Itron Networked Solutions (SSNI) 10-K 9 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Mar. 03, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	ssni
Entity Registrant Name	SILVER SPRING NETWORKS INC
Entity Central Index Key	1,180,079
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Public Float			$ 454.6
Entity Common Stock, Shares Outstanding		50,887,105

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 65,264	$ 60,457
Short-term investments	59,181	60,339
Accounts receivable	47,813	54,740
Inventory	4,545	6,722
Deferred cost of revenue	196,868	29,585
Deferred tax assets		5,278
Prepaid expenses and other current assets	10,835	5,146
Total current assets	384,506	222,267
Property and equipment, net	14,106	12,860
Goodwill and intangible assets	14,390	8,221
Deferred cost of revenue, non-current	38,882	303,445
Deferred tax assets, non-current	1,069	354
Other long-term assets	4,772	1,047
Total assets	457,725	548,194
Current liabilities:
Accounts payable	30,623	27,530
Deferred revenue	305,471	91,688
Deferred tax liability		249
Accrued and other liabilities	42,751	24,421
Total current liabilities	378,845	143,888
Deferred revenue, non-current	96,342	517,905
Deferred tax liability, non-current		5,146
Other liabilities	16,403	15,074
Total liabilities	$ 491,590	$ 682,013
Commitments and contingencies (Note 16)
Stockholders’ deficit:
Common stock, $0.001 par value; 1,000,000 shares authorized; 50,621 and 49,062 shares issued and outstanding as of December 31, 2015 and 2014, respectively	$ 51	$ 47
Additional paid-in capital	594,301	573,344
Accumulated other comprehensive loss	(1,772)	(779)
Accumulated deficit	(626,445)	(706,431)
Total stockholders’ deficit	(33,865)	(133,819)
Total liabilities and stockholders’ deficit	$ 457,725	$ 548,194

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	50,621,000	49,062,000
Common stock, shares outstanding	50,621,000	49,062,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Product revenue	$ 353,041	$ 129,333	$ 224,310
Service revenue	136,518	61,955	102,548
Total revenue, net	489,559	191,288	326,858
Cost of revenue:
Product cost of revenue	202,430	77,158	150,315
Service cost of revenue	61,386	57,793	61,189
Total cost of revenue	263,816	134,951	211,504
Gross profit	225,743	56,337	115,354
Operating expenses:
Research and development	61,295	64,771	77,018
Sales and marketing	33,452	36,388	34,931
General and administrative	46,372	41,260	45,160
Restructuring	1,671	1,789
Total operating expenses	142,790	144,208	157,109
Operating income (loss)	82,953	(87,871)	(41,755)
Other income (expense), net:
Interest income	468	316	86
Interest expense	(52)	(132)	(1,199)
Other expense, net	(312)	(61)	(39)
Conversion of promissory notes and remeasurement of warrants and derivatives			(23,676)
Other income (expense), net	104	123	(24,828)
Income (loss) before income taxes	83,057	(87,748)	(66,583)
Provision for income taxes	3,071	1,422	224
Net income (loss)	79,986	(89,170)	(66,807)
Deemed dividend to convertible preferred stockholders			(105,000)
Net income (loss) attributable to common stockholders	$ 79,986	$ (89,170)	$ (171,807)
Net income (loss) per share attributable to common stockholders
Basic	$ 1.60	$ (1.84)	$ (4.54)
Diluted	$ 1.55	$ (1.84)	$ (4.54)
Weighted average shares used to compute net income (loss) per share attributable to common stockholders
Basic	49,963	48,377	37,877
Diluted	51,524	48,377	37,877

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)	$ 79,986	$ (89,170)	$ (66,807)
Other comprehensive (loss) income:
Change in foreign currency translation - net of adjustment	(837)	(770)	182
Net unrealized (loss) gain on available for sale investments (net of tax effect of $0, $0, and $51)	(156)	(139)	84
Other comprehensive (loss) income	(993)	(909)	266
Comprehensive income (loss)	$ 78,993	$ (90,079)	$ (66,541)

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net unrealized gain (loss) on available for sale investments, tax effect	$ 0	$ 0	$ 51

Consolidated Statements Of Conv

Consolidated Statements Of Convertible Preferred Stock And Stockholders Deficit - USD ($)	Total	Series E Preferred Stock	Private Placement [Member]	Initial Public Offering [Member]	Convertible Preferred Stock [Member]	Convertible Preferred Stock [Member]Series E Preferred Stock	Common Stock [Member]	Common Stock [Member]Private Placement [Member]	Common Stock [Member]Initial Public Offering [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Series E Preferred Stock	Additional Paid-in Capital [Member]Private Placement [Member]	Additional Paid-in Capital [Member]Initial Public Offering [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated deficit [Member]
Beginning Balance at Dec. 31, 2012	$ (499,508,000)				$ 270,725,000		$ 4,000			$ 51,078,000				$ (136,000)	$ (550,454,000)
Beginning Balance (in shares) at Dec. 31, 2012					22,366,000		3,764,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock	2,926,000									2,926,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock (in shares)							1,644,000
Shares withheld related to net share settlement of restricted stock	(8,019,000)									(8,019,000)
Shares withheld related to net share settlement of restricted stock (in shares)							(422,000)
Discount on Series E preferred stock		$ 105,000,000				$ (105,000,000)					$ 105,000,000
Deemed dividend to Series E preferred stock	105,000,000	$ (105,000,000)				$ 105,000,000					$ (105,000,000)
Conversion of preferred stock to common stock	270,725,000				$ (270,725,000)		$ 32,000			270,693,000
Conversion of preferred stock to common stock (in shares)					(22,366,000)		32,407,000
Conversion of preferred stock warrants to common stock warrants	66,000									66,000
Conversion of convertible promissory notes	79,441,000						$ 4,000			79,437,000
Conversion of convertible promissory notes (in shares)							3,765,000
Issuance of common stock			$ 12,000,000	$ 79,921,000				$ 1,000	$ 5,000			$ 11,999,000	$ 79,916,000
Issuance of common stock, shares			705,881					706,000	5,463,000
Issuance of common stock upon net exercise of common stock warrants (in shares)							57,000
Stock-based compensation	50,871,000									50,871,000
Tax benefit from shared-based award activity	0
Other comprehensive income	266,000													266,000
Net income (loss)	(66,807,000)														(66,807,000)
Ending Balance at Dec. 31, 2013	(78,118,000)						$ 46,000			538,967,000				130,000	(617,261,000)
Ending Balance (in shares) at Dec. 31, 2013							47,384,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock	1,113,000						$ 1,000			1,112,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock (in shares)							1,658,000
Shares withheld related to net share settlement of restricted stock	(6,453,000)						$ (1,000)			(6,452,000)
Shares withheld related to net share settlement of restricted stock (in shares)							(473,000)
Issuance of common stock in connection with employee stock purchase plan	5,907,000						$ 1,000			5,906,000
Issuance of common stock in connection with employee stock purchase plan (in shares)							493,000
Stock-based compensation	33,811,000									33,811,000
Tax benefit from shared-based award activity	100,000
Other comprehensive income	(909,000)													(909,000)
Net income (loss)	(89,170,000)														(89,170,000)
Ending Balance at Dec. 31, 2014	$ (133,819,000)						$ 47,000			573,344,000				(779,000)	(706,431,000)
Ending Balance (in shares) at Dec. 31, 2014	49,062,000						49,062,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock	$ 550,000						$ 4,000			546,000
Issuance of common stock upon exercise of stock options and vesting of restricted stock (in shares)							1,643,000
Shares withheld related to net share settlement of restricted stock	(5,788,000)									(5,788,000)
Shares withheld related to net share settlement of restricted stock (in shares)							(502,000)
Issuance of common stock in connection with employee stock purchase plan	3,244,000									3,244,000
Issuance of common stock in connection with employee stock purchase plan (in shares)							418,000
Stock-based compensation	22,802,000									22,802,000
Tax benefit from shared-based award activity	153,000									153,000
Other comprehensive income	(993,000)													(993,000)
Net income (loss)	79,986,000														79,986,000
Ending Balance at Dec. 31, 2015	$ (33,865,000)						$ 51,000			$ 594,301,000				$ (1,772,000)	$ (626,445,000)
Ending Balance (in shares) at Dec. 31, 2015	50,621,000						50,621,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flow - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 79,986	$ (89,170)	$ (66,807)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Deferred taxes	(1,492)	(225)	(205)
Depreciation and amortization	7,822	6,467	6,646
Stock-based compensation	26,479	33,861	52,504
Conversion of promissory notes and remeasurement of warrants and derivatives			23,676
Non-cash interest expense on convertible notes			935
Other non-cash adjustments	766	431	333
Changes in operating assets and liabilities:
Accounts receivable	7,398	15,554	(13,245)
Inventory	2,190	(2,271)	3,381
Prepaid expenses and other current assets	(5,128)	194	3,351
Contingent payments related to Detectent acquisition, held in escrow	(4,000)
Deferred cost of revenue	97,286	(56,907)	(30,960)
Accounts payable	3,101	(4,120)	2,848
Customer deposits	(448)	321	(61)
Deferred revenue	(208,305)	84,590	16,597
Accrued and other liabilities	14,032	2,510	1,021
Net cash provided by (used in) operating activities	19,687	(8,765)	14
Cash flows (used in) investing activities:
Business acquisition, net of cash acquired	(7,098)	(8,726)
Proceeds from sales of available-for-sale investments	15,690	53,450	9,122
Proceeds from maturities of available-for-sale investments	9,250	6,750
Purchases of available-for-sale investments	(24,180)	(57,671)	(72,339)
Purchases of property and equipment	(5,350)	(6,073)	(3,950)
Net cash used in investing activities	(11,688)	(12,270)	(67,167)
Cash flows (used in) provided by financing activities:
Payment upon termination of preferred stock warrants of a related party			(12,000)
Proceeds from initial public offering, net of offering costs			84,247
Proceeds from private placement of common stock with a related party			12,000
Payments on capital lease obligations	(1,163)	(1,550)	(2,034)
Proceeds from issuance of common stock, net of repurchases	3,794	7,020	2,909
Excess tax benefit from share-based payment awards	153
Taxes paid related to net share settlement of equity awards	(5,788)	(6,453)	(8,019)
Net cash (used in) provided by financing activities	(3,004)	(983)	77,103
Effect of exchange rate changes on cash and cash equivalents	(188)	(121)
Net increase (decrease) in cash and cash equivalents	4,807	(22,139)	9,950
Cash and cash equivalents—beginning of period	60,457	82,596	72,646
Cash and cash equivalents—end of period	65,264	60,457	82,596
Supplemental cash flow information—cash paid for income taxes	2,678	659	233
Supplemental cash flow information—cash paid for interest	51	132	263
Non-cash investing and financing activities:
Conversion of convertible preferred stock into common stock			270,725
Fair value of common stock issued on conversion of convertible promissory notes			79,441
Deferred offering costs not yet paid			20
Unpaid purchases of property and equipment	$ 2,862	523	832
Property and equipment acquired under capital lease			$ 1,767
Leasehold improvements funded by lease incentives		$ 650

