonics, and exchanged into 55,301,674 shares of the Company’s common stock, $0.001 par value per share, and (iii) all outstanding options and warrants to purchase shares of common stock of Senseonics were exchanged for or replaced with options and warrants to acquire shares of the Company’s common stock using the same exchange ratio. For periods prior to December 7, 2015, common share and per share amounts of Senseonics have been retrospectively adjusted to reflect the exchange ratio of one share for 2.0975 shares of common stock, except for the preferred stock, which was disclosed as its historical values prior to December 7, 2015. Common Stock At December 31, 2015 , the Company had authorized 250,000,000 shares of common stock and 75,760,061 shares of common stock were issued and outstanding . Preferred Stock In 1997, the Company completed a private offering of 599,997 shares of Series A Convertible Preferred Stock (the “Series A Stock”) for gross proceeds of $3.0 million at a purchase price of $5.00 per share. In 1998, the Company completed a private offering of 682,497 shares of Series B Convertible Preferred Stock (the “Series B Stock”) for gross proceeds of $6.8 million, and in 2000 completed a private offering of 520,000 shares of Series B Stock for gross proceeds of $5.2 million, both at a purchase price of $10.00 per share. In 2002, 2005 and 2009, the Company completed private offerings of an aggregate of 2,073,749 shares of Series C Convertible Preferred Stock (the “Series C Stock”) for aggregate gross proceeds of $41.5 million, at a purchase price of $20.00 per share. In 2011 and 2012, the Company completed private offerings of an aggregate of 11,984,151 shares of Series D Stock, for aggregate gross proceeds of $44.9 million at a purchase price of $3.75 per share. In addition, in 2011, $8.7 million in principal amount and accrued interest of convertible notes were converted into 2,418,864 shares of Series D Stock at a conversion price of $3.75 per share. In 2014, the Company completed private offerings of an aggregate of 5,374,334 shares of Series D Stock at a purchase price of $3.75 per share, for total proceeds of $20.2 million. In August 2015, the Company completed a private offering of 2,711,926 shares of Series E Convertible Preferred Stock (the “Series E Stock”) at a purchase price of $3.93 per share to total proceeds of $10.7 million. The Company recognized a beneficial conversion feature of $406,783 associated with the Series E Stock since the initial effective conversion price was determined to be less than the fair value of the underlying common stock into which the Series E Stock is convertible. The beneficial conversion feature was recognized as a “deemed dividend” at issuance since the Series E Stock is convertible at any time at the option of the holders. The Series A Stock, Series B Stock, Series C Stock, Series D Stock and Series E Stock (together, the “Preferred Stock”) are classified in permanent equity. As a part of the Acquisition, all shares of Preferred Stock were converted into shares of the Company’s common stock and the above balances subsequently converted at the stated exchange ratio of one share for 2.0975 shares. Voting The Preferred Stock vote together with all other classes and series of stock of the Company, as a single class, on all actions to be taken by the stockholders of the Company, except as otherwise required by law. Each share of Preferred Stock entitles each holder to a number of votes per share equal to the number of shares of common stock into which each share of Preferred Stock is then convertible. Dividend and Liquidation Preference The holders of Preferred Stock are entitled to receive such dividends as may be declared by the Board of Directors. In the event of any liquidation, dissolution or winding up of the Company, whether voluntary or involuntary, holders of Series E Stock and Series D Stock are entitled to be paid before any payment is made to holders of any other series of Preferred Stock or common stock. Holders of Series A Stock, Series B Stock, and Series C Stock, together, the “Junior Preferred,” are entitled to be paid before any payment is made to any holder of common stock. Payments are equal to the greater of (i) $3.93 per shares for Series E Stock, $3.75 per share for Series D Stock, $5.00 per share for Series A Stock, $10.00 per share for Series B Stock, and $20.00 per share for Series C Stock, plus declared but unpaid dividends or (ii) such amount per share as would have been payable had each such share been converted to common stock, as described below immediately prior to such liquidation, dissolution or winding up of the Company. Redemption None of the Preferred Stock contain redemption provisions. Stock-Based Compensation On May 8, 1997, the Company adopted the 1997 Stock Option Plan (the “Plan”), under which incentive stock options and non-qualified stock options may be granted to the Company’s employees and certain other persons in accordance with the Plan provisions. The Plan was amended in September 2001, to clarify certain provisions regarding the method of exercise, amendment and termination of the Plan, and the effect of changes in capitalization of the Company. The Board of Directors, which administers the Plan, determines the number of options granted, the vesting period and the exercise price. The Board of Directors may terminate the Plan at any time. Options granted under the Plan expire ten years after the date of grant. The Company retains the right of first offer to buy any shares issued under the Plan. The total number of shares of common stock that may be issued pursuant to options under the Plan may not exceed, in the aggregate, 9,175,860 shares of common stock, less any shares of common stock issued by the Company as restricted common stock. The Company recognizes the cost of employee services received in exchange for awards of equity instruments, such as stock options, based on the fair value of those awards at the date of grant. The estimated fair value of stock options on the date of grant is amortized on a straight-line basis over the requisite service period for each separately vesting portion of the award for those awards with service conditions only. For awards that also contain performance conditions, expense is recognized beginning at the time the performance condition is considered probable of being met over the remaining vesting period. Prior to the completion of the Acquisition, the fair value of the common stock was determined and approved by the Board of Directors after considering several factors, including the results obtained from an independent third-party valuation, the Company’s historical financial performance and financial position, the Company’s future prospects and opportunity for liquidity events, the price per share of its convertible preferred stock offerings and general industry and economic trends. In establishing the estimated fair value of the common stock, the Company considered the guidance set forth in American Institute of Certified Public Accountants Practice Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. Subsequent to the completion of the Acquisition, the fair value of the common stock was obtained from quoted market prices on the Over-the-Counter Bulletin Board (OTCBB) as provided by OTC Market Groups, Inc. Fair value is estimated at each grant date using the Black-Scholes Model with assumptions summarized in the following table: For the year ended December 31, 2015 2014 Expected term of options 6.5 years - 6.5 years Expected volatility rate - 54.25 % - 56.42 % Risk-free rate - 1.9 % - 2.10 % Expected dividend yield 0 % 0 % The risk-free interest rate assumption is based upon observed U.S. treasury yields for a period consistent with the expected term of the Company’s employee stock options. The expected term is the period of time for which the stock-based options are expected to be outstanding. Given the lack of historic exercise data, the expected life is determined using the “simplified method” which is defined as the mid-point between the vesting date and the end of the contractual term. The Company does not pay a dividend, and is not expected to pay a dividend in the foreseeable future. Due to a lack of a public market for the Company’s common stock for an extended period of time, the Company utilized comparable public companies’ volatility rates as a proxy of its expected volatility for purposes of the Black-Scholes Model. Stock-based compensation expense is recorded net of estimated forfeitures and is adjusted periodically for actual forfeitures. Pre-vesting forfeitures are based on the Company’s historical experience for the years ended December 31, 2015 and 2014 and have not been material. Employee stock-based compensation expense for employee granted stock options was $1.0 million and $0.5 million for the years ended December 31, 2015 and 2014 , respectively, of which $462,006 and $105,465 was classified as research and development expenses and $0.6 million and $433,733 was classified as administrative expenses in the accompanying consolidated statements of operations in the 2015 and 2014 periods, respectively. Stock-based compensation for expense restricted stock awards was $387,600 for the year ended December 31, 2015 , all of which was classified as administrative expense in the accompanying consolidated statements of operations in 2015 . There was no stock-based compensation expense for restricted stock awards for the year ended December 31, 2014 . As of December 31, 2015 , there was $2.6 million of total unrecognized compensation cost related to non-vested employee stock option awards, which is expected to be recognized over a weighted average period of 3.04 years. The aggregate intrinsic value of stock options outstanding at December 31, 2015 was $23.1 million, which approximated the aggregate intrinsic value