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Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2012	Feb. 28, 2013	Jun. 30, 2012
Document and Entity Information [Abstract]
Entity Registrant Name	Enphase Energy, Inc.
Entity Central Index Key	0001463101
Document Type	10-K
Document Period End Date	Dec. 31, 2012
Amendment Flag	false
Document Fiscal Year Focus	2012
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		41,223,308
Entity Well-Known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 136.6

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 45,294	$ 51,524
Accounts receivable, net of allowances of $1,177 and $144 as of December 31, 2012 and 2011	27,743	17,771
Inventory	19,843	11,228
Prepaid expenses and other	2,118	1,264
Total current assets	94,998	81,787
Property and equipment, net	25,541	18,411
Other assets	1,752	6,044
Total assets	122,291	106,242
Current liabilities:
Accounts payable	11,272	12,928
Accrued liabilities	19,266	10,100
Deferred revenues	933	23,414
Current portion of term loans	2,384	4,529
Convertible preferred stock warrant liability	0	1,399
Total current liabilities	33,855	52,370
Long-term liabilities:
Deferred revenues	7,537	3,670
Warranty obligations	15,260	6,733
Other liabilities	307	145
Term loans	8,677	10,148
Convertible notes	0	19,202
Total long-term liabilities	31,781	39,898
Total liabilities	65,636	92,268
Commitments and contingencies
Stockholders’ equity:
Common stock, $0.00001 par value, 100,000 shares authorized, 40,856 shares issued and outstanding at December 31, 2012; 41,410 shares authorized, 1,698 shares issued and outstanding at December 31, 2011	0	0
Additional paid-in capital	183,629	9,103
Accumulated deficit	(127,026)	(88,808)
Accumulated other comprehensive income	52	83
Total stockholders’ equity	56,655	13,974
Total liabilities and stockholders’ equity	122,291	106,242
Convertible preferred stock
Stockholders’ equity:
Preferred stock, value, issued	0	93,596
Preferred Stock
Stockholders’ equity:
Preferred stock, value, issued	$ 0	$ 0

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Allowances, accounts receivable	$ 1,177	$ 144
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, shares authorized	100,000,000	41,410,000
Common stock, shares issued	40,856,000	1,698,000
Common stock, shares outstanding	40,856,000	1,698,000
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	10,000,000	0
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Convertible preferred stock
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, shares authorized	0	23,559,000
Preferred stock, shares issued	0	22,221,000
Preferred stock, shares outstanding	0	22,221,000

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net revenues	$ 216,678	$ 149,523	$ 61,661
Cost of revenues	161,390	120,454	55,159
Gross profit	55,288	29,069	6,502
Operating expenses:
Research and development	35,601	25,099	14,296
Sales and marketing	25,973	17,454	6,558
General and administrative	24,875	15,228	6,365
Total operating expenses	86,449	57,781	27,219
Loss from operations	(31,161)	(28,712)	(20,717)
Other expense, net:
Interest income	17	4	39
Interest expense	(6,436)	(3,006)	(914)
Other income (expense)	13	(576)	(185)
Total other expense, net	(6,406)	(3,578)	(1,060)
Loss before income taxes	(37,567)	(32,290)	(21,777)
Provision for income taxes	(651)	0	0
Net loss attributable to common stockholders	$ (38,218)	$ (32,290)	$ (21,777)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	$ (1.24)	$ (25.73)	$ (28.96)
Shares used in computing net loss per share attributable to common stockholders, basic and diluted	30,740	1,255	752

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net loss attributable to common stockholders	$ (38,218)	$ (32,290)	$ (21,777)
Other comprehensive (loss) income:
Foreign currency translation adjustments	(31)	83	0
Other comprehensive (loss) income	(31)	83	0
Comprehensive loss attributable to common stockholders	$ (38,249)	$ (32,207)	$ (21,777)

- Definition

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References + Details

- Definition

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

+ References

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- Definition

Amount after tax, before reclassification adjustments, resulting from the process of expressing in the reporting currency of the reporting entity those amounts that are denominated or measured in a different currency, and from transactions whose terms are denominated in a currency other than the entity's functional currency.

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+ Details

Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Convertible preferred stock	Common Stock	Additional Paid-In-Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Series E Preferred Stock	Series E Preferred Stock Convertible preferred stock	Common Stock
BALANCE (in shares) at Dec. 31, 2009		14,790	732
BALANCE at Dec. 31, 2009	$ 13,627	$ 47,859	$ 0	$ 509	$ (34,741)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued during period, shares issued								7,431
Common stock issued during period, value							$ 45,737	$ 45,737
Exercise of stock options (in shares)	111		111
Exercise of stock options	$ 65			65
Stock-based compensation	829			829
Net loss	(21,777)				(21,777)
Foreign currency translation adjustment	0
BALANCE (in shares) at Dec. 31, 2010		22,221	843
BALANCE at Dec. 31, 2010	$ 38,481	$ 93,596	$ 0	1,403	(56,518)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	502		502
Exercise of stock options	$ 190			190
Stock-based compensation	2,120			2,120
Private placement of common stock, value	1,858			1,858
Private placement of common stock (in shares)			353
Fair value of warrants and common stock issued in connection with convertible notes	2,312			2,312
Fair value of beneficial conversion feature upon issuance of convertible notes	1,165			1,165
Fair value of beneficial conversion feature from accrued paid-in-kind interest of convertible notes	55			55
Net loss	(32,290)				(32,290)
Foreign currency translation adjustment	83					83
BALANCE (in shares) at Dec. 31, 2011		22,221	1,698
BALANCE at Dec. 31, 2011	13,974	$ 93,596	$ 0	9,103	(88,808)	83
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued during period, shares issued			10,315
Common stock issued during period, value	$ 53,826			53,826
Exercise of stock options (in shares)	59
Exercise of stock options	$ 255			255
Stock-based compensation	4,766			4,766
Issuance of common stock under employee stock plans (in shares)			138
Conversion of convertible preferred stock into common stock upon IPO (in shares)		(22,221)							25,171
Conversion of convertible preferred stock into common stock upon IPO	0	$ (93,596)		93,596
Conversion of convertible notes and paid-in-kind interest into common stock upon IPO (in shares)			3,534
Conversion of convertible notes and paid-in-kind interest into common stock upon IPO	21,204			21,204
Reclassification of preferred stock warrant liability to additional paid in capital upon IPO	879			879
Net loss	(38,218)				(38,218)
Foreign currency translation adjustment	(31)					(31)
BALANCE (in shares) at Dec. 31, 2012		0	40,856
BALANCE at Dec. 31, 2012	$ 56,655	$ 0	$ 0	$ 183,629	$ (127,026)	$ 52

Consolidated Statement of Stockholders' Equity (Parenthetical) $ in Thousands	12 Months Ended
	Dec. 31, 2010 USD ($) $ / shares
Series E Preferred Stock
Share Price \| $ / shares	$ 6.17
Payments of financing costs \| $	$ 145

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flows from operating activities:
Net loss	$ (38,218)	$ (32,290)	$ (21,777)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	5,568	3,032	1,550
Provision for doubtful accounts	1,068	127	0
Net loss on disposal of assets	120	0	24
Non-cash interest expense	4,777	1,835	90
Stock-based compensation	4,766	2,120	829
Change in fair value of convertible preferred stock warrants	(520)	321	189
Changes in operating assets and liabilities:
Accounts receivable	(11,040)	(9,874)	(1,655)
Inventory	(8,615)	(6,708)	(3,038)
Prepaid expenses and other assets	(711)	(1,648)	(298)
Accounts payable, accrued and other liabilities	16,774	17,275	4,877
Deferred revenues	(18,614)	25,443	1,357
Net cash used in operating activities	(44,645)	(367)	(17,852)
Cash flows from investing activities:
Purchases of property and equipment	(12,990)	(14,662)	(3,262)
Net cash used in investing activities	(12,990)	(14,662)	(3,262)
Cash flows from financing activities:
Proceeds from issuance of convertible preferred stock	0	0	45,882
Proceeds from issuance of convertible notes	0	20,000	0
Proceeds from private placement of common stock	0	1,858	0
Principal payments under capital leases	(96)	(169)	(65)
Proceeds from borrowings under term loans	10,000	9,898	7,000
Repayments of term loans	(14,103)	(1,863)	(178)
Proceeds from issuance of common stock under employee stock plans	255	190	61
Proceeds from issuance of common stock in IPO, net of underwriting discounts and commissions	58,609	0	0
Net cash provided by financing activities	51,436	26,482	52,465
Effect of exchange rate changes on cash	(31)	78	0
Net (decrease) increase in cash and cash equivalents	(6,230)	11,531	31,351
Cash and cash equivalents — Beginning of period	51,524	39,993	8,642
Cash and cash equivalents — End of period	45,294	51,524	39,993
Supplemental disclosures of cash flow information:
Cash paid for interest	1,681	1,235	695
Non-cash financing and investing activities:
Assets acquired under capital lease	0	295	0
Purchases of property and equipment included in accounts payable	772	903	521
Offering costs not yet paid	0	371	0
Conversion of convertible notes into common stock upon IPO	21,204	0	0
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon IPO	879	0	0
Convertible debt
Cash flows from financing activities:
Payments of costs related to issuance of convertible notes and financing costs	0	(274)	0
Debt, excluding convertible debt
Cash flows from financing activities:
Payments of costs related to issuance of convertible notes and financing costs	(1,031)	(573)	(90)
Convertible preferred stock
Cash flows from financing activities:
Payment of costs related to issuance of convertible preferred stock and offering costs	0	0	(145)
Common Stock
Cash flows from financing activities:
Payment of costs related to issuance of convertible preferred stock and offering costs	$ (2,198)	$ (2,585)	$ 0

Organization and Description of Business

12 Months Ended

Dec. 31, 2012

Organization, Consolidation and Presentation of Financial Statements [Abstract]

ORGANIZATION AND DESCRIPTION OF BUSINESS

Enphase Energy, Inc. and subsidiaries (the “Company”) designs, develops, and sells microinverter systems for the solar photovoltaic industry. The Company was incorporated in 2006 and began selling its products in 2008. The Company’s microinverter system consists of (i) an Enphase microinverter and related accessories that convert direct current (“DC”) power to grid-compliant alternating current (“AC”) power; (ii) an Envoy communications gateway device that collects and transmits performance information from each solar module to the Company’s hosted data center; and (iii) the Enlighten web-based software platform that collects and processes this information to enable customers to monitor and manage their solar power systems. The Company sells microinverter systems primarily to distributors who resell them to solar installers. The Company also sells directly to large installers as well as through original equipment manufacturers (“OEMs”) and strategic partners.

On April 4, 2012, the Company consummated its initial public offering (“IPO”). As a result, the following transactions were recorded in the Company’s consolidated financial statements during the second quarter of 2012:

•

the Company issued 10,315,151 shares of common stock (including exercise of the full over-allotment by the underwriters of 1,345,454 shares of common stock), at an offering price of $6.00 per share, for gross proceeds of $61.9 million. Certain related parties, who owned convertible preferred and common stock and held convertible notes, purchased 2,500,000 shares of the total amount of shares issued of the Company’s common stock at the $6.00 offering price. The net proceeds from the sale of the shares were $53.8 million, after deducting the underwriters’ discounts and commissions of $3.3 million and other offering costs of $4.8 million;


•	the 22,220,856 outstanding shares of the Company’s convertible preferred stock ($93.6 million carrying value) automatically converted into 25,171,017 shares of common stock;


•	the convertible preferred stock warrant liability ($0.9 million carrying value) was reclassified to additional paid-in capital and the warrants to purchase 187,243 shares of convertible preferred stock became warrants to purchase 199,458 shares of common stock;


•	the outstanding balance of principal and accrued paid-in-kind interest thereon ($21.2 million gross carrying value) for the Convertible Notes (see Note 8) automatically converted into 3,533,988 shares of common stock at a conversion price equal to the initial public offering price of $6.00 per share;


•	the aggregate debt issuance costs and debt discounts of $2.8 million related to the Convertible Facility (see Note 8) were written-off to interest expense as a result of the conversion of the outstanding notes and the automatic termination of the $80.0 million Convertible Facility; and


•	the Company filed an amended and restated certificate of incorporation, which authorized 100,000,000 shares of common stock and 10,000,000 shares of preferred stock.

- Definition

The entire disclosure for the organization, consolidation and basis of presentation of financial statements disclosure, and significant accounting policies of the reporting entity. May be provided in more than one note to the financial statements, as long as users are provided with an understanding of (1) the significant judgments and assumptions made by an enterprise in determining whether it must consolidate a VIE and/or disclose information about its involvement with a VIE, (2) the nature of restrictions on a consolidated VIE's assets reported by an enterprise in its statement of financial position, including the carrying amounts of such assets, (3) the nature of, and changes in, the risks associated with an enterprise's involvement with the VIE, and (4) how an enterprise's involvement with the VIE affects the enterprise's financial position, financial performance, and cash flows. Describes procedure if disclosures are provided in more than one note to the financial statements.

+ References + Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Principles of Consolidation—The accompanying 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 the Company’s consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of income and expenses during the reporting period. These estimates are based on information available as of the date of the financial statements; therefore, actual results could differ materially from management’s estimates using different assumptions or under different conditions.