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	1. DESCRIPTION OF BUSINESS, BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES DESCRIPTION OF BUSINESS Silver Spring Networks, Inc. (the “Company”, “we”, “us” and “our”) has over ten years of experience creating, building and successfully deploying large scale networks and solutions enabling the “internet of things” for critical infrastructure. The “internet of things” refers to a system where a diversity of physical devices have the capacity to communicate using internet technologies. Our first area of focus was in energy, creating a leading grid network by applying advanced networking technology and solutions to the power grid. We have broadened our focus beyond the smart grid to other utility networks including gas and water, and other critical infrastructure such as street lights, enabling smarter and more efficient cities. Longer term, we look to expand our reach into an even broader range of IoT markets by working with our customers, partners and developers to open their networks to third parties and support a wider range of devices, applications and solutions. BASIS OF PRESENTATION The consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States, or GAAP. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation. SIGNIFICANT ACCOUNTING POLICIES Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and the accompanying notes during the reporting period. Estimates are used for revenue and cost recognition, allowance for doubtful accounts receivable, inventory valuation, estimates related to recovery of long-lived assets and goodwill, restructuring accruals, Cash, Cash Equivalents and Short-term Investments Cash equivalents consist of highly liquid investments with insignificant interest rate risk and original maturities at the time of purchase of three months or less, and consist of money market funds. Short-term investments consist of high grade investment securities with original maturities at the time of purchase of greater than three months, and are available for use in current operations. We classify all of our cash equivalents and short-term investments as available-for-sale, which are recorded at fair value. Unrealized gains and losses are included in accumulated other comprehensive (loss) income in stockholders’ deficit. Realized gains and losses are included in other income and expense, net. We evaluate our short-term investments for impairment each reporting period. Determining whether a decline in fair value is other-than-temporary requires management judgment based on the specific facts and circumstances of each security. We consider various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value has been less than our cost basis, the investment's financial condition, and near-term prospects of the investee. If we determine that the decline in an investment's fair value is other than temporary, the difference is recognized as an impairment loss in its consolidated statements of operations. Amounts are reclassified out of accumulated other comprehensive (loss) income into earnings using the specific identification method. Inventory Inventory is stated at the lower of cost or market. Cost is computed using standard cost, which approximates actual cost on a first-in, first-out basis. We evaluate our ending inventories for excess quantities and obsolescence based on forecasted demand within specific time horizons, technological obsolescence, and an assessment of any inventory that is not of saleable condition. Actual demand may differ from forecasted demand, and such differences may have a material effect on recorded inventory values and operating results. In addition, we enter into purchase commitments with third-party contract manufacturers to manage lead times and meet product forecasts and with other parties to purchase various key components used in the manufacture of our products. Accruals are established for estimated losses on purchased components for which we believe it is probable that they will not be recoverable in future operations. To the extent that such forecasts are not achieved, commitments and associated accruals may change. Revenue Recognition We generally market our products and services directly to customers. We also contract with third-party device manufacturers, which integrate our communications modules into their devices. Our solutions, which include our UtilOS network operating system, SilverLink Control Platform and SilverLink Applications, networking hardware, and communications modules, provides customers with two-way communication from our communications modules to their back office. Our hardware devices include UtilOS embedded software, which functions together with the tangible hardware elements to deliver the tangible products’ essential functionality. Our SilverLink Control Platform and SilverLink Applications of products includes software that is not embedded with the tangible hardware elements, but that is also necessary to deliver the tangible products’ essential network functionality, as well as other application software that provides additional functionality to the network solution. We derive revenue from sales of products, including hardware and software, as well as services, including network design and deployment support, managed services and SaaS, and ongoing customer support. We enter into separate arrangements with third-party device manufacturers to integrate our communications modules with their devices pursuant to our customers’ specifications. While we may receive payment directly from these third-party device manufacturers, the timing of revenue recognition related to communications modules delivered to third-party device manufacturers is ultimately determined based upon acceptance by our customers. Substantially all of our sales of communications modules have been fulfilled through third-party device manufacturers in this manner. We enter into multiple deliverable arrangements with customers to deploy our networking platform and solutions, which include the delivery of hardware and software, as well as services. Judgment is required in determining the separate units of accounting, which depends on whether the delivered items have standalone value to customers. When we sell our products and services separately, or when the customer could resell them on a standalone basis, we treat the delivered elements as having standalone value. In our typical customer arrangements, we consider the following to be separate units of accounting: (i) our hardware together with the related embedded software; (ii) our network management software within our SilverLink Control Platform and SilverLink Applications suite that provides the tangible product’s essential network functionality and related hardware for which the network management software is intended to be used; (iii) other application software within our SilverLink Control Platform and SilverLink Applications suite not essential for the customer to obtain functionality of the hardware; and (iv) our service offerings, which include professional services, managed services and SaaS, and ongoing customer support. We determine total arrangement consideration, and exclude amounts that are contingent upon the delivery of additional items or meeting other specified performance conditions, including potential refunds or penalty provisions. We allocate the total arrangement consideration to the deliverables based on our determination of the units of accounting and their relative selling prices. As we have not yet established vendor-specific objective evidence, or VSOE, or identified third-party evidence of fair value for these units of accounting, we use our best estimate of selling price to perform the relative fair value allocation. Judgment is also required in determining how to measure and allocate arrangement consideration among the separate units of accounting. The process for performing an assessment of our best estimate of selling price for our products and services is based on quantitative and qualitative aspects of multiple factors. These factors include market conditions, such as competitive alternatives and pricing practices, as well as company-specific factors, such as standalone sales, nature and size of the customer, contractually stated prices, costs to manufacture products or provide services and profit objectives. In establishing such profit objectives, we consider prices in previous contracts, size of the transaction, and the drivers, if any, that could influence future margins. The following revenue recognition criteria are applied to the units of accounting in all customer arrangements, as well as those in which orders of communications modules are fulfilled through third-party device manufacturers as described above. We do not recognize revenue for a unit of accounting until all of the following criteria have been met: · Persuasive evidence of an arrangement exists . Binding contracts or purchase orders are used to determine the existence of an arrangement. · Delivery has occurred . Shipping documents and customer acceptance provisions, where applicable, are used to verify delivery. · The fee is fixed or determinable . We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. · Collectibility is reasonably assured . We assess collectibility based primarily on creditworthiness of the customer or third-party device manufacturer as determined by credit assessments and payment history. Substantially all of our customer arrangements include acceptance provisions that require testing of the network against specific performance criteria. We consider the following factors in our assessment of whether the acceptance provisions are substantive: · whether the criteria are based on our standard performance criteria or are customer-specific; · if the criteria are customer-specific, availability of objective and sufficient evidence to reliably demonstrate that the delivered products and services will meet all of the specified criteria prior to receipt of customer acceptance; · our experience with similar types of arrangements or products, as well as our experience with the specific customer; · whether we would be successful in enforcing a claim for payment even in the absence of acceptance confirmation from the customer; · the nature and complexity of the acceptance testing, including the planned duration of the acceptance period; and · the significance of financial penalties, if any, associated with not meeting performance criteria. From incorporation through December 31, 2014, we deferred revenue for arrangements that contain customer-specific acceptance criteria until we determine whether acceptance was achieved due to our limited experience with customer deployments during that period. We perform an ongoing evaluation of the sufficiency of historical experience in determining the effect of customer-specific acceptance terms on timing of revenue recognition. During the quarter ended March 31, 2015, following the completion of analyses of historical experience, we determined that we have sufficient objective evidence to conclude that (i) network solution testing conducted in prior deployments can be relied upon to demonstrate that products and services delivered for deployments of other customers will meet acceptance testing criteria, provided that such prior deployments have similar characteristics and substantially similar testing criteria, or (ii) in absence of such evidence from prior deployments, network solution testing in the initial service area for a specific customer deployment can be relied upon to demonstrate that products and services delivered for subsequent service areas within that same deployment will meet subsequent acceptance testing criteria, provided that such initial network solution testing is successfully completed, and the testing criteria in the initial service area are substantially similar to the agreed-upon testing criteria for the remaining service areas. Receipt of acceptance from these customers is no longer considered necessary as (i) substantially similar acceptance testing criteria have been met in similar deployments of other customers, or (ii) substantially similar acceptance testing criteria have been met in the initial service area within the customer’s deployment, and all other revenue recognition criteria were met. As a result of the above change in assessment of the impact of customer-specific acceptance criteria, revenue and cost of revenue recognized during the year ended December 31, 2015 in the consolidated statements of operations included revenue of $139.4 million, which otherwise would have been deferred before the change in assessment, and excluded cost of revenue of $55.9 million, which otherwise would have been recognized in the period before the change in such assessment. This resulted in a $83.5 million increase in net income, a $1.67 increase to basic net income per share, and a $1.62 increase to diluted net income per share during the year ended December 31, 2015. Once we have satisfied the necessary acceptance provisions, we recognize revenue as follows: · Revenue from software that functions together with the tangible hardware elements to deliver the tangible products’ essential functionality is recognized upon delivery of both the software and related hardware elements, assuming all other revenue recognition criteria are met. · Application software and related post contract support services which are not considered essential to the functionality of hardware devices are within the scope of ASC 985-605. In accordance with ASC 985-605, revenues are recognized ratably over the longest service period for post-contract customer support, or PCS, and professional services as we have not established VSOE for software or the related software elements. · Revenue from our service offerings, including professional services such as network design and deployment support, managed services and SaaS, and ongoing customer support is recognized as services are delivered or on a proportional performance basis depending on the underlying pattern of performance. · Revenue from hardware is recognized when title and risk of loss transfers. Amounts that are invoiced prior to a transaction meeting all of the above revenue recognition criteria are recorded in deferred revenue until such criteria are satisfied. For all periods presented herein, the amount and timing of revenue and product cost recognition has been, and for the near-term will be, dependent primarily on our ability to meet substantive customer acceptance criteria. We consider a variety of factors in estimating the timing of customer acceptance, which includes contractual milestones, project schedules, availability of resources, the nature and extent of remaining testing cycles, and other relevant information provided by our project management team. Accordingly, we expect that the timing of recognition of revenue and related product costs on both a quarterly and annual basis will not be easily predictable. In addition, it is possible that the amount of current deferred revenue and related deferred cost of revenue reflected as of a balance sheet date will be significantly higher or lower than the amount of deferred revenue and related deferred cost of revenue that is ultimately recognized as revenue and cost of revenue within the 12 months following the balance sheet date. We classify deferred revenue and deferred cost of revenue that we expect to recognize during the 12 months following the balance sheet date as current deferred revenue and current deferred cost of revenue on our balance sheet and the remainder as non-current deferred revenue and non-current deferred cost of revenue. Certain of our customer and third-party device manufacturer contracts include contingency provisions, which impact our revenue recognition as such contingent amounts limit the amount of the total arrangement consideration under multiple deliverable contracts that can be allocated to delivered and accepted products and services. Amounts that are invoiced prior to a transaction meeting all of the revenue recognition criteria, including contingency provisions, are recorded in deferred revenue until such provisions have lapsed. For the years ended December 31, 2015 and 2014, such amounts were $32.1 million and $26.2 million, respectively, related to those arrangements for which we have started recognizing revenue. These contingencies are related to potential penalties for late delivery, liquidated damages related to failure to meet milestones or deliver specified products or services, or credits to be issued upon the failure to meet service level criteria. The amounts that could be paid under these provisions are typically limited and capped at amounts that do not exceed specific thresholds. Accordingly, even in situations where we have received customer acceptance, we limit the revenue recognized for accepted products and services by the amount that could be paid under these provisions. We do not recognize these deferred amounts until the provisions have lapsed. Predicting when such provisions will lapse is subject to significant uncertainty as the timing is dependent on a variety of factors, including the progress and completion of deployments. Related to the contingency provisions described above, $1.2 million and $4.6 million, respectively, were recorded as current deferred revenue and $30.9 million and $21.6 million, respectively, were recorded as non-current revenue as of December 31, 2015 and 2014. In cases where we sell third-party products and services such as meters, hardware, services, software or software maintenance as part of the overall solution, we evaluate whether we act as principal or agent under the arrangement. The evaluation considers multiple factors, including whether we are the primary obligor under the arrangement with the customer, whether we bear the risk of loss and credit risk associated with the supply of third-party products and services, whether we have the ability to change the product or perform part of the service, and whether we have the ability to control the price charged to our customers for the third-party products and services. Revenue is presented on a gross basis when we conclude that we are the principal under the arrangement with respect to third-party products and services, and revenue is presented on a net basis when we conclude that we are acting as the agent. Substantially all of our revenue related to third-party products and services is recognized on a gross basis as we are generally acting as the principal under our arrangements. Shipping charges billed to customers were not significant for the years ended December 31, 2015, 2014, and 2013. Shipping charges are included in revenue, and the related shipping costs are included in cost of revenue in the accompanying consolidated statements of operations. Cost of Revenue Cost of revenue consists of cost of product and service revenue. Cost of product revenue includes contract manufacturing costs, including raw materials, components and associated freight, and normal yield loss. In addition, cost of product revenue includes compensation, benefits and stock-based compensation provided to our manufacturing personnel, overhead and other direct costs. Product costs are deferred upon shipment and are recognized in the period in which we recognize the related revenue. Period costs, which consist primarily of logistics costs, manufacturing ramp-up costs, expenses for inventory obsolescence, standard warranty costs and lower of cost or market adjustments are recognized in the period in which they are incurred. Costs of providing services include personnel-related costs, depreciation and amortization, and software hosting costs. Costs of providing services are not deferred and are included in cost of revenue in the period in which they are incurred. Deferred Revenue and Deferred Cost of Revenue Deferred revenue results from transactions where we have billed the customer for product shipped or services performed but all revenue recognition criteria have not yet been met. Deferred cost of revenue is recorded for products for which ownership (typically title and risk of loss) has transferred to the customer, but for which criteria for revenue recognition have not been met. We only defer tangible direct costs associated with hardware products delivered. Cost of revenue for providing services is not deferred, but is expensed in the period incurred. Deferred cost of revenue associated with deferred product revenue is recorded at the standard, which approximates actual, inventory cost at the time of shipment. We evaluate deferred cost of revenue for recoverability based on multiple factors, including whether net revenues less related direct costs will exceed the amount of deferred cost of revenue based on the terms of the overall arrangement. To the extent that deferred cost of revenue is determined to be unrecoverable, we adjust deferred cost of revenue with a charge to product cost of revenue in the current period. In connection with our recoverability assessments, we have not incurred significant impairment charges during the years ended December 31, 2015, 2014, and 2013. We recognize deferred revenue and associated deferred cost of revenue in the consolidated statements of operations once all revenue recognition criteria have been met. Product Warranty We provide warranties for substantially all of our products. Our standard warranty period extends from one to five years. We accrue for costs of standard warranty at the time of product shipment, and record changes in estimates to warranty accruals when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. At the time of product shipment, we estimate and accrue for the amount of standard warranty cost and record the amount as a cost of revenue. Determining the amount of warranty costs requires management to make estimates and judgments based on historical claims experience, industry benchmarks, test data and various other assumptions including estimated field failure rates that are believed to be reasonable under the circumstances. The amount of warranty costs accrued are net of warranty obligations to be fulfilled by our suppliers. The results of these judgments formed the basis for our estimate of the total charge to cover anticipated customer warranty, repair, return and replacement and other associated costs. Should actual product failure rates, claim levels, material usage or supplier warranties on parts used in our products differ from our original estimates, revisions to the estimated warranty liability could result in adjustments to our cost of revenue in future periods. Certain of our standard product warranty obligations require us to reimburse a customer for installation and other related costs in the event that field reliability rates fall below contractually specified thresholds. We consider the probability that we will have to pay such incremental warranty costs based on the expected performance of a delivered product when we record new warranty obligations issued in a period as well as when we determine if any changes are required to our original estimates for pre-existing warranty obligations. Our warranty obligations are affected by product failure rates, claims levels, material usage and supplier warranties on parts included in our products. Because our products are relatively new and we do not have the benefit of long-term experience observing products’ performance in the field, it is possible that the estimates of a product’s lifespan and incidence of claims could vary from period to period. In certain customer arrangements, we have provided extended warranties for periods of up to 15 years following the initial standard warranty period. We recognize revenue associated with extended warranties over the extended warranty period when the extended warranty period commences. Costs associated with providing extended warranties are expensed as incurred during the extended warranty period. Supplier Concentrations and Other Inventory Risks We have arrangements under which substantially all of our manufacturing activity is subcontracted to third-party vendors. Currently we have our manufacturing relationships with Plexus Corp. and Celestica, Inc. We plan to shift the entire production of our products currently manufactured by Plexus to a combination of Flextronics International Ltd. and Celestica during 2016. These vendors provide or will provide us with a wide range of operational and manufacturing services, including material procurement, final assembly, test quality control, warranty repair, and shipment to our customers and third-party vendors. Contract manufacturing activities are conducted in the United States and Thailand and are undertaken based on management’s product demand forecasts. Our contract manufacturers procure components necessary to assemble the products anticipated by management’s forecast and test the products according to our quality specifications. If the components are unused for specified periods of time, we may incur carrying charges or obsolete material charges for components that our contract manufacturers purchased to build products to meet our product demand forecasts. Our communications modules and other hardware products consist of commodity parts and certain custom components. Our components are generally available from multiple sources or suppliers. However, some components used in our products are purchased from single or limited sources. Finished goods are reported as inventory until title transfers to the customer. Consigned finished goods inventory that is maintained at customer locations is also reported as inventory until consumption or acceptance of the product by the customer. We account for consigned inventory on a first-in, first-out basis and record lower of cost or market or obsolete material charges when appropriate. Concentration of Credit and Customer Risks Our sales are currently concentrated with a small group of customers and third-party device manufacturers principally located in the United States and Australia. In evaluating customer concentration risk, we attribute revenue to our customers, including amounts billed to third-party device manufacturers for our communications modules. The following table summarizes the percentage of revenue related to our customers’ deployments in excess of 10% of total revenue: Year Ended December 31, 2015 2014 2013 ComEd 31 % — % — % PHI 27 — — CHED — 21 — Progress — 13 — PG&E — — 39 FPL — — 20 Each of these total revenue percentages includes amounts related to the customers’ deployments that were billed directly to our third-party device manufacturers, as well as direct revenue from the customers. We typically extend credit to our customers and third-party device manufacturers and do not require collateral or other security in support of accounts receivable. We attempt to mitigate the credit risk in our trade receivables through our credit evaluation process and payment terms. We analyze the need to reserve for potential credit losses and record allowances for doubtful accounts when necessary. To date, we have not had any significant write-offs of uncollectible accounts receivable, and there was insignificant allowance for doubtful accounts as of December 31, 2015 and 2014. The following table summarizes the percentage of accounts receivable from customers and third-party device manufacturers in excess of 10% of accounts receivable: Year Ended December 31, 2015 2014 AusNet 17 % — % FPL 15 — CPS 11 11 ComEd 11 19 PG&E 10 — Dominion — 13 Advertising Costs We expense advertising costs as incurred. Advertising costs were $1.9 million, $2.2 million, and $2.2 million for each of the years ended December 31, 2015, 2014, and 2013. Property and Equipment, Net Property and equipment are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the following estimated useful lives: Software 3 to 7 years Computer and network equipment 2 to 5 years Machinery and equipment 3 years Furniture and fixtures 3 to 7 years Leasehold improvements Lesser of the lease term or the estimated useful lives of the improvements, generally 1 to 10 years Software Development Costs Under our current practice of developing new products, technological feasibility of the underlying software is not established until substantially all product development and testing is complete, which generally includes the development of a working model. Our products are released within a short period of time after achieving technological feasibility. As a result, costs subsequent to achieving technological feasibility have not been significant, and all software development costs generally have been expensed as incurred. We capitalize certain costs for our internal-use software incurred during the application development stage. Costs related to preliminary project activities and post implementation activities were expensed as incurred. Internal-use software is amortized on a straight line basis over its estimated useful life. The estimated useful life is determined based on management’s judgment on how long the core technology and functionality serves the internal needs. Management evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. To date, amortization expense, including amounts written-off related to capitalized costs have been insignificant. There were insignificant capitalized costs included in property and equipment, net of amortization and write-off in the consolidated balance sheets as of December 31, 2015 and 2014. Intangible and Long-Lived Assets We evaluate long-lived assets and amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable in accordance with Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 360, Property, Plant and Equipment Goodwill Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in a business combination. Goodwill is not subject to amortization but is subject to annual assessment, at a minimum, for impairment in accordance with ASC Topic 350, Intangibles — Goodwill and Other Research and Development Costs to research, design, and develop the Company’s products Corporate Bonus Incentive Plan Our corporate bonus incentive plan is funded by a combination of cash and restricted stock units, at management’s discretion. We accrue and record the related corporate bonus amounts payable, both in cash and restricted stock units, under this plan in the period in which it is earned. The Compensation Committee may make incentive awards based on such terms, conditions and criteria as it considers appropriate. Stock awards issued in connection with this plan are generally fully vested at the time of grant. Because the award of share-based payments described above represents an obligation to issue a variable number of the Company’s shares determined on the basis of a monetary value derived solely on variations in an operating performance measure (and not on the basis of variations in the fair value of the entity’s equity shares), the award is considered a share-based liability in accordance with ASC Topic 480, Distinguishing Liabilities from Equity Stock-Based Compensation We measure and recognize compensation expense for all stock-based awards made to employees and directors, including stock options, restricted stock, restricted stock units, performance stock units, and employee stock purchase plan, based on estimated fair values. The fair values of stock options and our 2012 Employee Stock Purchas

Net Loss Per Share

Net Loss Per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	2. NET INCOME (LOSS) PER SHARE In connection with our IPO in March 2013, all of our outstanding convertible preferred stock converted into common stock. In addition, we recognized a deemed dividend of $105.0 million to common stockholders on the date of conversion. Basic net income (loss) per share applicable to common stockholders is computed by dividing the net income (loss) applicable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net income (loss) per share applicable to common stockholders is computed by dividing the net income (loss) applicable to common stockholders by the weighted-average number of shares of common stock outstanding plus dilutive common shares outstanding during the period. Dilutive consist of common shares issuable upon issuances of Employee Stock Purchase Plan (“ESPP”), vesting of contingently issuable , The Company includes the common shares underlying PSUs in the calculation of diluted net income per share when they become contingently issuable and excludes such shares when they are not contingently issuable. Potentially dilutive common shares were excluded from the computation of diluted net loss per share because their effect would be anti-dilutive. The following table sets forth the computation of historical basic and diluted net income (loss) per share (in thousands, except per share data): Year Ended December 31, 2015 2014 2013 Net income (loss) $ 79,986 $ (89,170 ) $ (66,807 ) Deemed dividend to convertible preferred shareholders — — (105,000 ) Net income (loss) attributable to common stockholders $ 79,986 $ (89,170 ) $ (171,807 ) Net income (loss) per share attributable to common stockholders Basic $ 1.60 $ (1.84 ) $ (4.54 ) Diluted $ 1.55 $ (1.84 ) $ (4.54 ) Weighted average shares used to compute net income (loss) per share attributable to common stockholders Basic 49,963 48,377 37,877 Diluted 51,524 48,377 37,877 The following potential common shares outstanding were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive (in thousands): Year Ended December 31, 2015 2014 2013 Employee equity awards 3,572 6,922 7,760 Also excluded from the computation of diluted net income (loss) per share for the year ended December 31, 2013 was the impact of issuing shares for the potential conversion of the subordinated convertible notes, which converted in connection with our IPO.

Cash, Cash Equivalents, and Sho

Cash, Cash Equivalents, and Short-Term Investments	12 Months Ended
	Dec. 31, 2015
Cash Cash Equivalents And Short Term Investments [Abstract]
Cash, Cash Equivalents, and Short-Term Investments	3. CASH, CASH EQUIVALENTS, AND SHORT-TERM INVESTMENTS Cash, cash equivalents, and short-term investments consisted of the following as of December 31, 2015 (in thousands): Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 59,263 $ — $ — $ 59,263 Cash equivalents: Money market mutual funds 6,001 — — 6,001 Total cash and cash equivalents 65,264 — — 65,264 Short-term fixed income securities: U.S. government and agency obligations 38,396 4 (110 ) 38,290 U.S. and foreign corporate debt securities 18,945 2 (52 ) 18,895 Foreign governments and multi-national agency obligations 2,000 — (4 ) 1,996 Total short-term investments 59,341 6 (166 ) 59,181 Total cash, cash equivalents and short-term investments $ 124,605 $ 6 $ (166 ) $ 124,445 Cash, cash equivalents, and short-term investments consisted of the following as of December 31, 2014 (in thousands): Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 54,239 $ — $ — $ 54,239 Cash equivalents: Money market mutual funds 6,218 — — 6,218 Total cash and cash equivalents 60,457 — — 60,457 Short-term fixed income securities: U.S. government and agency obligations 38,718 46 (18 ) 38,746 U.S. and foreign corporate debt securities 19,625 9 (33 ) 19,601 Foreign governments and multi-national agency obligations 2,000 — (8 ) 1,992 Total short-term investments 60,343 55 (59 ) 60,339 Total cash, cash equivalents and short-term investments $ 120,800 $ 55 $ (59 ) $ 120,796 As of December 31, 2015, approximately 84% and 11% of our cash, cash equivalents, and short-term investments were held with two financial institutions. As of December 31, 2014, approximately 46% and 42% of our cash, cash equivalents, and short-term investments were held with two financial institutions. Contractual Maturities The contractual maturities of cash equivalents and short-term investments held at December 31, 2015 consisted of the following (in thousands): December 31, 2015 December 31, 2014 Amortized Aggregate Amortized Aggregate Cost Basis Fair Value Cost Basis Fair Value Due within one year $ 25,183 $ 25,163 $ 20,588 $ 20,599 Due from 1 year through 3 years 40,159 40,019 45,973 45,958 Total cash equivalents and short-term investments $ 65,342 $ 65,182 $ 66,561 $ 66,557 The following table presents gross unrealized losses and fair values for those investments that were in an unrealized loss position as of December 31, 2015 and 2014, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in thousands): As of December 31, 2015 As of December 31, 2014 Total (Less Than 12 Months) Total (Less Than 12 Months) Fair Value Unrealized Loss Fair Value Unrealized Loss U.S. and foreign corporate debt securities $ 15,894 $ (52 ) $ 14,563 $ (33 ) Foreign governments and multi-national agency obligations 1,996 (4 ) 1,992 (8 ) U.S. government and agency obligations 31,792 (110 ) 13,523 (18 ) Total $ 49,682 $ (166 ) $ 30,078 $ (59 ) As of December 31, 2015 and 2014, there were no investments with unrealized losses for a period in excess of 12 months. We periodically review our marketable debt securities for other-than-temporary impairment. We consider factors such as the duration, severity and the reason for the decline in value, the potential recovery period and our intent to sell. We also consider whether it is more likely than not that we will be required to (i) sell the debt securities before recovery of their amortized cost basis, and (ii) the amortized cost basis cannot be recovered as a result of credit losses. As of December 31, 2015, we anticipate that we will recover the entire amortized cost basis of such available-for-sale debt securities and has determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the year ended December 31, 2015 and 2014. There were insignificant gross realized gains or losses from available-for-sale securities during the years ended December 31, 2015 and 2014.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. FAIR VALUE MEASUREMENTS We determine the fair values of our financial instruments based on a fair value hierarchy, which requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The classification of a financial asset or liability within the hierarchy is based upon the lowest level input that is significant to the fair value measurement. Under ASC Topic 820, Fair Value Measurement and Disclosures Level 1—Quoted prices (unadjusted) in active markets for identical assets or liabilities. Level 2—Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. Level 3—Unobservable inputs in which there is little or no market data, which requires us to develop our own assumptions. Level 1 measurements are obtained from real-time quotes for transactions in active exchange markets involving identical assets. Level 2 measurements are obtained from readily available pricing sources for comparable instruments, identical instruments in less active markets, or models using market observable inputs. We did not have any transfers of financial instruments between valuation levels during the year ended December 31, 2015 and 2014. Assets Measured at Fair Value on a Recurring Basis As of December 31, 2015, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands): Fair Value Measurement Using Quoted Prices in Significant Active Markets for Other Significant Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,001 $ — $ — $ 6,001 Total cash equivalents 6,001 — — 6,001 Short-term investments: U.S. Government and agency obligations — 38,290 — 38,290 U.S. and foreign corporate debt securities — 18,895 — 18,895 Foreign governments and multi-national agency obligations — 1,996 — 1,996 Total short-term investments — 59,181 — 59,181 Total assets measured at fair value $ 6,001 $ 59,181 $ — $ 65,182 As of December 31, 2014, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands): Fair Value Measurement Using Quoted Prices in Significant Active Markets for Other Significant Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,218 $ — $ — $ 6,218 Total cash equivalents 6,218 — — 6,218 Short-term investments: U.S. Government and agency obligations — 38,746 — 38,746 U.S. and foreign corporate debt securities — 19,601 — 19,601 Foreign governments and multi-national agency obligations — 1,992 — 1,992 Total short-term investments — 60,339 — 60,339 Total assets measured at fair value $ 6,218 $ 60,339 $ — $ 66,557 As of December 31, 2015 and 2014, there were no liabilities that are measured and recorded at fair value on a recurring basis. As of December 31, 2015 and 2014, there were no assets and liabilities that are measured and recorded at fair value on a nonrecurring basis except for assets and liabilities valued on the date of acquisition for businesses acquired during 2014 and 2015. See Note 5. Business Acquisition. Assets and Liabilities Not Measured at Fair Value The carrying amounts of our accounts receivable, accounts payable, and other accrued liabilities approximate fair value due to their short maturities.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Acquisitions	5. BUSINESS ACQUISITIONS Our consolidated financial statements include the operating results of acquired businesses from the date of each acquisition. The Company completed one business combination, Detectent, Inc. in 2015 and one business combination, Streetlight.Vision, in 2014. Acquisition of Detectent On January 16, 2015, we completed the acquisition of Detectent, Inc. (“Detectent”), a privately held corporation that provides customer intelligence solutions for utilities leveraging its data analytics platform, based in Escondido, California. Detectent’s SaaS, subscription, and software solutions help improve advanced metering infrastructure and utility grid operations, ensure revenue protection, and deliver enhanced customer engagement programs. In accordance with the Agreement and Plan of Merger, dated as of January 6, 2015, by and among Silver Spring, Detectent and a wholly-owned subsidiary of Silver Spring, Detectent became our wholly-owned subsidiary. The total consideration was $11.6 million, including $7.6 million of cash paid on the acquisition date and $4.0 million of deferred cash consideration (“contingent payments”) to be paid over a two-year period subject to the retention of key employees of Detectent (“retention period”). Contingent payments associated with future employment conditions will be recorded as compensation expense over the retention period. During the year ended December 31, 2015, we recorded $1.9 million in compensation expense in the consolidated statement of operations with a corresponding $1.0 million short term portion recorded in Accrued and other liabilities and $0.9 million long term portion in Other liabilities in the consolidated balance sheets. In accordance with ASC Topic 805, Business Combinations Cash consideration $ 7,616 Less: Fair value of net identifiable assets acquired (3,164 ) Goodwill $ 4,452 The goodwill arising from the Detectent acquisition is largely attributable to the synergies expected to be realized and is not deductible for U.S. federal The following table summarizes the fair value of the identifiable assets acquired and liabilities assumed at the acquisition date and is based on management’s best estimates. Assets acquired and liabilities assumed as of January 16, 2015 (in thousands): Cash $ 518 Net other tangible liabilities (26 ) Intangible assets subject to amortization: Developed technology 1,900 Customer relationships 1,500 Non-compete agreements 100 Order backlog 300 Deferred tax liabilities in connection with acquired intangible assets and other fair value adjustments, net (1,128 ) Total fair value of net identifiable assets acquired $ 3,164 Certain closing balance sheet items in connection with the acquisition of Detectent were finalized during the year ended December 31, 2015. As a result, the net other tangible liabilities decreased by $0.5 million, offset by an increase in deferred tax liabilities and other fair value adjustment of $0.2 million. The net impact of $0.3 million of these items was accounted for as measurement period adjustments during the year ended December 31, 2015 with a corresponding adjustment to goodwill. Developed technology relates to Detectent’s technology and knowhow which is currently generating revenue. Customer relationships relate to Detectent’s ability to sell existing, in-process and future versions of its products to its existing customers. Non-compete agreements represent the value of the non-compete and non-solicit agreements signed by key employees of Detectent. Order backlog represents future revenue to be derived from confirmed orders. Developed technology and order backlog were valued using the relief from royalty method based on discounted cash flow (“DCF”). A discount rate of 18.6% was used to value developed technology and 18.1% to value order backlog. The customer relationships and non-compete agreements were valued using multi-period excess earnings method under the income approach based on DCF and using a discount rate of 20.1%. The discount rate used in the present value calculation was derived from a weighted average cost of capital analysis, adjusted to reflect additional benefits or risks related to each asset’s characteristics. The intangible assets are subject to amortization and are amortized on a straight-line basis over their weighted average expected useful lives of approximately one to five years. Deferred tax assets and liabilities resulting from the acquisition of Detectent have been netted, where applicable. Following the Detectent acquisition, Detectent became part of our U.S. tax group and the deferred tax liability of $1.1 million which was recognized in the purchase price accounting has been netted with our existing deferred tax assets. As a result, there was a $1.1 million reversal in the valuation allowance that was recorded as a tax benefit in our financial statements during the year ended December 31, 2015. During the year ended December 31, 2015, we expensed $2.6 million of acquisition-related costs, of which $0.5 million was included in research and development expenses and $1.9 million was included in general and administration expenses in our consolidated statement of operations. Detectent’s financial results have been included in our consolidated financial statements since the acquisition date. Revenue from Detectent was approximately $1.5 million, or 0.3%, of our total consolidated revenue recognized during year ended December 31, 2015. Acquisition of Streetlight.Vision On May 23, 2014, we acquired 100% of the outstanding shares of Streetlight.Vision (“SLV”), a company incorporated under the laws of France, which provides street light control and management software, and paid $8.8 million in cash consideration. In accordance with ASC 805, the acquisition of SLV was accounted for under the acquisition method of accounting and we recorded goodwill of $4.7 million at the time of acquisition. Certain closing balance sheet items in connection with the acquisition of SLV were finalized during the first quarter of 2015. As a result, the net assets acquired decreased by $0.1 million which was accounted for as measurement period adjustments with a corresponding adjustment to goodwill during the first quarter of 2015. Intangible assets of $4.3 million consisted primarily of developed technology, customer relationships, trade name and IPR&D. The goodwill arising from the SLV acquisition was largely attributable to the synergies expected to be realized and was not deductible for U.S. federal income tax purposes.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. GOODWILL AND INTANGIBLE ASSETS Goodwill: The following table presents goodwill as of December 31, 2015 and 2014 and changes in the carrying amount of goodwill (in thousands): December 31, 2015 2014 Balance, beginning of period $ 4,729 $ 447 Goodwill acquired during the period 4,792 4,685 Goodwill measurement period adjustment (295 ) 85 Currency translation adjustment (454 ) (488 ) Balance, end of period $ 8,772 $ 4,729 In addition, we also adjusted goodwill by $0.3 million and $0.1 million as a measurement period adjustment during the year ended December 31, 2015 and 2014, respectively. Of the total goodwill, goodwill related to SLV is designated in a currency other than United States Dollars and is adjusted each reporting period for the change in foreign exchange rates between the balance sheet dates. Intangible Assets: The following table summarizes the gross carrying amount and accumulated amortization for the intangible assets resulting from acquisitions: As of December 31, 2015 As of December 31, 2014 Useful Lives (in years) Gross Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Purchased technology 4-5 years $ 4,865 $ 2,180 $ 2,685 $ 2,396 $ 1,139 $ 1,257 Customer relationships 2-7 years 3,640 973 2,667 2,140 417 1,723 Trade name 6 years 369 103 266 269 26 243 In-process research and development Indefinite — — — 269 - 269 Total $ 8,874 $ 3,256 $ 5,618 $ 5,074 $ 1,582 $ 3,492 Intangible assets subject to amortization are amortized over their useful lives as shown in the table above. During the year ended December 31, 2015, we recorded intangible assets of $3.8 million in connection with our acquisition of Detectent. During the three months ended December 31, 2015, we completed in-process research and development intangible assets of $0.3 million and will start amortization over its useful life effective January 1, 2016. This is now included as part of purchased technology as of December 31, 2015. The following table illustrates the amortization expense included in the consolidated statements of operations for the years ended December 31, 2015, 2014 and 2013 (in thousand): Year Ended December 31, Amortization of purchased intangible assets: 2015 2014 2013 Cost of revenue $ 1,041 $ 417 $ 192 Selling and marketing 601 197 — General and administrative 32 — — Total $ 1,674 $ 614 $ 192 The estimated future amortization expense of purchased intangible assets with definite lives for the next five years is as follows (in thousands): Year Ended 2016 $ 1,464 2017 1,452 2018 1,212 2019 1,061 2020 317 2021 and thereafter 112 $ 5,618