of options vested and expected to vest as of December 31, 2015 as a result of immaterial pre-vesting forfeitures. The total fair value of options that vested during 2015 and 2014 were approximately $0.8 million and $0.5 million, respectively. Stock option activity under the Plan during the year ended December 31, 2015 is as follows: Weighted- Number of Average Shares in Exercise (in thousands) Price Options outstanding as of December 31, 2014 $ Options granted $ Options exercised $ Options canceled/forfeited $ Options outstanding as of December 31, 2015 $ Options vested and expected to vest as of December 31, 2015 $ Certain of the outstanding options to purchase shares of common stock provide for performance based-conditions required for vesting in addition to service-based vesting. Vesting of these options is based on the Company obtaining CE Mark enabling the sale of the Company’s product in Europe; vesting begins once the Company has deemed it probable that the performance condition will be met. Outstanding stock options at December 31, 2015 have a weighted-average remaining contractual life of 7.8 years, which approximates the weighted-average remaining contractual life of the options vested and expected to vest at December 31, 2015 , and will vest ratably over a minimum period of two years. At December 31, 2015 , there were 4,369,239 exercisable stock options with a weighted-average exercise price of $0.57 and a weighted-average remaining contractual life of 6.6 years. The aggregate intrinsic value of the options currently exercisable at December 31, 2015 was $11.7 million. For the years ended December 31, 2015 and 2014 , 121,250 and 18,664 options were exercised, respectively, with an aggregate intrinsic value at the time of exercise of $123,224 and $1,557 , respectively. During the second quarter of 2015, the Company modified certain outstanding stock options, including acceleration of vesting on certain options, and the removal of certain performance conditions on other options. No other terms of the awards were modified. The modification of the vesting period resulted in $34,912 of additional expense on the date of modification. The modification of the performance conditions resulted in incremental compensation cost of $0.9 million, of which $245,636 was expensed upon modification. The remaining incremental compensation cost will be recognized over the remaining vesting of two years for the 2013 grants and between 2.68 and 3.18 years for the 2014 grants. The weighted average grant date fair value of the unvested stock option awards outstanding at December 31, 2015 and 2014 was $0.62 and $0.35 , respectively. The weighted average grant-date fair value of stock options granted in 2015 and 2014 was $1.02 and $0.34 per share, respectively. The weighted average grant date fair value of the stock option awards vested, exercised and forfeited/cancelled for the year ended December 31, 2015 were $0.65 , $0.33 and $0.33 , respectively. Restricted Stock Awards At times, the Company may grant shares of common stock that contain ownership restrictions based on service, performance, or other measures (“Restricted Stock Awards”). Restricted Stock Awards vest as the stated restrictions lapse, and do not require the payment by the recipient. The Company granted 398,525 Restricted Stock Awards during year ended December 31, 2015 , half of which were vested upon grant and half of which will not vest until specific performance conditions are met. The Restricted Stock Award has no expiration date. The total fair value of the Restricted Stock Awards granted during the year ended December 31, 2015 , based on the fair market value of the Company’s common stock on the date of grant of $1.95 per share, was $0.8 million. The aggregate intrinsic value of unvested Restricted Stock Awards as of December 31, 2015 , based on the fair market value of the Company’s common stock at the end of the reporting period, was $0.6 million. The fair value at the time of the grant is expensed in coordination with the vesting schedule; 50% upon issuance of the grant and 50% upon fulfillment of the agreed upon performance condition. Pre-vesting forfeitures were estimated to be approximately 0% . The total fair value of Restricted Stock Awards vested during the year ended December 31, 2015 was approximately $0.6 million. A summary of the Company’s Restricted Stock Awards as of December 31, 2015 is presented below: Number of Shares (in thousands) Restricted Stock Awards nonvested at December 31, 2014 — Granted Vested Cancelled and forfeited — Restricted Stock Awards nonvested at December 31, 2015 Vested and expected to vest at December 31, 2015 As of December 31, 2015 , there was approximately $387,600 remaining in unrecognized compensation cost related to Restricted Stock Awards. The cost is expected to be recognized upon fulfillment of the performance condition.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Taxes
Income Taxes	10. Income Taxes No provision for U.S. federal or state income taxes has been recorded as the Company has incurred net operating losses since inception and provides a full valuation allowance against its net deferred income tax assets. The tax effect of temporary differences that give rise to the net deferred income tax asset at December 31, 2015 and 2014 is as follows: in thousands December 31, Deferred income tax assets (Liabilities ) 2015 2014 Net operating loss carryforwards $ $ Capitalized start-up costs R&E credit carryforwards Stock based compensation — Other Deferred income tax assets Valuation allowance Net deferred income tax assets (liabilities) $ — $ — At December 31, 2015 and 2014 , the Company provided a full valuation allowance against its net deferred tax assets since realization of these benefits could not be reasonably assured. Changes in the valuation allowance during years ended December 31, 2015 and 2014 are as follows (in thousands): Beginning Balance at Year of Year Additions Deductions End of Year 2014 $ $ $ — $ 2015 $ $ $ — $ The increase in valuation allowance is primarily due to net losses and credits incurred in both 2015 and 2014 . This increase in valuation allowance is based on management's assessment that it is more likely than not that the Company will not realize these deferred tax assets. Capitalized start-up costs represent expenses incurred in the organization and start-up of the Company. For U.S. federal and state tax purposes, start-up and organizational costs incurred before October 22, 2004 will be amortized over sixty months and those incurred on and after October 22, 2004 will be amortized over one hundred and eighty months once an active trade or business commences. At December 31, 2015 , the Company had NOL carryforwards of $103.0 million and had research and experimental credit carryforwards of $5.1 million. These carryforwards will expire in varying amounts between 2018 and 2034. Under the provisions of the Internal Revenue Code, certain substantial changes in the Company’s ownership may result in a limitation on the amount of NOL carryforwards and research and development credit carryforwards which can be available in future years. No income tax benefit was recognized in the Company’s Statement of Operations for stock-based compensation arrangements due to the Company’s net loss position. A reconciliation of the Company’s estimated U.S. federal statutory rate to the Company’s effective income tax rate for the years ended December 31, 2015 and 2014 is as follows: 2015 2014 Tax at U.S. Federal Statutory rate % % State taxes, net Research and development credit Other non-deductible items Increase in valuation allowance Effective income tax rate % % A breakdown of the Company’s uncertain tax position during 2015 and 2014 is as follows (in thousands): 2015 2014 Gross unrecognized tax benefit at beginning of year $ $ Increase from tax positions taken in prior years — Increase from tax positions in current year Settlements with taxing authorities — — Lapse of statute of limitations / expiration — — Gross unrecognized tax benefit at end of year $ $ As of December 31, 2015 and 2014 , the Company had uncertain tax positions totaling $1.2 million and $1.0 million, respectively. The Company did not incur any penalties or interest payable to taxing authorities in 2015 and 2014 . The Company’s U.S. Federal and state income tax returns from 1996 to 2014 remain subject to examination by the tax authorities. The Company’s 1996 through 2010 years remain open for examination, even though the statute of limitations has expired, due to the net operating losses and credits carried forward for use in prospective years.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions
Related Party Transactions	11. Related Party Transactions In December 2015, a board member received a Restricted Stock Award of 398,525 shares of common stock pursuant to an agreement entered into with the board member to supersede a pre-existing agreement. One half of the shares covered by this Restricted Stock Award were fully vested on grant. The remainder will vest in full upon our completion of a public offering or private placement of our equity securities in which gross proceeds of at least $40.0 million are raised, which we refer to as a qualified financing. Additionally, upon a qualified financing, the board member will be entitled to receive a cash payment that, when combined with the value of the restricted stock grant, equals a percentage of the Company’s valuation ranging between 0.75% to 1.25% of the Company’s valuation, with the actual percentage determined based on the Company’s valuation. On December 7, 2015, the Company entered into a note purchase agreement with a stockholder, Energy Capital, pursuant to which Energy Capital may lend an aggregate principal amount of up to $10.0 million. See Note 8 for a further discussion of the Energy Capital borrowing facility

