Hansen Medical (HNSN) 10-Q 9 May 14 2014 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2014	Apr. 30, 2014
Document Information [Line Items]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'HNSN	'
Entity Registrant Name	'HANSEN MEDICAL INC	'
Entity Central Index Key	'0001276591	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	111,962,074

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$30,976	$27,995
Short-term investments	2,028	1,945
Accounts receivable, net of allowance of $0 and $554, as of March 31, 2014 and December 31, 2013, respectively	4,395	5,114
Inventories	12,028	12,203
Prepaids and other current assets	1,629	1,914
Total current assets	51,056	49,171
Property and equipment, net	3,882	3,641
Restricted cash	5,394	5,394
Other assets	1,582	2,953
Total assets	61,914	61,159
Current liabilities:	'	'
Accounts payable	3,174	3,337
Accrued liabilities	4,274	3,934
Current portion of deferred revenue	3,044	2,912
Total current liabilities	10,492	10,183
Deferred revenue, net of current portion	136	203
Long-term debt	33,608	33,358
Other long-term liabilities	546	539
Total liabilities	44,782	44,283
Commitments and contingencies (Note 7)	'	'
Stockholders' equity:	'	'
Preferred stock, par value $0.0001: Authorized: 10,000 shares; issued and outstanding: none	'	'
Common stock, par value $0.0001: Authorized: 200,000 shares; issued and outstanding: 110,991 and 99,014 shares at March 31, 2014 and December 31, 2013, respectively	11	10
Additional paid-in capital	383,785	369,170
Accumulated other comprehensive income	445	360
Accumulated deficit	-367,109	-352,664
Total stockholders' equity	17,132	16,876
Total liabilities and stockholders' equity	$61,914	$61,159

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, except Per Share data, unless otherwise specified
Accounts receivable, allowance	$0	$554
Preferred stock, par value	$0.00	$0.00
Preferred stock, shares authorized	10,000	10,000
Preferred stock, shares issued	'	'
Preferred stock, shares outstanding	'	'
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	200,000	200,000
Common stock, shares issued	110,991	99,014
Common stock, shares outstanding	110,991	99,014

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Revenues:	'	'
Product	$2,352	$1,626
Service	1,347	1,325
Total revenues	3,699	2,951
Cost of revenues:	'	'
Product	2,744	1,859
Service	557	623
Total cost of revenues	3,301	2,482
Gross profit	398	469
Operating expenses:	'	'
Research and development	4,415	4,112
Selling, general and administrative	9,161	7,418
Loss on settlement of litigation	'	4,500
Total operating expenses	13,576	16,030
Loss from operations	-13,178	-15,561
Interest and other expense, net	-1,249	-1,588
Loss before income taxes	-14,427	-17,149
Income tax expense	-18	-38
Net loss	($14,445)	($17,187)
Basic and diluted net loss per share	($0.14)	($0.26)
Shares used to compute basic and diluted net loss per share	103,334	67,296

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Loss (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Net loss	($14,445)	($17,187)
Other comprehensive income (loss), net:	'	'
Change in unrealized gains and losses on investments	83	667
Foreign currency translation adjustment	2	-29
Change in other comprehensive income (loss)	85	638
Comprehensive loss	($14,360)	($16,549)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities	'	'
Net loss	($14,445)	($17,187)
Adjustments to reconcile net loss to net cash used in operating activities:	'	'
Loss on settlement of litigation	'	4,500
Depreciation and amortization	665	813
Stock-based compensation	757	1,140
Amortization of common stock warrants	'	74
Net realized gains and losses on investments	'	636
Provision (benefit) for doubtful accounts	-100	'
Loss on sale of financing receivable	19	'
Changes in operating assets and liabilities:	'	'
Accounts receivable	819	1,858
Inventories	-604	-1,606
Prepaids and other current assets	287	-34
Other long-term assets	1,352	36
Accounts payable	-164	-34
Accrued liabilities	340	165
Deferred revenue	65	-324
Other long-term liabilities	257	43
Net cash used in operating activities	-10,752	-9,920
Cash flows from investing activities	'	'
Purchase of property and equipment	-126	-78
Proceeds from sales and maturities of short-term investments	'	6,704
Net cash (used in) provided by investing activities	-126	6,626
Cash flows from financing activities	'	'
Proceeds from exercise of common stock options	479	114
Proceeds from exercise of Series A warrants	14,000	'
Withholding taxes paid on vested restricted stock units	-620	'
Net cash provided by financing activities	13,859	114
Net increase (decrease) in cash and cash equivalents	2,981	-3,180
Cash and cash equivalents at beginning of year	27,995	32,749
Cash and cash equivalents at end of year	$30,976	$29,569

The_Company

The Company	3 Months Ended
	Mar. 31, 2014
The Company	'
	1	The Company
	Nature of Operations
	Hansen Medical, Inc. (the “Company”) develops, manufactures and markets a new generation of medical robotics designed for accurate positioning, manipulation and stable control of catheters and catheter-based technologies. The Company was incorporated in the state of Delaware on September 23, 2002. The Company is headquartered in Mountain View, California. In March 2007, the Company established Hansen Medical UK Ltd., a wholly-owned subsidiary located in the United Kingdom and, in May 2007, the Company established Hansen Medical, GmbH, a wholly-owned subsidiary located in Germany. Both subsidiaries are engaged in marketing the Company’s products in Europe.
	Need to Raise Additional Capital
	From inception to March 31, 2014, the Company has incurred losses totaling approximately $367.1 million and has not generated positive cash flows from operations. The Company expects such losses to continue through at least the year ending December 31, 2014 as it continues to commercialize its technologies and develop new applications and technologies. The Company faces significant uncertainty related to recently introduced legislation impacting our healthcare system and how such changes will affect the procurement policies of our hospital customer base. The Company also faces uncertainty related to the commercialization of its Magellan Robotic System and its projected revenue is heavily dependent on a successful commercialization of this system. The Company anticipates its existing cash, cash equivalents, short-term investment and restricted cash balances as of March 31, 2014 and the estimated amounts received through the sale of its products and services will not be sufficient to meet its anticipated cash requirements for the next twelve months. In order to continue operations, the Company will need to raise additional funding and may attempt to do so at any time by selling equity or debt securities, licensing core or non-core intellectual property assets, entering into future research and development funding arrangements, refinancing or restructuring existing debt arrangements or entering into a credit facility in order to meet its continuing cash needs. The Company cannot guarantee that future equity or debt financing or credit facilities will be available in amounts or on terms acceptable to it, if at all. The Company can not guarantee that it will be able to license core or non-core intellectual property assets or enter into future research and development funding arrangements. If such financing, licensing, funding or credit arrangements do not meet the Company’s longer term needs or if future sales do not meet the Company’s current forecast, the Company may be required to extend its existing liquidity by adopting cost-cutting measures, including reductions in its work force, reducing the scope of, delaying or eliminating some or all of its planned research, development and commercialization activities and/or reducing marketing, customer support or other resources devoted to the Company’s products. Any of these factors could harm the Company’s financial condition. Failure to meet projected revenue levels, raise additional funding or manage spending may adversely impact the Company’s ability to achieve its long term intended business objectives. The Company will continue to evaluate its financial condition based upon changing future economic conditions and the achievement of estimated revenue and will consider the implementation of cost reductions if and as circumstances warrant.
	Going Concern
	These condensed consolidated financial statements are prepared on a going concern basis that contemplates the realization of assets and discharge of liabilities in the normal course of business. As of March 31, 2014, the Company’s cash, cash equivalents, short-term investments and restricted cash balances were $38.4 million. The Company incurred an operating loss of $14.4 million and negative cash flows from operations of $10.8 million for the three months ended March 31, 2014. The Company is subject to minimum liquidity requirements under its existing borrowing arrangements with White Oak Global Advisors, LLC which require the Company to maintain $15.0 million in liquidity at all times, consisting of at least $13.0 million in cash, cash equivalents and investments, of which $5.0 million is required to be restricted subject to lenders’ control, and up to $2.0 million in certain accounts receivable. Based on the Company’s current operating projections, the Company does not have sufficient liquidity to meet its anticipated cash requirements through the next twelve months. These factors raise substantial doubt about the Company’s ability to continue as a going concern. In order to continue its operations, the Company will need to either obtain sufficient additional financing or adopt cost-cutting measures to sufficiently extend its cash and liquidity. There can be no assurance, however, that such a financing will be successfully completed on terms acceptable to the Company or that the Company can implement cost cutting measures sufficient to extend its cash and liquidity. Management is currently considering various financing alternatives. The accompanying consolidated financial statements do not include any adjustments that might result from the outcome of this uncertainty.