Risks and Uncertainties—The Company is subject to risks inherent in a business with a limited operating history, including, but not limited to, new and rapidly evolving markets, advances and trends in the development of new technology and services, unfavorable economic and market conditions, competition from larger and more established companies, limited management resources and dependence on a limited number of contract manufacturers and suppliers. The inability to anticipate or to respond adequately to technological developments in the Company's industry, changes in customer or supplier requirements, or changes in regulatory requirements or industry standards could have a material adverse effect on the Company's business and operating results.

Revenue Recognition—The Company generates revenue from sales of its microinverter systems, which include microinverter units and related accessories, an Envoy communications gateway device, and an Enlighten web-based monitoring service, to distributors, large installers, OEMs and strategic partners. Enlighten service revenue represented less than 1% of the total revenues for all periods presented.

Revenues from sales of microinverters and related accessories, and communication gateways are recognized when: (i) persuasive evidence of an arrangement exists; (ii) delivery of the products has occurred in accordance with the terms of the sales agreement and title of and risk of loss have passed to the customer; (iii) the sale price is fixed or determinable; and (iv) collection is reasonably assured. Provisions for rebates, sales incentives, and discounts to customers are accounted for as reductions in revenue in the same period the related sales are recorded.

Prior to June 2011, the Company sold Envoy communications gateway devices and its Enlighten web-based monitoring service separately. Beginning in June 2011, each sale of an Envoy communications gateway device includes the Enlighten web-based monitoring service. The allocation of revenue between the two deliverables is based on the Company's best estimate of selling price determined by considering multiple factors including, internal costs, gross margin and historical pricing practices. After allocating the overall consideration from such sale to each deliverable using a best estimate of the selling price, (i) revenue from the sale of Envoy devices is recognized upon shipment, assuming all other revenue recognition criteria have been met and (ii) revenue from the web-based monitoring service is recognized ratably over the estimated economic life of the related Envoy devices of 10 years.

Deferred revenues consist of payments received from customers in advance of revenue recognition for the Company’s products and services described above. As of December 31, 2012, deferred revenues consist entirely of service revenue. As of December 31, 2011, deferred revenues consist of service revenue and $23.0 million of deferred revenues for products.

Cost of Revenues—The Company includes the following in cost of revenues: product costs, warranty, manufacturing personnel and logistics costs, inventory write-downs, hosting services costs related to the Company’s Enlighten service offering, and depreciation and amortization of manufacturing test equipment.

Cash and Cash Equivalents—The Company considers all highly liquid investments, such as certificates of deposit and money market instruments with maturities of three months or less at the time of acquisition to be cash equivalents. For all periods presented, its cash balances consist of amounts held in non-interest-bearing deposits and money market accounts.

Fair Value of Financial Instruments—The carrying amounts of cash and cash equivalents, accounts receivable and accounts payable approximate fair value due to their relatively short-term nature. The carrying values of the Company's variable rate term loans approximate fair value. The fair value of the convertible notes outstanding at December 31, 2011 was estimated to be $21.7 million based on a valuation model that incorporates relevant Level 3 market inputs.

Derivative Instruments—The Company operates and conducts business in foreign countries where its foreign entities use the local currency as their respective functional currency. As a result, the Company is exposed to movements in foreign currency exchange rates. The Company utilizes foreign currency forward contracts to reduce the impact of foreign currency fluctuations related to anticipated cash receipts from expected future revenues denominated in Euros and intercompany transaction gains or losses. The foreign currency forward contracts are accounted for as derivatives whereby the fair value of the contracts is reported as other current assets or current liabilities in the accompanying consolidated balance sheets, and gains and losses resulting from changes in the fair value are reported in other income (expense), net, in the accompanying consolidated statements of operations.

Allowances for Doubtful Accounts—The Company maintains allowances for doubtful accounts for uncollectible accounts receivable. Management estimates anticipated losses from doubtful accounts based on days past due, collection history and other factors. The allowance for doubtful accounts was $1.2 million and $0.1 million at December 31, 2012 and 2011, respectively.

Inventory—Inventory is valued at the lower of cost or market. The Company determines cost on a first-in first-out basis. Certain factors could affect the realizable value of its inventory, including customer demand and market conditions. Management assesses the valuation on a quarterly basis and writes down the value for any excess and obsolete inventory based upon expected demand, anticipated sales price, effect of new product introductions, product obsolescence, customer concentrations, product merchantability and other factors. Inventory write-downs are equal to the difference between the cost of inventories and their estimated net realizable market value.

Property and Equipment—Property and equipment are stated at cost less accumulated depreciation. Cost includes the price paid to acquire or construct the asset as well as any expenditure that substantially adds to the value of or significantly extends the useful life of an existing asset. Repair and maintenance costs are expensed as incurred. Depreciation and amortization is computed using the straight-line method over the estimated useful lives of the assets, which range from three to ten years. Leasehold improvements are amortized over the shorter of the lease term or expected useful life of the improvements.

Capitalized Software Costs—Costs related to internal-use software are capitalized when preliminary development efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and the software will be used as intended. Such costs are amortized on a straight-line basis over their estimated useful lives. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred.

Long-Lived Assets—Management evaluates long-lived assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to future undiscounted net cash flows expected to be generated by the asset. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the fair value of the assets.

Warranty Obligations—The Company provides a limited warranty against defects in materials and workmanship under normal use and service conditions for its microinverters. The warranty obligation is generally in the form of product replacement. The first and second generation microinverters (sold through the third quarter of 2012) include a 15-year limited warranty period. The third generation microinverters (sold since the second quarter of 2011) include a limited warranty of up to 25 years.

Estimated warranty costs are included in cost of revenues and are accrued at the time of sale on a per unit sold basis. Such estimates are based on various factors including assumptions (for each generation of microinverters) about the frequency of product failures, future warranty claim rates, and replacement costs as follows:

•

Product failure rates are estimated primarily by using field monitoring of the actual failure rates of the microinverters the Company has sold to date. In addition, due to the Company's limited operating history, it also utilizes third party data collected on similar equipment deployed in outdoor environments similar to those in which its microinverters are installed, as well as accelerated life cycle testing, which simulates the service life of the product in a short period of time. The accelerated life cycle tests incorporate test methodologies derived from standard tests used by solar module vendors to evaluate the period over which solar modules wear out. Predicted failure rates are updated periodically based on field return data.


•	Future warranty claim rates are estimated based upon historical claim rates and expectations of future claim rate percentages over the warranty period. Due to the inherent uncertainties included in making estimates related to customers' future behavior, the Company's estimated future warranty claim rates may change.


•	Corresponding replacement costs are updated periodically to reflect changes in the actual and estimated production costs for the Company's microinverters. The Company's estimated costs of warranty for previously sold products may change to the extent future products are not compatible with earlier generation products under warranty.

The calculation of estimated warranty obligations requires management to make significant assumptions. Since the Company has only been producing microinverters for a relatively short period, the calculation of warranty obligations is inherently uncertain. If actual experience related to product failure rates, claim rates or cost to replace differs materially from management's estimates, the Company may be required to revise those estimates, resulting in adjustments to its financial results in the period during which such changes in estimates are made. Such adjustments could materially adversely affect the Company's gross profit and operating results. Changes in estimates related to warranty obligations resulted in net increases in warranty expense of $7.6 million, $1.8 million and $0 in 2012, 2011 and 2010, respectively (see Note 5).

Research and Development Costs—The Company expenses research and development costs as incurred. Research and development costs totaled $35.6 million, $25.1 million and $14.3 million in 2012, 2011 and 2010, respectively.

Stock-Based Compensation—Share-based payments are required to be recognized in the Company’s consolidated statements of operations based on their fair values and the estimated number of shares expected to vest. The Company measures stock-based compensation expense for all share-based payment awards, including stock options made to employees and directors, based on the estimated fair values on the date of the grant. The fair value of each stock option granted is estimated using the Black-Scholes option valuation model. Stock-based compensation, net of estimated forfeitures, is recognized on a straight-line basis over the requisite service period, which is typically four years.

Comprehensive Loss—Comprehensive loss consists of two components, net loss and other comprehensive income (loss). Other comprehensive income (loss) refers to gains and losses that are recorded as an element of stockholders’ equity but are excluded from net income. The Company’s other comprehensive income (loss) consists of foreign currency translation adjustments for all periods presented.

Convertible Preferred Stock Warrants—Prior to its initial public offering, the Company recorded its freestanding warrants to purchase its convertible preferred stock as liabilities at their fair value upon issuance by utilizing a Monte Carlo simulation model that takes into account estimated probabilities of possible outcomes. The fair value of the warrants were subject to remeasurement at each balance sheet date with any change in value being reflected as other income (expense). Upon the completion of the initial public offering in April 2012, the convertible preferred stock warrants became warrants to purchase shares of the Company's common stock and, as a result, qualified for equity classification. The then-current aggregate fair value of these warrants of $0.9 million was reclassified from current liabilities to additional paid-in capital, a component of stockholders’ equity, and the Company has ceased to record any further periodic fair value adjustments.

Income Taxes—The Company records income taxes using the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected tax consequences of temporary differences between the tax bases of assets and liabilities for financial reporting purposes and amounts recognized for income tax purposes. In estimating future tax consequences, generally all expected future events other than enactments or changes in the tax law or rates are considered. Valuation allowances are provided when necessary to reduce deferred tax assets to the amount expected to be realized.

The Company operates in various tax jurisdictions and is subject to audit by various tax authorities. The Company follows accounting for uncertainty in income taxes which requires that the tax effects of a position be recognized only if it is “more likely than not” to be sustained based solely on its technical merits as of the reporting date. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.

Deferred Offering Costs—Deferred offering costs include costs directly attributable to the Company’s initial public offering. These costs totaled $4.8 million and were charged to additional paid-in capital upon the completion of the Company’s initial public offering in April 2012.

Deferred Financing Costs—Deferred financing costs are included in other assets and are amortized over the life of the respective debt facility.

Inventory

12 Months Ended

Dec. 31, 2012

Inventory Disclosure [Abstract]

INVENTORY

Inventory as of December 31, 2012 and 2011, consists of the following (in thousands):



	December 31,
	2012		2011
Raw materials	$	2,223	$	1,848
Finished goods	17,620		9,380
Total inventory	$	19,843	$	11,228

In 2012, 2011 and 2010, the Company recorded write-downs of inventories of $0.8 million, $2.7 million and $0.1 million, respectively.

Property and Equipment, Net

12 Months Ended

Dec. 31, 2012

Property, Plant and Equipment [Abstract]

PROPERTY AND EQUIPMENT, NET

As of December 31, 2012 and 2011, property and equipment, net consists of the following (in thousands):



	Estimated Useful Life (Years)	December 31,
	Estimated Useful Life (Years)	2012			2011
Equipment and machinery	5	$	18,723		$	11,243
Furniture and fixtures	5–7	2,788			990
Computer equipment	3	1,688			1,200
Capitalized software	3	5,760			2,515
Leasehold improvements	3–10	5,642			694
Construction in progress		1,419			7,499
Total		36,020			24,141
Less accumulated depreciation and amortization		(10,479		)	(5,730		)
Property and equipment, net		$	25,541		$	18,411

Depreciation and amortization was $5.6 million, and $3.0 million and $1.6 million in 2012, 2011 and 2010, respectively.

Included in property and equipment are assets acquired under capital lease obligations with an original cost of $350,000 and $494,000 and $199,000 as of December 31, 2012, 2011 and 2010, respectively. Accumulated amortization was $107,000, $180,000 and $149,000 as of December 31, 2012, 2011 and 2010, respectively.

Capitalized Internal Use Software—The Company capitalized $881,000, $806,000 and $815,000 internal use software costs for 2012, 2011 and 2010, respectively. Capitalized software costs are being amortized ratably over the estimated useful lives and are included within amortization expense in the amount of $516,000, $654,000 and $423,000 for 2012, 2011 and 2010, respectively.

- Definition

The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures.

+ References + Details

Warranty Obligations

12 Months Ended

Dec. 31, 2012

Product Warranties Disclosures [Abstract]

WARRANTY OBLIGATIONS

Changes in the Company’s warranty obligations in 2012, 2011 and 2010 were as follows (in thousands):



	December 31,
	2012			2011			2010
Balance, at beginning of year	$	8,738		2,668			$	1,087
Warranty expense	15,825			7,030			1,896
Settlements	(3,225		)	(960		)	(315		)
Balance, at end of year	21,338			8,738			2,668
Less current portion	(6,078		)	(2,005		)	(340		)
Long-term portion	$	15,260		$	6,733		$	2,328

In 2012, warranty expense included $7.6 million resulting from changes in estimates comprised of increases to warranty expense of $10.2 million related to analyses of accumulated information with respect to the estimated long-term performance and related replacement costs of the Company's previous generation products, offset by decreases to warranty expense of $2.6 million from reductions in estimated replacement costs and claim rates. In the fourth quarter of 2012, the Company revised its accounting presentation to present warranty obligations on a gross basis. Previously, warranty obligations were shown net of any warranty related inventory write-downs. Warranty expense for 2012 and warranty obligations as of December 31, 2012 include $1.6 million which had been presented as inventory write-downs in the nine months ended September 30, 2012. The revision had no impact on previously reported gross profit, net loss, accumulated deficit or cash used in operating activities.

In 2011, warranty expense included $1.8 million resulting from changes in estimates to reflect increased estimated replacement costs for certain products.

In 2010, no adjustments for material changes in estimates were recognized.

Fair Value Measurements

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

FAIR VALUE MEASUREMENTS

FAIR VALUE OF FINANCIAL INSTRUMENTS

The accounting guidance defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required to be recorded at fair value, the Company considers the principal or most advantageous market in which it would transact and considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of nonperformance.