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Measurements
Fair Value Measurements	12. Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to settle a liability in an orderly transaction between market participants at the measurement date. Fair value has a three level hierarchy from highest priority (Level 1) to lowest priority (Level 3). The fair value hierarchy reflects whether the inputs are observable from independent sources or rely on unobservable inputs based on our market assumptions. The three levels of the fair value hierarchy are described below: · Level 1 - Quoted prices for identical assets or liabilities (unadjusted) in active markets. · Level 2 - Observable inputs other than quoted prices that are either directly or indirectly observable for the assets or liability. · Level 3 - Unobservable inputs that are supported by little or no market activity. The levels are not necessarily an indication of the risk of liquidity associated with the financial assets or liabilities disclosed. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company has segregated its financial assets and liabilities that are measured at fair value on a recurring basis into the most appropriate level within the fair value hierarchy based on the inputs used to determine the fair value at the measurement date in the table below. The inputs used in measuring the fair value of the Company’s money market funds included in cash equivalents are considered to be Level 1 in accordance with the three-tier fair value hierarchy. The fair market values are based on period-end statements supplied by the various banks and brokers that held the majority of the funds. The following table represents the fair value hierarchy of the Company’s financial assets and liabilities measured at fair value on a recurring basis at December 31, 2015 and 2014 December 31, 2015 (in thousands) Total Level 1 Level 2 Level 3 Money market funds $ $ $ — $ — December 31, 2014 (in thousands) Total Level 1 Level 2 Level 3 Money market funds $ $ $ — $ — Warrant liability $ $ — $ — $ Prior to the Acquisition, the warrant instruments required liability accounting, as a result of their non-standard anti-dilutions provisions, and recorded at fair value using the Black-Scholes Model. These warrants were measured on a recurring basis at their fair value with inputs categorized as Level 3 in the fair value hierarchy. The resulting gain or loss on revaluation was recorded as other income (expense) in the consolidated statements of operations. The Company revalued the warrants for the final time immediately prior to the Acquisition and reclassified it into stockholders’ equity. When determining the fair value of the Company’s financial instruments using the Black-Scholes Model, the Company is required to use various estimates and unobservable inputs, including, among other things, fair value of the underlying stock, expected volatility of stock price, expected dividends, and the risk-free interest rate. Changes in any of the assumptions related to the unobservable inputs identified above may change the fair value of the instrument. Increases in the fair value of the underlying stock, anticipated volatility and expected dividends generally result in increases in fair value, while decreases in the unobservable inputs generally result in decreases in fair value. The fair value of the warrant liability was measured upon issuance of the warrants and again as of December 31, 2014 . The key assumptions used in the Black-Scholes Model with respect to these valuations are summarized in the following table: As of Immediately Issuance December 31, prior to Date 2014 the Acquisition Expected term of warrants years years years Expected volatility rate % % % Risk-free rate % % % Expected dividend yield % % % The expected term assumption is based on the warrant's contractual term. Since the Company was not a publicly traded company in 2014, the expected volatility rate is based on historical volatility of similar companies within the diabetes device industries. The risk-free rate is based on the U.S. Treasury implied yield at the time of measurement. The Company estimates the fair value per share of its Series D Stock at the date of measurement taking into account recent transactions. The following table presents a summary of changes in the fair value of Level 3 warrant liability measured at fair value on a recurring basis for the years ended December 31, 2015 and 2014 Reclassification of warrant Balance at Change in fair liability to Balance at Description December 31, Established in value during stockholders' December 31, (in thousands) 2014 2015 2015 equity 2015 Warrant liability $ $ — $ $ $ — Balance at Balance at Description December 31, Established in Change in December 31, (in thousands) 2013 2014 Fair Value 2014 Warrant liability $ — $ $ $ Financial Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The Company has no financial assets and liabilities that are measured at fair value on a non-recurring basis. Non-Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company has no non-financial assets and liabilities that are measured at fair value on a recurring basis. Non-Financial Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The Company measures its long-lived assets, including property and equipment, at fair value on a non-recurring basis. These assets are recognized at fair value when they are deemed to be impaired. No such fair value impairment was recognized in 2015 and 2014.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events
Subsequent Events	13. Subsequent Events On February 4, 2016, the Company entered into a Second Amendment (the “Amendment”) to Loan and Security Agreement with Oxford Finance, effective as of January 29, 2016. The Amendment, among other things, modifies the amortization schedule of the loan and security agreement's required monthly payments. If (i) the Company receives a CE mark for its continuous glucose monitoring system, Eversense, by March 4, 2016 or (ii) the Company receives net cash proceeds of at least $2.5 million from the sale of equity securities or a convertible note to Energy Capital by March 4, 2016 (a “Second Equity Event”) and receives a CE mark for Eversense by March 31, 2016 ((i) and (ii), each, a “CE Mark Approval”) the monthly payments will convert to payments of principal and interest, beginning on August 1, 2016, with the principal amount being amortized over the ensuing 36 months. If a CE Mark Approval does not occur, the monthly payments will convert to payments of principal and interest beginning on April 1, 2016, with the principal amount being amortized over the ensuing 40 months. In addition, the Amendment extends the amount of time the Company has to borrow an additional $5.0 million under the loan agreement on the same terms and conditions of the existing Oxford notes. The Company can borrow the additional $5.0 million following a CE Mark Approval until the earliest of (i) March 4, 2016, if a Second Equity Event does not occur by March 4, 2016, (ii) March 31, 2016, if a Second Equity Event occurs by March 4, 2016. In January 2016, the Company amended the lease agreement related to its corporate offices to expand the leased premises an additional 11,889 square feet for a total of 32,805 square feet. The existing lease term is through May 2018 and was extended for an additional five years through May 2023. With respect to the expanded premises only during the remaining lease term and the entire premises during the expanded lease term, the future total minimum lease payments under the amended lease will be an additional $3.6 million and will expire May, 2023. The Company has one option to extend the term of the lease for an additional five -year period with respect to the entire premises.