Convertible Preferred Stock And

Convertible Preferred Stock And Preferred Stock Warrants	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Convertible Preferred Stock And Preferred Stock Warrants	7. CONVERTIBLE PREFERRED STOCK AND PREFERRED STOCK WARRANTS Convertible Preferred Stock In connection with our IPO in March 2013, our previously authorized and outstanding convertible preferred stock was converted into 32,406,995 shares of common stock. Included in this amount were incremental shares issued to Series D and Series E preferred stockholders in accordance with their contractual conversion rights which stated that if the IPO conversion price for Series D and Series E preferred stockholders was below $38.927 and $50.00 per share, respectively, then we would issue to the eligible holders additional shares of common stock for no additional consideration pursuant to an automatic adjustment in our certificate of incorporation. The additional shares resulted in a beneficial conversion feature for Series E preferred stock and we recognized a $105.0 million deemed dividend to Series E preferred stockholders at the conversion date. This non-cash charge impacts net loss applicable to our common stockholders and basic and diluted net loss per share applicable to common stockholders. Warrant Termination and Concurrent Private Placement with a Related Party Prior to our IPO, entities affiliated with Foundation Capital, together Foundation Capital, beneficially owned 32.7% of our common stock. Foundation Capital is considered a related party, as Warren Weiss, a general partner with Foundation Capital, is also a member of our Board of Directors. Foundation Capital held warrants to purchase 41,993 shares of our Series A Preferred Stock and 333,333 shares of our Series C Preferred Stock prior to our IPO. All such warrants terminated immediately prior to the effectiveness of our IPO in exchange for the aggregate payment by us of $12.0 million to these entities. In connection with the transaction, we reduced our preferred stock warrant liability by $11.2 million and recorded a loss of $0.8 million in the year ended December 31, 2013. We also entered into a private placement purchase agreement whereby Foundation Capital purchased an aggregate of $12.0 million of shares of our common stock at the same price as the price offered to the public, or 705,881 shares based on the IPO price of $17.00 per share. This private placement purchase was consummated on the same day that our IPO closed.

Common Stock

Common Stock	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Common Stock	8. COMMON STOCK Initial Public Offering In March 2013, we completed our IPO in which we issued and sold 5,462,500 shares of common stock at a public offering price of $17.00 per share. We received net proceeds of $84.2 million after deducting underwriting discounts and commissions of $6.5 million and offering costs of $2.2 million incurred in fiscal 2013 prior to our IPO. In addition, we reclassified previously capitalized offering expenses of $4.2 million against the IPO proceeds in our consolidated statements of convertible preferred stock and shareholders’ deficit in the year ended December 31, 2013. Concurrently with our IPO, we issued and sold in a private placement 705,881 shares of common stock at the public offering price of $17.00 per share, which resulted in net proceeds of $12.0 million. In addition, in connection with our IPO: · All of our outstanding convertible preferred stock converted into 32,406,995 shares of common stock. · Our $24.0 million and $30.0 million convertible notes together with contractual accrued interest of $2.3 million converted into 3,764,954 shares of common stock. In connection with the conversion, we recorded a loss on debt extinguishments of $22.9 million. · We reduced our preferred stock warrant liability by $11.2 million and recorded a loss of $0.8 million in the year ended December 31, 2013 resulting from our payment of $12.0 million as consideration for the termination of certain warrants to purchase shares of Series A preferred stock and all warrants to purchase shares of Series C preferred stock, which occurred immediately prior to the effectiveness of our IPO. · We recognized stock-based compensation expense of $14.6 million in the year ended December 31, 2013 upon the effectiveness of the Registration Statement on Form S-1 in connection with our incentive bonus plans. · We recognized stock-based compensation expense of approximately $4.7 million in the year ended December 31, 2013 related to the modification of stock options held by current employees. Restated Certificate of Incorporation and Amended and Restated Bylaws Our restated certificate of incorporation and amended and restated bylaws became effective upon the closing date of our IPO. Our restated certificate of incorporation: (a) eliminated the references to the terms of our existing series of preferred stock, which converted to common stock in connection with the IPO; (b) increased the authorized number of shares of common stock to 1,000,000,000 shares; (c) authorized 10,000,000 shares of undesignated preferred stock; (d) provided that holders of common stock will not be entitled to vote on amendments to the restated certificate that relate solely to the terms of any preferred stock designated by our Board of Directors if the holders of such preferred stock are entitled to vote on such amendment; (e) provided that our Board of Directors are classified into three classes of directors; (f) provided that at least two-thirds of the voting power of all of the then-outstanding shares of our capital stock is required to amend the bylaws; (g) provided that stockholders cannot call a special meeting of stockholders, act by written consent without a meeting, fill vacancies in the Board of Directors, remove a director other than for cause, or change the authorized number of directors; and (h) included certain other provisions customary for public companies. Equity Incentive Plan and Employee Stock Purchase Plan Our Board of Directors adopted the 2012 Equity Incentive Plan (“2012 Plan”), which became effective on March 12, 2013 and serves as the successor to our 2003 Stock Option Plan, or the 2003 Plan. Pursuant to the 2012 Plan, 3,400,000 shares of our common stock were initially reserved for grant, plus (1) any shares that were reserved and available for issuance under the 2003 Plan at the time the 2012 Plan became effective, and (2) any shares that become available upon forfeiture or repurchase by us under the 2003 Plan and a stock option plan assumed in connection with a previous acquisition, will be reserved for issuance. In addition, the number of shares of our common stock available for grant and issuance shall be increased on January 1 of each calendar year during the term of the Plan by the lesser of (i) four percent (4%) of the number of shares of our common stock issued and outstanding on each December 31 immediately prior to the date of increase, or (ii) such number of shares determined by the Board. Under the 2012 Plan, we may grant both incentive and non-statutory stock options, restricted stock, restricted stock units, and performance stock units to employees, directors and service providers. We may grant options to purchase shares of common stock to employees, directors and service providers at prices not less than the fair market value on the date of grant for both Incentive Stock Options, (“ISOs”), or Nonqualified Stock Options, (“NQSOs”). ISOs granted to a person who, at the time of the grant, owns more than 10% of the voting power of all classes of stock must be at no less than 110% of the fair market value and expire five years from the date of grant. All other options generally have a contractual term of 10 years. Options generally vest over four years. RSUs generally vest between two to four years. The PSUs which are currently outstanding generally vest over three years. On January 1, 2015, the total shares reserved for issuance under the 2012 Plan were automatically increased by 1,962,491 shares. Our Board of Directors adopted the 2012 Employee Stock Purchase Plan, or ESPP, which became effective on March 12, 2013, pursuant to which 400,000 shares of our common stock have been reserved for future issuance. In addition, on each January 1 for the first ten calendar years after the first Offering Date, the aggregate number of shares of our common stock reserved for issuance under the ESPP shall be increased automatically by the number of shares equal to 1% of the total number of outstanding shares of our common stock on the immediately preceding December 31 subject to restrictions defined in the ESPP. Eligible employees can enroll and elect to contribute up to 15% of their compensation through payroll withholdings in each offering period, subject to certain limitations. Each offering period is six months in duration. The purchase price of the stock is the lower of 85% of the fair market value on (a) the first day of the offering period or (b) the purchase date. On January 1, 2015, the total shares reserved for issuance under the ESPP were automatically increased by 490,622 shares. As of December 31, 2015 and 2014, there were 4.9 million and 4.3 million shares, respectively, of common stock reserved for future grants under our 2012 Employee Stock Purchase Plan and our 2012 Plan. Inducement Grants On July 28, 2015, we entered into an employment agreement with Michael Bell as our President and Chief Executive Officer (“CEO”). In connection with his employment, we granted Mr. Bell a stock option to purchase 250,000 shares of our common stock, 125,000 restricted stock units (“RSUs”) and 125,000 performance stock units (“PSUs”) as inducement grants made outside of the 2012 Plan in reliance upon NYSE Rule 303A.08. The stock option grant has an exercise price equal to the closing market value of the our common stock on the date of grant, and vests (i) with respect to 25% of the underlying shares on the one-year anniversary of his first day of employment with the Company, and (ii) with respect to an additional 1/48th of the underlying shares each month thereafter, until such time as the option is vested and exercisable with respect to all of the shares. The RSUs vest (i) with respect to 25% of the shares on the one-year anniversary of the date of grant, and (ii) with respect to an additional 1/16th of the shares on each three-month anniversary thereafter, until such time as all of the RSUs are vested. The PSUs will become eligible to vest when the average closing price during the 45 consecutive trading days reaches the share price thresholds specified in his grant at any time before the three-year anniversary of the grant date. Performance Stock Awards In 2015, we granted to our current CEO, former CEO, CFO and other executive officers PSUs to acquire up to a certain maximum number of shares of our common stock to be earned based on the common stock price reaching certain share price targets over a period of three years, subject to such individual’s continued service to the Company as a director, officer, employee or consultant. The PSUs will become eligible to vest when the average closing price during the 45 consecutive trading days reaches the share price thresholds specified in such individual’s grant at any time before the three-year anniversary of the grant date. We determined the value of these PSUs using a Monte-Carlo simulation. The fair value of the PSUs is determined to be $6.8 million that will be recognized over the requisite service period using the accelerated method. Common Stock Warrants In March 2011, we granted a warrant to purchase 50,000 shares of common stock at $0.005 per share. The warrant was immediately exercisable and non-forfeitable, and would have expired on the earlier of a change in control or March 31, 2016. In connection with our IPO, warrants to purchase shares of our preferred stock converted into warrants to purchase 20,768 shares of our common stock, at a weighted average exercise price of $13.91 per share. As of December 31, 2013, we issued 57,370 shares of common stock pursuant to the net exercise of all of our common stock warrants.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	9. STOCK-BASED COMPENSATION We recorded stock-based compensation expense as follows (in thousands): Year Ended December 31, 2015 2014 2013 Cost of revenue $ 6,135 $ 7,610 $ 12,275 Research and development 8,060 9,677 17,333 Sales and marketing 4,104 6,062 7,060 General and administrative 8,180 10,512 15,836 Stock-based compensation expense $ 26,479 $ 33,861 $ 52,504 Of the total stock-based compensation, we recorded $5.6 We issue new common shares upon exercise of stock options. The following table summarizes our stock option activity and related information as follows (in thousands, except per share data): Options Outstanding Weighted Weighted Average Average Exercise Remaining Aggregate Number of Price per Contractual Intrinsic Shares Share Term (years) Value Balance at December 31, 2012 4,616 $ 21.73 Options granted 1,168 18.36 Options exercised (631 ) 4.74 Options cancelled or expired (427 ) 27.52 Balance at December 31, 2013 4,726 $ 11.88 6.43 $ 43 Options granted 732 14.67 Options exercised (378 ) 2.94 Options cancelled or expired (555 ) 17.57 Balance at December 31, 2014 4,525 $ 12.38 5.67 $ 8,699 Options granted 669 10.36 Options exercised (234 ) 2.38 Options cancelled or expired (528 ) 17.52 Balance at December 31, 2015 4,432 $ 11.99 5.36 $ 17,290 As of December 31, 2015: Options vested and expected to vest 4,398 $ 11.98 5.33 $ 17,225 Options exercisable 3,223 $ 11.67 4.07 $ 14,470 The aggregate intrinsic value disclosed above represents the total intrinsic value (the difference between the fair value of our common stock as of December 31, 2015 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on December 31, 2015. This amount is subject to change based on changes to the fair value of our common stock. During the years ended December 31, 2015, 2014, and 2013, the total cash received from the exercise of stock options was $0.6 million, $1.1 million, and $2.9 million, net of repurchases, respectively, and the total intrinsic value of stock options exercised was $2.1 million, $3.6 million, and $9.5 million, respectively. Restricted Stock Units The following table summarizes our restricted stock units activity and related information as follows (in thousands, except per share data): Restricted Stock Units Outstanding Weighted Weighted Average Average Grant Remaining Aggregate Number of Date Fair Value Contractual Intrinsic Shares per Share Term Value Balance at December 31, 2012 231 $ 449.51 Restricted stock units granted 3,662 48.41 Restricted stock units vested (1,020 ) 23.36 Restricted stock units cancelled (116 ) 49.69 Balance at December 31, 2013 2,757 $ 19.14 1.18 $ 57,951 Restricted stock units granted 1,218 10.72 Restricted stock units vested (1,280 ) 18.77 Restricted stock units cancelled (497 ) 17.50 Balance at December 31, 2014 2,198 $ 15.06 1.08 $ 18,532 Restricted stock units granted 1,713 12.67 Performance restricted stock units granted 995 6.85 Restricted stock units vested (1,407 ) 15.32 Restricted stock units cancelled (413 ) 14.00 Balance at December 31, 2015 3,086 $ 11.11 1.73 $ 44,473 The fair values of restricted stock units are determined based upon the fair value of the underlying common stock at the date of grant. The total fair value on the respective vesting dates of restricted stock units during the years ended December 31, 2015, 2014 and 2013 was $16.5 million, $17.3 million and $19.5 million, respectively. Valuation of Employee Stock-Based Compensation We recognize compensation expense for stock-based awards based on their grant-date fair value on a straight-line basis over the service period for which such awards are expected to be outstanding. The fair value of stock options granted pursuant to our equity incentive plans and ESPP is determined using the Black-Scholes-Merton option pricing model. The fair value of performance stock awards is determined using a Monte-Carlo simulation. The determination of fair value is affected by the estimates of our valuation, as well as assumptions regarding subjective and complex variables such as expected employee exercise and forfeiture behavior and our expected stock-price volatility over the expected term of the award. Generally, assumptions are based on historical information and judgment was required to determine if historical trends may be indicators of future outcomes. The fair value of each option grant is estimated on the date of grant. We currently have no history or expectation of paying cash dividends on our common stock. The risk-free interest rate is based on the U.S. Treasury yield for a term consistent with the expected term of the awards in effect at the time of grant. The expected term represent the weighted-average period the stock options are expected to remain outstanding. The expected term is determined based on historical exercise behavior, post-vesting termination patterns, options outstanding and future expected exercise behavior. Until December 31, 2014, we estimated the volatility of our common stock at the date of grant using a combination of our own historical and implied volatility and based on the historical and implied volatility of the stock prices of a peer group of publicly-traded companies for a period equal to the expected life of our stock options. Effective January 1, 2015, we estimate the volatility of our common stock at the date of grant based on our own historical and implied volatility of the stock prices as we believe that we now have sufficient company specific data and provides a reasonable basis on which to base an estimate of expected volatility and we have no reason to believe that our future volatility will differ materially during the expected or contractual term, as applicable, from the volatility calculated from this past information. The following table summarizes the assumptions relating to our stock options, ESPP and market-based PSUs: Year Ended December 31, 2015 2014 2013 Stock options (1) Expected volatility 59 – 66% 43 – 47% 47 – 52% Expected dividends —% —% —% Expected life in years 5.85 – 6.08 6.08 5.00 – 6.08 Risk-free interest rate 1.54 – 1.78% 1.81 – 1.98% 0.87 – 1.96% Weighted average grant date fair value per share $ 5.82 $ 6.60 $ 19.11 ESPP (1) Expected volatility 33 – 62% 33 – 36% 52% Expected dividends —% —% —% Expected life in years < 1 year < 1 year < 1 year Risk-free interest rate 0.05 – 0.24% 0.05 – 0.08% 0.87% Market-based PSUs (2) Expected volatility 60 – 65% — — Expected dividends —% — — Risk-free interest rate 1.02 – 1.22% — — Weighted average fair value per share 6.85 — — (1) The Black-Scholes-Merton option-pricing model is utilized to estimate the fair value of stock options and ESPP. (2) The fair value market-based PSUs utilize the Monte Carlo simulation option pricing model. The Company amortizes the fair value of these awards over the derived service period. Provided that the derived service is rendered, the total fair value of the market-based PSUs at the date of grant is recognized as compensation expense even if the market condition is not achieved. However, the number of shares that ultimately vest can vary significantly with the performance of the specified market criteria. The following table presents unrecognized compensation cost, adjusted for estimated forfeitures, recognized over a weighted-average period related to unvested stock options, ESPP, RSUs, and PSUs as of December 31, 2015. Weighted Unrecognized Average Compensation Period Cost (Years) Stock options $ 6.9 2.6 ESPP, RSUs, and PSUs $ 24.9 2.6