Summary_of_Significant_Account

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2014
Summary of Significant Accounting Policies	'
	2	Summary of Significant Accounting Policies
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and therefore do not contain all of the information and footnotes required by GAAP and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for annual financial statements. The Company’s fiscal year ends on December 31. The condensed consolidated balance sheet as of December 31, 2013 was derived from audited financial statements. In the opinion of the Company’s management, these statements include all adjustments, which are of a normal recurring nature, necessary to present a fair presentation. Interim results are not necessarily indicative of results for a full year or any other interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 as filed with the SEC.
	The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates relate to the recognition of revenue, the evaluation of customer credit risk, the valuation of investments, inventory valuations, the determination of impairment of assets, stock-based compensation, loss contingencies and the valuation of our deferred tax assets, among others. Actual results may differ from those estimates.
	Revenue Recognition
	The Company’s revenues are primarily derived from the sale of the Sensei system and the Magellan Robotic System and the associated catheters as well as the sale of customer service contracts. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is probable.
		•	Persuasive Evidence of an Arrangement. Persuasive evidence of an arrangement for sales of systems is generally determined by a sales contract signed and dated by both the customer and the Company, including approved terms and conditions and the receipt of an approved purchase order. Evidence of an arrangement for the sale of disposable products is determined through an approved purchase order from the customer. Evidence of an arrangement for the sale of customer service is determined through either a signed sales contract or an approved purchase order from the customer. Sales to customers are generally not subject to any performance, cancellation, termination or return rights.
		•	Delivery.
		•	Systems and Disposable Products. Typically, ownership of systems, catheters and other disposable products passes to customers upon shipment, at which time delivery is deemed to be complete.
		•	Customer Service Revenue. The Company recognizes customer service revenue from the sale of product maintenance plans. Revenue from customer services, whether sold individually or as a separate unit of accounting in a multi-element arrangement, is deferred and amortized over the service period, which is typically one year.
		•	Multiple-element Arrangements. It is common for the sale of Sensei and Magellan systems to include multiple elements which qualify as separate units of accounting. These elements commonly include the sale of the system and a product maintenance plan, in addition to installation of the system and initial training. Less commonly, these elements may include the sale of certain disposable products or other elements. Generally, under multiple-element arrangements, the systems are delivered at the beginning of the arrangement and the related revenue is recognized at that time. Installation and training is generally completed within 90 days at which time the revenue is recognized. Customer service revenue associated with the product maintenance plan is recognized ratably over the service period, which is typically one year. Other elements are recognized once delivered in accordance with contract terms. In arrangements that include multiple elements, the Company allocates revenue to the various elements based on vendor-specific objective evidence of fair value (“VSOE”) of the elements if VSOE exists. VSOE for each element is based on the price for which the item is sold separately, determined based on historical evidence of stand-alone sales of these elements or stated renewal rates for the element. If VSOE does not exist for an element, the Company allocates revenue based on third-party evidence (“TPE”) of selling price for the elements if TPE exists. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in standalone sales to similarly-situated customers. If neither VSOE nor TPE exist for a specific element, the Company allocates revenue to the various elements based on its best estimate of the selling price for that element or estimated selling price (“ESP”) using a top-down approach, which takes into account the Company’s target prices and overall pricing objectives. In situations where the Company has delivered certain elements but not delivered other elements, the Company, after it has allocated revenue to the various elements under the relative selling price method based on VSOE, TPE or ESP, defers revenue for the undelivered elements. Because the Company has neither VSOE nor TPE for its systems, the allocation of revenue is based on ESP for the systems sold. The Company determines ESP for its systems by considering multiple factors, including, but not limited to, features and functionality of the system, geographies, type of customer, and market conditions. The Company regularly reviews ESP and maintains internal controls over the establishment and updates of these estimates.
		•	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment The Company’s standard terms do not allow for contingencies, such as trial or evaluation periods, refundable orders, payments contingent upon the customer obtaining financing or other contingencies which would impact the customer’s obligation. In situations where these or other contingencies are included, all related revenue is deferred until the contingency is resolved. In the third quarter of 2012, the Company began shipping systems under a limited commercial evaluation program to allow certain strategic accounts to install and utilize systems for a limited trial period while the purchase opportunity is being evaluated by the hospital. Systems under this program remain the property of the Company and are recorded in inventory and a sale only occurs upon the issuance of a purchase order from the customer.
		•	Collectability. The Company assesses whether collection is probable based on a number of factors, including the customer’s past transaction history and credit worthiness. If collection of the sales price is not deemed probable, the revenue is deferred and recognized at the time collection becomes probable, which is usually upon receipt of cash. The Company’s sales contracts generally do not allow the customer the right of cancellation, refund or return, except as provided under the Company’s standard warranty. If such rights were allowed, all related revenues would be deferred until such rights expired.
	Significant management judgments and estimates are made in connection with the determination of revenue to be recognized and the period in which it is recognized. If different judgments and estimates were utilized, the amount of revenue to be recognized and the period in which it is recognized could differ materially from the amounts reported.
	Concentration of Credit Risk
	The Company had three customers who constituted 28%, 15%, and 12%, respectively of the Company’s net accounts receivable at March 31, 2014. The Company had three customers who constituted 26%, 22%, and 10%, respectively of the Company’s net accounts receivable at December 31, 2013. Two customers accounted for 30% and 13%, respectively of revenues during the three months ended March 31, 2014. Two customers accounted for 15% and 10%, respectively of revenues during the three months ended March 31, 2013. As of March 31, 2014, the Company has not experienced any significant losses on its accounts receivable.
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The standard will be effective for the Company beginning January 1, 2014. The Company adopted this guidance in the first quarter of 2014. The adoption of ASU 2013-11 did not have a material impact on the Company’s consolidated financial position or results of operations.