Summary of Significant Accoun20

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Basis of Accounting	Basis of Accounting The accompanying consolidated financial statements have been prepared in accordance with the requirements of U.S. generally accepted accounting principles (“U.S. GAAP”). The consolidated financial statements reflect the accounts of Senseonics Holdings and its wholly-owned subsidiary Senseonics as of December 31, 2015 . All intercompany transactions and balances have been eliminated in consolidation.
Reclassification	Reclassification Sales and marketing expenses of $94,546 included in administrative expenses in 2014 have been reclassified to sales and marketing expenses to conform to 2015 presentation.
Segment Information	Segment Information Operating segments are defined as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker (CODM), or decision-making group, in deciding how to allocate resources and in accessing performance. The Company views its operations and manages its business in one segment, glucose monitoring systems.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the reported amounts of revenues and expenses during the reporting period. In the accompanying consolidated financial statements, estimates are used for, but not limited to, valuation of common and preferred stock, stock-based compensation, the fair value of warrant liabilities, recoverability of long-lived assets, deferred taxes and valuation allowances, depreciable lives of property and equipment, and estimated accruals for preclinical study costs, which are accrued based on estimates of work performed under contracts. Actual results could differ from those estimates; however management does not believe that such differences would be material.
Fair Value Disclosures	Fair Value Disclosures The carrying amounts of short-term financial instruments, including cash and cash equivalents, prepaid expenses and other current assets, and accounts payable and other current liabilities approximate fair value as of December 31, 2015 and 2014 , because of the relatively short-term maturity of these instruments. The fair value of the note payable approximates its carrying value as of December 31, 2015 and 2014 and is based on the effective interest rate compared to the current market rates, which is a Level 2 fair value measurement as described below. See Note 12 for further discussion of fair value measurements.
Cash and Cash Equivalents and Concentration of Credit Risk	Cash and Cash Equivalents and Concentration of Credit Risk Cash equivalents are highly-liquid instruments with original maturities of three months or less and consist of U.S. Government and U.S. Government agency securities and money market funds with major commercial banks and financial institutions. Cash equivalents are recorded at cost plus accrued interest. The Company’s cash and cash equivalents potentially subject the Company to credit and liquidity risk. The Company maintains cash deposits at major financial institutions with high credit quality and, at times, the balances of those deposits may exceed the Federal Deposit Insurance Corporation limits of $250,000. The Company has not experienced and does not anticipate any losses on deposits with commercial banks and financial institutions that exceed the federally insured amounts.
Property and Equipment	Property and Equipment Property and equipment are stated at historical cost and depreciated on a straight-line basis over the estimated useful lives, generally five years. Equipment under capital leases is depreciated on a straight-line basis over the lesser of its estimated useful life or the lease term. Leasehold improvements are depreciated over the shorter of the remaining lease term or useful lives of the assets. Upon disposition of the assets, the costs and related accumulated depreciation are removed from the accounts and any resulting gain or loss is included in the results of operations. Repairs and maintenance costs are included as expense in the accompanying statement of operations. Management reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of the long-lived asset is measured by a comparison of the carrying amount of the asset to future undiscounted net cash flows expected to be generated by the asset. If the undiscounted cash flows are less than the carrying amount, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets. Management did not identify any indicators of impairment in 2015 and 2014.
Treasury Stock	Treasury Stock The Company records purchases of common stock for treasury at cost, and carries the cost of treasury stock as a reduction in stockholder’ equity. The Company maintained 43,907 shares of common stock in treasury as of December 31, 2014; the treasury stock was retired effective with the Acquisition. There is no treasury stock outstanding as of December 31, 2015.
Revenue Recognition	Revenue Recognition Product sales revenues are recognized when persuasive evidence of an arrangement exists, delivery has occurred, the price is fixed or determinable and collectability is probable. These criteria are generally anticipated to be met as products are shipped to customers. When revenue arrangements provide the customer with a contractual right of return, revenue is deferred until the right of return lapses or a reasonable estimate of returns can be determined.
Research and Development Costs	Research and Development Costs Research and development costs are expensed as incurred. Research and development expenses include costs related to employee compensation, preclinical and clinical trials, manufacturing, supplies, outsource testing, consulting and depreciation and other facilities-related expenses.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes the cost of employee services received in exchange for awards of equity instruments, such as stock options, based on the fair value of those awards at the date of grant. The estimated fair value of stock options on the date of grant is amortized on a straight-line basis over the requisite service period for each separately vesting portion of the award for those awards with service conditions only. For awards that also contain performance conditions, expense is recognized beginning at the time the performance condition is considered probable of being met over the remaining vesting period. The Company uses the Black-Scholes-Merton option pricing model (“Black-Scholes Model”) to determine the fair value of stock ‑option awards. Valuation of stock awards requires management to make assumptions and to apply judgment to determine the fair value of the awards. These assumptions and judgments include estimating the fair value of the Company’s common stock, future volatility of the Company’s stock price, dividend yields, future employee turnover rates, and future employee stock option exercise behaviors. Changes in these assumptions can affect the fair value estimate. Under Accounting Standards Codification (“ASC”) 718, the cumulative amount of compensation cost recognized for instruments classified as equity that ordinarily would result in a future tax deduction under existing tax law shall be considered to be a deductible difference in applying ASC 740 , Income Taxes . The deductible temporary difference is based on the compensation cost recognized for financial reporting purposes; however, these provisions currently do not impact the Company, as all the deferred tax assets have a full valuation allowance. Since the Company had net operating loss (“NOL”) carryforwards as of December 31, 2015 and 2014 , no excess tax benefits for the tax deductions related to share-based awards were recognized in the statements of operations.
Comprehensive Income	Comprehensive Income ASC 220-10, Reporting Comprehensive Income, requires the presentation of the comprehensive income or loss and its components as part of the financial statements. For the years ended December 31, 2015 and 2014, the Company’s net loss equals comprehensive loss.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are determined based on differences between the financial reporting and tax basis of assets and liabilities and are measured using the enacted tax rates and laws that are in effect when the differences are expected to reverse. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period that such tax rate changes are enacted. The measurement of a deferred tax asset is reduced, if necessary, by a valuation allowance if it is more likely than not that some portion or all of the deferred tax asset will not be realized. Management uses a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return, as well as guidance on derecognition, classification, interest and penalties and financial statement reporting disclosures. For those benefits to be recognized, a tax position must be more-likely-than-not to be sustained upon examination by taxing authorities. In the ordinary course of business, transactions occur for which the ultimate outcome may be uncertain. Management does not expect the outcome related to accrued uncertain tax provisions to have a material adverse effect on the Company’s financial position, results of operations or cash flows. The Company recognizes interest and penalties accrued on any unrecognized tax exposures as a component of income tax expense. The Company did not have any amounts accrued relating to interest and penalties as of December 31, 2015 and 2014 . The Company is subject to taxation in various jurisdictions in the United States and remains subject to examination by taxing jurisdictions for the year 1996 and all subsequent periods due to the availability of NOL carryforwards. In addition, all of the net operating losses and research and development credit carryforwards that may be used in future years are still subject to adjustment.
Loss per Share	Loss per Share Basic loss per share is computed by dividing net loss available to common shareholders by the weighted average number of shares of common stock outstanding during the period. For periods of net loss, diluted loss per share is calculated similarly to basic loss per share because the impact of all potential common shares is anti-dilutive. The total number of anti-dilutive shares was 14,261,768 and 34,435,548 at December 31, 2015 and 2014 , consisting of convertible preferred shares, common stock options and stock purchase warrants, which have been excluded from the computation of diluted loss per share, as follows: December 31, 2015 2014 Convertible preferred shares — Common stock options Stock purchase warrants Total anti-dilutive outstanding For periods of net income, and when the effects are not anti-dilutive, diluted earnings per share is computed by dividing net income available to common shareholders by the weighted-average number of shares outstanding plus the impact of all potential dilutive common shares, consisting primarily of common stock options and stock purchase warrants using the treasury stock method. For periods prior to December 7, 2015, common share and per share amounts of Senseonics have been retrospectively adjusted to reflect each historical common share for 2.0975 common shares.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Not Yet Adopted In May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance for revenue recognition for contracts, superseding the previous revenue recognition requirements, along with most existing industry-specific guidance. The guidance requires an entity to review contracts in five steps: 1) identify the contract, 2) identify performance obligations, 3) determine the transaction price, 4) allocate the transaction price, and 5) recognize revenue. The new standard will result in enhanced disclosures regarding the nature, amount, timing and uncertainty of revenue arising from contracts with customers. The standard is effective for the Company’s reporting year beginning January 1, 2018 and early adoption is permitted starting January 1, 2017. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In August 2014, the FASB issued guidance requiring management to evaluate on a regular basis whether any conditions or events have arisen that could raise substantial doubt about the entity’s ability to continue as a going concern. The guidance 1) provides a definition for the term “substantial doubt,” 2) requires an evaluation every reporting period, interim periods included, 3) provides principles for considering the mitigating effect of management’s plans to alleviate the substantial doubt, 4) requires certain disclosures if the substantial doubt is alleviated as a result of management’s plans, 5) requires an express statement, as well as other disclosures, if the substantial doubt is not alleviated, and 6) requires an assessment period of one year from the date the consolidated financial statements are issued. The standard is effective for the Company’s reporting year beginning January 1, 2017 and early adoption is permitted. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In April 2015, the FASB issued accounting guidance requiring that debt issuance costs related to a recognized liability be presented on the balance sheet as a direct reduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected. The standard is effective for reporting periods beginning after December 15, 2015. The Company is currently evaluating the impact, if any, that this new accounting pronouncement will have on its consolidated financial statements. In April 2015, the FASB issued accounting guidance related to Internal-Use Software specifically for the Customer’s Accounting for Fees Paid in a Cloud Computing Arrangement. The amendments in this Update provide guidance to customers about whether a cloud computing arrangement includes a software license. If a cloud computing arrangement includes a software license, then the customer should account for the software license element of the arrangement consistent with the acquisition of other software licenses. If a cloud computing arrangement does not include a software license, the customer should account for the arrangement as a service contract. The standard is effective for reporting periods beginning after December 15, 2015. An entity can elect to adopt the amendments either 1) prospectively for all arrangements entered into or materially modified after the effective date or 2) retrospectively. The Company decided to adopt the standards prospectively and will be accounting for the new cloud arrangements in accordance with the new standards. The Company has evaluated all other issued and unadopted Accounting Standards Updates and believes the adoption of these standards will not have a material impact on the results of operations, financial position, or cash flows.