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. INCOME TAXES The components of income (loss) before income taxes are as follows (in thousands): Year Ended December 31, 2015 2014 2013 United States $ 116,530 $ (57,125 ) $ (28,774 ) Foreign (33,473 ) (30,623 ) (37,809 ) Income (loss) before income taxes $ 83,057 $ (87,748 ) $ (66,583 ) The provision for income taxes consists of the following (in thousands): Year Ended December 31, 2015 2014 2013 Current: United States federal $ — $ — $ — State 4,488 1,191 (115 ) Foreign 192 613 452 Total current provision for income taxes 4,680 1,804 337 Deferred: United States federal (1,091 ) — (47 ) State (37 ) — 123 Foreign (481 ) (382 ) (189 ) Total deferred benefit for income taxes (1,609 ) (382 ) (113 ) Provision for income taxes $ 3,071 $ 1,422 $ 224 The provision for income taxes differs from the amount computed by applying the federal statutory income tax rate of 35% to loss before income taxes as follows (in thousands): Year Ended December 31, 2015 2014 2013 Federal statutory tax expense (benefit) $ 29,070 $ (30,031 ) $ (23,304 ) Research tax credit (548 ) (574 ) (884 ) Effect of non-U.S. operations 11,331 10,754 13,320 Change in valuation allowance (40,521 ) 18,166 (925 ) Stock-based compensation expense 573 1,982 3,455 Loss on debt extinguishments — — 8,287 State taxes 2,937 792 8 Other 229 333 267 Provision for income taxes $ 3,071 $ 1,422 $ 224 Excess tax benefits associated with stock option exercises and other equity awards are credited to stockholders' equity. The income tax benefits resulting from stock awards that were credited to stockholders' equity were $0.2 million and $0.1 million for the years ended December 31, 2015 and 2014, respectively. Deferred income taxes reflect the tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The components of our deferred tax assets and liabilities are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss and tax credit carryforwards $ 84,060 $ 129,471 Deferred revenue 119,440 159,523 Stock-based compensation expense 12,434 12,241 Accruals and reserves 12,551 7,452 Intangible assets 1,696 1,434 Other 333 355 Gross deferred tax assets 230,514 310,476 Valuation allowance (142,635 ) (186,273 ) Deferred tax assets 87,879 124,203 Deferred tax liabilities Property and equipment, net (1,552 ) (1,612 ) Deferred cost of revenue (85,258 ) (122,116 ) Deferred tax liabilities (86,810 ) (123,728 ) Net deferred tax assets $ 1,069 $ 475 As of December 31, 2015, we had federal and state net operating loss carryforwards of $175.9 million and $276.8 million, respectively. If not utilized, the federal and state net operating loss carryforwards will begin to expire in 2029 and 2016, respectively. In addition, we had federal and California research tax credit carryforwards of $10.4 million and $12.8 million, respectively. The federal credit carryforwards will begin to expire in 2023, and the California credit carryforwards have no expiration date. Under Section 382 of the Internal Revenue Code of 1986, as amended, or the Code, our ability to utilize net operating loss carryforwards or other tax attributes, such as research tax credits, in any taxable year may be limited if we experience an “ownership change.” A Section 382 “ownership change” generally occurs if one or more stockholders or groups of stockholders who own at least 5% of our stock increase their ownership by more than 50 percentage points over their lowest ownership percentage within a rolling three-year period. Similar rules may apply under state tax laws. It is possible that an ownership change, or any future ownership change, could have a material effect on the use of our net operating loss carryforwards or other tax attributes, which could adversely affect our operating results. Below summarizes the change in deferred tax assets valuation allowance (in thousands): Balance at Beginning of Period Net Change Balance at End of Period Deferred tax assets valuation allowances Year ended December 31, 2013 $ 166,995 $ 1,097 $ 168,092 Year ended December 31, 2014 168,092 18,181 186,273 Year ended December 31, 2015 186,273 (43,638 ) 142,635 Undistributed earnings of our foreign subsidiaries amounted to $3.8 million as of December 31, 2015. Those earnings are considered to be indefinitely reinvested and, accordingly, no U.S. income taxes have been provided thereon. Upon distribution of those earnings in the form of dividends or otherwise, we would be subject to both U.S. income taxes (subject to an adjustment for foreign tax credits) and foreign withholding taxes. The income tax liability that might be incurred if these earnings were to be distributed is not material to the financial statements because of the Company’s full valuation allowance position. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2015 2014 2013 Unrecognized tax benefits — $ 10,645 $ 8,715 $ 5,586 Gross increase for tax positions of prior years 85 165 1,216 Gross decrease for tax positions of prior years (34 ) (13 ) — Gross increase for tax positions of current year 1,414 1,778 1,913 Unrecognized tax benefits balance — $ 12,110 $ 10,645 $ 8,715 As of December 31, 2015, $0.3 million of the gross unrecognized tax benefits have been recorded as long-term liabilities. The remainder is reflected as a reduction of deferred tax assets. Up to $9.8 million and $8.7 million of unrecognized tax benefits at December 31, 2015 and 2014, respectively, would reduce the effective income tax rate in future periods if recognized. However, one or more of these unrecognized tax benefits relate to deferred tax assets that could be subject to a valuation allowance if and when recognized in a future period, which could impact the timing and amount of any related effective tax rate benefit. We recognize interest and penalties related to uncertain tax positions in income tax expense. To the extent accrued interest and penalties do not ultimately become payable, amounts accrued will be reduced and reflected as a reduction of the provision for income taxes in the period that such determination is made. Due to our net operating loss position, we have not recorded interest and penalties related to uncertain tax positions as of December 31, 2015. We file income tax returns in the United States, including various states, and certain foreign jurisdictions. The tax years 2003 to 2015 remain open to examination by the major taxing jurisdictions in which we are subject to tax. As of December 31, 2015, we were not under examination by the Internal Revenue Service or any state or foreign tax jurisdiction.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Information	11. SEGMENT INFORMATION We operate in one reportable segment. Our chief operating decision makers are our CEO and CFO, who review consolidated operating results to make decisions about allocating resources and assessing performance for the entire company. Revenue by geography is based on the billing address of the customer. The following table presents revenue by geographic region (in thousands): Year Ended December 31, 2015 2014 2013 Revenue: United States $ 425,951 $ 101,579 $ 285,430 Australia 45,247 62,745 40,939 All Other 18,361 26,964 489 Total $ 489,559 $ 191,288 $ 326,858 Substantially all of our long-lived assets are located in the United States.

Balance Sheet Details

Balance Sheet Details	12 Months Ended
	Dec. 31, 2015
Disclosure Text Block Supplement [Abstract]
Balance Sheet Details	12. BALANCE SHEET DETAILS Deferred Revenue and Deferred Cost of Revenue The following table details the activity in deferred revenue (in thousands): Year Ended December 31, 2015 2014 Deferred revenue, beginning of period $ 609,593 $ 524,653 Revenue deferred in the period 281,779 276,228 Revenue recognized in the period (489,559 ) (191,288 ) Deferred revenue, end of period $ 401,813 $ 609,593 The following table details the activity in deferred cost of revenue (in thousands): Year Ended December 31, 2015 2014 Deferred cost of revenue, beginning of period $ 333,030 $ 276,123 Costs deferred related to revenue deferred in the period 91,044 123,001 Cost of revenue recognized in the period (188,324 ) (66,094 ) Deferred cost of revenue, end of period $ 235,750 $ 333,030 Inventory Inventory consisted of the following (in thousands): December 31, 2015 2014 Component parts $ 1,201 $ 2,843 Finished goods 3,344 3,879 Inventory $ 4,545 $ 6,722 Inventory included consigned inventory totaling $2.0 million and $3.0 million as of December 31, 2015 and 2014, respectively. Property and Equipment, Net Property and equipment, net, consisted of the following (in thousands): December 31, 2015 2014 Computer and network equipment $ 16,568 $ 14,708 Software 13,719 13,460 Machinery and equipment 15,141 10,538 Furniture and fixtures 1,543 1,335 Leasehold improvements 2,915 2,565 Total property and equipment 49,886 42,606 Less: Accumulated depreciation and amortization (35,780 ) (29,746 ) Property and equipment, net $ 14,106 $ 12,860 Depreciation and amortization expense associated with property and equipment, including amounts for assets held under capital leases, was $6.1 million, $5.9 million, and $6.5 million for the years ended December 31, 2015, 2014, and 2013, respectively. Machinery and equipment included $4.8 million and $4.8 million of assets held under capital leases at December 31, 2015 and 2014, respectively, with corresponding accumulated amortization of $4.4 million and $3.5 million, respectively. Software included $3.5 million and $3.5 million of assets held under capital leases at December 31, 2015 and 2014, respectively, with corresponding accumulated amortization of $3.3 and $2.9 million, respectively. Accrued and Other Liabilities Accrued and other liabilities consisted of the following (in thousands): December 31, 2015 2014 Accrued payroll and related expenses $ 14,249 $ 8,912 Accrued operating expenses 5,937 2,548 Warranty obligations, current 8,601 3,838 Sales, property and income taxes 4,850 1,996 Current portion of capital lease obligation 285 1,163 Other deferred revenue 8,326 4,955 Other 503 1,009 Accrued and other liabilities $ 42,751 $ 24,421 Other Liabilities Other liabilities consisted of the following (in thousands): December 31, 2015 2014 Warranty obligations, non-current $ 2,898 $ 3,397 Other deferred revenue 11,099 9,816 Deferred rent long term 944 1,368 Other 1,462 493 Other liabilities $ 16,403 $ 15,074 Product Warranty Product warranty obligation is presented as follows on the consolidated balance sheets (in thousands): December 31, 2015 2014 Warranty obligation, current - classified in accrued and other liabilities $ 8,601 $ 3,838 Warranty obligation, non-current - classified in other liabilities 2,898 3,397 $ 11,499 $ 7,235 Product warranty activity is as follows (in thousands): Year Ended December 31, 2015 2014 2013 Warranty obligation—beginning of period $ 7,235 $ 6,089 $ 6,316 Warranty expense for new warranties issued 450 669 1,406 Utilization of warranty obligation (2,131 ) (2,562 ) (1,767 ) Changes in estimates for pre-existing warranties 5,945 3,039 134 Warranty obligation—end of period $ 11,499 $ 7,235 $ 6,089 Accumulated Other Comprehensive (Loss) Income (AOCI), Net of Tax The components of accumulated other comprehensive (loss) income, net of tax, were as follows (in thousands): Unrealized Gains Foreign Currency (Losses) on Available Adjustment for Sale Securities Total Balance as of December 31, 2013 $ 46 $ 84 $ 130 Other comprehensive (loss) income before reclassification (770 ) (11 ) (781 ) Amounts reclassified from AOCI — (128 ) (128 ) Other comprehensive (loss) income (770 ) (139 ) (909 ) Balance as of December 31, 2014 $ (724 ) $ (55 ) $ (779 ) Other comprehensive (loss) income before reclassification (837 ) (110 ) (947 ) Amounts reclassified from AOCI — (46 ) (46 ) Other comprehensive (loss) income (837 ) (156 ) (993 ) Balance as of December 31, 2015 $ (1,561 ) $ (211 ) $ (1,772 )

Borrowings

Borrowings	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Borrowings	13. BORROWINGS Credit Facility We had available a line of credit with a bank, which provided for advances and the issuance of letters of credit of up to $50 million. Loans under the credit agreement bear interest at the bank’s prime rate plus a margin. We terminated this credit agreement during December 2015. On December 18, 2015, we entered into a senior secured credit facilities credit agreement (“Credit Facility”) with Silicon Valley Bank (“SVB”) and HSBC Bank USA, National Association (“HSBC”). The Credit Facility provides for a revolving loan facility to the Company in an aggregate amount not to exceed $75.0 million, with an available letter of credit sub-facility in the aggregate amount of $75.0 million and an available swingline sub-facility in the aggregate amount of $5.0 million. The revolving loans and any swingline loans made pursuant to the Credit Facility bear interest at a rate per annum equal to (i) the higher of (a) the prime rate in effect on such day, and (b) the federal funds effective rate plus 0.5%, but in any case at a minimum rate of 0.0% per annum, plus (ii) 0.75%, and mature in December 2017. The Company’s obligations under the Credit Facility are secured by a security interest in substantially all of the assets of the Company (excluding intellectual property assets) and any domestic subsidiaries, subject to certain customary exceptions. As of December 31, 2015, there were no borrowings outstanding under the Credit Facility; however, $22.7 million of letters of credit were outstanding, including $13.0 million relating to EON Patent Litigation as discussed under Note 16, Commitments and Contingencies The Company also has the option to prepay its borrowings under the Credit Facility without penalty prior to maturity. The Credit Facility contains customary representations and warranties and affirmative and negative covenants. Among other negative covenants, the Company must comply with certain financial covenants, including maintaining a minimum adjusted quick ratio or in certain events a minimum consolidated adjusted EBITDA, as such terms are defined and set forth in the Credit Facility. The Credit Facility contains customary events of default, including, among others: non-payment of principal, interest or other amounts when due; inaccuracy of representations and warranties; violation of covenants; cross-defaults with certain other indebtedness; certain undischarged judgments; bankruptcy, insolvency or inability to pay debts; and a change of control of the Company. Upon the occurrence and during the continuance of an event of default, the lenders may terminate the commitments under the Credit Facility and declare the loans and all other obligations under the Credit Facility immediately due and payable. As of December 31, 2015, we were in compliance with the financial covenants in the credit agreement. Subordinated Convertible Notes In December 2011, we issued a subordinated convertible note for an aggregate principal amount of $24.0 million, with a maturity date of December 6, 2014. Interest accrued for the first six months at a rate of 3.0% per year and increased by 1.0% every six months to a maximum of 6.0% per year. In February 2012, we issued a subordinated convertible note for an aggregate principal amount of $30.0 million, with a maturity date of February 21, 2015. Interest accrued for the first six months at a rate of 3.0% per year and increased by 1.0% every six months to a maximum of 6.0% per year. The unpaid principal amount of the two subordinated convertible notes, together with any interest accrued but unpaid thereon, was convertible upon certain events, including closing of an IPO of our common stock. In connection with our IPO, the two subordinated convertible notes, together with contractual accrued interest of $2.3 million thereon through March 18, 2013, the closing date of our IPO, converted into 3,764,954 shares of common stock based on the outstanding principal and accrued interest at a conversion price equal to 88% of the IPO price of $17.00 per share. The conversion of the convertible notes and issuance of common stock were accounted for as debt extinguishments and as a result, we recorded a loss on debt extinguishments of $22.9 million in the year ended December 31, 2013.

Benefit Plan

Benefit Plan	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Benefit Plan	14. BENEFIT PLAN In 2003, our Board of Directors approved the adoption of a savings plan under Section 401(k) of the Internal Revenue Code of 1986, as amended (the “Code”). The plan covers eligible employees who elect to participate. We are allowed to make discretionary profit sharing and qualified non-elective contributions as defined by the Plan and as approved by the Board of Directors. We have not historically matched eligible participants’ 401(k) contributions. No discretionary profit sharing contributions have been made to date.

Restructuring

Restructuring	12 Months Ended
	Dec. 31, 2015
Restructuring And Related Activities [Abstract]
Restructuring	15. RESTRUCTURING 2014 Restructuring Plan During the three months ended September 30, 2014, we initiated a restructuring plan (the “2014 Restructuring Plan”) to refocus our strategy, optimize our structure, and improve operational efficiencies. The 2014 Restructuring Plan included a worldwide workforce reduction. As a result, we recorded $1.6 and $1.8 million in severance costs as restructuring charges during the year ended December 31, 2015 and 2014, respectively, in the consolidated statement of operations. Any changes in the estimates of executing the approved plans are reflected in our results of operations. Accrued liabilities related to restructuring actions are as following (in thousands): Severance Costs Professional fees Total December 31, 2013 Additions $ 1,888 $ — $ 1,888 Utilizations (1,653 ) — (1,653 ) December 31, 2014 (1) $ 235 $ — $ 235 Additions $ 1,213 $ 458 $ 1,671 Utilizations (1,387 ) (458 ) (1,845 ) December 31, 2015 (1) $ 61 $ — $ 61 (1)