Fair_Value_of_Assets_and_Liabi

Fair Value of Assets and Liabilities	3 Months Ended
	Mar. 31, 2014
Fair Value of Assets and Liabilities	'
	3	Fair Value of Assets and Liabilities
	The amortized cost and fair value of assets, along with gross unrealized gains and losses, for the periods ended March 31, 2014 and December 31, 2013 were as follows (in thousands):
			Amortized		Gross		Gross		Fair		Balance Sheet Classification
			Cost		Unrealized		Unrealized		Value
					Gains		Losses				Cash and		Short-term		Restricted
											cash		Investments		Cash
											Equivalents
	March 31, 2014:
	Cash		$	10,144	$	—	$	—	$	10,144	$	10,144	$	—	$	—
	Money market funds			26,226		—		—		26,226		20,832		—		5,394
	Corporate equity securities			1,572		456		—		2,028		—		2,028		—
			$	37,942	$	456	$	—	$	38,398	$	30,976	$	2,028	$	5,394
	December 31, 2013:
	Cash		$	1,665	$	—	$	—	$	1,665	$	1,665	$	—	$	—
	Money market funds			31,724		—		—		31,724		26,330		—		5,394
	Corporate equity securities			1,572		373		—		1,945		—		1,945		—
			$	34,961	$	373	$	—	$	35,334	$	27,995	$	1,945	$	5,394
	The Company periodically assesses whether significant facts and circumstance have arisen to indicate that an impairment, which is other than temporary, of the fair value of any underlying investment has occurred. In fiscal 2010, 2011 and 2013, the Company determined that the impairment of its investment in Luna Innovations’, or Luna, common stock was other than temporary and as such wrote down the value of that investment and recorded a loss of $1.9 million, $0.3 million and $0.6 million, respectively in other expense on the consolidated statement of operations. No investments have been in an unrealized loss position for longer than twelve months.
	Fair Value Measurements
	GAAP defines fair value as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, authoritative guidance establishes a three-tier value hierarchy, which prioritizes the inputs used in measuring fair value as follows:
	•   Level 1 Inputs		Quoted prices (unadjusted) in active markets for identical assets or liabilities.
	•   Level 2 Inputs		Inputs other than quoted prices in active markets that are observable either directly or indirectly.
	•   Level 3 Inputs		Unobservable inputs in which there is little or no market data, which require the Company to develop its own assumptions.
	This hierarchy requires the use of observable market data when available and to minimize the use of unobservable inputs when determining fair value. Investment instruments valued using Level 1 inputs include money market securities and certain of the corporate equity securities which were obtained by the Company as part of the Luna litigation settlement, which are currently marketable.
	Investment instruments valued using Level 2 inputs include investment-grade corporate debts, such as bonds and commercial paper and U.S. governmental agency securities. The fair value of these investments is determined based on modeling techniques that include inputs such as the credit rating of the company issuing the debt and the observable market value of similarly-termed corporate debts with similar credit ratings.
	The fair value hierarchy of the Company’s assets is as follows (in thousands):
			Fair Value Measurements Using
			Quoted Prices in		Significant other		Unobservable		Total
			Active Markets for		Observable		Inputs
			Identical Assets		Inputs		(Level 3 Inputs)
			(Level 1 Inputs)		(Level 2 Inputs)
	March 31, 2014:
	Money market funds		$	26,226	$	—	$	—	$	26,226
	Corporate equity securities			2,028		—		—		2,028
			$	28,254	$	—	$	—	$	28,254
	December 31, 2013:
	Money market funds		$	31,724	$	—	$	—	$	31,724
	Corporate equity securities			1,945		—		—		1,945
			$	33,669	$	—	$	—	$	33,669
	The fair value of the Company’s long-term debt was estimated to be $33.6 million as of March 31, 2014 based on an internal valuation model that utilized the then-current rates available to the Company for debt of a similar term and remaining maturity, which constitutes Level 2 inputs under the fair value hierarchy. Considerable judgment is required in interpreting market data to develop estimates of fair value. Accordingly, the fair value estimate presented herein is not necessarily indicative of the amount that the Company or holders of the instruments could realize in a current market exchange. The use of different assumptions and/or estimation methodologies may have a material effect on the estimated fair value. See Note 8 for further information regarding the Company’s long-term debt.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2014
Inventories	'
	4	Inventories (in thousands)
			March 31,		December 31,
			2014		2013
	Raw materials		$	4,216	$	4,167
	Work in process			4,731		5,285
	Finished goods			3,081		2,751
	Inventories		$	12,028	$	12,203

Agreements_with_Intuitive_Surg

Agreements with Intuitive Surgical	3 Months Ended
	Mar. 31, 2014
Agreements with Intuitive Surgical	'
	5	Agreements with Intuitive Surgical
	In October 2012, the Company signed an updated license agreement with Intuitive Surgical Operations, Inc. and Intuitive Surgical, Inc. (collectively, “Intuitive Surgical”), under which Intuitive Surgical paid the Company a $20 million licensing fee, and a stock purchase agreement to sell 5,291,000 shares of the Company’s common stock to Intuitive Surgical for an aggregate purchase price of $10 million. The amendment of the license agreement is an update to the co-exclusive cross license agreement signed by the companies in 2005. Under the terms of the amended agreement, Intuitive Surgical’s existing co-exclusive rights to the Company’s patent portfolio to certain non-vascular procedures have been extended to include patents filed or conceived by the Company subsequent to the original 2005 agreement up to and including the period three years subsequent to the amendment though the Company has no obligations to conduct any research activities under the amendment. The Company retains the right to use its intellectual property for all clinical applications, both vascular and non-vascular.

Agreements_with_Philips

Agreements with Philips	3 Months Ended
	Mar. 31, 2014
Agreements with Philips	'
	6	Agreements with Philips
	In February 2011, the Company entered, directly and through a wholly-owned subsidiary, into patent and technology license, sublicense and purchase agreements with Philips to allow them to develop and commercialize the non-robotic applications of the Company’s Fiber Optic Shape Sensing and Localization (“FOSSL”) technology. Under the terms of the agreements, Philips has the exclusive right to develop and commercialize the FOSSL technology in the non-robotic vascular, endoluminal and orthopedic fields. Philips also receives non-exclusive rights in other non-robotic medical device fields, but not to any multi-degree of freedom robotic applications. If Philips does not meet certain specified commercialization obligations, the Company has the rights to re-acquire the licenses granted to Philips for pre-determined payments, which payments in the aggregate would be greater than the upfront payment amounts received by the Company from Philips in connection with the agreements related to the FOSSL technology. The agreement also contains customary representations, warranties and indemnification provisions by each party. Each party may terminate the agreements for material breach by the other party. Philips also has the right to terminate the agreement and its rights under the agreement if the Company is acquired by a competitor of the relevant business unit of Philips.
	Also in February 2011, the Company amended its extended joint development agreement with Philips, increasing the amount of funding provided by Philips for the development of the Vascular System and potentially extending and increasing certain royalty fees to be paid to Philips based on sales of Vascular robotic platform and associated catheters (the “Vascular System”), subject to caps based on the amounts Philips contributes to the development of the system. Under the amendment, the Company will be eligible to receive up to an additional $78.0 million in future payments associated with the successful commercialization by Philips or its collaborators of products containing FOSSL technology. Approximately two-thirds of these potential future payments could arise from Philips’ sublicensing the FOSSL technology and approximately one-third of the potential future payments are based on Philips’ royalty obligations on its sales of products containing the FOSSL technology. The Company would receive less than half of Philips’ proceeds for its sublicensing FOSSL technology, if and following Philips entering into an applicable sublicensing transaction. Philips’ FOSSL-related royalty obligations are calculated on a consistent annual basis between 2014 and 2020 and arise in any year only to the extent that Philips achieves a substantial number of commercial placements of FOSSL-enabled products in the calendar year.

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments and Contingencies	'
	7	Commitments and Contingencies
	Operating Commitments
	The Company rents its office and laboratory facilities in Mountain View, California under an operating lease which has been extended until January 2020, with an option to extend the lease for another five years. The Company also leases approximately 3,300 square feet of office space in London, England. That lease ends in June 2020, but the Company has an option to exit the lease in 2015.
	As of March 31, 2014, future minimum payments under the leases are as follows (in thousands):
	Years ending December 31,		Future Minimum
			Lease Payments
	2014 (remainder of the year)		$	1,612
	2015			1,979
	2016			2,140
	2017			2,205
	Thereafter			4,415
	Total		$	12,351
	Rent expense on a straight-line basis was $0.7 million and $0.6 million for the three months ended March 31, 2014 and 2013, respectively.
	Post-contract Customer Service and Warranties
	The Company generally provides one year of post-contract customer service on the sale of its systems. Post-contract customer service revenue is recognized ratably over the term of the service period and associated expenses are charged to cost of revenues as incurred. The Company provides a limited warranty on the sale of systems and catheters and records a warranty reserve at the time of sale to cover the estimated warranty costs. The Company’s warranty obligation may be impacted by product failure rates, material usage and service costs associated with its warranty obligations. The Company periodically evaluates and adjusts the warranty reserve to the extent actual warranty expense differs from the original estimates. Movement in the warranty liability was as follows (in thousands):
			Three Months Ended March 31,
			2014			2013
	Balance at beginning of period		$	9		$	9
	Warranties issued during the period			66			92
	Warranty costs incurred during the period			(66	)		(92	)
	Balance at end of period		$	9		$	9
	Other
	The Company has minimum royalty obligations of $100,000 per year under a license agreement with Mitsubishi Electric Research Laboratories, Inc. which reduces to $55,000 per year if the license becomes non-exclusive. The royalty obligation expires in 2018. The Company also has minimum royalty obligations of $200,000 per year under the terms of its cross license agreement with Intuitive Surgical. Additionally, the Company also has royalty obligations under the amended joint development agreement with Philips which provides for the payment of royalties to Philips through October 2017.
	Legal Proceedings
	From time to time, the Company is involved in litigation that it believes is of the type common to companies engaged in its line of business, including commercial disputes and employment issues. As of the date of this Quarterly Report on Form 10-Q, the Company was not involved in any pending legal proceedings that it believes could have a material adverse effect on its financial condition, results of operations or cash flows. From time to time, the Company may pursue litigation to assert its legal right and such litigation may be costly and divert the efforts and attention of its management and technical personnel which could adversely affect its business.