Summary of Significant Accoun21

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Summary of Significant Accounting Policies
Schedule of anti-dilutive shares which have been excluded from the computation of diluted loss per share	December 31, 2015 2014 Convertible preferred shares — Common stock options Stock purchase warrants Total anti-dilutive outstanding

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property and Equipment
Schedule of property and equipment	Property and equipment consisted of the following as of December 31, 2015 and 2014 (in thousands) December 31, 2015 2014 Laboratory equipment $ $ Office furniture and equipment Software — Leasehold improvements Less: Accumulated depreciation Property and equipment, net $ $

Other Balance Sheet Details (Ta

Other Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2015
Other Balance Sheet Details
Schedule of Accrued expenses and other current liabilities	Accrued expenses and other current liabilities consisted of the following as of December 31, 2015 and 2014 (in thousands): December 31, 2015 2014 Clinical and preclinical $ $ Compensation and benefits Financing Costs — Contract manufacturing Legal Audit and tax related Other Deferred rent, current portion — Total $ $

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments and Contingencies
Schedule of operating lease future minimum lease payments	The contractually required cash payments under this lease at December 31, 2015 are as follows: 2016 $ 2017 2018 Total minimum lease payments $

Notes Payable and Stock Purch25

Notes Payable and Stock Purchase Warrants (Tables)	12 Months Ended
	Dec. 31, 2015
Notes Payable and Stock Purchase Warrants
Schedule of future maturities of the Oxford notes	The following are the scheduled maturities of the Oxford notes as of December 31, 2015 , assuming the Company does not receive its CE mark by February 1, 2016, in which case, principal payments will begin on February 1, 2016 (in thousands): 2016 $ 2017 2018 2019

Stockholder's Equity (Deficit)

Stockholder's Equity (Deficit) (Tables)	12 Months Ended
	Dec. 31, 2015
Stockholders' Equity (Deficit)
Schedule of assumptions of Black-Scholes option pricing model	For the year ended December 31, 2015 2014 Expected term of options 6.5 years - 6.5 years Expected volatility rate - 54.25 % - 56.42 % Risk-free rate - 1.9 % - 2.10 % Expected dividend yield 0 % 0 %
Schedule of stock option activity	Weighted- Number of Average Shares in Exercise (in thousands) Price Options outstanding as of December 31, 2014 $ Options granted $ Options exercised $ Options canceled/forfeited $ Options outstanding as of December 31, 2015 $ Options vested and expected to vest as of December 31, 2015 $
Schedule of Restricted Stock Awards activity	Number of Shares (in thousands) Restricted Stock Awards nonvested at December 31, 2014 — Granted Vested Cancelled and forfeited — Restricted Stock Awards nonvested at December 31, 2015 Vested and expected to vest at December 31, 2015

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Taxes
Schedule of deferred income tax assets and liabilities	in thousands December 31, Deferred income tax assets (Liabilities ) 2015 2014 Net operating loss carryforwards $ $ Capitalized start-up costs R&E credit carryforwards Stock based compensation — Other Deferred income tax assets Valuation allowance Net deferred income tax assets (liabilities) $ — $ —
Schedule of change in valuation allowance	Changes in the valuation allowance during years ended December 31, 2015 and 2014 are as follows (in thousands): Beginning Balance at Year of Year Additions Deductions End of Year 2014 $ $ $ — $ 2015 $ $ $ — $
Schedule of reconciliation of U.S. federal statutory rate to Company's effective tax rate	2015 2014 Tax at U.S. Federal Statutory rate % % State taxes, net Research and development credit Other non-deductible items Increase in valuation allowance Effective income tax rate % %
Schedule of uncertain tax positions	A breakdown of the Company’s uncertain tax position during 2015 and 2014 is as follows (in thousands): 2015 2014 Gross unrecognized tax benefit at beginning of year $ $ Increase from tax positions taken in prior years — Increase from tax positions in current year Settlements with taxing authorities — — Lapse of statute of limitations / expiration — — Gross unrecognized tax benefit at end of year $ $

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Measurements
Schedule of financial assets and liabilities measured at fair value on a recurring basis	December 31, 2015 (in thousands) Total Level 1 Level 2 Level 3 Money market funds $ $ $ — $ — December 31, 2014 (in thousands) Total Level 1 Level 2 Level 3 Money market funds $ $ $ — $ — Warrant liability $ $ — $ — $
Schedule of assumptions used to determine fair value of warrant liability	As of Immediately Issuance December 31, prior to Date 2014 the Acquisition Expected term of warrants years years years Expected volatility rate % % % Risk-free rate % % % Expected dividend yield % % %
Schedule of changes in the fair value of Level 3 warrant liability measured at fair value on a recurring basis	Reclassification of warrant Balance at Change in fair liability to Balance at Description December 31, Established in value during stockholders' December 31, (in thousands) 2014 2015 2015 equity 2015 Warrant liability $ $ — $ $ $ — Balance at Balance at Description December 31, Established in Change in December 31, (in thousands) 2013 2014 Fair Value 2014 Warrant liability $ — $ $ $

Organization - Significant Tran

Organization - Significant Transaction (Details)	Dec. 07, 2015$ / sharesshares	Dec. 06, 2015	Dec. 31, 2015$ / shares	Dec. 31, 2014$ / shares
Significant Transaction
Common stock, par value per share (in dollars per share)			$ 0.001	$ 0.001
Exchange ratio		2.0975
ASN Technologies, Inc. | Common Shares Exchanged in Reverse Capitalization
Significant Transaction
Shares issued | shares	55,301,674
ASN Technologies, Inc. | Common Stock
Significant Transaction
Common stock, par value per share (in dollars per share)	$ 0.001
ASN Technologies, Inc. | Common Stock | Common Shares Exchanged in Reverse Capitalization
Significant Transaction
Common stock, par value per share (in dollars per share)	$ 0.001
Shares issued | shares	1,955,929
ASN Technologies, Inc. | Common Stock | Common Stock, Senseonics, Inc. | Common Shares Exchanged in Reverse Capitalization
Significant Transaction
Exchange ratio	2.0975
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement
Significant Transaction
Ownership interest in new entity held by former shareholders of acquired entity (as a percent)	80.00%
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement | Capital Stock, Senseonics, Inc.
Significant Transaction
Interest in capital stock acquired (as a percent)	100.00%
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement | Common Stock
Significant Transaction
Common stock, par value per share (in dollars per share)	$ 0.001
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement | Common Stock | Common Shares Exchanged in Reverse Capitalization
Significant Transaction
Exchange ratio	2.0975
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement | Common Stock | Common Stock, Senseonics, Inc.
Significant Transaction
Shares issued | shares	1,955,929
ASN Technologies, Inc. | Senseonics Reverse Merger Agreement | Common Stock | Preferred Stock, Senseonics, Inc.
Significant Transaction
Shares issued | shares	55,301,674
Senseonics, Incorporated | Common Stock, Senseonics, Inc.
Significant Transaction
Common stock, par value per share (in dollars per share)	$ 0.01