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	16. COMMITMENTS AND CONTINGENCIES Operating and Capital Leases Our primary operating lease commitment at December 31, 2015, related to our headquarters in Redwood City, California, requires monthly lease payments through April 2016. We recognize rent expense on a straight-line basis over the lease period. Where leases contain escalation clauses, rent abatements, or concessions, such as rent holidays and landlord or tenant incentives or allowances, we apply them in the determination of straight-line rent expense over the lease term. Rent expense for all facility leases was $5.3 million, $5.3 million, and $4.9 million for the years ended December 31, 2015, 2014 and 2013, respectively. On October 27, 2015, we entered into two substantially similar lease agreements with the Landlord pursuant to which we will lease an aggregate of approximately 191,800 square feet of space (the “Premises”), located in the buildings at 210 West Tasman Drive and 230 West Tasman Drive, San Jose, California 95134. We intend to use the Premises as our new worldwide corporate headquarters. The initial lease term shall be for 10 years and 6 months, and commence upon the earlier of April 1, 2016 or the date that we first conduct business in any portion of the Premises (the “Initial Lease Term”). We have the option to extend the Initial Lease Term for up to two consecutive terms, each for an additional five year period. The landlord will deliver possession of approximately 143,900 square feet of the Premises on January 1, 2016, and the remaining approximately 47,900 square feet on January 1, 2017. The base annual rent will range from $1.0 million to $7.1 million during the Initial Lease Term, for an aggregate base rent obligation of $60.8 million. We are also responsible for certain other costs under the lease agreements, including certain tenant improvement costs, operating expenses, taxes, assessments, insurance, and utilities, net of an allowance for tenant improvements by the landlord. As of December 31, 2015, the future minimum commitments under our operating and capital leases were as follows (in thousands): Operating Capital Leases Leases 2016 $ 3,928 $ 112 2017 4,687 — 2018 5,750 — 2019 6,351 — 2020 6,364 — 2021 and thereafter 39,997 — Net minimum lease payments $ 67,077 $ 112 Less amount representing interest (4 ) Present value of net minimum capital lease payments $ 108 Legal Contingencies EON Patent Litigation . In June 2011, EON Corp. IP Holdings, LLC, a non-producing entity, or EON, filed suit in United States District Court for the Eastern District of Texas, Tyler Division against us and a number of smart grid providers. The lawsuit alleges infringement of United States Patent Nos. 5,388,101, 5,481,546, and 5,592,491 (the “EON Patents”), by certain networking technology and services that we and the other defendants provide. Other defendants included Landis+Gyr AG (which was acquired by Toshiba Corporation), Aclara Power-Line Systems Inc., Elster Solutions, LLC, Itron, Inc. and Trilliant Networks Inc., all of which settled with EON prior to trial. We filed answers, affirmative defenses and counterclaims denying the plaintiff’s allegations and asserting that the plaintiff’s patents are invalid. A trial was held in June 2014. After the trial, the jury determined that we had infringed certain, but not all, of the claims under the EON Patents, and returned a verdict against us in the amount of $18.8 million. The court ruled there was insufficient evidence to support EON’s allegation of willful infringement and granted our motion to dismiss that claim. In June 2014, we filed post-trial motions with the court seeking, among other things, judgment as a matter of law to set aside the jury verdict, or in the alternative, a new trial. In its post-trial motions, EON sought pre-judgment interest and attorneys’ fees. Following post-trial motions, the court reduced the damage award to approximately $13.0 million, and in December 2014, entered a final judgment in that amount plus approximately $1.5 million in pre-judgment interest. The court subsequently revised the final judgment to include additional costs of about $0.2 million and entered an amended final judgment in December 2014. All of the EON Patents have expired and therefore EON is not seeking, and EON may not recover, any additional sums as royalties for our sales of products going forward. In December 2014, we filed a notice of appeal with the U.S. Court of Appeals for the Federal Circuit in Washington, D.C. In order to stay the execution of the final judgment pending the appeal, in December 2014 we filed a surety bond in the amount of $17.6 million, which includes an additional 20% of the final judgment for post-judgment interest and expenses expected to be incurred during the appeal process, in accordance with court rules. The bond was issued by Zurich Insurance and is collateralized with a standby letter of credit in the amount of $13.0 million, the amount of the damage award, as stated in Note 13, Borrowings. Transdata/OG&E Patent Litigation . In September 2011, TransData, Inc., or TransData, filed suit in United States District Court for the Western District of Oklahoma, against Oklahoma Gas & Electric Company (“OG&E”), alleging infringement of United States Patent Nos. 6,181,294, 6,462,713, and 6,903,699 by certain wireless communication-enabled meters, including General Electric Company meters with our wireless modules. We agreed with General Electric Company to contribute to pay the defense of OG&E in connection with the TransData suit. An early claim construction hearing was held regarding one claim term in February 2013, and a hearing for the full claim construction was held in September 2013, on which the court issued an order in October 2013. In May 2014, General Electric Company filed reexamination requests on the TransData patents at issue with the U.S. Patent and Trademark Office (the “USPTO”). The reexaminations are currently proceeding. In August and September 2014, General Electric Company also petitioned the USPTO for inter partes review of each patent. In October 2014, OG&E filed a motion to stay the litigation pending the reexamination of the patents by the USPTO, which the court denied in January 2015. In March 2015, the USPTO issued decisions declining to institute the inter partes review. Additionally, the USPTO has indicated that all claims for which reexamination was requested are allowable without amendment. In August 2015, the court ruled that TransData is limited to alleging infringement by only one type of General Electric Company meter, and that any other General Electric Company meters used by OG&E are, as a matter of law, not infringing. OG&E filed a motion requesting a final judgment of non-infringement in October 2015. The case was dismissed in January 2016. TransData/Meter Manufacturer Patent Litigation. In September 2015, TransData filed separate suits in the Eastern District of Texas against meter manufacturers General Electric Company and GE Energy Management Services, Inc. (“GE”) and Landis+Gyr, Inc. and Landis+Gyr Technology, Inc. (“L+G”), alleging infringement of United States Patent Nos. 6,181,294, 6,462,713, and 6,903,699 by certain wireless communication-enabled meters, including meters with our wireless modules. GE and L+G have each requested indemnification from us for the claims asserted against them under the terms of our master agreement. We have denied L+G’s request. In December 2015, GE settled with TransData in exchange for a release and license, and we agreed to contribute to the settlement between GE and TransData in exchange for a release of claims from GE. In January 2016, the suit against GE was dismissed. Linex Patent Litigation . In March 2013, Linex Technologies, Inc., a non-producing entity, or Linex, filed suit against us in United States District Court for the Southern District of Florida. Linex alleged that certain of our networking technology infringes United States Patent Nos. 6,493,377 and 7,167,503. We filed an answer in May 2013. In January 2014, the court granted the plaintiff’s request for a stay of the matter, pending reexamination of the patents at issue by the USPTO. In September 2014, Linex amended certain patent claims and canceled certain other patent claims based upon the USPTO’s completed reexaminations, and in October 2014, the court lifted the stay of the matter. In January 2015, Linex filed an amended complaint to incorporate facts related to the completed reexaminations, and we filed an answer responding to the complaint and raising additional defenses. In June 2015, the court stayed the action pending the USPTO’s completion of further ex parte reexaminations of the patents at issue, one of which has been completed. We believe that we have meritorious defenses to Linex’s allegations and intend to continue vigorously defending against the action. JSDQ Mesh Technologies Patent Litigation . In September 2015, JSDQ Mesh Technologies LLC (“JSDQ”), a non-producing entity, filed suit against us and our customer, Pepco Holdings, Inc., in United States District Court for the District of Delaware. The complaint alleges infringement of United States Patent Nos. 7,286,828, RE43675 and RE44607 by certain networking technology that we provide. We agreed to indemnify, assume control of the defense and resolve the claim against Pepco Holdings. In December 2015, we settled with JSDQ for an immaterial amount. Atlas/ComEd & Exelon and Atlas/PG&E Patent Litigation . In November 2015, Atlas IP, LLC filed separate suits against our customers Commonwealth Edison Company (“ComEd”) and Pacific Gas and Electric Co. (“PG&E”), alleging infringement of United States Patent No. 5,371,734 by communications between smart meters and access points over a neighborhood area network using wireless communication modules and networking equipment supplied by us. The suit against ComEd was filed in the Northern District of Illinois and also names Exelon Corp. (“Exelon”) as a defendant. The suit against PG&E was filed in the Northern District of California. We have agreed to assume the defense in both suits. In January 2016, we filed a motion to dismiss the ComEd complaint and to remove Exelon as a defendant. In February 2016, the court granted our motion to dismiss the complaint, and dismissed Exelon from the case with prejudice. Atlas IP filed an amended complaint against ComEd in February 2016. We filed a motion to dismiss the PG&E complaint in January 2016. The court has not yet issued a ruling. In addition to the matters described above, from time to time we may be subject to other legal proceedings and claims in the ordinary course of business. We have received, and may in the future continue to receive, claims from third parties asserting infringement of their intellectual property rights. We may, from time to time, also be subject to various legal or government claims, disputes, or investigations. Such matters may include, but not be limited to, claims, disputes, or investigations related to warranty, refund, breach of contract, employment, intellectual property, government regulation, compliance or other matters. Future litigation may be necessary to defend ourselves and our customers by determining the scope, enforceability and validity of third-party rights or to establish our rights. There can be no assurance with respect to the outcome of any current or future litigation brought against us or pursuant to which we have indemnification obligations and the outcome could have a material adverse impact on our business, operating results and financial condition. As of December 31, 2015, we have recorded a charge of $3.6 million related to certain legal proceedings described above. Other than for the matters we have recognized in the consolidated financial statements, we have not recorded any amounts for contingent losses associated with the matters described above based on its belief that losses, while reasonably possible, are not probable. Unless otherwise stated, we are currently unable to predict the final outcome of these lawsuits and therefore cannot determine the likelihood of loss nor estimate a range of possible loss. We are directly involved with various unresolved legal actions and claims, and are indirectly involved with proceedings by administrative bodies such as public utility commissions, arising in the ordinary course of business. We do not believe that any liability from any reasonably foreseeable disposition of such legal actions and claims, individually or in the aggregate, would have a material effect on our consolidated financial statements. There are many uncertainties associated with any litigation or claim, and we cannot be certain that these actions or other third-party claims will be resolved without costly litigation, fines and/or substantial settlement payments. If that occurs, our business, financial condition and results of operations could be materially and adversely affected. If information becomes available that causes us to determine that a loss in any of our pending litigation matters, claims or settlements is probable, and a reasonable estimate of the loss associated with such events can be made, we will record the estimated loss at that time. Customer Performance and Other Commitments Certain customer agreements require us to obtain letters of credit or surety bonds in support of our obligations under such arrangements. These letters of credit or surety bonds typically provide a guarantee to the customer for future performance, which usually covers the deployment phase of a contract and may on occasion cover the operations and maintenance phase of service contracts. As of December 31, 2015 and 2014, we had a total of $22.7 million and $17.0 million, respectively, including $13.0 million related to EON Patent Litigation mentioned above, of standby letters of credit issued under the Credit Facility with a financial institution, of which $4.4 million (AUD$6.2 million) and $0.5 million (AUD$0.6 million), respectively, were denominated in Australian dollars. In accordance with the terms of our Credit Facility, increases or decreases in the exchange rate between the Australian dollar and the U.S. dollar will increase or decrease the amount available to us under the Credit Facility. As of December 31, 2015 and 2014, we had an unsecured surety bond of $20.3 million and $20.3 million, respectively. The surety bond provides a financial guarantee to support performance obligations under certain customer agreements. In the event any such letters of credit or surety bonds are called, we would be obligated to reimburse the issuer of the letter of credit or surety bond. We do not believe there will be any claims against currently outstanding letters of credit or surety bonds. Indemnification Commitments Directors, Officers and Employees . In accordance with our bylaws and/or pursuant to indemnification agreements we have entered into with directors, officers and certain employees, we have indemnification obligations to our directors, officers and employees for claims brought against these persons arising out of certain events or occurrences while they are serving at our request in such a capacity. We maintain a director and officer liability insurance coverage to reduce our exposure to such obligations, and payments made under these agreements. To date, there have been no indemnification claims by these directors, officers and employees. Customers and Third-Party Device Manufacturers . Refer to the discussion above under the heading Legal Contingencies for a description of our indemnification obligations. Our contracts with customers and third-party device manufacturers typically provide indemnification for claims filed by third-parties alleging that our products and services sold to the customer or manufacturer infringe or misappropriate any patent, copyright, trademark or other intellectual property right. In our customer contracts, we also typically provide an indemnification for third-party claims resulting from death, personal injury or property damage caused by the negligence or willful misconduct of our employees and agents in connection with the performance of certain contracts. Under our customer and third-party device manufacturer indemnities, we typically agree to defend the utility customer or third-party device manufacturer, as the case may be, from such claims, and pay any resulting costs, damages and attorneys’ fees awarded against the indemnified party with respect to such claims, provided that (a) the indemnified party promptly notifies us in writing of the claim, (b) the indemnified party provides reasonable assistance to us at our expense, and (c) we have sole control of the defense and all related settlement negotiations. Insurance . We maintain various insurance coverages, subject to policy limits, that enable us to recover a portion of any amounts paid by us in connection with our obligation to indemnify our customers and third-party device manufacturers. However, because our maximum liability associated with such indemnification obligations generally is not stated explicitly in the related agreements, and further because many states prohibit limitations of liability for such indemnified claims, the maximum potential amount of future payments we could be required to make under these indemnification provisions could significantly exceed insurance policy limits.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	17. SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) The following tables set forth selected unaudited quarterly statements of operations data for each of the last eight quarters in the years ended December 31, 2015 and 2014 (in thousands, except per share data). Three Months Ended December 31, September 30, June 30, March 31, December 31, September 30, June 30, March 31, 2015 2015 2015 2015 2014 2014 2014 2014 Revenue, net $ 199,247 $ 69,505 $ 77,167 $ 143,640 $ 77,411 $ 28,041 $ 41,607 $ 44,229 Cost of revenue 97,902 36,518 57,211 72,185 47,233 26,738 28,195 32,785 Gross profit 101,345 32,987 19,956 71,455 30,178 1,303 13,412 11,444 Operating expenses 35,600 33,381 36,495 37,314 28,786 38,723 38,084 38,615 Operating income (loss) 65,745 (394 ) (16,539 ) 34,141 1,392 (37,420 ) (24,672 ) (27,171 ) Other income (expense), net (159 ) (99 ) 74 288 68 7 85 (37 ) Income (loss) before income taxes 65,586 (493 ) (16,465 ) 34,429 1,460 (37,413 ) (24,587 ) (27,208 ) Provision (benefit) for income taxes 3,708 129 (290 ) (476 ) 959 (140 ) 4 599 Net income (loss) $ 61,878 $ (622 ) $ (16,175 ) $ 34,905 $ 501 $ (37,273 ) $ (24,591 ) $ (27,807 ) Net income (loss) per share Basic $ 1.23 $ (0.01 ) $ (0.32 ) $ 0.71 $ 0.01 $ (0.77 ) $ (0.51 ) $ (0.58 ) Diluted $ 1.19 $ (0.01 ) $ (0.32 ) $ 0.69 $ 0.01 $ (0.77 ) $ (0.51 ) $ (0.58 ) Weighted compute net income (loss) per share Basic $ 50,481 $ 50,188 $ 49,862 $ 49,306 $ 48,929 $ 48,551 $ 48,315 $ 47,693 Diluted $ 52,167 $ 50,188 $ 49,862 $ 50,899 $ 50,191 $ 48,551 $ 48,315 $ 47,693