Longterm_Debt

Long-term Debt	3 Months Ended
	Mar. 31, 2014
Long-term Debt	'
	8	Long-term Debt
	Oxford Loan
	In December 2011, the Company entered into a $30.0 million loan and security agreement with Oxford Finance LLC and Silicon Valley Bank (the “Oxford Loan”). Under the agreement, the Company was obligated to pay interest only payments on the Oxford Loan through June 30, 2013, following which time the Oxford Loan required interest and principal payments through January 1, 2016. The Oxford Loan accrued interest at a stated rate of 9.45% and included an additional final interest payment of 3.95% of the original principal amount. The Oxford Loan provided for a prepayment option that allowed the Company to prepay all of the outstanding principal balance, subject to a pre-payment fee. In August 2013, the Oxford Loan was fully repaid and extinguished under the loan agreement’s prepayment option.
	In connection with the Oxford Loan, the Company issued warrants to purchase 660,793 shares of common stock. The warrants have an exercise price of $2.27 per share and expire in December 2018.
	White Oak Loan
	In July 2013, the Company executed a secured term loan agreement with White Oak Global Advisors, LLC (“White Oak”), as a lender and agent for several lenders. On August 23, 2013, the loan agreement was amended and restated and the loan was funded. The amended loan agreement provides for term loan debt financing of $33.0 million with a single principal balloon payment due at maturity on December 30, 2017. Cash interest accrues at an 11.0% per annum rate and is payable quarterly. Additionally, a 3.0% per annum payment-in-kind accrues quarterly and is accretive to the principal amount owed under the agreement. Substantially all of the proceeds from the loan were used to fully repay and extinguish the prior Oxford Loan. In connection with the loan, the Company incurred costs of approximately $1.5 million including payments to the lender agent totaling $0.7 million and the placement agent totaling $0.3 million that in aggregate are accounted for as debt issuance costs and amortized to interest expense over the life of the loan. Under the amended loan agreement, the Company is obligated to pay White Oak certain servicing, administration and monitoring fees of $32,000 annually. The Company may prepay all or a portion of the outstanding principal balance, subject to paying a prepayment fee of 3.5% of the principal amount of the loan prepaid if the prepayment is made on or before the third anniversary of the funding of the loan or 1.0% of the principal amount of the loan prepaid if the prepayment is made after the third anniversary and on or before the fourth anniversary of the funding of the loan. In addition, if the Company elects to prepay all or a portion of the outstanding principal balance on or prior to August 23, 2014, the Company will be required to pay an additional make-whole amount pursuant to the agreement. The Company is also required to make mandatory prepayments upon certain events of loss and certain dispositions of the Company’s assets as described in the amended loan agreement. In the first quarter of 2014, the Company recognized expense of $0.1 million for the amortization of debt issuance costs related to the White Oak loan.
	The loan is collateralized by substantially all of the Company’s assets then owned or thereafter acquired, other than its intellectual property, and all proceeds and products thereof. Two of the Company’s wholly-owned subsidiaries, AorTx, Inc. and Hansen Medical International, Inc., have entered into agreements to guarantee the Company’s obligations under the amended loan agreement and have granted first priority security interests in their assets, excluding any of their intellectual property, to secure their guarantee obligations. Under the amended loan agreement, neither the Company nor AorTx, Inc. and Hansen Medical International, Inc. may grant a lien on any intellectual property to third parties. The Company additionally agreed to pledge to lenders shares of each of its direct and indirect subsidiaries as collateral for the loan. Pursuant to the loan agreement, the Company is subject to certain affirmative and negative covenants and also to minimum liquidity requirements which require the Company to maintain $15.0 million in liquidity at all times, consisting of at least $13.0 million in cash, cash equivalents and investments, of which $5.0 million is required to be restricted subject to lenders’ control, and up to $2.0 million in certain accounts receivable. The loan also limits the Company’s ability to (a) undergo certain change of control events; (b) convey, sell, lease, transfer, assign or otherwise dispose of any of its assets; (c) create, incur, assume, or be liable with respect to certain indebtedness, not including, among other items, subordinated debt; (d) grant liens; (e) pay dividends and make certain other restricted payments; (f) make certain investments; (g) make payments on any subordinated debt; or (g) enter into transactions with any of its affiliates outside of the ordinary course of business, or permit its subsidiaries to do the same. We are also required to make mandatory prepayments upon certain events of loss and certain dispositions of our assets described in the amended loan agreement. In the event the Company were to violate any covenants or if White Oak has reason to believe that the Company has violated any covenants including a significant adverse event clause, and such violations are not cured pursuant to the terms of the loan and security agreement, the Company would be in default under the loan and security agreement, which would entitle lenders to exercise their remedies, including the right to accelerate the debt, upon which the Company may be required to repay all amounts then outstanding under the loan and security agreement. As of March 31, 2014, the Company was in compliance with all financial covenants.
	Future annual payments due on the debt outstanding as of March 31, 2014 are as follows (in thousands):
	Year ending December 31,
	2014 (remainder of the year)		$	2,846
	2015			3,879
	2016			4,009
	2017			41,781
	Total remaining payments			52,515
	Less: Amount representing interest			(18,907	)
				33,608
	Less: Current portion of long-term debt			—
	Long-term debt, net of current portion		$	33,608

Stockholders_Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2014
Stockholders' Equity	'
	9	Stockholders’ Equity
	Stock-based Compensation
	Total stock-based compensation expense was allocated as follows (in thousands):
			Three Months Ended March 31,
			2014			2013
	Cost of revenues		$	44		$	120
	Research and development			180			333
	Selling, general and administrative			533			687
	Total		$	757		$	1,140
	The Company uses the Black-Scholes option pricing model to determine the fair value of stock options. The determination of the fair value of stock options on the date of grant is affected by our stock price as well as assumptions regarding a number of complex and subjective variables. These variables include the Company’s expected stock price volatility over the term of the award, expected term, risk-free interest rate and expected dividend rate. The Company estimates the expected term based on its historical experience of grants, exercise pattern and post-vesting cancellations. The Company considered its historical volatility over the expected term and implied volatility of traded stock options in developing its estimate of volatility. The estimated grant date fair values of the employee stock options issued under the 2006 Equity Incentive Plan for the periods presented were calculated using the following assumptions:
			Three Months Ended March 31,
			2014		2013
	Expected volatility		72%-74%		87%
	Risk-free interest rate		1.2%-1.5%		0.6%-0.7%
	Expected term (in years)		4.34		4.38
	Dividend yield		0%		0%
	The estimated fair values of the shares issued under the Company’s Employee Stock Purchase Plan were calculated using the following assumptions:
			Three Months Ended March 31,
			2014			2013
	Expected volatility			99	%		72	%
	Risk-free interest rate			0.1	%		0.1	%
	Expected term (in years)			0.5			0.5
	Dividend yield			0	%		0	%
	Stock Option and Equity Incentive Plans
	Option activity under the Company’s 2002 Stock Option Plan and 2006 Equity Incentive Plan was as follows:
			Shares			Weighted-			Weighted-		Aggregate
						Average			Average		Intrinsic
						Exercise			Remaining		Value
						Price			Contractual
									Term
			(in thousands)						(in years)		(in thousands)
	Balance at January 1, 2014			7,779		$	3.24			4.76	$	169
	Granted			958		$	2.32
	Exercised			(466	)	$	2.08
	Cancelled and expired			(1,003	)	$	6.82
	Balance at March 31, 2014			7,268		$	2.7			5.37	$	2,979
	Options vested and expected to vest at March 31, 2014			7,151		$	2.67			5.39	$	2,944
	Options vested at March 31, 2014			3,804		$	3.15			4.09	$	1,396
	As of March 31, 2014, total unamortized stock-based compensation related to unvested stock options was $4.2 million, with a weighted-average recognition period of 2.51 years.
	Restricted stock unit activity under the 2006 Equity Incentive Plan was as follows:
			Restricted Stock			Weighted-
			Units			Average Grant-
						Date Fair Value
			(in thousands)
	Balance at January 1, 2014			1,318		$	1.99
	Awarded			224		$	2.51
	Vested			(624	)	$	2
	Cancelled			(387	)	$	2.01
	Balance at March 31, 2014			531		$	2.19
	As of March 31, 2014, total unamortized stock-based compensation related to unvested restricted stock units was $0.9 million, with a weighted-average remaining recognition period of 2.62 years.
	As of March 31, 2014, 6,373,228 shares of common stock were available for grant under the 2006 Equity Incentive Plan.
	Equity Transactions
	In the first quarter of 2014, subsequent to the receipt of regulatory approval for the new 6Fr Magellan catheter in the U.S., Series A warrants for 11.4 million shares of the Company’s common stock were exercised for total proceeds of $14.0 million in accordance with the terms and conditions of a securities purchase agreement dated July 30, 2013. As of March 31, 2014, the Company had remaining outstanding warrants exercisable for up to 22.8 million shares of common stock, which if exercised in full would yield gross proceeds of approximately $39.8 million.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2014
Income Taxes	'
	10	Income Taxes
	The Company’s tax provision for the three months ended March 31, 2014 was $18 thousand, which primarily related to foreign taxes. The Company currently has uncertain tax positions related to research and development credits. If the Company is able to eventually recognize these uncertain tax positions, all of the unrecognized benefit would reduce the Company’s effective tax rate. The Company currently has a full valuation allowance against its net deferred tax asset which would impact the timing of the effective tax rate benefit should any of these uncertain tax positions be favorably settled in the future.