Organization - Significant Tr30

Organization - Significant Transaction - Transfer of assets (Details) - ASN Technologies, Inc. - ASN Former Operations - Former Officer, Director and Shareholder	Dec. 07, 2015USD ($)
Transfer of former operations
Noncash consideration received, amount	$ 9,000
Gain (loss) on transfer of former operations	$ 0

Summary of Significant Accoun31

Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended		23 Months Ended
	Dec. 31, 2015USD ($)segmentshares	Dec. 31, 2014USD ($)shares	Dec. 06, 2015
Reclassification
Sales and marketing expenses	$ 792,000	$ 95,000
General and Administrative Expense	$ 9,807,000	$ 5,726,000
Segment Information
Number of operating segments | segment	1
Property and Equipment
Useful lives	5 years
Treasury Stock
Treasury stock, at cost; shares held | shares	0	43,907
Stock-Based Compensation
Excess tax benefits for the tax deductions related to share-based awards	$ 0	$ 0
Income Taxes
Accrued for income tax penalties and interest	$ 0	$ 0
Loss per Share
Securities excluded from computation of diluted loss per share | shares	14,261,768	34,435,548
Exchange ratio			2.0975
Adjustment
Reclassification
Sales and marketing expenses		$ 94,546
General and Administrative Expense		$ (94,546)
Convertible preferred stock
Loss per Share
Securities excluded from computation of diluted loss per share | shares		23,653,592
Common Stock options
Loss per Share
Securities excluded from computation of diluted loss per share | shares	9,251,164	8,393,081
Stock purchase warrants
Loss per Share
Securities excluded from computation of diluted loss per share | shares	5,010,604	2,388,875

Property and Equipment - Compon

Property and Equipment - Components (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property and Equipment
Property and Equipment	$ 969	$ 910
Accumulated depreciation	(658)	(683)
Property and Equipment, net	311	227
Laboratory equipment
Property and Equipment
Property and Equipment	518	404
Office furniture and equipment
Property and Equipment
Property and Equipment	57	67
Software
Property and Equipment
Property and Equipment		45
Leasehold improvements
Property and Equipment
Property and Equipment	$ 394	$ 394

Property and Equipment - Deprec

Property and Equipment - Depreciation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Property and Equipment - Other information
Depreciation expense	$ 118,174	$ 189,325
Disposals	$ 143,155	$ 1,070,595

Other Balance Sheet Details - A

Other Balance Sheet Details - Accrued expenses and other current liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Balance Sheet Details
Clinical and preclinical	$ 871	$ 327
Compensation and benefits	605	336
Financing Costs	655
Contract manufacturing	754	141
Legal	243	158
Audit and tax related	376	176
Other	183	23
Deferred rent, current portion	7
Total	$ 3,694	$ 1,161

Commitments and Contingencies -

Commitments and Contingencies - Operating Lease (Details) - Research and office space	12 Months Ended
	Dec. 31, 2015USD ($)ft²item	Dec. 31, 2014USD ($)
Operating Leases
Leased space, in square feet | ft²	20,000
Number of renewal options | item	1
Renewal term of lease	5 years
Operating lease expense	$ 386,438	$ 386,438
Contractually required cash payments
2,016	393,000
2,017	405,000
2,018	171,000
Total	$ 969,000

Commitments and Contingencies36

Commitments and Contingencies - Minimum Payments (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Commitments and contingencies
Research and development expense	$ 18,251,000	$ 12,881,000
Corporate development agreement
Commitments and contingencies
Research and development expense	0	$ 289,000
Future maturities
Future minimum payments	$ 820,000

401(k) Plan (Details)

401(k) Plan (Details)	12 Months Ended
	Dec. 31, 2015USD ($)
401(k) Plan
Employer contributions to the 401(k) plan	$ 0

Notes Payable and Stock Purch38

Notes Payable and Stock Purchase Warrants - Term Notes Payable (Details) - Oxford Notes - USD ($)	Dec. 23, 2014	Jul. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Long term debt
Proceeds from issuance of debt, gross	$ 6,000,000	$ 4,000,000
Interest rate (as a percent)	6.95%	6.95%
Deferred finance costs	$ 121,200
Final fee due at maturity of term notes payable	$ 900,000
Interest Expense
Long term debt
Accretion of debt discount			$ 72,229	$ 20,514
Before CE Mark Received
Long term debt
Frequency of payment	monthly	monthly
Type of payment required	interest only	interest only
CE Mark received by February 1, 2016
Long term debt
Frequency of payment	monthly	monthly
Type of payment required	principal and interest	principal and interest
Date of first principal and interest payment	Aug. 1, 2016	Aug. 1, 2016
Repayment period	36 months	36 months
CE Mark not received by February 1, 2016
Long term debt
Frequency of payment	monthly	monthly
Type of payment required	principal and interest	principal and interest
Date of first principal and interest payment	Feb. 1, 2016	Feb. 1, 2016
Repayment period	42 months	42 months

Notes Payable and Stock Purch39

Notes Payable and Stock Purchase Warrants - Scheduled Maturities (Details) - Oxford Notes - CE Mark not received by February 1, 2016 $ in Thousands	Dec. 31, 2015USD ($)
Scheduled maturities of Oxford notes
2,016	$ 2,389
2,017	2,786
2,018	2,985
2,019	$ 1,840

Notes Payable and Stock Purch40

Notes Payable and Stock Purchase Warrants - Energy Capital, LLC Borrowing Facility (Details) - Energy Capital	Dec. 07, 2015USD ($)
Long term debt
Maximum principal amount available under facility	$ 10,000,000
Minimum proceeds from a capital stock offering	20,000,000
Maximum available cash	500,000
Minimum available cash	500,000
Minimum threshold of proceeds from an underwritten public offering of equity securities which will trigger repayment of principal and interest under the credit facility	$ 45,000,000
Minimum period of after the closing of an underwritten public offering, for which the entity must receive the threshold amount of proceeds from such public offering	10 days

Notes Payable and Stock Purch41

Notes Payable and Stock Purchase Warrants - Stock Purchase Warrants (Details)	Dec. 07, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2011$ / sharesshares	Dec. 06, 2015
Stock Purchase Warrants
Warrant liability | $		$ 197,000
Exchange ratio				2.0975
Oxford Notes | Senseonics Reverse Merger Agreement | Warrants Shares Exchanged in Reverse Capitalization | Common Stock
Stock Purchase Warrants
Number of shares called by warrants	(167,573)
Exercise price of warrant (in dollars per share) | $ / shares	$ 1.79
Exchange ratio	2.0975
Oxford Notes | Warrant liability | Senseonics Reverse Merger Agreement | Warrants Shares Exchanged in Reverse Capitalization | Common Stock
Stock Purchase Warrants
Warrant liability | $	$ 205,150
Oxford Notes | Oxford Stock Purchase Warrants | Warrant liability
Stock Purchase Warrants
Number of warrants issued		4
Term of stock purchase warrants		10 years
Exercise price of warrant (in dollars per share) | $ / shares		$ 3.75
Convertible Notes | Convertible Notes Stock Purchase Warrants | Senseonics Reverse Merger Agreement | Warrants Shares Exchanged in Reverse Capitalization | Common Stock
Stock Purchase Warrants
Number of shares called by warrants	(4,843,031)
Exercise price of warrant (in dollars per share) | $ / shares	$ 1.79
Exchange ratio	2.0975
Convertible Notes | Preferred Stock | Convertible Notes Stock Purchase Warrants
Stock Purchase Warrants
Term of stock purchase warrants			10 years
Series D Preferred Stock | Oxford Notes | Oxford Stock Purchase Warrants | Warrant liability
Stock Purchase Warrants
Number of shares called by warrants		79,892
Series D Preferred Stock | Convertible Notes | Preferred Stock | Convertible Notes Stock Purchase Warrants
Stock Purchase Warrants
Number of shares called by warrants			2,308,972
Exercise price of warrant (in dollars per share) | $ / shares			$ 3.75