The fair value hierarchy requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset’s or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Three levels of inputs may be used to measure fair value:


•	Level 1—Valuations based on quoted prices in active markets for identical assets or liabilities that the Company is able to access. Since valuations are based on quoted prices that are readily and regularly available in an active market, valuation of such assets or liabilities do not entail a significant degree of judgment.


•	Level 2—Valuations based on one or more quoted prices in markets that are not active or for which all significant inputs are observable, either directly or indirectly.


•	Level 3—Valuations based on inputs that are unobservable and significant to the overall fair value measurement.

Derivative Instruments—The Company utilizes foreign currency forward contracts to reduce the impact of foreign currency fluctuations related to anticipated cash receipts from expected future revenues denominated in Euros and intercompany transaction gains or losses.

A summary of the Company's open foreign currency forward contracts at December 31, 2012 is as follows (all open contracts are obligations for the Company to deliver the foreign currency) (in thousands):



Maturity Date	Foreign Quantity		Contract Value		Market Value		Asset (Liability)
January 15, 2013	€	4,800	$	6,058	$	5,790	$	(268	)

In 2012, the Company recognized losses of $505,000 related to foreign currency forward contracts.

The following table presents the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):



	December 31,
	2012		2011
Financial Liabilities:
Preferred stock warrant liability (Level 3)	$	—	$	1,399
Foreign currency forward contracts (Level 2)	268		—
Total	$	268	$	1,399

- Definition

The entire disclosure of the fair value measurement of assets and liabilities, which includes financial instruments measured at fair value that are classified in shareholders' equity, which may be measured on a recurring or nonrecurring basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19279-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19190-110258

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 32
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 6
-Footnote 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 157
-Paragraph 33
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Long-Term Debt

12 Months Ended

Dec. 31, 2012

Long-term Debt, by Current and Noncurrent [Abstract]

LONG-TERM DEBT

The Company’s long-term debt was comprised of the following at December 31, 2012 and 2011 (in thousands):



	December 31,
	2012			2011
Term loans, net of unamortized discount of $0 and $435, respectively	$	7,400		$	9,935
Equipment financing facility, net of unamortized discount of $94 and $156, respectively	3,661			4,742
Total debt	11,061			14,677
Less current portion	(2,384		)	(4,529		)
Long-term portion	$	8,677		$	10,148

As of December 31, 2012, the amount of future principal repayments due on the total debt is as follows (in thousands):



2013	$	2,447
2014	3,538
2015	2,973
2016	2,197
Total	$	11,155

Wells Fargo Bank, N.A.—On November 7, 2012, the Company entered into a new $50.0 million revolving credit facility (the “Revolver”) with Wells Fargo Bank, N.A. (“Wells Fargo”). The Revolver matures on November 7, 2015. The amount of loans available to be drawn under the Revolver is subject to a borrowing base calculation that limits availability to a percentage of eligible domestic accounts receivable plus a percentage of the value of eligible domestic inventory, less certain reserves. Wells Fargo and Hercules Technology Growth Capital, Inc. ("Hercules") are parties to an intercreditor agreement, pursuant to which Hercules has a first lien on certain of the Company's assets and a second priority on its other assets. Subject to the intercreditor agreement, loans under the Revolver are secured by a pledge of substantially all of the Company's assets other than intellectual property. Loans under the Revolver bear interest in cash at an annual rate equal to, at the Company's option, either LIBOR or a “base rate” that is comprised of, among other things, the prime rate, plus a margin that is between 1.5% and 4.25% depending on the currency borrowed and the specific term of repayment. The Revolver contains customary affirmative and negative covenants and events of default, and requires the Company to maintain at least $15.0 million of liquidity at all times, of which at least $8.0 million must be undrawn availability. As of December 31, 2012, $21.2 million was available for borrowing and the Company has not drawn any loans under the Revolver.

Hercules Technology Growth Capital—On November 7, 2012, the Company entered into a loan and security agreement with Hercules, pursuant to which it borrowed $7.4 million (the "Initial Term Loan") and may borrow an additional $15.6 million in term loans (the "Additional Term Loans"). Borrowings of the Initial Term Loan and any Additional Term Loans are subject to certain customary conditions precedent (including, in the case of Additional Term Loans, year-to-date achievement of at least 70% of projected EBITDA and revenue), and are only available for drawing during the 15-day period following delivery to Hercules of the Company's quarterly financial statements for fiscal 2013. In addition, the additional term loans must be drawn, if at all, not later than March 31, 2014. The Company used the proceeds of the Initial Term Loan to replenish cash on hand, which had previously been used to repay the approximately $7.5 million in outstanding term loans owed to Horizon Technology Finance Corporation ("Horizon"). Loans under the Hercules facility bear interest at an annual rate equal to the higher of (i) the prime rate plus 8.25% or (b) 11.5%. All loans under the Hercules facility will mature on August 1, 2016. Interest is payable in cash on a monthly basis, and the loans will amortize in equal monthly installments commencing on March 1, 2014, in the case of the Initial Term Loan, and on December 1, 2013, in the case of Additional Term Loans (or, if no Additional Term Loan is drawn until after December 1, 2013, then the month following the drawing of such additional loan). The Hercules facility contains customary affirmative and negative covenants and events of default, but does not include any financial maintenance covenants. Prepayments of loans under the facility are subject to early payment penalties. Loans under the Hercules facility are secured by a pledge of substantially all the Company's assets other than intellectual property. As of December 31, 2012, the principal balance under the Initial Term Loan was $7.4 million.

Equipment Financing Facility—On June 13, 2011, the Company entered into a $5.0 million equipment financing facility with Hercules. The equipment financing facility has a variable interest rate set at the higher of 5.75% above the prime lending rate and 9.0% annually and expires July 1, 2014. This facility is secured by the financed equipment and restricts the Company’s ability to pay dividends and take on certain types of additional liens. In connection with this facility, the Company issued warrants to purchase 25,285 shares of Series E convertible preferred stock (see Note 10). As of December 31, 2012, the principal balance under the equipment financing facility was $3.8 million.

Horizon Technology Finance Corporation—As of December 31, 2011, the total outstanding principal balance of term loans with Horizon was $10.3 million. Borrowings under the term loans bore interest at an annual interest rate ranging from 10.75% to 12.6%. In connection with the borrowings, the Company issued warrants to purchase 161,958 shares of the Company's Series E Preferred Stock at an exercise price of $6.17 per share with an aggregate fair value at issuance of $0.7 million.

In November 2012, the Company repaid all outstanding amounts owed to Horizon in anticipation of proceeds from a loan and security agreement with Hercules, as discussed above. The facility with Horizon was terminated concurrently with the repayment of the loans outstanding thereunder.

Bridge Bank, N.A. and Comerica Bank—As of December 31, 2011, the Company had a $33.0 million revolving line of credit facility with Bridge Bank, N.A. and Comerica Bank under which there was no outstanding balance. In November 2012, the Company terminated this facility and replaced it with a $50.0 million revolving credit facility with Wells Fargo, as discussed above.

Convertible Facility	12 Months Ended
Convertible Facility	Dec. 31, 2012
Debt Disclosure [Abstract]
CONVERTIBLE FACILITY	CONVERTIBLE FACILITY Convertible Facility—In 2011, the Company entered into a junior secured convertible loan facility, or Convertible Facility, with certain existing preferred stockholders that provided for up to $80.0 million in borrowings. Pursuant to the facility, the Company issued $20.0 million in convertible notes, which provided the note holders the right to convert, at their election, all principal and accrued interest into shares of the Company’s common stock at a conversion price of $8.8984 per share. In addition, the Company issued to the note holders (i) 352,665 shares of common stock at $5.27 per share, and (ii) warrants to purchase 131,516 shares of the Company’s common stock at $5.27 per share that were immediately exercisable and have a contractual term of five years from the date of issuance. The Company recorded $3.1 million in debt discounts and debt issuance costs related to the transactions at the respective issuance dates. On March 27, 2012, the Convertible Facility was amended to provide for the automatic conversion of the principal and accrued paid-in-kind interest into common stock upon consummation of an IPO at a conversion price equal to the lesser of $8.8984 or the IPO price. On April 4, 2012, the convertible notes and accrued paid-in-kind interest automatically converted into 3,533,988 shares of common stock, based upon the IPO price of $6.00 per share. As a result of the conversion, the Company recorded a charge of $2.8 million to interest expense during the nine months ended September 30, 2012 for the extinguishment of debt relative to the unamortized debt issuance costs and debt discounts. Pursuant to its terms, the Convertible Facility terminated upon consummation of the IPO on April 4, 2012.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References + Details

Commitments and Contingencies

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

COMMITMENTS AND CONTINGENCIES

Operating Leases—The Company leases office facilities under noncancelable operating leases that expire on various dates through 2022. The terms of the lease agreements generally provide for rental payments on a graduated basis, and certain leases require the Company to pay its portion of executory costs such as taxes, insurance, and operating expenses. The Company recognizes rent expense on a straight-line basis over the lease term.

Rent expense for 2012, 2011 and 2010 was $2.4 million, $1.2 million and $0.6 million, respectively.

The Company’s minimum lease payments under noncancelable operating leases, exclusive of executory costs, as of December 31, 2012 are as follows (in thousands):



2013	$	1,743
2014	1,766
2015	1,844
2016	1,861
2017	1,619
Thereafter	7,361
Total minimum lease payments	$	16,194

The Company has an agreement to lease approximately 96,000 square feet of office space for its corporate headquarters, which expires in April 2022.

Purchase Obligations—The Company has contractual obligations to purchase goods and services, which specify fixed or minimum quantities to be purchased; fixed, minimum, or variable price provisions; and the approximate timing of the transaction. Purchase obligations do not include contracts that may be canceled without penalty.

The Company utilizes third parties to manufacture its products. As of December 31, 2012, the Company had purchase obligations with third party manufacturers and suppliers totaling approximately $115.6 million. Certain agreements specify future quantities and pricing of products to be supplied by the Company's contract manufacturers for periods up to seven years. Of the $115.6 million included in purchase obligations, $98.6 million are cancelable; however if canceled, the agreement requires the Company to pay cancellation penalties of up to $5.4 million.

Contingencies —From time to time, the Company may be involved in litigation relating to claims arising out of its operations. The Company is not currently involved in any material legal proceedings. The Company may, however, be involved in material legal proceedings in the future. Such matters are subject to uncertainty and there can be no assurance that such legal proceedings will not have a material adverse effect on its business, results of operations, financial position or cash flows.

- Definition

The entire disclosure for commitments and contingencies.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6449706&loc=d3e16207-108621

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6398077&loc=d3e12565-110249

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6952336&loc=d3e14435-108349

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.25)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 440
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6394976&loc=d3e25287-109308

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 14
-Paragraph 3
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 9, 10, 11, 12
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Stockholders' Equity and Warrants

12 Months Ended

Dec. 31, 2012

Equity [Abstract]

STOCKHOLDERS' EQUITY AND WARRANTS

Convertible Preferred Stock

In connection with the Company's initial public offering in April 2012, all 22.2 million shares of its convertible preferred stock outstanding automatically converted into 25.2 million shares of common stock.

Warrant Transactions

Warrants to Purchase Convertible Preferred Stock

Prior to its initial public offering, the Company issued warrants to purchase its Series E convertible preferred stock as part of several financing transactions. These warrants became warrants to purchase common stock upon the completion of the initial public offering. The Company recorded the fair value of the convertible preferred stock warrants at the time of grant using the Monte Carlo simulation model with the following assumptions:



	On Date of Issuance
Expected term (in years)	4.5—6.0
Expected volatility	60.5%—73.0%
Annual risk-free rate of return	1.5%—2.7%
Dividend yield	0%

The following table summarizes the changes in fair value of the convertible preferred stock warrant liability, which was subject to fair value measurement on a recurring basis while outstanding, using significant unobservable inputs (Level 3), for the years presented (in thousands):



Balance at December 31, 2010	$	610
Issuance of warrant to purchase 48,587 shares of Series E convertible preferred stock at $6.174 per share	286
Issuance of warrant to purchase 25,285 shares of Series E convertible preferred stock at $8.8984 per share	182
Fair value adjustments recognized in other (income) expense	321
Balance at December 31, 2011	1,399
Fair value adjustments recognized in other (income) expense	(520		)
Reclassification of preferred stock warrant liability to APIC upon IPO	(879		)
Balance at December 31, 2012	$	—

As of December 31, 2012, warrants to purchase 330,974 shares of the Company's common stock were outstanding with exercise prices ranging from $5.27—$6.17. Such warrants are exercisable and will expire on various dates from 2016 through 2021.