Description of Business and S26

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Basis Of Presentation	The consolidated financial statements and accompanying notes have been prepared in accordance with accounting principles generally accepted in the United States, or GAAP. The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. Intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and the accompanying notes during the reporting period. Estimates are used for revenue and cost recognition, allowance for doubtful accounts receivable, inventory valuation, estimates related to recovery of long-lived assets and goodwill, restructuring accruals,
Cash, Cash Equivalents and Short-term Investments	Cash, Cash Equivalents and Short-term Investments Cash equivalents consist of highly liquid investments with insignificant interest rate risk and original maturities at the time of purchase of three months or less, and consist of money market funds. Short-term investments consist of high grade investment securities with original maturities at the time of purchase of greater than three months, and are available for use in current operations. We classify all of our cash equivalents and short-term investments as available-for-sale, which are recorded at fair value. Unrealized gains and losses are included in accumulated other comprehensive (loss) income in stockholders’ deficit. Realized gains and losses are included in other income and expense, net. We evaluate our short-term investments for impairment each reporting period. Determining whether a decline in fair value is other-than-temporary requires management judgment based on the specific facts and circumstances of each security. We consider various factors in determining whether to recognize an impairment charge, including the length of time the investment has been in a loss position, the extent to which the fair value has been less than our cost basis, the investment's financial condition, and near-term prospects of the investee. If we determine that the decline in an investment's fair value is other than temporary, the difference is recognized as an impairment loss in its consolidated statements of operations. Amounts are reclassified out of accumulated other comprehensive (loss) income into earnings using the specific identification method.
Inventory	Inventory Inventory is stated at the lower of cost or market. Cost is computed using standard cost, which approximates actual cost on a first-in, first-out basis. We evaluate our ending inventories for excess quantities and obsolescence based on forecasted demand within specific time horizons, technological obsolescence, and an assessment of any inventory that is not of saleable condition. Actual demand may differ from forecasted demand, and such differences may have a material effect on recorded inventory values and operating results. In addition, we enter into purchase commitments with third-party contract manufacturers to manage lead times and meet product forecasts and with other parties to purchase various key components used in the manufacture of our products. Accruals are established for estimated losses on purchased components for which we believe it is probable that they will not be recoverable in future operations. To the extent that such forecasts are not achieved, commitments and associated accruals may change.
Revenue Recognition	Revenue Recognition We generally market our products and services directly to customers. We also contract with third-party device manufacturers, which integrate our communications modules into their devices. Our solutions, which include our UtilOS network operating system, SilverLink Control Platform and SilverLink Applications, networking hardware, and communications modules, provides customers with two-way communication from our communications modules to their back office. Our hardware devices include UtilOS embedded software, which functions together with the tangible hardware elements to deliver the tangible products’ essential functionality. Our SilverLink Control Platform and SilverLink Applications of products includes software that is not embedded with the tangible hardware elements, but that is also necessary to deliver the tangible products’ essential network functionality, as well as other application software that provides additional functionality to the network solution. We derive revenue from sales of products, including hardware and software, as well as services, including network design and deployment support, managed services and SaaS, and ongoing customer support. We enter into separate arrangements with third-party device manufacturers to integrate our communications modules with their devices pursuant to our customers’ specifications. While we may receive payment directly from these third-party device manufacturers, the timing of revenue recognition related to communications modules delivered to third-party device manufacturers is ultimately determined based upon acceptance by our customers. Substantially all of our sales of communications modules have been fulfilled through third-party device manufacturers in this manner. We enter into multiple deliverable arrangements with customers to deploy our networking platform and solutions, which include the delivery of hardware and software, as well as services. Judgment is required in determining the separate units of accounting, which depends on whether the delivered items have standalone value to customers. When we sell our products and services separately, or when the customer could resell them on a standalone basis, we treat the delivered elements as having standalone value. In our typical customer arrangements, we consider the following to be separate units of accounting: (i) our hardware together with the related embedded software; (ii) our network management software within our SilverLink Control Platform and SilverLink Applications suite that provides the tangible product’s essential network functionality and related hardware for which the network management software is intended to be used; (iii) other application software within our SilverLink Control Platform and SilverLink Applications suite not essential for the customer to obtain functionality of the hardware; and (iv) our service offerings, which include professional services, managed services and SaaS, and ongoing customer support. We determine total arrangement consideration, and exclude amounts that are contingent upon the delivery of additional items or meeting other specified performance conditions, including potential refunds or penalty provisions. We allocate the total arrangement consideration to the deliverables based on our determination of the units of accounting and their relative selling prices. As we have not yet established vendor-specific objective evidence, or VSOE, or identified third-party evidence of fair value for these units of accounting, we use our best estimate of selling price to perform the relative fair value allocation. Judgment is also required in determining how to measure and allocate arrangement consideration among the separate units of accounting. The process for performing an assessment of our best estimate of selling price for our products and services is based on quantitative and qualitative aspects of multiple factors. These factors include market conditions, such as competitive alternatives and pricing practices, as well as company-specific factors, such as standalone sales, nature and size of the customer, contractually stated prices, costs to manufacture products or provide services and profit objectives. In establishing such profit objectives, we consider prices in previous contracts, size of the transaction, and the drivers, if any, that could influence future margins. The following revenue recognition criteria are applied to the units of accounting in all customer arrangements, as well as those in which orders of communications modules are fulfilled through third-party device manufacturers as described above. We do not recognize revenue for a unit of accounting until all of the following criteria have been met: · Persuasive evidence of an arrangement exists . Binding contracts or purchase orders are used to determine the existence of an arrangement. · Delivery has occurred . Shipping documents and customer acceptance provisions, where applicable, are used to verify delivery. · The fee is fixed or determinable . We assess whether the fee is fixed or determinable based on the payment terms associated with the transaction and whether the sales price is subject to refund or adjustment. · Collectibility is reasonably assured . We assess collectibility based primarily on creditworthiness of the customer or third-party device manufacturer as determined by credit assessments and payment history. Substantially all of our customer arrangements include acceptance provisions that require testing of the network against specific performance criteria. We consider the following factors in our assessment of whether the acceptance provisions are substantive: · whether the criteria are based on our standard performance criteria or are customer-specific; · if the criteria are customer-specific, availability of objective and sufficient evidence to reliably demonstrate that the delivered products and services will meet all of the specified criteria prior to receipt of customer acceptance; · our experience with similar types of arrangements or products, as well as our experience with the specific customer; · whether we would be successful in enforcing a claim for payment even in the absence of acceptance confirmation from the customer; · the nature and complexity of the acceptance testing, including the planned duration of the acceptance period; and · the significance of financial penalties, if any, associated with not meeting performance criteria. From incorporation through December 31, 2014, we deferred revenue for arrangements that contain customer-specific acceptance criteria until we determine whether acceptance was achieved due to our limited experience with customer deployments during that period. We perform an ongoing evaluation of the sufficiency of historical experience in determining the effect of customer-specific acceptance terms on timing of revenue recognition. During the quarter ended March 31, 2015, following the completion of analyses of historical experience, we determined that we have sufficient objective evidence to conclude that (i) network solution testing conducted in prior deployments can be relied upon to demonstrate that products and services delivered for deployments of other customers will meet acceptance testing criteria, provided that such prior deployments have similar characteristics and substantially similar testing criteria, or (ii) in absence of such evidence from prior deployments, network solution testing in the initial service area for a specific customer deployment can be relied upon to demonstrate that products and services delivered for subsequent service areas within that same deployment will meet subsequent acceptance testing criteria, provided that such initial network solution testing is successfully completed, and the testing criteria in the initial service area are substantially similar to the agreed-upon testing criteria for the remaining service areas. Receipt of acceptance from these customers is no longer considered necessary as (i) substantially similar acceptance testing criteria have been met in similar deployments of other customers, or (ii) substantially similar acceptance testing criteria have been met in the initial service area within the customer’s deployment, and all other revenue recognition criteria were met. As a result of the above change in assessment of the impact of customer-specific acceptance criteria, revenue and cost of revenue recognized during the year ended December 31, 2015 in the consolidated statements of operations included revenue of $139.4 million, which otherwise would have been deferred before the change in assessment, and excluded cost of revenue of $55.9 million, which otherwise would have been recognized in the period before the change in such assessment. This resulted in a $83.5 million increase in net income, a $1.67 increase to basic net income per share, and a $1.62 increase to diluted net income per share during the year ended December 31, 2015. Once we have satisfied the necessary acceptance provisions, we recognize revenue as follows: · Revenue from software that functions together with the tangible hardware elements to deliver the tangible products’ essential functionality is recognized upon delivery of both the software and related hardware elements, assuming all other revenue recognition criteria are met. · Application software and related post contract support services which are not considered essential to the functionality of hardware devices are within the scope of ASC 985-605. In accordance with ASC 985-605, revenues are recognized ratably over the longest service period for post-contract customer support, or PCS, and professional services as we have not established VSOE for software or the related software elements. · Revenue from our service offerings, including professional services such as network design and deployment support, managed services and SaaS, and ongoing customer support is recognized as services are delivered or on a proportional performance basis depending on the underlying pattern of performance. · Revenue from hardware is recognized when title and risk of loss transfers. Amounts that are invoiced prior to a transaction meeting all of the above revenue recognition criteria are recorded in deferred revenue until such criteria are satisfied. For all periods presented herein, the amount and timing of revenue and product cost recognition has been, and for the near-term will be, dependent primarily on our ability to meet substantive customer acceptance criteria. We consider a variety of factors in estimating the timing of customer acceptance, which includes contractual milestones, project schedules, availability of resources, the nature and extent of remaining testing cycles, and other relevant information provided by our project management team. Accordingly, we expect that the timing of recognition of revenue and related product costs on both a quarterly and annual basis will not be easily predictable. In addition, it is possible that the amount of current deferred revenue and related deferred cost of revenue reflected as of a balance sheet date will be significantly higher or lower than the amount of deferred revenue and related deferred cost of revenue that is ultimately recognized as revenue and cost of revenue within the 12 months following the balance sheet date. We classify deferred revenue and deferred cost of revenue that we expect to recognize during the 12 months following the balance sheet date as current deferred revenue and current deferred cost of revenue on our balance sheet and the remainder as non-current deferred revenue and non-current deferred cost of revenue. Certain of our customer and third-party device manufacturer contracts include contingency provisions, which impact our revenue recognition as such contingent amounts limit the amount of the total arrangement consideration under multiple deliverable contracts that can be allocated to delivered and accepted products and services. Amounts that are invoiced prior to a transaction meeting all of the revenue recognition criteria, including contingency provisions, are recorded in deferred revenue until such provisions have lapsed. For the years ended December 31, 2015 and 2014, such amounts were $32.1 million and $26.2 million, respectively, related to those arrangements for which we have started recognizing revenue. These contingencies are related to potential penalties for late delivery, liquidated damages related to failure to meet milestones or deliver specified products or services, or credits to be issued upon the failure to meet service level criteria. The amounts that could be paid under these provisions are typically limited and capped at amounts that do not exceed specific thresholds. Accordingly, even in situations where we have received customer acceptance, we limit the revenue recognized for accepted products and services by the amount that could be paid under these provisions. We do not recognize these deferred amounts until the provisions have lapsed. Predicting when such provisions will lapse is subject to significant uncertainty as the timing is dependent on a variety of factors, including the progress and completion of deployments. Related to the contingency provisions described above, $1.2 million and $4.6 million, respectively, were recorded as current deferred revenue and $30.9 million and $21.6 million, respectively, were recorded as non-current revenue as of December 31, 2015 and 2014. In cases where we sell third-party products and services such as meters, hardware, services, software or software maintenance as part of the overall solution, we evaluate whether we act as principal or agent under the arrangement. The evaluation considers multiple factors, including whether we are the primary obligor under the arrangement with the customer, whether we bear the risk of loss and credit risk associated with the supply of third-party products and services, whether we have the ability to change the product or perform part of the service, and whether we have the ability to control the price charged to our customers for the third-party products and services. Revenue is presented on a gross basis when we conclude that we are the principal under the arrangement with respect to third-party products and services, and revenue is presented on a net basis when we conclude that we are acting as the agent. Substantially all of our revenue related to third-party products and services is recognized on a gross basis as we are generally acting as the principal under our arrangements. Shipping charges billed to customers were not significant for the years ended December 31, 2015, 2014, and 2013. Shipping charges are included in revenue, and the related shipping costs are included in cost of revenue in the accompanying consolidated statements of operations.
Cost of Revenue	Cost of Revenue Cost of revenue consists of cost of product and service revenue. Cost of product revenue includes contract manufacturing costs, including raw materials, components and associated freight, and normal yield loss. In addition, cost of product revenue includes compensation, benefits and stock-based compensation provided to our manufacturing personnel, overhead and other direct costs. Product costs are deferred upon shipment and are recognized in the period in which we recognize the related revenue. Period costs, which consist primarily of logistics costs, manufacturing ramp-up costs, expenses for inventory obsolescence, standard warranty costs and lower of cost or market adjustments are recognized in the period in which they are incurred. Costs of providing services include personnel-related costs, depreciation and amortization, and software hosting costs. Costs of providing services are not deferred and are included in cost of revenue in the period in which they are incurred.
Deferred Revenue and Deferred Cost of Revenue	Deferred Revenue and Deferred Cost of Revenue Deferred revenue results from transactions where we have billed the customer for product shipped or services performed but all revenue recognition criteria have not yet been met. Deferred cost of revenue is recorded for products for which ownership (typically title and risk of loss) has transferred to the customer, but for which criteria for revenue recognition have not been met. We only defer tangible direct costs associated with hardware products delivered. Cost of revenue for providing services is not deferred, but is expensed in the period incurred. Deferred cost of revenue associated with deferred product revenue is recorded at the standard, which approximates actual, inventory cost at the time of shipment. We evaluate deferred cost of revenue for recoverability based on multiple factors, including whether net revenues less related direct costs will exceed the amount of deferred cost of revenue based on the terms of the overall arrangement. To the extent that deferred cost of revenue is determined to be unrecoverable, we adjust deferred cost of revenue with a charge to product cost of revenue in the current period. In connection with our recoverability assessments, we have not incurred significant impairment charges during the years ended December 31, 2015, 2014, and 2013. We recognize deferred revenue and associated deferred cost of revenue in the consolidated statements of operations once all revenue recognition criteria have been met.
Product Warranty	Product Warranty We provide warranties for substantially all of our products. Our standard warranty period extends from one to five years. We accrue for costs of standard warranty at the time of product shipment, and record changes in estimates to warranty accruals when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. At the time of product shipment, we estimate and accrue for the amount of standard warranty cost and record the amount as a cost of revenue. Determining the amount of warranty costs requires management to make estimates and judgments based on historical claims experience, industry benchmarks, test data and various other assumptions including estimated field failure rates that are believed to be reasonable under the circumstances. The amount of warranty costs accrued are net of warranty obligations to be fulfilled by our suppliers. The results of these judgments formed the basis for our estimate of the total charge to cover anticipated customer warranty, repair, return and replacement and other associated costs. Should actual product failure rates, claim levels, material usage or supplier warranties on parts used in our products differ from our original estimates, revisions to the estimated warranty liability could result in adjustments to our cost of revenue in future periods. Certain of our standard product warranty obligations require us to reimburse a customer for installation and other related costs in the event that field reliability rates fall below contractually specified thresholds. We consider the probability that we will have to pay such incremental warranty costs based on the expected performance of a delivered product when we record new warranty obligations issued in a period as well as when we determine if any changes are required to our original estimates for pre-existing warranty obligations. Our warranty obligations are affected by product failure rates, claims levels, material usage and supplier warranties on parts included in our products. Because our products are relatively new and we do not have the benefit of long-term experience observing products’ performance in the field, it is possible that the estimates of a product’s lifespan and incidence of claims could vary from period to period. In certain customer arrangements, we have provided extended warranties for periods of up to 15 years following the initial standard warranty period. We recognize revenue associated with extended warranties over the extended warranty period when the extended warranty period commences. Costs associated with providing extended warranties are expensed as incurred during the extended warranty period.
Supplier Concentrations and Other Inventory Risks	Supplier Concentrations and Other Inventory Risks We have arrangements under which substantially all of our manufacturing activity is subcontracted to third-party vendors. Currently we have our manufacturing relationships with Plexus Corp. and Celestica, Inc. We plan to shift the entire production of our products currently manufactured by Plexus to a combination of Flextronics International Ltd. and Celestica during 2016. These vendors provide or will provide us with a wide range of operational and manufacturing services, including material procurement, final assembly, test quality control, warranty repair, and shipment to our customers and third-party vendors. Contract manufacturing activities are conducted in the United States and Thailand and are undertaken based on management’s product demand forecasts. Our contract manufacturers procure components necessary to assemble the products anticipated by management’s forecast and test the products according to our quality specifications. If the components are unused for specified periods of time, we may incur carrying charges or obsolete material charges for components that our contract manufacturers purchased to build products to meet our product demand forecasts. Our communications modules and other hardware products consist of commodity parts and certain custom components. Our components are generally available from multiple sources or suppliers. However, some components used in our products are purchased from single or limited sources. Finished goods are reported as inventory until title transfers to the customer. Consigned finished goods inventory that is maintained at customer locations is also reported as inventory until consumption or acceptance of the product by the customer. We account for consigned inventory on a first-in, first-out basis and record lower of cost or market or obsolete material charges when appropriate.
Concentration of Credit and Customer Risks	Concentration of Credit and Customer Risks Our sales are currently concentrated with a small group of customers and third-party device manufacturers principally located in the United States and Australia. In evaluating customer concentration risk, we attribute revenue to our customers, including amounts billed to third-party device manufacturers for our communications modules. The following table summarizes the percentage of revenue related to our customers’ deployments in excess of 10% of total revenue: Year Ended December 31, 2015 2014 2013 ComEd 31 % — % — % PHI 27 — — CHED — 21 — Progress — 13 — PG&E — — 39 FPL — — 20 Each of these total revenue percentages includes amounts related to the customers’ deployments that were billed directly to our third-party device manufacturers, as well as direct revenue from the customers. We typically extend credit to our customers and third-party device manufacturers and do not require collateral or other security in support of accounts receivable. We attempt to mitigate the credit risk in our trade receivables through our credit evaluation process and payment terms. We analyze the need to reserve for potential credit losses and record allowances for doubtful accounts when necessary. To date, we have not had any significant write-offs of uncollectible accounts receivable, and there was insignificant allowance for doubtful accounts as of December 31, 2015 and 2014. The following table summarizes the percentage of accounts receivable from customers and third-party device manufacturers in excess of 10% of accounts receivable: Year Ended December 31, 2015 2014 AusNet 17 % — % FPL 15 — CPS 11 11 ComEd 11 19 PG&E 10 — Dominion — 13
Advertising Costs	Advertising Costs We expense advertising costs as incurred. Advertising costs were $1.9 million, $2.2 million, and $2.2 million for each of the years ended December 31, 2015, 2014, and 2013.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are stated at cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the following estimated useful lives: Software 3 to 7 years Computer and network equipment 2 to 5 years Machinery and equipment 3 years Furniture and fixtures 3 to 7 years Leasehold improvements Lesser of the lease term or the estimated useful lives of the improvements, generally 1 to 10 years
Software Development Costs	Software Development Costs Under our current practice of developing new products, technological feasibility of the underlying software is not established until substantially all product development and testing is complete, which generally includes the development of a working model. Our products are released within a short period of time after achieving technological feasibility. As a result, costs subsequent to achieving technological feasibility have not been significant, and all software development costs generally have been expensed as incurred. We capitalize certain costs for our internal-use software incurred during the application development stage. Costs related to preliminary project activities and post implementation activities were expensed as incurred. Internal-use software is amortized on a straight line basis over its estimated useful life. The estimated useful life is determined based on management’s judgment on how long the core technology and functionality serves the internal needs. Management evaluates the useful lives of these assets on an annual basis and tests for impairment whenever events or changes in circumstances occur that could impact the recoverability of these assets. To date, amortization expense, including amounts written-off related to capitalized costs have been insignificant. There were insignificant capitalized costs included in property and equipment, net of amortization and write-off in the consolidated balance sheets as of December 31, 2015 and 2014.
Intangible and Long-Lived Assets	Intangible and Long-Lived Assets We evaluate long-lived assets and amortizable intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable in accordance with Financial Accounting Standards Board, or FASB, Accounting Standards Codification, or ASC, Topic 360, Property, Plant and Equipment
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in a business combination. Goodwill is not subject to amortization but is subject to annual assessment, at a minimum, for impairment in accordance with ASC Topic 350, Intangibles — Goodwill and Other
Research and Development	Research and Development Costs to research, design, and develop the Company’s products
Corporate Bonus Incentive Plan	Corporate Bonus Incentive Plan Our corporate bonus incentive plan is funded by a combination of cash and restricted stock units, at management’s discretion. We accrue and record the related corporate bonus amounts payable, both in cash and restricted stock units, under this plan in the period in which it is earned. The Compensation Committee may make incentive awards based on such terms, conditions and criteria as it considers appropriate. Stock awards issued in connection with this plan are generally fully vested at the time of grant. Because the award of share-based payments described above represents an obligation to issue a variable number of the Company’s shares determined on the basis of a monetary value derived solely on variations in an operating performance measure (and not on the basis of variations in the fair value of the entity’s equity shares), the award is considered a share-based liability in accordance with ASC Topic 480, Distinguishing Liabilities from Equity
Stock-Based Compensation	Stock-Based Compensation We measure and recognize compensation expense for all stock-based awards made to employees and directors, including stock options, restricted stock, restricted stock units, performance stock units, and employee stock purchase plan, based on estimated fair values. The fair values of stock options and our 2012 Employee Stock Purchase Plan (please refer to Note 9. Stock Based Compensation
Income Taxes	Income Taxes We account for income taxes in accordance with ASC Topic 740, Income Taxes, which requires the asset and liability approach for financial accounting and reporting of income taxes. Deferred income taxes are recorded 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. The carrying value of net deferred tax assets reflects that we have been unable to generate sufficient taxable income in certain tax jurisdictions. We record a valuation allowance to reduce our deferred tax assets to the amount of future tax benefit that we believe is more likely than not to be realized. The deferred tax assets are still available for us to use in the future to offset taxable income, which would result in the recognition of a tax benefit and a reduction in our effective tax rate. Actual operating results and the underlying amount and category of income in future years could render our current assumptions, judgments and estimates of the realizability of deferred tax assets inaccurate, which could have a material impact on its financial position or results of operations. We follow a two-step approach to recognizing and measuring tax benefits associated with uncertain tax positions taken or expected to be taken in a tax return. The first step is to determine if, based on the technical merits, it is more likely than not that the tax position will be sustained upon examination by a taxing authority, including resolution of any related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount that is more than 50% likely to be realized upon ultimate settlement with a taxing authority. We recognize any interest and penalties related to uncertain tax positions in the provision for income taxes line of our consolidated statements of operations. Accrued interest and penalties are included within the related tax liability line in the consolidated balance sheets.
Foreign Currency Translation and Remeasurement	Foreign Currency Translation and Remeasurement The Company translates the assets and liabilities of its non-U.S. dollar functional currency subsidiaries into U.S. dollars using exchange rates in effect at the end of each period. Revenue and expenses for these subsidiaries are translated using rates that approximate those in effect during the period. Gains and losses from these translations are recognized in foreign currency translation included in accumulated other comprehensive income (loss) in the statement of convertible preferred stock and stockholders’ deficit. The Company’s subsidiaries that use the U.S dollar as their functional currency remeasure monetary assets and liabilities at exchange rates in effect at the end of each period, and inventories, property and nonmonetary assets and liabilities at historical rates.
Loss Contingencies	Loss Contingencies We are subject to the possibility of various loss contingencies arising in the course of business. We use significant judgment and assumptions to estimate the likelihood of the loss or impairment of an asset or the incurrence of a liability in determining loss contingencies. An estimated loss contingency is accrued when it is probable that a liability has been incurred or an asset has been impaired and the amount of loss can be reasonably estimated. We record a charge equal to the minimum estimated liability for litigation costs or a loss contingency only when both of the following conditions are met: (i) information available prior to issuance of our consolidated financial statements indicates that it is probable that an asset had been impaired or a liability had been incurred at the date of the financial statements and (ii) the range of loss can be reasonably estimated. We regularly evaluate current information available to us to determine whether such accruals should be adjusted and whether new accruals are required.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2015, the FASB issued Accounting Standards Update (“ASU”) No. 2015-17, Balance Sheet Classification of Deferred Taxes In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) Revenue Recognition

Description of Business and S27

Description of Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Schedule of Percentage of Revenue Related to Customers' Deployments	The following table summarizes the percentage of revenue related to our customers’ deployments in excess of 10% of total revenue: Year Ended December 31, 2015 2014 2013 ComEd 31 % — % — % PHI 27 — — CHED — 21 — Progress — 13 — PG&E — — 39 FPL — — 20
Schedule of Percentage of Accounts Receivable from Customers and Third Party	The following table summarizes the percentage of accounts receivable from customers and third-party device manufacturers in excess of 10% of accounts receivable: Year Ended December 31, 2015 2014 AusNet 17 % — % FPL 15 — CPS 11 11 ComEd 11 19 PG&E 10 — Dominion — 13
Property and Equipment Estimated Useful Lives	Depreciation is calculated using the straight-line method over the following estimated useful lives: Software 3 to 7 years Computer and network equipment 2 to 5 years Machinery and equipment 3 years Furniture and fixtures 3 to 7 years Leasehold improvements Lesser of the lease term or the estimated useful lives of the improvements, generally 1 to 10 years

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Computation of Historical Basic and Diluted Net Income (Loss) Per Share	The following table sets forth the computation of historical basic and diluted net income (loss) per share (in thousands, except per share data): Year Ended December 31, 2015 2014 2013 Net income (loss) $ 79,986 $ (89,170 ) $ (66,807 ) Deemed dividend to convertible preferred shareholders — — (105,000 ) Net income (loss) attributable to common stockholders $ 79,986 $ (89,170 ) $ (171,807 ) Net income (loss) per share attributable to common stockholders Basic $ 1.60 $ (1.84 ) $ (4.54 ) Diluted $ 1.55 $ (1.84 ) $ (4.54 ) Weighted average shares used to compute net income (loss) per share attributable to common stockholders Basic 49,963 48,377 37,877 Diluted 51,524 48,377 37,877
Common Shares Outstanding were Excluded from Computation of Diluted Net Loss Per Share	The following potential common shares outstanding were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive (in thousands): Year Ended December 31, 2015 2014 2013 Employee equity awards 3,572 6,922 7,760