Stockholders' Equity (Deficit)

Stockholders' Equity (Deficit) - Class of Stock Disclosures (Details)	Dec. 07, 2015$ / sharesshares	Dec. 06, 2015	Dec. 31, 2015$ / sharesshares	Dec. 31, 2014$ / sharesshares
Stockholders' Equity, par value and other disclosures
Common stock, par value | $ / shares			$ 0.001	$ 0.001
Exchange ratio		2.0975
Authorized common stock			250,000,000	65,679,406
Common stock issued			75,760,061	1,962,486
Common stock, shares outstanding			75,760,061	1,918,579
Senseonics, Incorporated | Common Stock, Senseonics, Inc.
Stockholders' Equity, par value and other disclosures
Common stock, par value | $ / shares	$ 0.01
ASN Technologies, Inc. | Common Shares Exchanged in Reverse Capitalization
Stockholders' Equity, par value and other disclosures
Shares issued	55,301,674
ASN Technologies, Inc. | Common Stock
Stockholders' Equity, par value and other disclosures
Common stock, par value | $ / shares	$ 0.001
ASN Technologies, Inc. | Common Stock | Common Shares Exchanged in Reverse Capitalization
Stockholders' Equity, par value and other disclosures
Common stock, par value | $ / shares	$ 0.001
Shares issued	1,955,929
ASN Technologies, Inc. | Common Stock | Common Stock, Senseonics, Inc. | Common Shares Exchanged in Reverse Capitalization
Stockholders' Equity, par value and other disclosures
Exchange ratio	2.0975

Stockholders' Equity (Deficit43

Stockholders' Equity (Deficit) - Preferred Stock (Details)	1 Months Ended	12 Months Ended						23 Months Ended	24 Months Ended	96 Months Ended
	Aug. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2015$ / shares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2011USD ($)$ / sharesshares	Dec. 31, 2000USD ($)$ / sharesshares	Dec. 31, 1998USD ($)$ / sharesshares	Dec. 31, 1997USD ($)$ / sharesshares	Dec. 06, 2015	Dec. 31, 2012USD ($)$ / sharesshares	Dec. 31, 2009USD ($)$ / sharesshares
Offerings
Exchange ratio								2.0975
Convertible preferred stock
Offerings
Exchange ratio		2.0975
Convertible preferred stock | Series A Preferred Stock
Offerings
Liquidation preference (in USD per share)		$ 5
Convertible preferred stock | Series A Preferred Stock | Private offering
Offerings
Preferred stock, shares sold | shares							599,997
Gross proceeds | $							$ 3,000,000
Purchase price (in dollars per share)							$ 5
Convertible preferred stock | Series B Preferred Stock
Offerings
Liquidation preference (in USD per share)		10
Convertible preferred stock | Series B Preferred Stock | Private offering
Offerings
Preferred stock, shares sold | shares					520,000	682,497
Gross proceeds | $					$ 5,200,000	$ 6,800,000
Purchase price (in dollars per share)					$ 10	$ 10
Convertible preferred stock | Series C Preferred Stock
Offerings
Liquidation preference (in USD per share)		20
Convertible preferred stock | Series C Preferred Stock | Private offering
Offerings
Preferred stock, shares sold | shares										2,073,749
Gross proceeds | $										$ 41,500,000
Purchase price (in dollars per share)										$ 20
Convertible preferred stock | Series D Preferred Stock
Offerings
Principal amount and accrued interest of convertible notes converted | $				$ 8,700,000
Debt converted, shares issued | shares				2,418,864
Conversion price (in dollars per share)				$ 3.75
Liquidation preference (in USD per share)		3.75
Convertible preferred stock | Series D Preferred Stock | Private offering
Offerings
Preferred stock, shares sold | shares			5,374,334						11,984,151
Gross proceeds | $			$ 20,200,000						$ 44,900,000
Purchase price (in dollars per share)			$ 3.75						$ 3.75
Convertible preferred stock | Series E Preferred Stock
Offerings
Liquidation preference (in USD per share)		$ 3.93
Convertible preferred stock | Series E Preferred Stock | Private offering
Offerings
Preferred stock, shares sold | shares	2,711,926
Gross proceeds | $	$ 10,700,000
Purchase price (in dollars per share)	$ 3.93
Beneficial conversion feature recognized | $	$ 406,783

Stockholders' Equity (Deficit44

Stockholders' Equity (Deficit) - Black-Scholes Option Pricing Assumptions (Details) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Minimum
Fair value of stock-option awards
Expected term of options		6 years 3 months
Expected volatility rate	54.02%	55.52%
Risk-free rate	0.70%	2.00%
Maximum
Fair value of stock-option awards
Expected term of options	6 years 6 months	6 years 6 months
Expected volatility rate	54.25%	56.42%
Risk-free rate	1.90%	2.10%
Expected dividend yield	0.00%	0.00%
1997 Stock Option Plan
Stock-Based Compensation
Expiration period	10 years
Total shares that may be issued	9,175,860

Stockholders' Equity (Deficit45

Stockholders' Equity (Deficit) - Stock-Based Compensation Expense (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Nonvested options, unrecognized compensation and other information
Total intrinsic value of stock options outstanding	$ 23,100,000
Total intrinsic value of stock options vested and expected to vest	23,100,000
Total fair value of options vested	800,000	$ 500,000
Employee granted stock options
Stock-Based Compensation
Total stock-based compensation	1,000,000	500,000
Nonvested options, unrecognized compensation and other information
Unrecognized compensation cost	$ 2,600,000
Weighted average period expected to recognize unrecognized compensation cost	3 years 15 days
Employee granted stock options | Research and development
Stock-Based Compensation
Total stock-based compensation	$ 462,006	105,465
Employee granted stock options | Administrative
Stock-Based Compensation
Total stock-based compensation	600,000	433,733
Restricted Stock Award
Stock-Based Compensation
Total stock-based compensation		$ 0
Restricted Stock Award | Administrative
Stock-Based Compensation
Total stock-based compensation	$ 387,600

Stockholders' Equity (Deficit46

Stockholders' Equity (Deficit) - Stock Option Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Stock option activity
Options exercised	(121,250)	(18,664)
1997 Stock Option Plan
Stock option activity
Options outstanding- Beginning	8,393,000
Options granted	1,540,000
Options exercised	(121,000)
Options canceled/forfeited	(561,000)
Options outstanding- Ending	9,251,000	8,393,000
Options vested and expected to vest	9,251,000
Weighted Average Exercise Price Per Share
Options outstanding- Beginning (in dollars per share)	$ 0.53
Options granted (in dollars per share)	1.90
Options exercised (in dollars per share)	0.51
Options canceled/forfeited (in dollars per share)	0.50
Options outstanding- Ending (in dollars per share)	0.74	$ 0.53
Options vested and expected to vest (in dollars per share)	$ 0.74