- Definition

The entire disclosure for shareholders' equity, comprised of portions attributable to the parent entity and noncontrolling interest, if any, including other comprehensive income (as applicable). Including, but not limited to: (1) balances of common stock, preferred stock, additional paid-in capital, other capital and retained earnings; (2) accumulated balance for each classification of other comprehensive income and total amount of comprehensive income; (3) amount and nature of changes in separate accounts, including the number of shares authorized and outstanding, number of shares issued upon exercise and conversion, and for other comprehensive income, the adjustments for reclassifications to net income; (4) rights and privileges of each class of stock authorized; (5) basis of treasury stock, if other than cost, and amounts paid and accounting treatment for treasury stock purchased significantly in excess of market; (6) dividends paid or payable per share and in the aggregate for each class of stock for each period presented; (7) dividend restrictions and accumulated preferred dividends in arrears (in aggregate and per share amount); (8) retained earnings appropriations or restrictions, such as dividend restrictions; (9) impact of change in accounting principle, initial adoption of new accounting principle and correction of an error in previously issued financial statements; (10) shares held in trust for Employee Stock Ownership Plan (ESOP); (11) deferred compensation related to issuance of capital stock; (12) note received for issuance of stock; (13) unamortized discount on shares; (14) description, terms, and number of warrants or rights outstanding; (15) shares under subscription and subscription receivables, effective date of new retained earnings after quasi-reorganization and deficit eliminated by quasi-reorganization and, for a period of at least ten years after the effective date, the point in time from which the new retained dates; and (16) retroactive effective of subsequent change in capital structure.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(d),(e))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21484-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 4.E)
-URI http://asc.fasb.org/extlink&oid=6228006&loc=d3e74512-122707

Reference 4: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-31)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (SAB TOPIC 4.C)
-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187143-122770

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-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6405834&loc=d3e23285-112656

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Preferred Stock
-URI http://asc.fasb.org/extlink&oid=6521494

Reference 12: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 13: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21564-112644

Reference 14: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Research Bulletin (ARB)
-Number 43
-Section B
-Paragraph 7, 11A
-Chapter 1
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 16: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 5
-Paragraph 15
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 17: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph d
-Article 4

Reference 18: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30, 31
-Article 5

Reference 19: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section E

Reference 20: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Article 4

Reference 21: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 4
-Section C

Reference 22: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 23: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

+ Details

Stock-Based Compensation

12 Months Ended

Dec. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

STOCK-BASED COMPENSATION

Equity Incentive Plans

2006 Plan—Prior to the adoption and effectiveness of the 2011 Equity Incentive Plan (the “2011 Plan”), as discussed below, certain employees, officers, directors and non-employees were granted options to purchase shares of common stock and stock purchase rights under the Company's 2006 Equity Incentive Plan (the “2006 Plan”). Equity awards granted under the 2006 Plan generally vest over a four-year period from the date of grant with a contractual term of up to 10 years. Common shares purchased under the 2006 Plan were subject to certain restrictions, including the right of first refusal by the Company for sale or transfer of these shares to outside parties. The Company's right of first refusal terminated upon completion of the IPO (see Note 1). As of December 31, 2012 and 2011, there were 6.4 million and 6.3 million shares of common stock outstanding under the 2006 Plan, respectively. Upon the effectiveness of the 2011 Plan on March 29, 2012, which replaces the 2006 Plan, no further stock options or other stock awards may be granted under the 2006 Plan. All outstanding stock options and other equity awards previously granted under the 2006 Plan remain subject to the terms of the 2006 Plan.

2011 Plan—Under the 2011 Plan, the Company may, initially, issue up to 2,643,171 shares of its common stock pursuant to stock options, stock appreciation rights, restricted stock awards, restricted stock unit awards, performance-based stock awards, and other forms of equity compensation, or collectively, stock awards, all of which may be granted to employees, including officers, and to non-employee directors and consultants. The Company utilizes stock options as its primary vehicle for equity compensation. Options granted under the 2011 Plan before August 1, 2012 generally expire 10 years after the grant date and options granted thereafter generally expire 7 years after the grant date. Equity awards granted under the 2011 Plan generally vest over a four-year period from the date of grant based on continued employment. The number of shares of the Company's common stock reserved for issuance under the 2011 Plan will automatically increase, on each January 1, by 4.5% of the total number of shares of the Company's common stock outstanding on December 31 of the preceding calendar year, or such lesser number of shares of common stock as determined by the board of directors. As of December 31, 2012, there were 320,855 shares of common stock available for issuance pursuant to future grants under the 2011 Plan.

2011 Employee Stock Purchase Plan—In 2011, the board of directors adopted the 2011 Employee Stock Purchase Plan (“ESPP”) which became effective immediately upon the execution and delivery of the underwriting agreement for the Company’s IPO on March 29, 2012. The ESPP initially authorizes the issuance of 669,603 shares of the Company's common stock pursuant to purchase rights granted to employees. The number of shares of common stock reserved for issuance will automatically increase, on each January 1, by 330,396 shares of the Company's common stock or a lesser number of shares of common stock as determined by the Company's board of directors. The ESPP is administered by the board of directors, who has delegated its authority to administer the ESPP to the compensation committee.

The ESPP is implemented by concurrent offering periods, the duration of which may not exceed 27 months. An offering period may contain up to four interim purchase periods. In general, offering periods consists of the 24 months periods commencing on each May 1 and November 1 of a calendar year.

Generally, all full time employees, including executive officers, are eligible to participate in the ESPP. The ESPP permits eligible employees to purchase the Company’s common stock through payroll deductions, which may not exceed 15% of the employee’s total compensation subject to certain limits. Stock may be purchased under the plan at a price equal to 85% of the fair market value of the Company’s stock on either the date of purchase or the first day of an offering period, whichever is lower. A two year look-back feature in the Company's ESPP causes an offering period to reset if the fair value of the Company’s common stock on a purchase date is less than that on the initial offering date for that offering period. The reset feature, when triggered, will be accounted for as a modification to the original offering, resulting in additional expense to be recognized over the 24-month period of the new offering. During any calendar year, participants may not purchase shares of common stock having a value greater than $25,000, based on the fair market value per share of the common stock at the beginning of an offering period.

The board of directors may terminate or amend the ESPP, subject to stockholder approval in some circumstances. Unless terminated earlier by the board of directors, the ESPP has a term of 10 years.

The first offering period began on March 29, 2012 and has a duration of 25 months consisting of four purchase periods. For the first purchase period only, eligible participants were permitted to remit catch-up amounts (up to a maximum aggregate withholding of 15 percent of their earnings during the first purchase period) to the Company at any time through October 15, 2012. As such, the grant date was determined to be October 15, 2012 and compensation expense related to ESPP of $247,000 was recorded in the fourth quarter of 2012.

As of December 31, 2012, there were 610,290 shares of the Company's common stock pursuant to purchase rights granted to employees available for issuance under the ESPP.

Stock Options

A summary of the Company’s stock option activity for 2010, 2011 and 2012 is as follows (in thousands, except per share data):



	Shares		Weighted- Average Exercise Price per Share
Options outstanding — December 31, 2009	3,595		$	0.39
Granted	2,548		1.57
Exercised	(111	)	0.59
Canceled	(230	)	0.53
Options outstanding — December 31, 2010	5,802		0.90
Granted	1,110		6.16
Exercised	(502	)	0.38
Canceled	(154	)	2.82
Options outstanding — December 31, 2011	6,256		1.83
Granted	2,478		7.35
Exercised	(59	)	1.26
Canceled	(506	)	5.55
Options outstanding — December 31, 2012	8,169		3.28

The following table summarizes information about stock options outstanding at December 31, 2012:



	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number of Shares (in thousands)	Weighted- Average Remaining Life (in years)	Weighted- Average Exercise Price		Number of Shares (in thousands)	Weighted- Average Exercise Price
$0.27–$0.27	2,543	6.5	$	0.27	2,290	$	0.27
0.54–0.91	312	2.3	0.70		301	0.70
1.63–1.63	1,783	7.3	1.63		1,162	1.63
2.00–5.11	1,153	6.6	3.27		518	2.59
5.23–8.43	1,620	9.1	7.24		205	7.07
8.82–10.35	575	8.6	9.50		153	9.57
11.00–11.00	183	9.1	11.00		28	11.00
Total	8,169	7.3	3.28		4,657	1.57

The intrinsic value of options exercised during 2012 was $0.3 million. As of December 31, 2012, there were 7.9 million options outstanding that were vested, exercisable and expected to vest. Such options have a weighted-average exercise price of $3.19 and a weighted-average remaining contractual term of 7.2 years. As of December 31, 2012, the aggregate intrinsic value was $11.5 million for the 4.7 million exercisable shares. The intrinsic value is based on the Company’s common stock fair value of $3.65 per share as of December 31, 2012.

Restricted Stock Units

The following is a summary of restricted stock unit activity for the year ended December 31, 2012 (in thousands, except per share data):



	Restricted Stock Units		Weighted Average Fair Value per Share at Grant Date
Outstanding at December 31, 2011	—		$	—
Granted	282		5.69
Vested	(20	)	2.00
Canceled	(14	)	6.90
Outstanding at December 31, 2012	248		5.53

The intrinsic value of restricted stock units vested during 2012 was $39,000. As of December 31, 2012, the restricted stock units outstanding had a weighted average remaining contractual term of 1.7 years with an intrinsic value of $0.9 million.

The following table summarizes the components of total stock-based compensation expense included in the consolidated statement of operations for the periods presented (in thousands):



	Year Ended December 31,
	2012		2011		2010
Cost of revenues	$	196	$	39	$	9
Research and development	1,728		795		286
Sales and marketing	1,254		671		256
General and administrative	1,588		615		278
Total stock-based compensation expense	$	4,766	$	2,120	$	829

The following table summarizes stock-based compensation associated with each type of award:



	Year Ended December 31,
	2012		2011		2010
Stock options and restricted stock units	$	4,519	$	2,120	$	829
ESPP	247		—		—
Total stock-based compensation expense	$	4,766	$	2,120	$	829

Valuation Assumptions

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

Stock Options



	Year Ended December 31,
	2012			2011			2010
Expected term (in years)	5.7			6.0			6.0
Expected volatility	74.5		%	72.0		%	73.3		%
Annual risk-free rate of return	0.9		%	1.8		%	2.2		%
Dividend yield	0.0		%	0.0		%	0.0		%
Weighted-average fair value on grant date	$	4.69		$	5.08		$	1.73

As of December 31, 2012, there was approximately $12.9 million of total unrecognized compensation cost related to unvested stock options, restricted stock units and ESPP, net of expected forfeitures, which is expected to be recognized over a weighted-average period of 3.0 years.

No income tax benefit has been recognized relating to stock-based compensation expense and no tax benefits have been realized from exercised stock options.

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 50
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6406099&loc=d3e25284-112666

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6418621&loc=d3e17540-113929

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5444-113901

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Staff Accounting Bulletin (SAB)
-Number Topic 14

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 123R
-Paragraph 64, 65, A240
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 93-6
-Paragraph 53
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Income Taxes

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

INCOME TAXES

No provision for U.S. federal or state income taxes has been made due to cumulative losses since the commencement of operations.

A provision for income taxes of $0.7 million has been recognized for 2012 related to the Company's foreign operations.

A reconciliation of total income tax expense and the amount computed by applying the federal statutory income tax rate of 34% to loss before income taxes for 2012, 2011 and 2010 is as follows (in thousands):



	Year Ended December 31,
	2012			2011			2010
Income tax benefit at statutory rate	$	(12,773	)	$	(10,883	)	$	(7,284	)
State taxes, net of federal benefit	(1,478		)	(1,956		)	190
Change in valuation allowance	12,574			12,451			6,783
Other nondeductible/nontaxable items	2,155			388			311
Uncertain tax positions	173			—			—
Provision for income taxes	$	651		$	—		$	—

A summary of significant components of the Company’s deferred tax assets and liabilities as of December 31, 2012 and 2011 is as follows (in thousands):



	December 31,
	2012			2011
Current:
Reserves and allowances	$	11,523		$	4,641
Valuation allowance	(11,523		)	(4,637		)
Total Current	—			4
Non-current:
Net operating losses	14,364			15,653
Stock-based compensation	919			410
Deferred revenue	1,425			1,435
Fixed assets and intangibles	10,301			4,716
Other	880			—
Valuation allowance	(27,889		)	(22,193		)
Total non-current	—			21
Deferred tax liability	—			(25		)
Net deferred tax assets	$	—		$	—

Due to the history of losses the Company has generated since inception, the Company believes that it is more-likely-than-not that all of the deferred tax assets will not be realized as of December 31, 2012. Therefore, the Company has recorded a full valuation allowance on its deferred tax assets.

The Company has net operating loss carryforwards for federal and California income tax purposes of approximately $54 million and $49 million, respectively, as of December 31, 2012. The federal and state net operating loss carryforwards, if not utilized, will expire beginning in 2026 and 2016, respectively. Utilization of the net operating loss carryforwards may be subject to a substantial annual limitation due to the ownership change limitations provided by the Internal Revenue Code of 1986, as amended (the "Code"), and similar state provisions. The annual limitation may result in the expiration of net operating losses before utilization. The Company has not completed a study to assess whether an ownership change has occurred or whether there have been multiple ownership changes since the Company became a “loss corporation” under the Code. Due to the existence of the valuation allowance, it is not expected that any possible limitation will have an impact on the results of operations or financial position of the Company.

The accounting for uncertain tax positions prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The Company is required to recognize in the financial statements the impact of a tax position, if that position is more-likely-than-not of being sustained on audit, based on the technical merits of the position. The gross unrecognized tax benefits have increased from $0 at December 31, 2011 to $160,000 at December 31, 2012, due to increases in tax positions for the current year of $110,000 and increases in tax positions for prior year of $50,000. The unrecognized tax benefits of $160,000 at December 31, 2012, if recognized, would reduce our annual effective tax rate. The Company also accrued interest and penalties of $13,000 to unrecognized tax benefits during 2012.

The Company does not have any tax positions for which it is reasonably possible the total amount of gross unrecognized tax benefits will increase or decrease over the next year. The unrecognized tax benefits may increase or change during the next year for items that arise in the ordinary course of business. The Company records interest related to uncertain tax positions as interest and any penalties as other expense.