Cash, Cash Equivalents, and S29

Cash, Cash Equivalents, and Short-Term Investments (Tables)	12 Months Ended
	Dec. 31, 2015
Cash Cash Equivalents And Short Term Investments [Abstract]
Cash, Cash Equivalents, and Short-Term Investments	Cash, cash equivalents, and short-term investments consisted of the following as of December 31, 2015 (in thousands): Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 59,263 $ — $ — $ 59,263 Cash equivalents: Money market mutual funds 6,001 — — 6,001 Total cash and cash equivalents 65,264 — — 65,264 Short-term fixed income securities: U.S. government and agency obligations 38,396 4 (110 ) 38,290 U.S. and foreign corporate debt securities 18,945 2 (52 ) 18,895 Foreign governments and multi-national agency obligations 2,000 — (4 ) 1,996 Total short-term investments 59,341 6 (166 ) 59,181 Total cash, cash equivalents and short-term investments $ 124,605 $ 6 $ (166 ) $ 124,445 Cash, cash equivalents, and short-term investments consisted of the following as of December 31, 2014 (in thousands): Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 54,239 $ — $ — $ 54,239 Cash equivalents: Money market mutual funds 6,218 — — 6,218 Total cash and cash equivalents 60,457 — — 60,457 Short-term fixed income securities: U.S. government and agency obligations 38,718 46 (18 ) 38,746 U.S. and foreign corporate debt securities 19,625 9 (33 ) 19,601 Foreign governments and multi-national agency obligations 2,000 — (8 ) 1,992 Total short-term investments 60,343 55 (59 ) 60,339 Total cash, cash equivalents and short-term investments $ 120,800 $ 55 $ (59 ) $ 120,796
Contractual Maturities of Cash Equivalents and Short-Term Investments	The contractual maturities of cash equivalents and short-term investments held at December 31, 2015 consisted of the following (in thousands): December 31, 2015 December 31, 2014 Amortized Aggregate Amortized Aggregate Cost Basis Fair Value Cost Basis Fair Value Due within one year $ 25,183 $ 25,163 $ 20,588 $ 20,599 Due from 1 year through 3 years 40,159 40,019 45,973 45,958 Total cash equivalents and short-term investments $ 65,342 $ 65,182 $ 66,561 $ 66,557
Schedule of Gross Unrealized Losses and Fair Values of Investments	The following table presents gross unrealized losses and fair values for those investments that were in an unrealized loss position as of December 31, 2015 and 2014, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in thousands): As of December 31, 2015 As of December 31, 2014 Total (Less Than 12 Months) Total (Less Than 12 Months) Fair Value Unrealized Loss Fair Value Unrealized Loss U.S. and foreign corporate debt securities $ 15,894 $ (52 ) $ 14,563 $ (33 ) Foreign governments and multi-national agency obligations 1,996 (4 ) 1,992 (8 ) U.S. government and agency obligations 31,792 (110 ) 13,523 (18 ) Total $ 49,682 $ (166 ) $ 30,078 $ (59 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets Recorded on Recurring Basis	As of December 31, 2015, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands): Fair Value Measurement Using Quoted Prices in Significant Active Markets for Other Significant Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,001 $ — $ — $ 6,001 Total cash equivalents 6,001 — — 6,001 Short-term investments: U.S. Government and agency obligations — 38,290 — 38,290 U.S. and foreign corporate debt securities — 18,895 — 18,895 Foreign governments and multi-national agency obligations — 1,996 — 1,996 Total short-term investments — 59,181 — 59,181 Total assets measured at fair value $ 6,001 $ 59,181 $ — $ 65,182 As of December 31, 2014, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands): Fair Value Measurement Using Quoted Prices in Significant Active Markets for Other Significant Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,218 $ — $ — $ 6,218 Total cash equivalents 6,218 — — 6,218 Short-term investments: U.S. Government and agency obligations — 38,746 — 38,746 U.S. and foreign corporate debt securities — 19,601 — 19,601 Foreign governments and multi-national agency obligations — 1,992 — 1,992 Total short-term investments — 60,339 — 60,339 Total assets measured at fair value $ 6,218 $ 60,339 $ — $ 66,557

Business Acquisitions (Tables)

Business Acquisitions (Tables) - Detectent Inc. [Member]	12 Months Ended
	Dec. 31, 2015
Schedule of Business Acquisition	The following table summarizes the fair value of total consideration transferred for the Detectent acquisition, the total fair value of net identifiable assets acquired and the resulting goodwill recorded (in thousands): Cash consideration $ 7,616 Less: Fair value of net identifiable assets acquired (3,164 ) Goodwill $ 4,452
Assets Acquired and Liabilities Assumed	Assets acquired and liabilities assumed as of January 16, 2015 (in thousands): Cash $ 518 Net other tangible liabilities (26 ) Intangible assets subject to amortization: Developed technology 1,900 Customer relationships 1,500 Non-compete agreements 100 Order backlog 300 Deferred tax liabilities in connection with acquired intangible assets and other fair value adjustments, net (1,128 ) Total fair value of net identifiable assets acquired $ 3,164

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table presents goodwill as of December 31, 2015 and 2014 and changes in the carrying amount of goodwill (in thousands): December 31, 2015 2014 Balance, beginning of period $ 4,729 $ 447 Goodwill acquired during the period 4,792 4,685 Goodwill measurement period adjustment (295 ) 85 Currency translation adjustment (454 ) (488 ) Balance, end of period $ 8,772 $ 4,729
Schedule of Intangible Assets	The following table summarizes the gross carrying amount and accumulated amortization for the intangible assets resulting from acquisitions: As of December 31, 2015 As of December 31, 2014 Useful Lives (in years) Gross Amount Accumulated Amortization Net Book Value Gross Carrying Amount Accumulated Amortization Net Book Value Purchased technology 4-5 years $ 4,865 $ 2,180 $ 2,685 $ 2,396 $ 1,139 $ 1,257 Customer relationships 2-7 years 3,640 973 2,667 2,140 417 1,723 Trade name 6 years 369 103 266 269 26 243 In-process research and development Indefinite — — — 269 - 269 Total $ 8,874 $ 3,256 $ 5,618 $ 5,074 $ 1,582 $ 3,492
Schedule of Amortization Expense	The following table illustrates the amortization expense included in the consolidated statements of operations for the years ended December 31, 2015, 2014 and 2013 (in thousand): Year Ended December 31, Amortization of purchased intangible assets: 2015 2014 2013 Cost of revenue $ 1,041 $ 417 $ 192 Selling and marketing 601 197 — General and administrative 32 — — Total $ 1,674 $ 614 $ 192
Schedule of Estimated Future Amortization Expense	The estimated future amortization expense of purchased intangible assets with definite lives for the next five years is as follows (in thousands): Year Ended 2016 $ 1,464 2017 1,452 2018 1,212 2019 1,061 2020 317 2021 and thereafter 112 $ 5,618

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	We recorded stock-based compensation expense as follows (in thousands): Year Ended December 31, 2015 2014 2013 Cost of revenue $ 6,135 $ 7,610 $ 12,275 Research and development 8,060 9,677 17,333 Sales and marketing 4,104 6,062 7,060 General and administrative 8,180 10,512 15,836 Stock-based compensation expense $ 26,479 $ 33,861 $ 52,504
Summary of Stock Option Activity	The following table summarizes our stock option activity and related information as follows (in thousands, except per share data): Options Outstanding Weighted Weighted Average Average Exercise Remaining Aggregate Number of Price per Contractual Intrinsic Shares Share Term (years) Value Balance at December 31, 2012 4,616 $ 21.73 Options granted 1,168 18.36 Options exercised (631 ) 4.74 Options cancelled or expired (427 ) 27.52 Balance at December 31, 2013 4,726 $ 11.88 6.43 $ 43 Options granted 732 14.67 Options exercised (378 ) 2.94 Options cancelled or expired (555 ) 17.57 Balance at December 31, 2014 4,525 $ 12.38 5.67 $ 8,699 Options granted 669 10.36 Options exercised (234 ) 2.38 Options cancelled or expired (528 ) 17.52 Balance at December 31, 2015 4,432 $ 11.99 5.36 $ 17,290 As of December 31, 2015: Options vested and expected to vest 4,398 $ 11.98 5.33 $ 17,225 Options exercisable 3,223 $ 11.67 4.07 $ 14,470
Summary of Restricted Stock Units Activity	The following table summarizes our restricted stock units activity and related information as follows (in thousands, except per share data): Restricted Stock Units Outstanding Weighted Weighted Average Average Grant Remaining Aggregate Number of Date Fair Value Contractual Intrinsic Shares per Share Term Value Balance at December 31, 2012 231 $ 449.51 Restricted stock units granted 3,662 48.41 Restricted stock units vested (1,020 ) 23.36 Restricted stock units cancelled (116 ) 49.69 Balance at December 31, 2013 2,757 $ 19.14 1.18 $ 57,951 Restricted stock units granted 1,218 10.72 Restricted stock units vested (1,280 ) 18.77 Restricted stock units cancelled (497 ) 17.50 Balance at December 31, 2014 2,198 $ 15.06 1.08 $ 18,532 Restricted stock units granted 1,713 12.67 Performance restricted stock units granted 995 6.85 Restricted stock units vested (1,407 ) 15.32 Restricted stock units cancelled (413 ) 14.00 Balance at December 31, 2015 3,086 $ 11.11 1.73 $ 44,473
Summary of Assumptions Relating to Stock Options, ESPP And Market-Based PSU	The following table summarizes the assumptions relating to our stock options, ESPP and market-based PSUs: Year Ended December 31, 2015 2014 2013 Stock options (1) Expected volatility 59 – 66% 43 – 47% 47 – 52% Expected dividends —% —% —% Expected life in years 5.85 – 6.08 6.08 5.00 – 6.08 Risk-free interest rate 1.54 – 1.78% 1.81 – 1.98% 0.87 – 1.96% Weighted average grant date fair value per share $ 5.82 $ 6.60 $ 19.11 ESPP (1) Expected volatility 33 – 62% 33 – 36% 52% Expected dividends —% —% —% Expected life in years < 1 year < 1 year < 1 year Risk-free interest rate 0.05 – 0.24% 0.05 – 0.08% 0.87% Market-based PSUs (2) Expected volatility 60 – 65% — — Expected dividends —% — — Risk-free interest rate 1.02 – 1.22% — — Weighted average fair value per share 6.85 — — (1) The Black-Scholes-Merton option-pricing model is utilized to estimate the fair value of stock options and ESPP. (2) The fair value market-based PSUs utilize the Monte Carlo simulation option pricing model. The Company amortizes the fair value of these awards over the derived service period. Provided that the derived service is rendered, the total fair value of the market-based PSUs at the date of grant is recognized as compensation expense even if the market condition is not achieved. However, the number of shares that ultimately vest can vary significantly with the performance of the specified market criteria.
Schedule of Unrecognized Compensation Cost recognized over Weighted Average Period	Weighted Unrecognized Average Compensation Period Cost (Years) Stock options $ 6.9 2.6 ESPP, RSUs, and PSUs $ 24.9 2.6

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Components of Income (Loss) Before Income Taxes	The components of income (loss) before income taxes are as follows (in thousands): Year Ended December 31, 2015 2014 2013 United States $ 116,530 $ (57,125 ) $ (28,774 ) Foreign (33,473 ) (30,623 ) (37,809 ) Income (loss) before income taxes $ 83,057 $ (87,748 ) $ (66,583 )
Schedule of Provision for Income Taxes	The provision for income taxes consists of the following (in thousands): Year Ended December 31, 2015 2014 2013 Current: United States federal $ — $ — $ — State 4,488 1,191 (115 ) Foreign 192 613 452 Total current provision for income taxes 4,680 1,804 337 Deferred: United States federal (1,091 ) — (47 ) State (37 ) — 123 Foreign (481 ) (382 ) (189 ) Total deferred benefit for income taxes (1,609 ) (382 ) (113 ) Provision for income taxes $ 3,071 $ 1,422 $ 224
Reconciliation of Federal Statutory Income Tax Rate to Effective Income Tax Rate	The provision for income taxes differs from the amount computed by applying the federal statutory income tax rate of 35% to loss before income taxes as follows (in thousands): Year Ended December 31, 2015 2014 2013 Federal statutory tax expense (benefit) $ 29,070 $ (30,031 ) $ (23,304 ) Research tax credit (548 ) (574 ) (884 ) Effect of non-U.S. operations 11,331 10,754 13,320 Change in valuation allowance (40,521 ) 18,166 (925 ) Stock-based compensation expense 573 1,982 3,455 Loss on debt extinguishments — — 8,287 State taxes 2,937 792 8 Other 229 333 267 Provision for income taxes $ 3,071 $ 1,422 $ 224
Schedule of Components of Deferred Tax Assets and Liabilities	The components of our deferred tax assets and liabilities are as follows (in thousands): December 31, 2015 2014 Deferred tax assets: Net operating loss and tax credit carryforwards $ 84,060 $ 129,471 Deferred revenue 119,440 159,523 Stock-based compensation expense 12,434 12,241 Accruals and reserves 12,551 7,452 Intangible assets 1,696 1,434 Other 333 355 Gross deferred tax assets 230,514 310,476 Valuation allowance (142,635 ) (186,273 ) Deferred tax assets 87,879 124,203 Deferred tax liabilities Property and equipment, net (1,552 ) (1,612 ) Deferred cost of revenue (85,258 ) (122,116 ) Deferred tax liabilities (86,810 ) (123,728 ) Net deferred tax assets $ 1,069 $ 475
Summary of Deferred Tax Assets Valuation Allowance	Below summarizes the change in deferred tax assets valuation allowance (in thousands): Balance at Beginning of Period Net Change Balance at End of Period Deferred tax assets valuation allowances Year ended December 31, 2013 $ 166,995 $ 1,097 $ 168,092 Year ended December 31, 2014 168,092 18,181 186,273 Year ended December 31, 2015 186,273 (43,638 ) 142,635
Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits	A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2015 2014 2013 Unrecognized tax benefits — $ 10,645 $ 8,715 $ 5,586 Gross increase for tax positions of prior years 85 165 1,216 Gross decrease for tax positions of prior years (34 ) (13 ) — Gross increase for tax positions of current year 1,414 1,778 1,913 Unrecognized tax benefits balance — $ 12,110 $ 10,645 $ 8,715

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Region	The following table presents revenue by geographic region (in thousands): Year Ended December 31, 2015 2014 2013 Revenue: United States $ 425,951 $ 101,579 $ 285,430 Australia 45,247 62,745 40,939 All Other 18,361 26,964 489 Total $ 489,559 $ 191,288 $ 326,858

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
	Dec. 31, 2015
Balance Sheet Component Details [Abstract]
Schedule Of Deferred Revenue	The following table details the activity in deferred revenue (in thousands): Year Ended December 31, 2015 2014 Deferred revenue, beginning of period $ 609,593 $ 524,653 Revenue deferred in the period 281,779 276,228 Revenue recognized in the period (489,559 ) (191,288 ) Deferred revenue, end of period $ 401,813 $ 609,593
Schedule Of Deferred Cost Of Revenue	The following table details the activity in deferred cost of revenue (in thousands): Year Ended December 31, 2015 2014 Deferred cost of revenue, beginning of period $ 333,030 $ 276,123 Costs deferred related to revenue deferred in the period 91,044 123,001 Cost of revenue recognized in the period (188,324 ) (66,094 ) Deferred cost of revenue, end of period $ 235,750 $ 333,030
Components of Inventory	Inventory consisted of the following (in thousands): December 31, 2015 2014 Component parts $ 1,201 $ 2,843 Finished goods 3,344 3,879 Inventory $ 4,545 $ 6,722
Schedule of Property and Equipment	Property and equipment, net, consisted of the following (in thousands): December 31, 2015 2014 Computer and network equipment $ 16,568 $ 14,708 Software 13,719 13,460 Machinery and equipment 15,141 10,538 Furniture and fixtures 1,543 1,335 Leasehold improvements 2,915 2,565 Total property and equipment 49,886 42,606 Less: Accumulated depreciation and amortization (35,780 ) (29,746 ) Property and equipment, net $ 14,106 $ 12,860
Schedule of Accrued and Other Liabilities	Accrued and other liabilities consisted of the following (in thousands): December 31, 2015 2014 Accrued payroll and related expenses $ 14,249 $ 8,912 Accrued operating expenses 5,937 2,548 Warranty obligations, current 8,601 3,838 Sales, property and income taxes 4,850 1,996 Current portion of capital lease obligation 285 1,163 Other deferred revenue 8,326 4,955 Other 503 1,009 Accrued and other liabilities $ 42,751 $ 24,421
Schedule of Other Liabilities	Other liabilities consisted of the following (in thousands): December 31, 2015 2014 Warranty obligations, non-current $ 2,898 $ 3,397 Other deferred revenue 11,099 9,816 Deferred rent long term 944 1,368 Other 1,462 493 Other liabilities $ 16,403 $ 15,074
Schedule of Product Warranty Obligation	Product warranty obligation is presented as follows on the consolidated balance sheets (in thousands): December 31, 2015 2014 Warranty obligation, current - classified in accrued and other liabilities $ 8,601 $ 3,838 Warranty obligation, non-current - classified in other liabilities 2,898 3,397 $ 11,499 $ 7,235
Schedule of Product Warranty Activity	Product warranty activity is as follows (in thousands): Year Ended December 31, 2015 2014 2013 Warranty obligation—beginning of period $ 7,235 $ 6,089 $ 6,316 Warranty expense for new warranties issued 450 669 1,406 Utilization of warranty obligation (2,131 ) (2,562 ) (1,767 ) Changes in estimates for pre-existing warranties 5,945 3,039 134 Warranty obligation—end of period $ 11,499 $ 7,235 $ 6,089
Accumulated Other Comprehensive (Loss) Income	The components of accumulated other comprehensive (loss) income, net of tax, were as follows (in thousands): Unrealized Gains Foreign Currency (Losses) on Available Adjustment for Sale Securities Total Balance as of December 31, 2013 $ 46 $ 84 $ 130 Other comprehensive (loss) income before reclassification (770 ) (11 ) (781 ) Amounts reclassified from AOCI — (128 ) (128 ) Other comprehensive (loss) income (770 ) (139 ) (909 ) Balance as of December 31, 2014 $ (724 ) $ (55 ) $ (779 ) Other comprehensive (loss) income before reclassification (837 ) (110 ) (947 ) Amounts reclassified from AOCI — (46 ) (46 ) Other comprehensive (loss) income (837 ) (156 ) (993 ) Balance as of December 31, 2015 $ (1,561 ) $ (211 ) $ (1,772 )

Restructuring (Tables)

Restructuring (Tables)	12 Months Ended
	Dec. 31, 2015
Restructuring And Related Activities [Abstract]
Accrued Liabilities Related to Restructuring Actions	Accrued liabilities related to restructuring actions are as following (in thousands): Severance Costs Professional fees Total December 31, 2013 Additions $ 1,888 $ — $ 1,888 Utilizations (1,653 ) — (1,653 ) December 31, 2014 (1) $ 235 $ — $ 235 Additions $ 1,213 $ 458 $ 1,671 Utilizations (1,387 ) (458 ) (1,845 ) December 31, 2015 (1) $ 61 $ — $ 61 (1)

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Commitments Under Operating and Capital Leases	As of December 31, 2015, the future minimum commitments under our operating and capital leases were as follows (in thousands): Operating Capital Leases Leases 2016 $ 3,928 $ 112 2017 4,687 — 2018 5,750 — 2019 6,351 — 2020 6,364 — 2021 and thereafter 39,997 — Net minimum lease payments $ 67,077 $ 112 Less amount representing interest (4 ) Present value of net minimum capital lease payments $ 108

Selected Quarterly Financial 39

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Schedule Of Quarterly Statements Of Operations Data	Three Months Ended December 31, September 30, June 30, March 31, December 31, September 30, June 30, March 31, 2015 2015 2015 2015 2014 2014 2014 2014 Revenue, net $ 199,247 $ 69,505 $ 77,167 $ 143,640 $ 77,411 $ 28,041 $ 41,607 $ 44,229 Cost of revenue 97,902 36,518 57,211 72,185 47,233 26,738 28,195 32,785 Gross profit 101,345 32,987 19,956 71,455 30,178 1,303 13,412 11,444 Operating expenses 35,600 33,381 36,495 37,314 28,786 38,723 38,084 38,615 Operating income (loss) 65,745 (394 ) (16,539 ) 34,141 1,392 (37,420 ) (24,672 ) (27,171 ) Other income (expense), net (159 ) (99 ) 74 288 68 7 85 (37 ) Income (loss) before income taxes 65,586 (493 ) (16,465 ) 34,429 1,460 (37,413 ) (24,587 ) (27,208 ) Provision (benefit) for income taxes 3,708 129 (290 ) (476 ) 959 (140 ) 4 599 Net income (loss) $ 61,878 $ (622 ) $ (16,175 ) $ 34,905 $ 501 $ (37,273 ) $ (24,591 ) $ (27,807 ) Net income (loss) per share Basic $ 1.23 $ (0.01 ) $ (0.32 ) $ 0.71 $ 0.01 $ (0.77 ) $ (0.51 ) $ (0.58 ) Diluted $ 1.19 $ (0.01 ) $ (0.32 ) $ 0.69 $ 0.01 $ (0.77 ) $ (0.51 ) $ (0.58 ) Weighted compute net income (loss) per share Basic $ 50,481 $ 50,188 $ 49,862 $ 49,306 $ 48,929 $ 48,551 $ 48,315 $ 47,693 Diluted $ 52,167 $ 50,188 $ 49,862 $ 50,899 $ 50,191 $ 48,551 $ 48,315 $ 47,693