Stockholders' Equity (Deficit47

Stockholders' Equity (Deficit) - Stock Option Additional Information (Details) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014
Option awards - additional information
Weighted-average remaining contractual life of outstanding stock options		7 years 9 months 18 days
Weighted-average remaining contractual life of outstanding stock options, vested and expected to vest		7 years 9 months 18 days
Vesting period		2 years
Number of options exercisable		4,369,239
Weighted-average exercise price of exercisable options		$ 0.57
Weighted-average remaining contractual life of exercisable options		6 years 7 months 6 days
Aggregate intrinsic value of options currently exercisable		$ 11,700,000
Options exercised		121,250	18,664
Aggregate intrinsic value of options exercised		$ 123,224	$ 1,557
Remaining vesting period		7 years 9 months 18 days
Weighted average grant date fair value of the nonvested stock option awards outstanding		$ 0.62	$ 0.35
Weighted average fair value of stock options granted		1.02	$ 0.34
Weighted average grant date fair value of stock options vested (in dollars per share)		0.65
Weighted average grant date fair value of stock options exercised		0.33
Weighted average grant date fair value of the stock option awards forfeited/cancelled		$ 0.33
Performance-based vesting conditions | 2014 grants | Minimum
Option awards - additional information
Weighted-average remaining contractual life of outstanding stock options, vested and expected to vest	2 years 8 months 5 days
Remaining vesting period	2 years 8 months 5 days
Performance-based vesting conditions | 2014 grants | Maximum
Option awards - additional information
Weighted-average remaining contractual life of outstanding stock options, vested and expected to vest	3 years 2 months 5 days
Remaining vesting period	3 years 2 months 5 days
Modified Common Stock options | Performance-based vesting conditions
Option awards - additional information
Additional expense recognized upon modification	$ 245,636
Incremental compensation expense	$ 900,000
Modified Common Stock options | Performance-based vesting conditions | 2013 grants
Option awards - additional information
Weighted-average remaining contractual life of outstanding stock options, vested and expected to vest	2 years
Remaining vesting period	2 years
Modified Common Stock options | Service-based vesting conditions
Option awards - additional information
Additional expense recognized upon modification	$ 34,912

Stockholders' Equity (Deficit48

Stockholders' Equity (Deficit) - Stockholders' Deficit - Restricted Stock Awards (Details) - Restricted Stock Award - USD ($)	12 Months Ended
	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	398,525
Grant date per share value	$ 1.95
Fair value of award	$ 800,000
Aggregate intrinsic value of unvested restricted stock awards	$ 600,000
Pre-vesting forfeitures percentage	0.00%
Fair value of restricted stock units vested	$ 600,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Granted	398,000
Vested	(199,000)
Restricted Stock Awards nonvested , Ending balance	199,000
Vested and expected to vest	398,000
Unrecognized compensation cost	$ 387,600
Vesting on grant date
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	50.00%
Fair value expense percentage upon issuance	50.00%
Performance-based vesting conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value expense percentage upon fulfillment of agreed upon performance condition	50.00%

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Taxes
Income tax provision	$ 0	$ 0
Deferred Income Tax Assets (Liabilities)
Net operating loss carryforwards	40,617,000	33,361,000
Capitalized start-up costs	19,546,000	16,090,000
R&E credit carryforwards	4,698,000	4,098,000
Stock-based compensation	777,000
Other	(6,000)	(17,000)
Deferred tax asset, gross	65,632,000	53,532,000
Valuation allowance	(65,632,000)	(53,532,000)
Net deferred income tax asset	$ 0	$ 0

Income Taxes - Deferred Tax Val

Income Taxes - Deferred Tax Valuation Allowance (Details) - Deferred tax valuation allowance - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Change in valuation allowance
Balance at beginning of year	$ 53,532	$ 45,743
Additions	12,100	7,789
Balance at end of year	$ 65,632	$ 53,532

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Loss and Tax Credit Carryforwards (Details)	12 Months Ended
	Dec. 31, 2015USD ($)
NOLs and Tax Credits
Net operating loss carryforwards	$ 103,000,000
Income tax (benefit) for stock-based compensation arrangements	0
Research and Development Credit Carryforwards
NOLs and Tax Credits
Tax credit carryforwards	$ 5,100,000
Capitalized Start-up Costs Prior to October 22, 2004
NOLs and Tax Credits
Amortization period for tax purposes	60 months
Capitalized Start-up Costs On or After October 22, 2004
NOLs and Tax Credits
Amortization period for tax purposes	180 months

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Reconciliation of the estimated U.S. federal statutory rate to the Company's effective income tax rate
Tax at U.S. Federal Statutory rate (as a percent)	34.00%	34.00%
State taxes, net (as a percent)	5.45%	5.39%
Research and development credit (as a percent)	2.01%	3.05%
Other non-deductible (as a percent)	(1.05%)	(1.20%)
Increase in valuation allowance (as a percent)	(40.41%)	(41.24%)
Effective income tax rate (as a percent)	0.00%	0.00%

Income Taxes - Uncertain Tax Po

Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Change in uncertain tax positions
Gross unrecognized tax benefit at beginning of year	$ 1,025	$ 922
Increase from tax positions taken in prior years		(12)
Increase from tax positions in current year	149	115
Gross unrecognized tax benefit at end of year	1,174	1,025
Amount of unrecognized tax benefits that, if recognized, would favorably impact the effective tax rate	$ 1,200	$ 1,000

Related Party Transactions - (D

Related Party Transactions - (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 07, 2015
Energy Capital
Related party transactions
Maximum principal amount available under facility			$ 10
Restricted Stock Award
Related party transactions
Restricted stock awarded to board member		398,525
Board Member | Restricted Stock Award
Related party transactions
Restricted stock awarded to board member	398,525
Minimum gross proceeds receivable for vesting of remaining stock under the award	$ 40
Board Member | Minimum | Restricted Stock Award
Related party transactions
Valuation percentage	0.75%
Board Member | Maximum | Restricted Stock Award
Related party transactions
Valuation percentage	1.25%
Energy Capital | Energy Capital
Related party transactions
Maximum principal amount available under facility			$ 10
Vesting on grant date | Restricted Stock Award
Related party transactions
Vesting percentage		50.00%
Vesting on grant date | Board Member
Related party transactions
Vesting percentage	50.00%

Fair Value Measurements - Recur

Fair Value Measurements - Recurring (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Warrant liability
Fair Value Measurements
Liabilities, fair value		$ 197
Money market funds
Fair Value Measurements
Assets, fair value	$ 3,938	18,876
Level 1 | Money market funds
Fair Value Measurements
Assets, fair value	$ 3,938	18,876
Level 3 | Warrant liability
Fair Value Measurements
Liabilities, fair value		$ 197

Fair Value Measurements - Valua

Fair Value Measurements - Valuation Assumptions (Details) - Recurring - Level 3 - Warrant liability	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 23, 2014	Jul. 20, 2014	Dec. 31, 2014
Fair value valuation assumptions
Expected term of warrants	10 years	8 years 7 months 24 days	9 years 7 months 2 days
Expected volatility rate	58.01%	53.94%	56.00%
Risk-free rate	2.44%	2.23%	2.42%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%

Fair Value Measurements - Chang

Fair Value Measurements - Change in Level 3 Fair Value (Details) - Warrant liability - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Changes in fair value of Level 3 warrant liability
Balance, beginning of period	$ 197	$ 0
Established in 2014		205
Change in Fair Value	(46)	(8)
Liability to reclassification of warrant stockholders	$ (151)
Balance, end of period		$ 197

Fair Value Measurements - Nonre

Fair Value Measurements - Nonrecurring (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value Measurements
Fair value of non-financial liabilities	$ 0
Nonrecurring
Fair Value Measurements
Financial assets, fair value	0
Financial liabilities, fair value	0
Fair value impairment recognized on long-lived assets	0	$ 0
Recurring
Fair Value Measurements
Fair value of non-financial assets	$ 0

Subsequent Events - (Details)

Subsequent Events - (Details) - Subsequent Event $ in Millions	Jan. 29, 2016USD ($)	Jan. 31, 2016USD ($)ft²item
Corporate Offices
Subsequent Event [Line Items]
Additional leased space, in square feet | ft²		11,889
Leased space, in square feet | ft²		32,805
Renewal term of lease		5 years
Increase to the future minimum lease payments		$ 3.6
Number of renewal options | item		1
Oxford Notes, Second Amendment
Subsequent Event [Line Items]
Minimum threshold of proceeds from the sale of equity securities or a convertible note to Energy Capital, LLC	$ 2.5
Term over which the principal amount will be amortized, conditions per amendment achieved	36 months
Term over which the principal amount will be amortized, CE mark not achieved	40 months
Additional borrowing capacity	$ 5