The Company’s tax returns continue to remain subject to examination by U.S. federal authorities for the years 2009 through 2012 and by California state authorities for the years 2008 through 2012.

- Definition

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

+ References

+ Details

Concentration of Credit Risk and Major Customers	12 Months Ended
Concentration of Credit Risk and Major Customers	Dec. 31, 2012
Segment Reporting [Abstract]
CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS	CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS The Company is potentially subject to financial instrument concentration of credit risk through its cash equivalents and trade accounts receivables. The Company places its cash and cash equivalents with major financial institutions, which it believes to be of high credit quality, in order to limit the exposure of each investment. Trade accounts receivables can be potentially exposed to a concentration of credit risk with its major customers. As of December 31, 2012, the Company had amounts due from two customers that represented 21% and 16% of the total accounts receivable balance. As of December 31, 2011, its two largest accounts receivable balances represented 24% and 10% of the total accounts receivable balance. In 2012, two customers accounted for 16%, and 11% of total net revenues. In 2011, three customers accounted for 17%, 11% and 10% of total net revenues. In 2010, two customers accounted for 14%, and 11% of total net revenues.

- Definition

The entire disclosure for any concentrations existing at the date of the financial statements that make an entity vulnerable to a reasonably possible, near-term, severe impact. This disclosure informs financial statement users about the general nature of the risk associated with the concentration, and may indicate the percentage of concentration risk as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6327-108592

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6442-108592

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 275
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=6927468&loc=d3e6351-108592

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 21
-URI http://asc.fasb.org/extlink&oid=7491637&loc=d3e13537-108611

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Statement of Position (SOP)
-Number 94-6
-Paragraph 21, 22, 24
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 107
-Paragraph 15A
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Net Loss Per Share Attributable to Common Stockholders

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

NET LOSS PER SHARE ATTRIBUTABLE TO COMMON STOCKHOLDERS

In April 2012, all of the Company’s then outstanding convertible preferred stock automatically converted into common stock in connection with its IPO. For periods that ended prior to the conversion, basic and diluted net income per common share were presented in conformity with the two-class method required for participating securities.

Under the two-class method, net loss is allocated between common shares and other participating securities to the extent that the securities are required to share in the losses. The Company’s convertible preferred stock did not meet the definition of a participating security in periods of net losses as the convertible preferred stockholders did not have a contractual obligation to share in the Company’s losses. Accordingly, net losses were attributable to common stockholders. Subsequent to the Company’s IPO and the automatic conversion of the outstanding convertible preferred stock, the Company had no other participating securities and the two-class method is no longer applicable.

Basic net loss per share attributable to common stockholders is calculated by dividing net loss attributable to common stockholders by the weighted average number of shares outstanding for the period. The disproportional change in loss per share in 2012 is attributed to the automatic conversion of our convertible preferred stock and convertible notes into 28.7 million shares of its common stock upon IPO.

Diluted net loss per share attributable to common stockholders is calculated by dividing net loss attributable to common stockholders by the weighted average number of common shares and potential dilutive common share equivalents outstanding during the period if the effect is dilutive. The Company’s potentially dilutive common shares include convertible notes and convertible preferred stock prior to their conversion, outstanding stock options and warrants and non-vested restricted stock units.

The following table presents the potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders for the periods presented because including them would have been anti-dilutive (in thousands):



	Year Ended December 31,
	2012	2011	2010
Convertible preferred stock	—	25,171	25,171
Stock options to purchase common stock	8,169	6,256	5,802
Convertible notes	—	2,328	—
Shares issuable pursuant to ESPP	5	—	—
Unvested restricted stock units	248	—	—
Common stock warrants	331	143	11
Convertible preferred stock warrants	—	215	141
Total	8,753	34,113	31,125

Geographic Information

12 Months Ended

Dec. 31, 2012

Segments, Geographical Areas [Abstract]

GEOGRAPHIC INFORMATION

The Company considers operating segments to be components of its entity in which separate financial information is available that is evaluated regularly by its chief operating decision maker in deciding how to allocate resources and in assessing performance. The Company's chief operating decision maker is the Chief Executive Officer. The Chief Executive Officer reviews financial information presented on a consolidated basis. The Company has one business activity, which entails the design, development, manufacture and sale of microinverter systems for the solar photovoltaic industry. There are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level. Accordingly, management has determined that the Company has a single reporting segment and operating unit structure.

The following tables present net revenues (based on the destination of the shipments) and long-lived assets by geographic region as of and for the periods presented (in thousands):

Net Revenues



	Year Ended December 31,
	2012		2011		2010
United States	$	189,711	$	128,692	$	53,383
International	26,967		20,831		8,278
Total	$	216,678	$	149,523	$	61,661

In 2011 and 2010, Canada accounted for approximately 12% and 13% of our net revenues, respectively.

Long-Lived Assets



	As of December 31,
	2012		2011		2010
United States	$	17,136	$	11,199	$	5,330
China	6,642		5,974		710
Other	1,763		1,238		63
Total	$	25,541	$	18,411	$	6,103

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
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-Paragraph 34
-URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8981-108599

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Reference 15: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 131
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2012
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS The Company recognized revenues of $16.8 million and $6.4 million in 2012 and 2011, respectively, from sales of microinverters to entities that are majority-owned by KPCB Holdings, Inc., as nominee (“KPCB”), a related party which has a significant ownership interest in the Company.

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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-Publisher FASB
-Name Accounting Standards Codification
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-Subparagraph (SX 210.4-08.(k))
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Paragraph b
-Article 3A

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph k
-Article 4

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 57
-Paragraph 1-4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Quarterly Financial Information

12 Months Ended

Dec. 31, 2012

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information

(Unaudited)

(In thousands, except per share data)



	Quarters Ended for Fiscal 2012
	March 31			June 30			September 30			December 31

Net revenues	$	42,600		$	55,697		$	60,813		$	57,568
Cost of revenues	33,293			42,096			44,489			41,512
Gross profit	9,307			13,601			16,324			16,056
Operating expenses:										—
Research and development	7,842			8,655			10,571			8,533
Sales and marketing	5,049			6,360			7,039			7,525
General and administrative	5,696			6,091			6,911			6,177
Total operating expenses	18,587			21,106			24,521			22,235
Loss from operations	(9,280		)	(7,505		)	(8,197		)	(6,179		)
Other expense, net	(839		)	(3,729		)	(580		)	(1,258		)
Loss before income taxes	(10,119		)	(11,234		)	(8,777		)	(7,437		)
Provision for income taxes	(65		)	(151		)	(130		)	(305		)
Net loss	$	(10,184	)	$	(11,385	)	$	(8,907	)	$	(7,742	)
Net loss per share, basic and diluted	$	(5.97	)	$	(0.29	)	$	(0.22	)	$	(0.19	)

	Quarters Ended for Fiscal 2011
	March 31			June 30			September 30			December 31
Net revenues	$	18,069		$	29,592		$	44,728		$	57,134
Cost of revenues	15,421			24,785			36,185			44,063
Gross profit	2,648			4,807			8,543			13,071
Operating expenses:
Research and development	5,345			6,143			6,431			7,180
Sales and marketing	3,010			4,265			4,567			5,612
General and administrative	3,250			3,889			3,980			4,109
Total operating expenses	11,605			14,297			14,978			16,901
Loss from operations	(8,957		)	(9,490		)	(6,435		)	(3,830		)
Other expense, net	(332		)	(798		)	(741		)	(1,707		)
Net loss	$	(9,289	)	$	(10,288	)	$	(7,176	)	$	(5,537	)
Net loss per share, basic and diluted	$	(10.95	)	$	(9.95	)	$	(4.77	)	$	(3.41	)

- Definition

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

+ References + Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2012

Accounting Policies [Abstract]

Principles of Consolidation

Use of Estimates

Risks and Uncertainties

Revenue Recognition

Cost of Revenues

Cash and Cash Equivalents

Fair Value of Financial Instruments

Derivatives Instruments

Allowances for Doubtful Accounts

Inventory

Property and Equipment

Capitalized Software Costs

Long-Lived Assets

Warranty Obligations

•


•	Future warranty claim rates are estimated based upon historical claim rates and expectations of future claim rate percentages over the warranty period. Due to the inherent uncertainties included in making estimates related to customers' future behavior, the Company's estimated future warranty claim rates may change.


•	Corresponding replacement costs are updated periodically to reflect changes in the actual and estimated production costs for the Company's microinverters. The Company's estimated costs of warranty for previously sold products may change to the extent future products are not compatible with earlier generation products under warranty.

Research and Development Costs

Share-Based Compensation

Comprehensive Loss

Convertible Preferred Stock Warrants

Income Taxes

Deferred Offering Costs

Deferred Financing Costs

Deferred Financing Costs—Deferred financing costs are included in other assets and are amortized over the life of the respective debt facility.

Inventory (Tables)

12 Months Ended

Dec. 31, 2012

Inventory Disclosure [Abstract]

Schedule of inventory

Inventory as of December 31, 2012 and 2011, consists of the following (in thousands):



	December 31,
	2012		2011
Raw materials	$	2,223	$	1,848
Finished goods	17,620		9,380
Total inventory	$	19,843	$	11,228

Property and Equipment, Net (Tables)

12 Months Ended

Dec. 31, 2012

Property, Plant and Equipment [Abstract]

Property, plant and equipment

As of December 31, 2012 and 2011, property and equipment, net consists of the following (in thousands):



	Estimated Useful Life (Years)	December 31,
	Estimated Useful Life (Years)	2012			2011
Equipment and machinery	5	$	18,723		$	11,243
Furniture and fixtures	5–7	2,788			990
Computer equipment	3	1,688			1,200
Capitalized software	3	5,760			2,515
Leasehold improvements	3–10	5,642			694
Construction in progress		1,419			7,499
Total		36,020			24,141
Less accumulated depreciation and amortization		(10,479		)	(5,730		)
Property and equipment, net		$	25,541		$	18,411

Warranty Obligations (Tables)

12 Months Ended

Dec. 31, 2012

Product Warranties Disclosures [Abstract]

Changes in the Company's product warranty liability

Changes in the Company’s warranty obligations in 2012, 2011 and 2010 were as follows (in thousands):



	December 31,
	2012			2011			2010
Balance, at beginning of year	$	8,738		2,668			$	1,087
Warranty expense	15,825			7,030			1,896
Settlements	(3,225		)	(960		)	(315		)
Balance, at end of year	21,338			8,738			2,668
Less current portion	(6,078		)	(2,005		)	(340		)
Long-term portion	$	15,260		$	6,733		$	2,328

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Disclosures [Abstract]

Summary of open foreign currency forward contracts



Maturity Date	Foreign Quantity		Contract Value		Market Value		Asset (Liability)
January 15, 2013	€	4,800	$	6,058	$	5,790	$	(268	)

Schedule of financial instruments that are measured at fair value on a recurring basis

The following table presents the Company’s financial instruments that were measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):



	December 31,
	2012		2011
Financial Liabilities:
Preferred stock warrant liability (Level 3)	$	—	$	1,399
Foreign currency forward contracts (Level 2)	268		—
Total	$	268	$	1,399

- Definition

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

+ References + Details

- Definition

Tabular disclosure of pertinent information about a derivative or group of derivatives on a disaggregated basis, such as for individual instruments, or small groups of similar instruments. May include a combination of the type of instrument, risks being hedged, notional amount, hedge designation, related hedged item, inception date, maturity date, or other relevant item.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2012

Long-term Debt, by Current and Noncurrent [Abstract]

Schedule of long-term debt

The Company’s long-term debt was comprised of the following at December 31, 2012 and 2011 (in thousands):



	December 31,
	2012			2011
Term loans, net of unamortized discount of $0 and $435, respectively	$	7,400		$	9,935
Equipment financing facility, net of unamortized discount of $94 and $156, respectively	3,661			4,742
Total debt	11,061			14,677
Less current portion	(2,384		)	(4,529		)
Long-term portion	$	8,677		$	10,148

Schedule of maturities of long-term debt

As of December 31, 2012, the amount of future principal repayments due on the total debt is as follows (in thousands):



2013	$	2,447
2014	3,538
2015	2,973
2016	2,197
Total	$	11,155

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
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-Paragraph 1
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-Paragraph 1
-Subparagraph (SX 210.4-08.(e),(f))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21538-112644

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 10: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644

Reference 11: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 22
-Article 5

+ Details

Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2012

Commitments and Contingencies Disclosure [Abstract]

Schedule of future minimum rental payments for operating leases

The Company’s minimum lease payments under noncancelable operating leases, exclusive of executory costs, as of December 31, 2012 are as follows (in thousands):



2013	$	1,743
2014	1,766
2015	1,844
2016	1,861
2017	1,619
Thereafter	7,361
Total minimum lease payments	$	16,194

Stockholders' Equity and Warrants (Tables)

12 Months Ended

Dec. 31, 2012

Equity [Abstract]

Schedule of valuation assumptions of convertible preferred stock warrants

The Company recorded the fair value of the convertible preferred stock warrants at the time of grant using the Monte Carlo simulation model with the following assumptions:



	On Date of Issuance
Expected term (in years)	4.5—6.0
Expected volatility	60.5%—73.0%
Annual risk-free rate of return	1.5%—2.7%
Dividend yield	0%