Net_Loss_Per_Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2014
Net Loss Per Share	'
	11	Net Loss Per Share
	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data):
			Three Months Ended
			March 31,
			2014			2013
	Net loss		$	(14,445	)	$	(17,187	)
	Weighted average shares used to calculated basic and diluted net loss per share			103,334			67,296
	Basic and diluted net loss per share		$	(0.14	)	$	(0.26	)
	The following securities that could potentially dilute basic net loss per share are not included in the calculation of diluted net loss per share because to do so would be anti-dilutive as of the end of each period presented (in thousands):
			March 31,
			2014			2013
	Stock options outstanding			7,268			8,351
	Unvested restricted stock units			531			1,838
	Estimated shares to be issued under the employee stock purchase plan			157			155
	Warrants			23,425			661

Subsequent_Events

Subsequent Event(s)	3 Months Ended
	Mar. 31, 2014
Subsequent Event(s)	'
	12	Subsequent Event(s)
	On May 6, 2014, the Company announced that effective May 23, 2014, Mr. Cary Vance will be appointed as its President, Chief Executive Officer and member of its Board of Directors. Mr. Christopher P. Lowe, the Company’s interim Chief Executive Officer will step down from that position on May 23, 2014 but will continue to serve as a member of the Company’s Board of Directors.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2014
Basis of Presentation	'
	Basis of Presentation
	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (“GAAP”) for interim financial information and therefore do not contain all of the information and footnotes required by GAAP and the rules and regulations of the Securities and Exchange Commission (the “SEC”) for annual financial statements. The Company’s fiscal year ends on December 31. The condensed consolidated balance sheet as of December 31, 2013 was derived from audited financial statements. In the opinion of the Company’s management, these statements include all adjustments, which are of a normal recurring nature, necessary to present a fair presentation. Interim results are not necessarily indicative of results for a full year or any other interim period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2013 as filed with the SEC.
	The accompanying condensed consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	'
	Use of Estimates
	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Significant estimates relate to the recognition of revenue, the evaluation of customer credit risk, the valuation of investments, inventory valuations, the determination of impairment of assets, stock-based compensation, loss contingencies and the valuation of our deferred tax assets, among others. Actual results may differ from those estimates.
Revenue Recognition	'
	Revenue Recognition
	The Company’s revenues are primarily derived from the sale of the Sensei system and the Magellan Robotic System and the associated catheters as well as the sale of customer service contracts. Under the Company’s revenue recognition policy, revenues are recognized when persuasive evidence of an arrangement exists, delivery to the customer has occurred or the services have been fully rendered, the sales price is fixed or determinable and collectability is probable.
		•	Persuasive Evidence of an Arrangement. Persuasive evidence of an arrangement for sales of systems is generally determined by a sales contract signed and dated by both the customer and the Company, including approved terms and conditions and the receipt of an approved purchase order. Evidence of an arrangement for the sale of disposable products is determined through an approved purchase order from the customer. Evidence of an arrangement for the sale of customer service is determined through either a signed sales contract or an approved purchase order from the customer. Sales to customers are generally not subject to any performance, cancellation, termination or return rights.
		•	Delivery.
		•	Systems and Disposable Products. Typically, ownership of systems, catheters and other disposable products passes to customers upon shipment, at which time delivery is deemed to be complete.
		•	Customer Service Revenue. The Company recognizes customer service revenue from the sale of product maintenance plans. Revenue from customer services, whether sold individually or as a separate unit of accounting in a multi-element arrangement, is deferred and amortized over the service period, which is typically one year.
		•	Multiple-element Arrangements. It is common for the sale of Sensei and Magellan systems to include multiple elements which qualify as separate units of accounting. These elements commonly include the sale of the system and a product maintenance plan, in addition to installation of the system and initial training. Less commonly, these elements may include the sale of certain disposable products or other elements. Generally, under multiple-element arrangements, the systems are delivered at the beginning of the arrangement and the related revenue is recognized at that time. Installation and training is generally completed within 90 days at which time the revenue is recognized. Customer service revenue associated with the product maintenance plan is recognized ratably over the service period, which is typically one year. Other elements are recognized once delivered in accordance with contract terms. In arrangements that include multiple elements, the Company allocates revenue to the various elements based on vendor-specific objective evidence of fair value (“VSOE”) of the elements if VSOE exists. VSOE for each element is based on the price for which the item is sold separately, determined based on historical evidence of stand-alone sales of these elements or stated renewal rates for the element. If VSOE does not exist for an element, the Company allocates revenue based on third-party evidence (“TPE”) of selling price for the elements if TPE exists. TPE is the price of the Company’s or any competitor’s largely interchangeable products or services in standalone sales to similarly-situated customers. If neither VSOE nor TPE exist for a specific element, the Company allocates revenue to the various elements based on its best estimate of the selling price for that element or estimated selling price (“ESP”) using a top-down approach, which takes into account the Company’s target prices and overall pricing objectives. In situations where the Company has delivered certain elements but not delivered other elements, the Company, after it has allocated revenue to the various elements under the relative selling price method based on VSOE, TPE or ESP, defers revenue for the undelivered elements. Because the Company has neither VSOE nor TPE for its systems, the allocation of revenue is based on ESP for the systems sold. The Company determines ESP for its systems by considering multiple factors, including, but not limited to, features and functionality of the system, geographies, type of customer, and market conditions. The Company regularly reviews ESP and maintains internal controls over the establishment and updates of these estimates.
		•	Sales Price Fixed or Determinable. The Company assesses whether the sales price is fixed or determinable at the time of the transaction. Sales prices are documented in the executed sales contract or purchase order received prior to shipment The Company’s standard terms do not allow for contingencies, such as trial or evaluation periods, refundable orders, payments contingent upon the customer obtaining financing or other contingencies which would impact the customer’s obligation. In situations where these or other contingencies are included, all related revenue is deferred until the contingency is resolved. In the third quarter of 2012, the Company began shipping systems under a limited commercial evaluation program to allow certain strategic accounts to install and utilize systems for a limited trial period while the purchase opportunity is being evaluated by the hospital. Systems under this program remain the property of the Company and are recorded in inventory and a sale only occurs upon the issuance of a purchase order from the customer.
		•	Collectability. The Company assesses whether collection is probable based on a number of factors, including the customer’s past transaction history and credit worthiness. If collection of the sales price is not deemed probable, the revenue is deferred and recognized at the time collection becomes probable, which is usually upon receipt of cash. The Company’s sales contracts generally do not allow the customer the right of cancellation, refund or return, except as provided under the Company’s standard warranty. If such rights were allowed, all related revenues would be deferred until such rights expired.
	Significant management judgments and estimates are made in connection with the determination of revenue to be recognized and the period in which it is recognized. If different judgments and estimates were utilized, the amount of revenue to be recognized and the period in which it is recognized could differ materially from the amounts reported.
Concentration of Credit Risk	'
	Concentration of Credit Risk
	The Company had three customers who constituted 28%, 15%, and 12%, respectively of the Company’s net accounts receivable at March 31, 2014. The Company had three customers who constituted 26%, 22%, and 10%, respectively of the Company’s net accounts receivable at December 31, 2013. Two customers accounted for 30% and 13%, respectively of revenues during the three months ended March 31, 2014. Two customers accounted for 15% and 10%, respectively of revenues during the three months ended March 31, 2013. As of March 31, 2014, the Company has not experienced any significant losses on its accounts receivable.
Recent Accounting Pronouncements	'
	Recent Accounting Pronouncements
	In July 2013, the Financial Accounting Standards Board (“FASB”) issued ASU 2013-11, Income Taxes (Topic 740): Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward, a Similar Tax Loss, or a Tax Credit Carryforward Exists. The standard will be effective for the Company beginning January 1, 2014. The Company adopted this guidance in the first quarter of 2014. The adoption of ASU 2013-11 did not have a material impact on the Company’s consolidated financial position or results of operations.