Schedule of changes in fair value using recurring basis



Balance at December 31, 2010	$	610
Issuance of warrant to purchase 48,587 shares of Series E convertible preferred stock at $6.174 per share	286
Issuance of warrant to purchase 25,285 shares of Series E convertible preferred stock at $8.8984 per share	182
Fair value adjustments recognized in other (income) expense	321
Balance at December 31, 2011	1,399
Fair value adjustments recognized in other (income) expense	(520		)
Reclassification of preferred stock warrant liability to APIC upon IPO	(879		)
Balance at December 31, 2012	$	—

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2012

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of summary of stock option activity

A summary of the Company’s stock option activity for 2010, 2011 and 2012 is as follows (in thousands, except per share data):



	Shares		Weighted- Average Exercise Price per Share
Options outstanding — December 31, 2009	3,595		$	0.39
Granted	2,548		1.57
Exercised	(111	)	0.59
Canceled	(230	)	0.53
Options outstanding — December 31, 2010	5,802		0.90
Granted	1,110		6.16
Exercised	(502	)	0.38
Canceled	(154	)	2.82
Options outstanding — December 31, 2011	6,256		1.83
Granted	2,478		7.35
Exercised	(59	)	1.26
Canceled	(506	)	5.55
Options outstanding — December 31, 2012	8,169		3.28

Schedule of stock options outstanding under the 2006 and 2011 Plans

The following table summarizes information about stock options outstanding at December 31, 2012:



	Options Outstanding				Options Exercisable
Range of Exercise Prices	Number of Shares (in thousands)	Weighted- Average Remaining Life (in years)	Weighted- Average Exercise Price		Number of Shares (in thousands)	Weighted- Average Exercise Price
$0.27–$0.27	2,543	6.5	$	0.27	2,290	$	0.27
0.54–0.91	312	2.3	0.70		301	0.70
1.63–1.63	1,783	7.3	1.63		1,162	1.63
2.00–5.11	1,153	6.6	3.27		518	2.59
5.23–8.43	1,620	9.1	7.24		205	7.07
8.82–10.35	575	8.6	9.50		153	9.57
11.00–11.00	183	9.1	11.00		28	11.00
Total	8,169	7.3	3.28		4,657	1.57

Schedule of restricted stock unit activity

The following is a summary of restricted stock unit activity for the year ended December 31, 2012 (in thousands, except per share data):



	Restricted Stock Units		Weighted Average Fair Value per Share at Grant Date
Outstanding at December 31, 2011	—		$	—
Granted	282		5.69
Vested	(20	)	2.00
Canceled	(14	)	6.90
Outstanding at December 31, 2012	248		5.53

Schedule of components of stock-based compensation expense in the consolidated statement of operations, by report line

The following table summarizes the components of total stock-based compensation expense included in the consolidated statement of operations for the periods presented (in thousands):



	Year Ended December 31,
	2012		2011		2010
Cost of revenues	$	196	$	39	$	9
Research and development	1,728		795		286
Sales and marketing	1,254		671		256
General and administrative	1,588		615		278
Total stock-based compensation expense	$	4,766	$	2,120	$	829

Schedule of stock-based compensation expense by award type

The following table summarizes stock-based compensation associated with each type of award:



	Year Ended December 31,
	2012		2011		2010
Stock options and restricted stock units	$	4,519	$	2,120	$	829
ESPP	247		—		—
Total stock-based compensation expense	$	4,766	$	2,120	$	829

Schedule of valuation assumptions of stock options

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

Stock Options



	Year Ended December 31,
	2012			2011			2010
Expected term (in years)	5.7			6.0			6.0
Expected volatility	74.5		%	72.0		%	73.3		%
Annual risk-free rate of return	0.9		%	1.8		%	2.2		%
Dividend yield	0.0		%	0.0		%	0.0		%
Weighted-average fair value on grant date	$	4.69		$	5.08		$	1.73

- Definition

Tabular disclosure of the allocation of equity-based compensation costs to a given line item on the balance sheet and income statement for the period. This may include the reporting line for the costs and the amount capitalized and expensed.

+ References + Details

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2012

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation



	Year Ended December 31,
	2012			2011			2010
Income tax benefit at statutory rate	$	(12,773	)	$	(10,883	)	$	(7,284	)
State taxes, net of federal benefit	(1,478		)	(1,956		)	190
Change in valuation allowance	12,574			12,451			6,783
Other nondeductible/nontaxable items	2,155			388			311
Uncertain tax positions	173			—			—
Provision for income taxes	$	651		$	—		$	—

Schedule of Deferred Tax Assets and Liabilities

A summary of significant components of the Company’s deferred tax assets and liabilities as of December 31, 2012 and 2011 is as follows (in thousands):



	December 31,
	2012			2011
Current:
Reserves and allowances	$	11,523		$	4,641
Valuation allowance	(11,523		)	(4,637		)
Total Current	—			4
Non-current:
Net operating losses	14,364			15,653
Stock-based compensation	919			410
Deferred revenue	1,425			1,435
Fixed assets and intangibles	10,301			4,716
Other	880			—
Valuation allowance	(27,889		)	(22,193		)
Total non-current	—			21
Deferred tax liability	—			(25		)
Net deferred tax assets	$	—		$	—

Net Loss Per Share Attributable to Common Stockholders (Tables)

12 Months Ended

Dec. 31, 2012

Earnings Per Share [Abstract]

Schedule of potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders



	Year Ended December 31,
	2012	2011	2010
Convertible preferred stock	—	25,171	25,171
Stock options to purchase common stock	8,169	6,256	5,802
Convertible notes	—	2,328	—
Shares issuable pursuant to ESPP	5	—	—
Unvested restricted stock units	248	—	—
Common stock warrants	331	143	11
Convertible preferred stock warrants	—	215	141
Total	8,753	34,113	31,125

Geographic Information (Tables)

12 Months Ended

Dec. 31, 2012

Segments, Geographical Areas [Abstract]

Net revenues and long-lived assets by geographic region

Net Revenues



	Year Ended December 31,
	2012		2011		2010
United States	$	189,711	$	128,692	$	53,383
International	26,967		20,831		8,278
Total	$	216,678	$	149,523	$	61,661

Long-Lived Assets



	As of December 31,
	2012		2011		2010
United States	$	17,136	$	11,199	$	5,330
China	6,642		5,974		710
Other	1,763		1,238		63
Total	$	25,541	$	18,411	$	6,103

Quarterly Financial Information (Tables)

12 Months Ended

Dec. 31, 2012

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

Quarterly Financial Information

(Unaudited)

(In thousands, except per share data)



	Quarters Ended for Fiscal 2012
	March 31			June 30			September 30			December 31

Net revenues	$	42,600		$	55,697		$	60,813		$	57,568
Cost of revenues	33,293			42,096			44,489			41,512
Gross profit	9,307			13,601			16,324			16,056
Operating expenses:										—
Research and development	7,842			8,655			10,571			8,533
Sales and marketing	5,049			6,360			7,039			7,525
General and administrative	5,696			6,091			6,911			6,177
Total operating expenses	18,587			21,106			24,521			22,235
Loss from operations	(9,280		)	(7,505		)	(8,197		)	(6,179		)
Other expense, net	(839		)	(3,729		)	(580		)	(1,258		)
Loss before income taxes	(10,119		)	(11,234		)	(8,777		)	(7,437		)
Provision for income taxes	(65		)	(151		)	(130		)	(305		)
Net loss	$	(10,184	)	$	(11,385	)	$	(8,907	)	$	(7,742	)
Net loss per share, basic and diluted	$	(5.97	)	$	(0.29	)	$	(0.22	)	$	(0.19	)

	Quarters Ended for Fiscal 2011
	March 31			June 30			September 30			December 31
Net revenues	$	18,069		$	29,592		$	44,728		$	57,134
Cost of revenues	15,421			24,785			36,185			44,063
Gross profit	2,648			4,807			8,543			13,071
Operating expenses:
Research and development	5,345			6,143			6,431			7,180
Sales and marketing	3,010			4,265			4,567			5,612
General and administrative	3,250			3,889			3,980			4,109
Total operating expenses	11,605			14,297			14,978			16,901
Loss from operations	(8,957		)	(9,490		)	(6,435		)	(3,830		)
Other expense, net	(332		)	(798		)	(741		)	(1,707		)
Net loss	$	(9,289	)	$	(10,288	)	$	(7,176	)	$	(5,537	)
Net loss per share, basic and diluted	$	(10.95	)	$	(9.95	)	$	(4.77	)	$	(3.41	)

Organization and Description of Business (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2012	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2012	Apr. 04, 2012
Organization and Description of Business (Textual) [Abstract]
Common stock issued during period, in connection with credit facility	10,315,151
Common stock exercise, allotment by underwriters	1,345,454
Common stock issued, price per share			$ 5.27			$ 6.00
Common stock issued, value	$ 61,900
Common stock purchased by related parties	2,500,000
Proceeds from the sale of common stock	$ 53,800	$ 58,609	$ 0	$ 0
Underwriters discounts and commissions	3,300
Other estimated offering costs	4,800
Convertible preferred stock, shares outstanding		0	0		22,200,000	22,220,856
Convertible preferred stock, carrying value						$ 93,600
Conversion of convertible preferred stock into common stock						25,171,017
Convertible preferred stock, warrant liability						$ 900
Convertible preferred stock, warrants to purchase						187,243
Number of common stock shares called by warrants						199,458
Convertible notes, outstanding balance of principal and accrued paid in kind interest						$ 21,200
Conversion of notes into common stock						3,533,988
Conversion price of convertible notes						$ 6.00
Debt issuance costs and discounts related to conversion		$ 2,800
Conversion of the outstanding notes and the automatic termination of the Convertible Facility	$ 80,000
Common stock, shares authorized		100,000,000	41,410,000			100,000,000
Preferred stock, shares authorized		10,000,000	0			10,000,000

Summary of Significant Accounting Policies Narrative (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 30, 2012
Accounting Policies [Line Items]
Fair Value of convertible notes outstanding					$ 21,700					$ 21,700
Allowance for doubtful accounts	$ 1,177				144				$ 1,177	144
Product warranty expense									7,600	1,800	$ 0
Research and development expense	$ 8,533	$ 10,571	$ 8,655	$ 7,842	7,180	$ 6,431	$ 6,143	$ 5,345	$ 35,601	25,099	$ 14,296
Stock-based compensation requisite service period									4 years
Fair value of warrants												$ 900
Deferred offering costs												$ 4,800
Product
Accounting Policies [Line Items]
Deferred revenue					$ 23,000					$ 23,000
First and second generation
Accounting Policies [Line Items]
Product warranty coverage period									15 years
Minimum
Accounting Policies [Line Items]
Property and equipment estimated useful life									3 years
Maximum
Accounting Policies [Line Items]
Property and equipment estimated useful life									10 years
Maximum \| Third generation
Accounting Policies [Line Items]
Product warranty coverage period									25 years
Maximum \| Enlighten web-based monitoring service
Accounting Policies [Line Items]
Percent of revenue represented by product line or service									1.00%	1.00%	1.00%
Revenue recognition period									10 years

Summary of Inventory (Details) - USD ($) $ in Thousands	12 Months Ended
Summary of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of inventory
Raw materials	$ 2,223	$ 1,848
Finished goods	17,620	9,380
Total inventory	19,843	11,228
Inventory (Textual) [Abstract]
Inventory write-downs	$ 800	$ 2,700	$ 100

- Definition

Charge to cost of goods sold that represents the reduction of the carrying amount of inventory, generally attributable to obsolescence or market conditions.

+ References + Details

Property and Equipment, Net Summary of Property and Equipment , Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 36,020	$ 24,141
Less accumulated depreciation and amortization	(10,479)	(5,730)
Property and equipment, net	$ 25,541	18,411
Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Equipment and machinery
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Property and equipment, gross	$ 18,723	11,243
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,788	990
Furniture and fixtures \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Furniture and fixtures \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	7 years
Computer equipment
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Property and equipment, gross	$ 1,688	1,200
Capitalized software
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Property and equipment, gross	$ 5,760	2,515
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,642	694
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,419	$ 7,499

Property and Equipment, Net Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 5,568	$ 3,032	$ 1,550
Assets acquired under capital lease obligations, gross	350	494	199
Accumulated amortization of leasehold assets	107	180	149
Additions to capitalized internal use computer software	881	806	815
Amortization of capitalized internal use computer software	$ 516	$ 654	$ 423

Warranty Obligations Summary of Warranty Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Changes in the Company's product warranty liability
Balance, at beginning of year	$ 8,738	$ 2,668	$ 1,087
Warranty expense	15,825	7,030	1,896
Settlements	(3,225)	(960)	(315)
Balance, at end of year	21,338	8,738	2,668
Less current portion	(6,078)	(2,005)	(340)
Long-term portion	$ 15,260	$ 6,733	$ 2,328

- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers. For classified balance sheets, represents the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References + Details

Warranty Obligations Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Warranty Obligations (Textual) [Abstract]
Changes in estimates related to warranty expense	$ 7.6		$ 0.0
Increase in estimated replacement costs	10.2
Reduction in estimated replacement costs	2.6
Warranty expense derived from inventory write-down	$ 1.6
Reduction in warranty expense to reflect lower replacement costs		$ 1.8

Fair Value Measurements Summary of Open Foreign Currency Forward Contracts (Details) - Dec. 31, 2012 - January 15, 2013 € in Thousands, $ in Thousands	EUR (€)	USD ($)
Summary of open foreign currency forward contracts
Foreign Quantity	€ 4,800	$ 6,058
Market Value		5,790
Asset (Liability)		$ (268)

Fair Value Measurements Heirarchy (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Company's financial instruments that measured at fair value on a recurring basis
Total	$ 268	$ 1,399
Recurring \| Level 3
Company's financial instruments that measured at fair value on a recurring basis
Preferred stock warrant liability (Level 3)	0	1,399
Recurring \| Level 2
Company's financial instruments that measured at fair value on a recurring basis
Foreign currency forward contracts (Level 2)	$ 268	$ 0

- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of mandatorily redeemable preferred stock which the Company has issued and which is outstanding as of the balance sheet date. A financial instrument issued in the form of shares is mandatorily redeemable if it embodies an unconditional obligation requiring the issuer to redeem the instrument by transferring its assets at a specified or determinable date (or dates) or upon an event certain to occur. A financial instrument that embodies a conditional obligation to redeem the instrument by transferring assets upon an event not certain to occur becomes mandatorily redeemable and, therefore, becomes a liability - if that event occurs, the condition is resolved, or the event becomes certain to occur. A mandatorily redeemable financial instrument is classified as a liability unless the redemption is required to occur only upon the liquidation or termination of the entity.