Fair_Value_of_Assets_and_Liabi1

Fair Value of Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2014
Amortized Cost and Fair Value of Assets, with Gross Unrealized Gains and Losses	'
	The amortized cost and fair value of assets, along with gross unrealized gains and losses, for the periods ended March 31, 2014 and December 31, 2013 were as follows (in thousands):
		Amortized		Gross		Gross		Fair		Balance Sheet Classification
		Cost		Unrealized		Unrealized		Value
				Gains		Losses				Cash and		Short-term		Restricted
										cash		Investments		Cash
										Equivalents
	March 31, 2014:
	Cash	$	10,144	$	—	$	—	$	10,144	$	10,144	$	—	$	—
	Money market funds		26,226		—		—		26,226		20,832		—		5,394
	Corporate equity securities		1,572		456		—		2,028		—		2,028		—
		$	37,942	$	456	$	—	$	38,398	$	30,976	$	2,028	$	5,394
	December 31, 2013:
	Cash	$	1,665	$	—	$	—	$	1,665	$	1,665	$	—	$	—
	Money market funds		31,724		—		—		31,724		26,330		—		5,394
	Corporate equity securities		1,572		373		—		1,945		—		1,945		—
		$	34,961	$	373	$	—	$	35,334	$	27,995	$	1,945	$	5,394
Fair Value Hierarchy of Company's Assets	'
	The fair value hierarchy of the Company’s assets is as follows (in thousands):
		Fair Value Measurements Using
		Quoted Prices in		Significant other		Unobservable		Total
		Active Markets for		Observable		Inputs
		Identical Assets		Inputs		(Level 3 Inputs)
		(Level 1 Inputs)		(Level 2 Inputs)
	March 31, 2014:
	Money market funds	$	26,226	$	—	$	—	$	26,226
	Corporate equity securities		2,028		—		—		2,028
		$	28,254	$	—	$	—	$	28,254
	December 31, 2013:
	Money market funds	$	31,724	$	—	$	—	$	31,724
	Corporate equity securities		1,945		—		—		1,945
		$	33,669	$	—	$	—	$	33,669

Inventories_Tables

Inventories (Tables)	3 Months Ended
	Mar. 31, 2014
Components of Inventories	'
		Inventories (in thousands)
			March 31,		December 31,
			2014		2013
	Raw materials		$	4,216	$	4,167
	Work in process			4,731		5,285
	Finished goods			3,081		2,751
	Inventories		$	12,028	$	12,203

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2014
Future Minimum Payments under Operating Leases	'
	As of March 31, 2014, future minimum payments under the leases are as follows (in thousands):
	Years ending December 31,	Future Minimum
		Lease Payments
	2014 (remainder of the year)	$	1,612
	2015		1,979
	2016		2,140
	2017		2,205
	Thereafter		4,415
	Total	$	12,351
Movement in Warranty Liability during Period	'
	Movement in the warranty liability was as follows (in thousands):
		Three Months Ended March 31,
		2014			2013
	Balance at beginning of period	$	9		$	9
	Warranties issued during the period		66			92
	Warranty costs incurred during the period		(66	)		(92	)
	Balance at end of period	$	9		$	9

Longterm_Debt_Tables

Long-term Debt (Tables)	3 Months Ended
	Mar. 31, 2014
Future Annual Payments Due on Amounts Outstanding	'
	Future annual payments due on the debt outstanding as of March 31, 2014 are as follows (in thousands):
	Year ending December 31,
	2014 (remainder of the year)	$	2,846
	2015		3,879
	2016		4,009
	2017		41,781
	Total remaining payments		52,515
	Less: Amount representing interest		(18,907	)
			33,608
	Less: Current portion of long-term debt		—
	Long-term debt, net of current portion	$	33,608

Stockholders_Equity_Tables

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2014
Total Stock-based Compensation	'
	Total stock-based compensation expense was allocated as follows (in thousands):
		Three Months Ended March 31,
		2014			2013
	Cost of revenues	$	44		$	120
	Research and development		180			333
	Selling, general and administrative		533			687
	Total	$	757		$	1,140
Assumptions Used to Estimate Grant Date Fair Values of Stock Options	'
	The estimated grant date fair values of the employee stock options issued under the 2006 Equity Incentive Plan for the periods presented were calculated using the following assumptions:
		Three Months Ended March 31,
		2014		2013
	Expected volatility	72%-74%		87%
	Risk-free interest rate	1.2%-1.5%		0.6%-0.7%
	Expected term (in years)	4.34		4.38
	Dividend yield	0%		0%
Assumptions Used to Estimate Grant Date Fair Values of Shares Issued Under the ESPP	'
	The estimated fair values of the shares issued under the Company’s Employee Stock Purchase Plan were calculated using the following assumptions:
		Three Months Ended March 31,
		2014			2013
	Expected volatility		99	%		72	%
	Risk-free interest rate		0.1	%		0.1	%
	Expected term (in years)		0.5			0.5
	Dividend yield		0	%		0	%
Summary of Option Activity Under Company's 2002 Stock Option Plan and 2006 Plan	'
	Option activity under the Company’s 2002 Stock Option Plan and 2006 Equity Incentive Plan was as follows:
		Shares			Weighted-			Weighted-		Aggregate
					Average			Average		Intrinsic
					Exercise			Remaining		Value
					Price			Contractual
								Term
		(in thousands)						(in years)		(in thousands)
	Balance at January 1, 2014		7,779		$	3.24			4.76	$	169
	Granted		958		$	2.32
	Exercised		(466	)	$	2.08
	Cancelled and expired		(1,003	)	$	6.82
	Balance at March 31, 2014		7,268		$	2.7			5.37	$	2,979
	Options vested and expected to vest at March 31, 2014		7,151		$	2.67			5.39	$	2,944
	Options vested at March 31, 2014		3,804		$	3.15			4.09	$	1,396
Summary of Restricted Stock Unit Activity	'
	Restricted stock unit activity under the 2006 Equity Incentive Plan was as follows:
		Restricted Stock			Weighted-
		Units			Average Grant-
					Date Fair Value
		(in thousands)
	Balance at January 1, 2014		1,318		$	1.99
	Awarded		224		$	2.51
	Vested		(624	)	$	2
	Cancelled		(387	)	$	2.01
	Balance at March 31, 2014		531		$	2.19

Net_Loss_Per_Share_Tables

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2014
Computation of Basic and Diluted Net Income (Loss) Per Share	'
	The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data):
		Three Months Ended
		March 31,
		2014			2013
	Net loss	$	(14,445	)	$	(17,187	)
	Weighted average shares used to calculated basic and diluted net loss per share		103,334			67,296
	Basic and diluted net loss per share	$	(0.14	)	$	(0.26	)
Common Stock Equivalents that are Not Included In the Calculation of Diluted Net Loss Per Share	'
	The following securities that could potentially dilute basic net loss per share are not included in the calculation of diluted net loss per share because to do so would be anti-dilutive as of the end of each period presented (in thousands):
		March 31,
		2014			2013
	Stock options outstanding		7,268			8,351
	Unvested restricted stock units		531			1,838
	Estimated shares to be issued under the employee stock purchase plan		157			155
	Warrants		23,425			661

The_Company_Additional_Informa

The Company - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Mar. 31, 2014	Aug. 23, 2013	Mar. 31, 2014	Aug. 23, 2013	Mar. 31, 2014	Aug. 23, 2013	Mar. 31, 2014	Aug. 23, 2013
				White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement	White Oak Loan Agreement
						Cash, Cash Equivalents and Investments	Cash, Cash Equivalents and Investments	Restricted Cash and Cash Equivalents	Restricted Cash and Cash Equivalents	Accounts Receivable	Accounts Receivable
Description of Business [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Accumulated net profit or loss from inception	$367,109,000	'	$352,664,000	'	'	'	'	'	'	'	'
Cash, cash equivalents, short-term investments and restricted cash	38,400,000	'	'	'	'	'	'	'	'	'	'
Operating loss	-14,427,000	-17,149,000	'	'	'	'	'	'	'	'	'
Cash flows from operations	-10,752,000	-9,920,000	'	'	'	'	'	'	'	'	'
Minimum liquidity requirement amount	'	'	'	$15,000,000	$15,000,000	$13,000,000	$13,000,000	$5,000,000	$5,000,000	$2,000,000	$2,000,000

Summary_of_Significant_Account2

Summary of Significant Accounting Policies - Additional Information (Detail)

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

3 Months Ended

12 Months Ended

Mar. 31, 2014

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2013

Mar. 31, 2014

Dec. 31, 2013

Accounts Receivable

Accounts Receivable

Sales

Sales

Customer 1

Customer 1

Customer 1

Customer 1

Customer 2

Customer 2

Customer 2

Customer 2

Customer 3

Customer 3

Customer

Customer

Customer

Customer

Accounts Receivable

Accounts Receivable

Sales

Sales

Accounts Receivable

Accounts Receivable

Sales

Sales

Accounts Receivable

Accounts Receivable

Summary Of Significant Accounting Policies [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Deferred and amortized service period

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Period for customer service revenue recognition

'1 year

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revenue recognition, period

'90 days

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Accounts receivable from number of customers

'

3

3

'

'

'

'

'

'

'

'

'

'

'

'

Concentration risk, percentage

'

'

'

'

'

28.00%

26.00%

30.00%

15.00%

15.00%

22.00%

13.00%

10.00%

12.00%

10.00%

Number of major customers

'

'

'

2

2

'

'

'

'

'

'

'

'

'

'

Amortized_Cost_and_Fair_Value_

Amortized Cost and Fair Value of Assets, with Gross Unrealized Gains and Losses (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	$37,942	$34,961
Gross Unrealized Gains	456	373
Gross Unrealized Losses	'	'
Fair Value	38,398	35,334
Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	10,144	1,665
Gross Unrealized Losses	'	'
Fair Value	10,144	1,665
Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	26,226	31,724
Gross Unrealized Losses	'	'
Fair Value	26,226	31,724
Corporate Equity Securities	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Amortized Cost	1,572	1,572
Gross Unrealized Gains	456	373
Gross Unrealized Losses	'	'
Fair Value	2,028	1,945
Cash and Cash Equivalents	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	30,976	27,995
Cash and Cash Equivalents | Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	10,144	1,665
Cash and Cash Equivalents | Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	20,832	26,330
Short-term Investments	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	2,028	1,945
Short-term Investments | Corporate Equity Securities	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	2,028	1,945
Restricted Cash	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	5,394	5,394
Restricted Cash | Money Market Funds	'	'
Cash Cash Equivalents And Short Term Investments [Line Items]	'	'
Fair Value	$5,394	$5,394

Fair_Value_of_Assets_and_Liabi2

Fair Value of Assets and Liabilities - Additional Information (Detail) (USD $)	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2011	Dec. 31, 2010
In Millions, unless otherwise specified	Securities	Luna Innovations Incorporated	Luna Innovations Incorporated	Luna Innovations Incorporated
Fair Value, Measurement Inputs, Disclosure [Line Items]	'	'	'	'
Available-for-sale securities, other than temporary impairment recorded loss in other expense	'	$0.60	$0.30	$1.90
Securities in loss position for less than 12 months	0	'	'	'
Long term debt, fair value	$33.60	'	'	'

Fair_Value_Hierarchy_of_Compan

Fair Value Hierarchy of Company's Assets (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	$28,254	$33,669
Money Market Funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	26,226	31,724
Corporate Equity Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	2,028	1,945
Level 1 Inputs	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	28,254	33,669
Level 1 Inputs | Money Market Funds	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	26,226	31,724
Level 1 Inputs | Corporate Equity Securities	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Assets	$2,028	$1,945

Components_of_Inventories_Deta

Components of Inventories (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Inventory [Line Items]	'	'
Raw materials	$4,216	$4,167
Work in process	4,731	5,285
Finished goods	3,081	2,751
Inventories	$12,028	$12,203

Agreements_with_Intuitive_Surg1

Agreements with Intuitive Surgical - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Oct. 31, 2012	Mar. 31, 2014
Licenses Agreements [Line Items]	'	'
Proceeds from licensing fees	$20	'
Stock purchase agreement to sell shares	5,291,000	'
Common stock agreement purchase price	$10	'
Agreement amendment period	'	'3 years

Agreements_with_Philips_Additi

Agreements with Philips - Additional Information (Detail) (USD $)	1 Months Ended	3 Months Ended
In Millions, unless otherwise specified	Feb. 28, 2011	Mar. 31, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]	'	'
Technology commercialization cash payments to be received in future	$78	'
Potential future payment from sublicensing technology under agreement	'Two-thirds	'
Potential future payment based on royalty obligation under agreement	'One-third	'
FOSSL-related royalty obligations	'	'Between 2014 and 2020

Commitments_and_Contingencies_1

Commitments and Contingencies - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Commitments [Line Items]	'	'
Rent Expense	$700,000	$600,000
Warranties, Description	'The Company generally provides one year of post-contract customer service on the sale of its systems. Post-contract customer service revenue is recognized ratably over the term of the service period and associated expenses are charged to cost of revenues as incurred. The Company provides a limited warranty on the sale of systems and catheters and records a warranty reserve at the time of sale to cover the estimated warranty costs.	'
Post-contract customer service period	'1 year	'
Mitsubishi	'	'
Other Commitments [Line Items]	'	'
Reduction royalty obligation	55,000	'
Royalty obligation expiration Year	'2018	'
Mitsubishi | Minimum	'	'
Other Commitments [Line Items]	'	'
Royalty obligations per year	100,000	'
Intuitive Surgical Inc | Minimum	'	'
Other Commitments [Line Items]	'	'
Royalty obligations per year	$200,000	'
Intuitive Surgical Inc | Maximum	'	'
Other Commitments [Line Items]	'	'
Royalty Payment Obligation	'2017-10	'
California	'	'
Other Commitments [Line Items]	'	'
Operating lease expiration year	31-Jan-20	'
Operating lease extended period	'5 years	'
UNITED KINGDOM	'	'
Other Commitments [Line Items]	'	'
Operating lease expiration year	30-Jun-20	'
Operating lease area leased for office space	3,300	'
Operating lease expiration year	'2015	'

Future_Minimum_Payments_under_

Future Minimum Payments under Operating Leases (Detail) (USD $)	Mar. 31, 2014
In Thousands, unless otherwise specified
Operating Leased Assets [Line Items]	'
2014 (remainder of the year)	$1,612
2015	1,979
2016	2,140
2017	2,205
Thereafter	4,415
Total	$12,351

Changes_in_Warranty_Liability_

Changes in Warranty Liability during Period (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Movement in Standard and Extended Product Warranty, Increase (Decrease) [Roll Forward]	'	'
Balance at beginning of period	$9	$9
Warranties issued during the period	66	92
Warranty costs incurred during the period	-66	-92
Balance at end of period	$9	$9