+ References + Details

Fair Value Measurements Narrative (Details) $ in Thousands	12 Months Ended
Fair Value Measurements Narrative (Details) $ in Thousands	Dec. 31, 2012 USD ($)
Fair Value Disclosures [Abstract]
Loss related to the fair value adjustment of outstanding derivative instruments	$ 505

Long-Term Debt Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Schedule of long-term debt
Total debt	$ 11,061	$ 14,677
Less current portion	(2,384)	(4,529)
Long-term portion	8,677	10,148
Term loans, net of unamortized discount of $0 and $435, respectively
Schedule of long-term debt
Total debt	7,400	9,935
Net of unamortized discount	0	435
Equipment financing facility, net of unamortized discount of $94 and $156, respectively
Schedule of long-term debt
Total debt	3,661	4,742
Net of unamortized discount	$ 94	$ 156

Long-Term Debt Schedule of Maturities (Details) $ in Thousands	Dec. 31, 2012 USD ($)
Long-term Debt, by Current and Noncurrent [Abstract]
2013	$ 2,447
2014	3,538
2015	2,973
2016	2,197
Total debt	$ 11,155

Long-Term Debt Narrative (Details)			1 Months Ended	12 Months Ended
Long-Term Debt Narrative (Details)	Nov. 07, 2012 USD ($)	Jun. 13, 2011 USD ($)	Nov. 30, 2011 USD ($) $ / Units shares	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Nov. 30, 2012 USD ($)	Apr. 04, 2012 shares
Long-Term Debt (Textual) [Abstract]
Long-term debt, gross				$ 11,155,000
Number of securities called by warrants \| shares							199,458
Convertible preferred stock warrant liability				$ 0	$ 1,399,000
Term loan \| Horizon Technology Finance Corporation
Long-Term Debt (Textual) [Abstract]
Repayment of term loans	$ 7,500,000
Long-term debt, gross					10,300,000
Number of securities called by warrants \| shares			161,958
Warrant to purchase common stock, price per share \| $ / Units			6.17
Convertible preferred stock warrant liability					$ 700,000
Term loan \| Horizon Technology Finance Corporation \| Minimum
Long-Term Debt (Textual) [Abstract]
Interest rate during period					10.75%
Term loan \| Horizon Technology Finance Corporation \| Maximum
Long-Term Debt (Textual) [Abstract]
Interest rate during period					12.60%
Term loan \| Hercules Technology Growth Capital, Inc
Long-Term Debt (Textual) [Abstract]
Convertible loan facility, maximum borrowing capacity	$ 7,400,000
Debt instrument additional borrowing amount			$ 15,600,000
Projected EBITDA and revenue to meet additional term loans, achievement percentage	70.00%
Line of credit facility extension term	15 days
Term Loan interest at an annual rate		9.00%		11.50%
Long-term debt, gross				$ 7,400,000
Term loan \| Hercules Technology Growth Capital, Inc \| Prime Rate
Long-Term Debt (Textual) [Abstract]
Term Loan interest at an prime rate		5.75%		8.25%
Equipment financing facility \| Hercules Technology Growth Capital, Inc
Long-Term Debt (Textual) [Abstract]
Convertible loan facility, maximum borrowing capacity		$ 5,000,000.0
Long-term debt, gross				$ 3,800,000
Number of securities called by warrants \| shares			25,285
Revolving Credit Facility \| Bridge Bank National Association and Comerica
Long-Term Debt (Textual) [Abstract]
Convertible loan facility, maximum borrowing capacity					$ 33,000,000.0
Revolving Credit Facility \| Wells Fargo Bank
Long-Term Debt (Textual) [Abstract]
Convertible loan facility, maximum borrowing capacity	$ 50,000,000					$ 50,000,000.0
Amount of liquidity required for debt compliance	15,000,000
Amount of undrawn credit for debt compliance	8,000,000
Convertible loan facility, remaining borrowing capacity	$ 21,200,000
Revolving Credit Facility \| Wells Fargo Bank \| Minimum \| London Interbank Offered Rate (LIBOR) or Base Rate
Long-Term Debt (Textual) [Abstract]
Term Loan interest at an prime rate	4.25%
Revolving Credit Facility \| Wells Fargo Bank \| Maximum \| London Interbank Offered Rate (LIBOR) or Base Rate
Long-Term Debt (Textual) [Abstract]
Term Loan interest at an prime rate	1.50%

Convertible Facility Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended		3 Months Ended	9 Months Ended	12 Months Ended
	Apr. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Sep. 30, 2012	Dec. 31, 2011	Dec. 31, 2012	Apr. 04, 2012	Mar. 27, 2012
Convertible Facility (Textual) [Abstract]
Common stock conversion price per share							$ 6.00
Common stock issued during period, in connection with credit facility			10,315,151
Common stock issued, price per share					$ 5.27		$ 6.00
Number of common stock shares called by warrants							199,458
Common Stock
Convertible Facility (Textual) [Abstract]
Number of common stock shares called by warrants						330,974
Convertible secured junior debt
Convertible Facility (Textual) [Abstract]
Convertible loan facility, maximum borrowing capacity					$ 80.0
Convertible facility convertible notes issued					$ 20.0
Common stock conversion price per share					$ 8.8984
Number of common stock shares called by warrants		131,516
Common stock exercisable contractual term		5 years
Debt discounts and issuance costs					$ 3.1
Convertible secured junior debt \| Debt agreement, as amended
Convertible Facility (Textual) [Abstract]
Common stock conversion price per share								$ 8.8984
Debt interest expense				$ 2.8
Convertible secured junior debt \| Common Stock
Convertible Facility (Textual) [Abstract]
Common stock issued during period, in connection with credit facility					352,665
Common stock issued, price per share		$ 5.27
Convertible secured junior debt \| Common Stock \| Debt agreement, as amended
Convertible Facility (Textual) [Abstract]
Common stock issued during period, in connection with credit facility	3,533,988
Common stock issued, price per share							$ 6.00

Commitments and Contingencies Future Minimum Payments for Operating Leases (Details) $ in Thousands	Dec. 31, 2012 USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Total minimum lease payments	$ 16,194

Commitments and Contingencies Narrative (Details) ft² in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2012 USD ($) ft²	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)
Commitments and Contingencies [Line Items]
Rent expense	$ 2.4	$ 1.2	$ 0.6
Corporate headquarters property Company agreed to lease \| ft²	96
Purchase obligation	$ 115.6
Cancelable portion of purchase obligation	98.6
Purchase obligation cancellation penalties	$ 5.4
Maximum
Commitments and Contingencies [Line Items]
Purchase obligation time period	7 years

Stockholders' Equity and Warrants Valuation Assumptions of Convertible Preferred Stock Warrants Under Monte Carlo Simulation Model (Details) - Convertible Preferred Stock Warrant Liability [Member] - Convertible preferred stock	12 Months Ended
	Dec. 31, 2012
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Dividend yield	0.00%
Minimum
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Expected term (in years)	4 years 6 months
Expected volatility	60.50%
Annual risk-free rate of return	1.50%
Maximum
Fair Value Assumptions and Methodology for Assets and Liabilities [Abstract]
Expected term (in years)	6 years
Expected volatility	73.00%
Annual risk-free rate of return	2.70%

Stockholders' Equity and Warrants Summary of the Changes in Convertible Stock Warrant Liability (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($) $ / Units shares	Dec. 31, 2010 USD ($)	Apr. 04, 2012 shares
Changes in Fair value using recurring basis
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon IPO	$ 879	$ 0	$ 0
Number of securities called by warrants \| shares				199,458
Convertible preferred stock warrant liability
Changes in Fair value using recurring basis
Beginning balance	1,399	610
Fair value adjustments recognized in other (income) expense	(520)	321
Reclassification of convertible preferred stock warrant liability to additional paid-in capital upon IPO	(879)
Ending balance	$ 0	1,399	$ 610
Series E Preferred Stock \| Convertible preferred stock warrant liability \| Warrants to purchase preferred stock - issue 1
Changes in Fair value using recurring basis
Issuance of warrant to purchase shares of Series E convertible preferred stock		$ 286
Number of securities called by warrants \| shares		48,587
Warrant to purchase common stock, price per share \| $ / Units		6.174
Series E Preferred Stock \| Convertible preferred stock warrant liability \| Warrants to purchase preferred stock - issue 2
Changes in Fair value using recurring basis
Issuance of warrant to purchase shares of Series E convertible preferred stock		$ 182
Number of securities called by warrants \| shares		25,285
Warrant to purchase common stock, price per share \| $ / Units		8.8984

Stockholders' Equity and Warrants Narrative (Details)	1 Months Ended
Stockholders' Equity and Warrants Narrative (Details)	Apr. 30, 2012 shares	Dec. 31, 2012 $ / Units shares	Apr. 04, 2012 shares	Dec. 31, 2011 shares
Stockholders Equity (Textual) [Abstract]
Convertible preferred stock, shares outstanding	22,200,000	0	22,220,856	0
Convertible preferred stock converted. shares	25,200,000
Number of securities called by warrants			199,458
Common Stock
Stockholders Equity (Textual) [Abstract]
Number of securities called by warrants		330,974
Common Stock \| Minimum
Stockholders Equity (Textual) [Abstract]
Warrant to purchase common stock, price per share \| $ / Units		5.27
Common Stock \| Maximum
Stockholders Equity (Textual) [Abstract]
Warrant to purchase common stock, price per share \| $ / Units		6.17

Stock-Based Compensation Stock Option Activity (Details) - $ / shares shares in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Company's stock option activity
Number of shares options outstanding, beginning	6,256	5,802	3,595
Number of shares outstanding, granted	2,478	1,110	2,548
Number of Shares Outstanding, Exercised	(59)	(502)	(111)
Number of Shares Outstanding, Cancelled	(506)	(154)	(230)
Number of shares options outstanding, ending	8,169	6,256	5,802
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Weighted-average exercise price per share options outstanding, beginning balance (usd per share)	$ 1.83	$ 0.90	$ 0.39
Weighted-average exercise price per share, granted (usd per share)	7.35	6.16	1.57
Weighted- Average Exercise Price per Share, Exercised (usd per share)	1.26	0.38	0.59
Weighted-average exercise price per share, cancelled (usd per share)	5.55	2.82	0.53
Weighted-average exercise price per share options outstanding, ending balance (usd per share)	$ 3.28	$ 1.83	$ 0.90

Stock-Based Compensation Range of Exercise Price (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2012 $ / shares shares
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Number of Shares Outstanding \| shares	8,169
Weighted- Average Remaining Life of Outstanding Options (in years)	7 years 3 months 18 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 3.28
Number of Shares Exercisable \| shares	4,657
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 1.57
$0.27–$0.27
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	0.27
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 0.27
Number of Shares Outstanding \| shares	2,543
Weighted- Average Remaining Life of Outstanding Options (in years)	6 years 6 months
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 0.27
Number of Shares Exercisable \| shares	2,290
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 0.27
0.54–0.91
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	0.54
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 0.91
Number of Shares Outstanding \| shares	312
Weighted- Average Remaining Life of Outstanding Options (in years)	2 years 3 months 18 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 0.70
Number of Shares Exercisable \| shares	301
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 0.70
1.63–1.63
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	1.63
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 1.63
Number of Shares Outstanding \| shares	1,783
Weighted- Average Remaining Life of Outstanding Options (in years)	7 years 3 months 18 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 1.63
Number of Shares Exercisable \| shares	1,162
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 1.63
2.00–5.11
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	2.00
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 5.11
Number of Shares Outstanding \| shares	1,153
Weighted- Average Remaining Life of Outstanding Options (in years)	6 years 7 months 6 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 3.27
Number of Shares Exercisable \| shares	518
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 2.59
5.23–8.43
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	5.23
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 8.43
Number of Shares Outstanding \| shares	1,620
Weighted- Average Remaining Life of Outstanding Options (in years)	9 years 1 month 6 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 7.24
Number of Shares Exercisable \| shares	205
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 7.07
8.82–10.35
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	8.82
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 10.35
Number of Shares Outstanding \| shares	575
Weighted- Average Remaining Life of Outstanding Options (in years)	8 years 7 months 6 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 9.50
Number of Shares Exercisable \| shares	153
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 9.57
Total
Exercise Price Range of Options Outstanding and Options Exercisable [Line Items]
Range of Exercise Prices - Lower Range Limit (usd per share)	11.00
Range of Exercise Prices - Upper Range Limit (usd per share)	$ 11.00
Number of Shares Outstanding \| shares	183
Weighted- Average Remaining Life of Outstanding Options (in years)	9 years 1 month 6 days
Weighted- Average Exercise Price of Options Outstanding (usd per share)	$ 11.00
Number of Shares Exercisable \| shares	28
Weighted- Average Exercise Price of Options Exercisable (usd per share)	$ 11.00