Long_Term_Debt_Additional_Info

Long - Term Debt - Additional Information (Detail) (USD $)

0 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

Aug. 23, 2013

Mar. 31, 2014

Mar. 31, 2014

Aug. 23, 2013

Mar. 31, 2014

Aug. 23, 2013

Mar. 31, 2014

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Aug. 23, 2013

Dec. 31, 2011

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

White Oak Loan Agreement

Oxford

Cash, Cash Equivalents and Investments

Cash, Cash Equivalents and Investments

Restricted Cash and Cash Equivalents

Restricted Cash and Cash Equivalents

Accounts Receivable

Accounts Receivable

Interest Payment in Cash

Payment in Kind (PIK)

Payment to Lender Agent

Payment to Placement Agent

Principal Prepaid Before Third Anniversary

Principal Prepaid After Third Anniversary

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement

$33,000,000

'

'

'

'

'

'

'

'

'

'

'

'

'

$30,000,000

Interest rate on pay off obligation

'

'

'

'

'

'

'

'

'

'

'

'

'

'

9.45%

Interest payment on the original principal

'

'

'

'

'

'

'

'

'

'

'

'

'

'

3.95%

Common stock warrants issued

'

'

'

'

'

'

'

'

'

'

'

'

'

'

660,793

Exercise price of common stock warrants

'

'

'

'

'

'

'

'

'

'

'

'

'

'

2.27

Expiration date of warrants

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'December 2018

Loan and security agreement, due date

30-Dec-17

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Loan and security agreement, interest rate

'

'

'

'

'

'

'

'

11.00%

3.00%

'

'

'

'

'

Capitalized debt issue costs

1,500,000

'

'

'

'

'

'

'

'

'

700,000

300,000

'

'

'

Administration and monitoring fee

32,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Prepayment fee of the principal

'

'

'

'

'

'

'

'

'

'

'

'

3.50%

1.00%

'

Amortization of debt issuance costs

'

100,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Minimum liquidity requirement amount

$15,000,000

$15,000,000

$13,000,000

$13,000,000

$5,000,000

$5,000,000

$2,000,000

$2,000,000

'

'

'

'

'

'

'

Future_Annual_Payments_Due_on_

Future Annual Payments Due on Amounts Outstanding (Detail) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Debt Instrument [Line Items]	'	'
2014 (remainder of the year)	$2,846	'
2015	3,879	'
2016	4,009	'
2017	41,781	'
Total remaining payments	52,515	'
Less: Amount representing interest	-18,907	'
Long-term debt, Net Total	33,608	'
Less: Current portion of long-term debt	'	'
Long-term debt, net of current portion	$33,608	$33,358

Total_Stock_Based_Compensation

Total Stock- Based Compensation (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Total Stock-based Compensation	'	'
Stock-based compensation	$757	$1,140
Cost of revenues	'	'
Total Stock-based Compensation	'	'
Stock-based compensation	44	120
Research and development	'	'
Total Stock-based Compensation	'	'
Stock-based compensation	180	333
Selling, general and administrative	'	'
Total Stock-based Compensation	'	'
Stock-based compensation	$533	$687

Assumptions_Used_to_Estimate_G

Assumptions Used to Estimate Grant Date Fair Values of Stock Options (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Stock Options	'	'
Estimated grant date fair values	'	'
Expected volatility	'	87.00%
Expected volatility, minimum	72.00%	'
Expected volatility, maximum	74.00%	'
Risk-free interest rate, minimum	1.20%	0.60%
Risk-free interest rate, maximum	1.50%	0.70%
Expected term (in years)	'4 years 4 months 2 days	'4 years 4 months 17 days
Dividend yield	0.00%	0.00%
Non-Employee Stock Options	'	'
Estimated grant date fair values	'	'
Expected volatility	99.00%	72.00%
Risk-free interest rate	0.10%	0.10%
Expected term (in years)	'6 months	'6 months
Dividend yield	0.00%	0.00%

Summary_of_Option_Activity_Und

Summary of Option Activity Under Company's 2002 Stock Option Plan and 2006 Plan (Detail) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'
Shares, Balance at January 1, 2014	7,779	'
Shares, Granted	958	'
Shares, Exercised	-466	'
Shares, Cancelled and expired	-1,003	'
Shares, Balance at March 31, 2014	7,268	7,779
Shares, Options vested and expected to vest at March 31, 2014	7,151	'
Shares, Options vested at March 31, 2014	3,804	'
Weighted- Average Exercise Price, Balance at January 1, 2014	$3.24	'
Weighted- Average Exercise Price, Granted	$2.32	'
Weighted- Average Exercise Price, Exercised	$2.08	'
Weighted- Average Exercise Price, Cancelled and expired	$6.82	'
Weighted- Average Exercise Price, Balance at March 31, 2014	$2.70	$3.24
Weighted- Average Exercise Price, Options vested and expected to vest at March 31, 2014	$2.67	'
Weighted- Average Exercise Price, Options vested at March 31, 2014	$3.15	'
Weighted- Average Remaining Contractual Term, Balance at January 1, 2014	'5 years 4 months 13 days	'4 years 9 months 4 days
Weighted- Average Remaining Contractual Term, Options vested and expected to vest at March 31, 2014	'5 years 4 months 21 days	'
Weighted- Average Remaining Contractual Term, Options vested at March 31, 2014	'4 years 1 month 2 days	'
Aggregate Intrinsic Value, Balance at January 1, 2013	$2,979	$169
Aggregate Intrinsic Value, Options vested and expected to vest at March 31, 2014	2,944	'
Aggregate Intrinsic Value, Options vested at March 31, 2014	$1,396	'

Stockholders_Equity_Additional

Stockholders' Equity - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2014
Share Based Compensation [Line Items]	'
Total unamortized stock-based compensation related to unvested stock options	$4,200,000
Weighted-average recognition period, unvested stock options	'2 years 6 months 4 days
Shares of common stock were available for grant under 2006 Equity Incentive Plan	6,373,228
Proceed from exercise of warrant	14,000,000
Restricted Stock Units (RSUs)	'
Share Based Compensation [Line Items]	'
Weighted-average recognition period, unvested stock options	'2 years 7 months 13 days
Unamortized stock-based compensation related to unvested restricted stock units	900,000
Series A Warrants	'
Share Based Compensation [Line Items]	'
Number of warrants exercised	11,400,000
Proceed from exercise of warrant	14,000,000
Common Stock issuable upon exercise of warrants	22,800,000
Value of warrants outstanding	$39,800,000

Summary_of_Restricted_Stock_Un

Summary of Restricted Stock Unit Activity (Detail) (Restricted Stock Units (RSUs), USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014
Restricted Stock Units (RSUs)	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Restricted Stock Units, Balance at January 1, 2014	1,318
Restricted Stock Units, Awarded	224
Restricted Stock Units, Vested	-624
Restricted Stock Units, Cancelled	-387
Restricted Stock Units, Balance at March 31, 2014	531
Weighted-Average Grant-Date Fair Value, Balance at January 1, 2014	$1.99
Weighted-Average Grant-Date Fair Value, Awarded	$2.51
Weighted-Average Grant-Date Fair Value, Vested	$2
Weighted-Average Grant-Date Fair Value, Cancelled	$2.01
Weighted-Average Grant-Date Fair Value, Balance at March 31, 2014	$2.19

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income Tax Disclosure [Line Items]	'	'
Income Tax provision	$18	$38

Computation_of_Basic_and_Dilut

Computation of Basic and Diluted Net Income (Loss) per Share (Detail) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Computation of basic and diluted net income (loss) per share	'	'
Net loss	($14,445)	($17,187)
Weighted average shares used to calculated basic and diluted net loss per share	103,334	67,296
Basic and diluted net loss per share	($0.14)	($0.26)

Potential_Shares_of_Common_Sto

Potential Shares of Common Stock Not Included In Calculation of Diluted Net Loss per Share (Detail)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Stock Options	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share	7,268	8,351
Unvested restricted stock units	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share	531	1,838
Estimated shares issuable under the employee stock purchase plan	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share	157	155
Warrants	'	'
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]	'	'
Antidilutive securities excluded from computation of earnings per share	23,425	661