Stock-Based Compensation Restricted Stock Unit Activity (Details) - Restricted stock units shares in Thousands	12 Months Ended
	Dec. 31, 2012 $ / shares shares
Restricted Stock Units [Roll Forward]
December 31, 2011 (shares) \| shares	0
Granted (shares) \| shares	282
Vested (shares) \| shares	(20)
Canceled (shares) \| shares	(14)
December 31, 2012 (shares) \| shares	248
Weighted Average Fair Value per Share at Grant Date [Roll Forward]
December 31, 2011 (usd per share) \| $ / shares	$ 0.00
Granted (usd per share) \| $ / shares	5.69
Vested (usd per share) \| $ / shares	2.00
Canceled (usd per share) \| $ / shares	6.90
December 31, 2012 (usd per share) \| $ / shares	$ 5.53

Stock-Based Compensation Components of Stock-based Compensation Expense by Report Line (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	$ 4,766	$ 2,120	$ 829
Cost of revenues
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	196	39	9
Research and development
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	1,728	795	286
Sales and marketing
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	1,254	671	256
General and administrative
Allocation of Stock-based Compensation Expense Included in the Consolidated Statement of Operations [Abstract]
Total stock-based compensation expense	$ 1,588	$ 615	$ 278

- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References + Details

Stock-Based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 4,766	$ 2,120	$ 829
Stock options and restricted stock units
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	4,519	2,120	829
ESPP
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense	$ 247	$ 0	$ 0

- Definition

+ References + Details

Stock-Based Compensation Valuation Assumptions of Stock Options Under Black-Scholes Model (Details) - Stock options - $ / shares	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
The Fair Value of Each Option Granted During the Period [Abstract]
Expected term (in years)	5 years 8 months 12 days	6 years	6 years
Expected volatility	74.50%	72.00%	73.30%
Annual risk-free rate of return	0.90%	1.80%	2.20%
Dividend yield	0.00%	0.00%	0.00%
Weighted-average fair value on grant date	$ 4.69	$ 5.08	$ 1.73

Stock-Based Compensation Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2012 USD ($) $ / shares shares	Dec. 31, 2012 USD ($) purchase_period $ / shares shares	Dec. 31, 2011 USD ($) shares	Dec. 31, 2010 USD ($) shares	Dec. 31, 2009 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares outstanding	8,169,000	8,169,000	6,256,000	5,802,000	3,595,000
Number of shares outstanding, granted		2,478,000	1,110,000	2,548,000
Expiration term of ESPP		10 years
Total stock-based compensation expense \| $		$ 4,766	$ 2,120	$ 829
Intrinsic value of options exercised \| $		$ 300
Number of options outstanding that were vested, exercisable and expected to vest	7,900,000	7,900,000
Weighted-average fair value value per share, vested \| $ / shares	$ 3.19	$ 3.19
Weighted-average remaining contractual term, vested		7 years 2 months 12 days
Aggregate intrinsic value, exercisable shares \| $	$ 11,500	$ 11,500
Number of shares exercisable	4,657,000	4,657,000
Common stock fair value, per share \| $ / shares	$ 3.65	$ 3.65
Total unrecognized compensation cost \| $	$ 12,900	$ 12,900
Weighted-average period		3 years
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of stock vested during period \| $		$ 39
Weighted average remaining contractual term		1 year 8 months 12 days
Intrinsic value of restricted stock units outstanding \| $	$ 900	$ 900
2006 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted period vest over		4 years
Common stock, shares outstanding	6,400,000	6,400,000	6,300,000
Number of shares outstanding, granted		0
2006 Plan \| Before August 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted contractual term		10 years
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted period vest over		4 years
Issue of common stock	2,643,171	2,643,171
Increase in number of shares of common stock reserved for issuance under the stock incentive plan		4.50%
Maximum number of shares that be issued pursuant to the exercise of incentive stock options	320,855	320,855
2011 Plan \| After August 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted contractual term		7 years
2011 Employee Stock Purchase Plan (ESPP)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity awards granted contractual term		10 years
Issue of common stock	669,603	669,603
Maximum number of shares that be issued pursuant to the exercise of incentive stock options	610,290	610,290
Yearly, share increase in reserved shares	330,396	330,396
Offering periods, description		27 months
Number of interim purchase periods \| purchase_period		4
General duration (in months) of employee stock purchase plan		24 months
Payroll deductions	15.00%	15.00%
Fair market value		85.00%
Look-back feature in ESPP		2 years
Recognition period for additional expense triggered by the reset feature		24 months
Purchase of common stock \| $		$ 25
Employee stock purchase plan offering period		25 months
Number of purchase periods \| purchase_period		4
Total stock-based compensation expense \| $	$ 247

Income Taxes Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Income tax benefit at statutory rate	$ (12,773)	$ (10,883)	$ (7,284)
State taxes, net of federal benefit	(1,478)	(1,956)	190
Change in valuation allowance	12,574	12,451	6,783
Income Tax Reconciliation Nondeductible and Nontaxable Expense Other	2,155	388	311
Uncertain tax positions	173	0	0
Provision for income taxes	$ 651	$ 0	$ 0

- Definition

The sum of the current income tax expense or benefit and the deferred income tax expense or benefit pertaining to pretax Income or Loss from continuing operations; income tax expense or benefit may include interest and penalties on tax uncertainties based on the entity's accounting policy.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 45
-Paragraph 25
-URI http://asc.fasb.org/extlink&oid=21917399&loc=d3e32247-109318

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h))
-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 740
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32672-109319

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 109
-Paragraph 45, 46
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 08
-Paragraph h
-Article 4

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Interpretation (FIN)
-Number 48
-Paragraph 15, 16, 19
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Income Taxes Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011
Current:
Reserves and allowances	$ 11,523	$ 4,641
Valuation allowance	(11,523)	(4,637)
Total Current	0	4
Non-current:
Net operating losses	14,364	15,653
Stock-based compensation	919	410
Deferred revenue	1,425	1,435
Fixed assets and intangibles	10,301	4,716
Other	880	0
Valuation allowance	(27,889)	(22,193)
Total non-current	0	21
Deferred tax liability	0	(25)
Deferred Tax Assets, Net	$ 0	$ 0

Income Taxes Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Line Items]
Provision for U.S. federal or state income taxes	$ 0
provision for income taxes related to foreign operations	$ 700
Federal statutory income tax rate	34.00%	34.00%	34.00%
Unrecognized Tax Benefits	$ 160	$ 0
Unrecognized Tax Benefits, Increases Resulting from Current Period Tax Positions	110
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions	50
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	13
Internal Revenue Service (IRS)
Income Taxes [Line Items]
Operating loss carryforwards	54,000
California
Income Taxes [Line Items]
Operating loss carryforwards	$ 49,000

Concentration of Credit Risk and Major Customers Narrative (Details)	12 Months Ended
	Dec. 31, 2012 customer	Dec. 31, 2011 accounts_receivable customer	Dec. 31, 2010 customer
Accounts Receivable
Revenue, Major Customer [Line Items]
Number of customers considered to give rise to concentration risk	2	2
Net Revenue
Revenue, Major Customer [Line Items]
Number of customers considered to give rise to concentration risk	2	3	2
Customer Providing Largest Concentration of Receivable \| Accounts Receivable \| Credit Concentration Risk
Revenue, Major Customer [Line Items]
Percentage of concentration risk	21.00%	24.00%
Customer Providing Second Largest Concentration of Receivable \| Accounts Receivable \| Credit Concentration Risk
Revenue, Major Customer [Line Items]
Percentage of concentration risk	16.00%	10.00%
Customer Accounting for the Largest Concentration of Revenue \| Net Revenue \| Customer Concentration Risk
Revenue, Major Customer [Line Items]
Percentage of concentration risk	16.00%	17.00%	14.00%
Customer Accounting for Second Largest Concentration of Revenue \| Net Revenue \| Customer Concentration Risk
Revenue, Major Customer [Line Items]
Percentage of concentration risk	11.00%	11.00%	11.00%
Customer Accounting for Third Largest Concentraion \| Net Revenue \| Customer Concentration Risk
Revenue, Major Customer [Line Items]
Percentage of concentration risk		10.00%

Net Loss Per Share Attributable to Common Stockholders Potential Common Shares Outstanding Excluded from Computation of Diluted Net Loss Per Share (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	8,753	34,113	31,125
Convertible preferred stock
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	0	25,171	25,171
Options outstanding
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	8,169	6,256	5,802
Convertible notes
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	0	2,328	0
Stock compensation plan
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	5	0	0
Restricted stock outstanding
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	248	0	0
Warrant
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	331	143	11
Warrants to purchase convertible preferred stock
The potential common shares outstanding that were excluded from the computation of diluted net loss per share attributable to common stockholders
Total	0	215	141

- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Antidilution
-URI http://asc.fasb.org/extlink&oid=6505113

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Diluted Earnings Per Share
-URI http://asc.fasb.org/extlink&oid=6510752

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Contingent Stock Agreement
-URI http://asc.fasb.org/extlink&oid=6508534

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 40
-Subparagraph c
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 13, 14
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Emerging Issues Task Force (EITF)
-Number 07-4
-Paragraph 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 128
-Paragraph 171
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Net Loss Per Share Attributable to Common Stockholders Narrative (Details) shares in Millions	12 Months Ended
	Dec. 31, 2012 shares
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Conversion of preferred stock into common stock (in shares)	28.7

- Definition

Number of shares issued during the period as a result of the conversion of convertible securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=6959260&loc=d3e187085-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.29-30)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 4, 5
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher AICPA
-Name Accounting Principles Board Opinion (APB)
-Number 12
-Paragraph 10
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Geographic Information Net Revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues	$ 57,568	$ 60,813	$ 55,697	$ 42,600	$ 57,134	$ 44,728	$ 29,592	$ 18,069	$ 216,678	$ 149,523	$ 61,661
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									189,711	128,692	53,383
International [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenues									$ 26,967	$ 20,831	$ 8,278

Geographic Information Long-Lived Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Long-lived assets by geographic region
Total	$ 25,541	$ 18,411	$ 6,103
United States
Long-lived assets by geographic region
Total	17,136	11,199	5,330
China
Long-lived assets by geographic region
Total	6,642	5,974	710
Other
Long-lived assets by geographic region
Total	$ 1,763	$ 1,238	$ 63

Geographic Information Narrative (Details)	12 Months Ended
Geographic Information Narrative (Details)	Dec. 31, 2011	Dec. 31, 2010
Geographic concentration risk \| Segment sales revenue \| CANADA
Segment Reporting Information [Line Items]
Percentage of total net revenues	12.00%	13.00%

Related Party Transactions Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
KPCB Holdings, Inc.
Related Party Transaction [Line Items]
Revenue from related parties	$ 16.8	$ 6.4

- Definition

Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

+ References + Details

Quarterly Financial Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly Financial Information Disclosure [Abstract]
Net revenues	$ 57,568	$ 60,813	$ 55,697	$ 42,600	$ 57,134	$ 44,728	$ 29,592	$ 18,069	$ 216,678	$ 149,523	$ 61,661
Cost of revenues	41,512	44,489	42,096	33,293	44,063	36,185	24,785	15,421	161,390	120,454	55,159
Gross profit	16,056	16,324	13,601	9,307	13,071	8,543	4,807	2,648	55,288	29,069	6,502
Operating expenses:
Research and development	8,533	10,571	8,655	7,842	7,180	6,431	6,143	5,345	35,601	25,099	14,296
Sales and marketing	7,525	7,039	6,360	5,049	5,612	4,567	4,265	3,010	25,973	17,454	6,558
General and administrative	6,177	6,911	6,091	5,696	4,109	3,980	3,889	3,250	24,875	15,228	6,365
Total operating expenses	22,235	24,521	21,106	18,587	16,901	14,978	14,297	11,605	86,449	57,781	27,219
Loss from operations	(6,179)	(8,197)	(7,505)	(9,280)	(3,830)	(6,435)	(9,490)	(8,957)	(31,161)	(28,712)	(20,717)
Other expense, net	(1,258)	(580)	(3,729)	(839)	(1,707)	(741)	(798)	(332)	(6,406)	(3,578)	(1,060)
Loss before income taxes	(7,437)	(8,777)	(11,234)	(10,119)					(37,567)	(32,290)	(21,777)
Provision for income taxes	(305)	(130)	(151)	(65)					(651)	0	0
Net loss attributable to common stockholders	$ (7,742)	$ (8,907)	$ (11,385)	$ (10,184)	$ (5,537)	$ (7,176)	$ (10,288)	$ (9,289)	$ (38,218)	$ (32,290)	$ (21,777)
Net loss per share attributable to common stockholders, basic and diluted (usd per share)	$ (0.19)	$ (0.22)	$ (0.29)	$ (5.97)	$ (3.41)	$ (4.77)	$ (9.95)	$ (10.95)	$ (1.24)	$ (25.73)	$ (28.96)