Description of Business and S40

Description of Business and Summary of Significant Accounting Policies (Narrative) (Detail)	3 Months Ended								12 Months Ended
	Dec. 31, 2015USD ($)$ / shares	Sep. 30, 2015USD ($)$ / shares	Jun. 30, 2015USD ($)$ / shares	Mar. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)$ / shares	Sep. 30, 2014USD ($)$ / shares	Jun. 30, 2014USD ($)$ / shares	Mar. 31, 2014USD ($)$ / shares	Dec. 31, 2015USD ($)segment$ / shares	Dec. 31, 2014USD ($)$ / shares	Dec. 31, 2013USD ($)$ / shares
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue	$ 199,247,000	$ 69,505,000	$ 77,167,000	$ 143,640,000	$ 77,411,000	$ 28,041,000	$ 41,607,000	$ 44,229,000	$ 489,559,000	$ 191,288,000	$ 326,858,000
Cost of revenue	97,902,000	36,518,000	57,211,000	72,185,000	47,233,000	26,738,000	28,195,000	32,785,000	263,816,000	134,951,000	211,504,000
Net income (loss)	$ 61,878,000	$ (622,000)	$ (16,175,000)	$ 34,905,000	$ 501,000	$ (37,273,000)	$ (24,591,000)	$ (27,807,000)	$ 79,986,000	$ (89,170,000)	$ (66,807,000)
Basic net (loss) income per share | $ / shares	$ 1.23	$ (0.01)	$ (0.32)	$ 0.71	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)	$ 1.60	$ (1.84)	$ (4.54)
Diluted net (loss) income per share | $ / shares	$ 1.19	$ (0.01)	$ (0.32)	$ 0.69	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)	$ 1.55	$ (1.84)	$ (4.54)
Deferred revenue	$ 401,813,000				$ 609,593,000				$ 401,813,000	$ 609,593,000	$ 524,653,000
Deferred revenue, current	305,471,000				91,688,000				305,471,000	91,688,000
Deferred revenue, non-current	96,342,000				517,905,000				$ 96,342,000	517,905,000
Extended product warranty period									15 years
Advertising costs									$ 1,900,000	2,200,000	2,200,000
Long-lived assets impairment charges									$ 0	0	0
Number of reportable segments | segment									1
Impairment losses									$ 0	0	0
Realized excess tax benefit									$ 153,000	100,000	$ 0
Minimum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Standard warranty period									1 year
Maximum [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Standard warranty period									5 years
Contingency Provisions [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Deferred revenue	32,100,000				26,200,000				$ 32,100,000	26,200,000
Deferred revenue, current	1,200,000				4,600,000				1,200,000	4,600,000
Deferred revenue, non-current	$ 30,900,000				$ 21,600,000				30,900,000	$ 21,600,000
Customer-Specific Acceptance Criteria [Member]
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue									139,400,000
Cost of revenue									55,900,000
Net income (loss)									$ 83,500,000
Basic net (loss) income per share | $ / shares									$ 1.67
Diluted net (loss) income per share | $ / shares									$ 1.62

Description of Business and S41

Description of Business and Summary of Significant Accounting Policies (Schedule of Percentage of Revenue Related to Customers' Deployments) (Detail) - Revenue [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
ComEd [Member]
Concentration Risk [Line Items]
Percentage of revenue	31.00%
PHI [Member]
Concentration Risk [Line Items]
Percentage of revenue	27.00%
CHED [Member]
Concentration Risk [Line Items]
Percentage of revenue		21.00%
Progress [Member]
Concentration Risk [Line Items]
Percentage of revenue		13.00%
PG&E [Member]
Concentration Risk [Line Items]
Percentage of revenue			39.00%
FPL [Member]
Concentration Risk [Line Items]
Percentage of revenue			20.00%

Description of Business and S42

Description of Business and Summary of Significant Accounting Policies (Schedule of Percentage of Accounts Receivable from Customers and Third Party) (Detail) - Accounts Receivable [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
AusNet [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable	17.00%
FPL [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable	15.00%
CPS [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable	11.00%	11.00%
ComEd [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable	11.00%	19.00%
PG&E [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable	10.00%
Dominion [Member]
Concentration Risk [Line Items]
Percentage of accounts receivable		13.00%

Description of Business and S43

Description of Business and Summary of Significant Accounting Policies (Property and Equipment Estimated Useful Lives) (Detail)	12 Months Ended
	Dec. 31, 2015
Software [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	3 years
Software [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	7 years
Computer and network equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	2 years
Computer and network equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	5 years
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	3 years
Furniture and fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	3 years
Furniture and fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	7 years
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment description of estimated useful lives	Lesser of the lease term or the estimated useful lives of the improvements, generally 1 to 10 years
Leasehold improvements [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	1 year
Leasehold improvements [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment estimated useful lives	10 years

Net Loss Per Share (Narrative)

Net Loss Per Share (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2013
Earnings Per Share [Abstract]
Deemed dividend to Series E preferred stock	$ 105,000	$ 105,000

Net Loss Per Share (Computation

Net Loss Per Share (Computation of Basic and Diluted Net Loss Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net income (loss)	$ 61,878	$ (622)	$ (16,175)	$ 34,905	$ 501	$ (37,273)	$ (24,591)	$ (27,807)		$ 79,986	$ (89,170)	$ (66,807)
Deemed dividend to convertible preferred stockholders									$ (105,000)			(105,000)
Net income (loss) attributable to common stockholders										$ 79,986	$ (89,170)	$ (171,807)
Net income (loss) per share attributable to common stockholders
Basic	$ 1.23	$ (0.01)	$ (0.32)	$ 0.71	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)		$ 1.60	$ (1.84)	$ (4.54)
Diluted	$ 1.19	$ (0.01)	$ (0.32)	$ 0.69	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)		$ 1.55	$ (1.84)	$ (4.54)
Weighted average shares used to compute net income (loss) per share attributable to common stockholders
Basic	50,481	50,188	49,862	49,306	48,929	48,551	48,315	47,693		49,963	48,377	37,877
Diluted	52,167	50,188	49,862	50,899	50,191	48,551	48,315	47,693		51,524	48,377	37,877

Net Loss Per Share (Common Shar

Net Loss Per Share (Common Shares Outstanding were Excluded from Computation of Diluted Net Loss Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee equity awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total common stock equivalents	3,572	6,922	7,760

Cash, Cash Equivalents, and S47

Cash, Cash Equivalents, and Short-Term Investments (Cash, Cash Equivalents, and Short-Term Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Available For Sale Securities [Line Items]
Cash, amortized cost and estimated fair value	$ 59,263	$ 54,239
Cash and cash equivalents	65,264	60,457	$ 82,596	$ 72,646
Total short-term investments, unrealized gains	6	55
Total short-term investments, unrealized losses	(166)	(59)
Total cash, cash equivalents and short-term investments, amortized cost	124,605	120,800
Total cash, cash equivalents and short-term investments, estimated fair value	124,445	120,796
U.S. Government And Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, estimated fair value	38,290	38,746
U.S. And Foreign Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, estimated fair value	18,895	19,601
Foreign Governments And Multi-National Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, estimated fair value	1,996	1,992
Short-Term Fixed Income Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, amortized cost	59,341	60,343
Total short-term investments, unrealized gains	6	55
Total short-term investments, unrealized losses	(166)	(59)
Total short-term investments, estimated fair value	59,181	60,339
Short-Term Fixed Income Securities [Member] | U.S. Government And Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, amortized cost	38,396	38,718
Total short-term investments, unrealized gains	4	46
Total short-term investments, unrealized losses	(110)	(18)
Total short-term investments, estimated fair value	38,290	38,746
Short-Term Fixed Income Securities [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, amortized cost	18,945	19,625
Total short-term investments, unrealized gains	2	9
Total short-term investments, unrealized losses	(52)	(33)
Total short-term investments, estimated fair value	18,895	19,601
Short-Term Fixed Income Securities [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Total short-term investments, amortized cost	2,000	2,000
Total short-term investments, unrealized losses	(4)	(8)
Total short-term investments, estimated fair value	1,996	1,992
Money market mutual funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Cash and cash equivalents	$ 6,001	$ 6,218

Cash, Cash Equivalents, and S48

Cash, Cash Equivalents, and Short-Term Investments (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015USD ($)FinancialInstitution	Dec. 31, 2014USD ($)FinancialInstitution
Cash and Cash Equivalents [Line Items]
Number of financial institutions | FinancialInstitution	2	2
Investments with unrealized losses for a period in excess of 12 months	$ 0	$ 0
Other-than-temporary impairments	$ 0	$ 0
Financial Institution One [Member]
Cash and Cash Equivalents [Line Items]
Percentage of cash, cash equivalents, and short-term investments held in financial institutions	84.00%	46.00%
Financial Institution Two [Member]
Cash and Cash Equivalents [Line Items]
Percentage of cash, cash equivalents, and short-term investments held in financial institutions	11.00%	42.00%

Cash, Cash Equivalents, and S49

Cash, Cash Equivalents, and Short-Term Investments (Contractual Maturities of Cash Equivalents and Short-Term Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash, Cash Equivalents, and Short-term Investments [Abstract]
Due within one year, Amortized Cost Basis	$ 25,183	$ 20,588
Due from 1 year through 3 years, Amortized Cost Basis	40,159	45,973
Total cash equivalents & short-term investments, Amortized Cost Basis	65,342	66,561
Due within one year, Aggregate Fair Value	25,163	20,599
Due from 1 year through 3 years, Aggregate Fair Value	40,019	45,958
Total cash equivalents & short-term investments, Aggregate Fair Value	$ 65,182	$ 66,557

Cash, Cash Equivalents, and S50

Cash, Cash Equivalents, and Short-Term Investments (Schedule of Gross Unrealized Losses and Fair Values of Investments) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	$ 49,682	$ 30,078
Unrealized Loss Total (Less Than 12 Months)	(166)	(59)
U.S. And Foreign Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	15,894	14,563
Unrealized Loss Total (Less Than 12 Months)	(52)	(33)
Foreign Governments And Multi-National Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	1,996	1,992
Unrealized Loss Total (Less Than 12 Months)	(4)	(8)
U.S. Government And Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	31,792	13,523
Unrealized Loss Total (Less Than 12 Months)	$ (110)	$ (18)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	$ 65,182	$ 66,557
Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	6,001	6,218
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	59,181	60,339
U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	38,290	38,746
U.S. Government And Agency Obligations [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	38,290	38,746
U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	18,895	19,601
U.S. And Foreign Corporate Debt Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	18,895	19,601
Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	1,996	1,992
Foreign Governments And Multi-National Agency Obligations [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	1,996	1,992
Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	6,001	6,218
Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	6,001	6,218
Cash Equivalents [Member] | Money market mutual funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	6,001	6,218
Cash Equivalents [Member] | Money market mutual funds [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total cash equivalents	6,001	6,218
Short-Term Fixed Income Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	59,181	60,339
Short-Term Fixed Income Securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	59,181	60,339
Short-Term Fixed Income Securities [Member] | U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	38,290	38,746
Short-Term Fixed Income Securities [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	18,895	19,601
Short-Term Fixed Income Securities [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total short-term investments, estimated fair value	$ 1,996	$ 1,992

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value of Financial Assets Recorded on Recurring Basis) (Narrative) (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial liabilities recorded at fair value on recurring basis	$ 0	$ 0
Financial assets recorded at fair value on nonrecurring basis	0	0
Financial liabilities recorded at fair value on nonrecurring basis	$ 0	$ 0

Business Acquisitions (Narrativ

Business Acquisitions (Narrative) (Details) - USD ($) $ in Thousands	Jan. 16, 2015	May. 23, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill measurement period adjustment			$ (295)	$ 85
Reversal of valuation allowance			(43,638)	18,181	$ 1,097
Goodwill			$ 8,772	$ 4,729	$ 447
Minimum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life			2 years
Maximum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life			7 years
Detectent Inc. [Member]
Business Acquisition [Line Items]
Total consideration	$ 11,600
Cash consideration	7,616
Contingent payments	4,000
Retention period			2 years
Compensation expense			$ 1,900
Goodwill measurement period adjustment			(300)
Decrease in other tangible liabilities			(500)
Deferred tax liabilities and other fair value adjustment			200
Deferred tax liabilities			1,100
Reversal of valuation allowance			(1,100)
Acquisition-related costs			2,600
Revenues			$ 1,500
Subsidiary revenue of the total revenue			0.30%
Goodwill	$ 4,452
Detectent Inc. [Member] | Research and Development [Member]
Business Acquisition [Line Items]
Acquisition-related costs			$ 500
Detectent Inc. [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Acquisition-related costs			$ 1,900
Detectent Inc. [Member] | Order Backlog [Member]
Business Acquisition [Line Items]
Discount rate	18.60%
Detectent Inc. [Member] | Order Backlog [Member]
Business Acquisition [Line Items]
Discount rate	18.10%
Detectent Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Discount rate	20.10%
Detectent Inc. [Member] | Non-Compete Agreements [Member]
Business Acquisition [Line Items]
Discount rate	20.10%
Detectent Inc. [Member] | Minimum [Member]
Business Acquisition [Line Items]
Intangible assets, useful life			1 year
Detectent Inc. [Member] | Maximum [Member]
Business Acquisition [Line Items]
Intangible assets, useful life			5 years
Streetlight Vision [Member]
Business Acquisition [Line Items]
Cash consideration		$ 8,800
Purchase agreements percent of shares acquired		100.00%
Decrease in net assets acquired		$ (100)
Goodwill		$ 4,700
Intangible assets			$ 4,300
Accrued and Other Liabilities [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Compensation expense			1,000
Other Liabilities [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Compensation expense			$ 900

Business Acquisitions (Schedule

Business Acquisitions (Schedule of Business Acquisition) (Details) - USD ($) $ in Thousands	Jan. 16, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 8,772	$ 4,729	$ 447
Detectent Inc. [Member]
Business Acquisition [Line Items]
Cash consideration	$ 7,616
Less: Fair value of net identifiable assets acquired	(3,164)
Goodwill	$ 4,452

Business Acquisitions (Assets A

Business Acquisitions (Assets Acquired and Liabilities Assumed) (Details) - Detectent Inc. [Member] $ in Thousands	Jan. 16, 2015USD ($)
Business Acquisition [Line Items]
Cash	$ 518
Net other tangible liabilities	(26)
Deferred tax liabilities in connection with acquired intangible assets and other fair value adjustments, net	(1,128)
Total fair value of net identifiable assets acquired	3,164
Order Backlog [Member]
Business Acquisition [Line Items]
Intangible assets subject to amortization	1,900
Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets subject to amortization	1,500
Non-Compete Agreements [Member]
Business Acquisition [Line Items]
Intangible assets subject to amortization	100
Order Backlog [Member]
Business Acquisition [Line Items]
Intangible assets subject to amortization	$ 300

Goodwill and Intangible Asset56

Goodwill and Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill And Intangible Assets Disclosure [Abstract]
Balance, beginning of period	$ 4,729	$ 447
Goodwill acquired during the period	4,792	4,685
Goodwill measurement period adjustment	(295)	85
Currency translation adjustment	(454)	(488)
Balance, end of period	$ 8,772	$ 4,729

Goodwill and Intangible Asset57

Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill measurement period adjustment		$ (295)	$ 85
Detectent Inc. [Member]
Business Acquisition [Line Items]
Goodwill measurement period adjustment		(300)
Intangible assets acquired		$ 3,800
Purchased Technology
Business Acquisition [Line Items]
Intangible assets acquired	$ 300

Goodwill And Intangible Asset58

Goodwill And Intangible Assets (Schedule Of Intangible Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Intangible Assets [Line Items]
Purchased intangible assets with finite lives, Accumulated Amortization	$ 3,256	$ 1,582
Purchased intangible assets with finite lives, Net Book Value	5,618
Intangible assets, Gross Carrying Amount	8,874	5,074
Intangible assets, Net Book Value	5,618	3,492
In-Process Research And Development [Member]
Schedule Of Intangible Assets [Line Items]
Indefinite-lived intangible assets		269
Purchased Technology [Member]
Schedule Of Intangible Assets [Line Items]
Purchased intangible assets with finite lives, Gross Carrying Amount	4,865	2,396
Purchased intangible assets with finite lives, Accumulated Amortization	2,180	1,139
Purchased intangible assets with finite lives, Net Book Value	$ 2,685	1,257
Purchased Technology [Member] | Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Useful Lives (in years)	4 years
Purchased Technology [Member] | Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Useful Lives (in years)	5 years
Customer Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Purchased intangible assets with finite lives, Gross Carrying Amount	$ 3,640	2,140
Purchased intangible assets with finite lives, Accumulated Amortization	973	417
Purchased intangible assets with finite lives, Net Book Value	$ 2,667	1,723
Customer Relationships [Member] | Minimum [Member]
Schedule Of Intangible Assets [Line Items]
Useful Lives (in years)	2 years
Customer Relationships [Member] | Maximum [Member]
Schedule Of Intangible Assets [Line Items]
Useful Lives (in years)	7 years
Trade Name [Member]
Schedule Of Intangible Assets [Line Items]
Useful Lives (in years)	6 years
Purchased intangible assets with finite lives, Gross Carrying Amount	$ 369	269
Purchased intangible assets with finite lives, Accumulated Amortization	103	26
Purchased intangible assets with finite lives, Net Book Value	$ 266	$ 243

Goodwill and Intangible Asset59

Goodwill and Intangible Assets (Schedule of Amortization Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 1,674	$ 614	$ 192
Total Cost Of Revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	1,041	417	$ 192
Sales And Marketing [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	601	$ 197
General and Administrative [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 32

Goodwill and Intangible Asset60

Goodwill and Intangible Assets (Schedule of Estimated Future Amortization Expense) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,016	$ 1,464
2,017	1,452
2,018	1,212
2,019	1,061
2,020	317
2021 and thereafter	112
Purchased intangible assets with finite lives, Net Book Value	$ 5,618

Convertible Preferred Stock a61

Convertible Preferred Stock and Preferred Stock Warrants (Narrative) (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2013	Dec. 31, 2013
Subsidiary, Sale of Stock [Line Items]
Deemed dividend		$ 105,000	$ 105,000
Payment upon termination of preferred stock warrants of a related party	$ 12,000		12,000
Loss due to reduction of preferred stock warrant liability	800		800
Reduction in preferred stock warranty			11,200
Proceeds from private placement of common stock with a related party	$ 12,000		$ 12,000
Private placement [Member]
Subsidiary, Sale of Stock [Line Items]
Common stock shares issued	705,881		705,881
Price per share issued at IPO	$ 17	$ 17	$ 17
Foundation Capital [Member]
Subsidiary, Sale of Stock [Line Items]
Affiliates ownership on common stock	32.70%	32.70%
Convertible Preferred Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Outstanding convertible securities converted into common stock	32,406,995
Series D preferred stock [Member]
Subsidiary, Sale of Stock [Line Items]
Conversion price for preferred stockholders, per share			38.927
Series E Preferred Stock
Subsidiary, Sale of Stock [Line Items]
Conversion price for preferred stockholders, per share			$ 50
Deemed dividend	$ 105,000		$ (105,000)
Series A Preferred Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Warrants held to purchase preferred stock shares	41,993	41,993
Series C Preferred Stock [Member]
Subsidiary, Sale of Stock [Line Items]
Warrants held to purchase preferred stock shares	333,333	333,333

Common Stock (Narrative) (Detai

Common Stock (Narrative) (Details) - USD ($)	Jul. 28, 2015	Mar. 31, 2013	Mar. 18, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Mar. 12, 2013
Common Stock [Line Items]
Proceeds from initial public offering, net of offering costs		$ 84,247,000				$ 84,247,000
Proceeds from private placement of common stock with a related party		12,000,000				12,000,000
Reduction in preferred stock warranty						11,200,000
Loss due to reduction of preferred stock warrant liability		800,000				800,000
Payments for termination of preferred stock warrants		12,000,000
Stock-based compensation expense				$ 26,479,000	$ 33,861,000	52,504,000
Common stock, shares authorized				1,000,000,000	1,000,000,000		1,000,000,000
Preferred stock, shares authorized							10,000,000
Stock options [Member]
Common Stock [Line Items]
Stock-based compensation expense						4,700,000
Restricted stock units [Member]
Common Stock [Line Items]
Fair value of performance stock awards				$ 16,500,000	$ 17,300,000	19,500,000
Performance Stock Awards [Member]
Common Stock [Line Items]
Consecutive trading period				45 days
Requisite service period				3 years
Fair value of performance stock awards				$ 6,800,000
2010 Corporate Bonus Incentive Plan And 2011 Corporate Bonus Incentive Plan [Member]
Common Stock [Line Items]
Stock-based compensation expense						14,600,000
2012 Equity Incentive Plan [Member]
Common Stock [Line Items]
Common stock shares reserved for issuance							3,400,000
Shares available for grant increase percent				4.00%
Increase in shares reserved for issuance					1,962,491
2012 Equity Incentive Plan [Member] | Stock options [Member]
Common Stock [Line Items]
Contractual term				10 years
Vesting period				4 years
2012 Equity Incentive Plan [Member] | Stock options [Member] | Principal Owner [Member]
Common Stock [Line Items]
Percent of voting power				10.00%
Purchase price of the stock as a percent of price of common stock				110.00%
Contractual term				5 years
2012 Equity Incentive Plan [Member] | Restricted stock units [Member] | Minimum [Member]
Common Stock [Line Items]
Vesting period				2 years
2012 Equity Incentive Plan [Member] | Restricted stock units [Member] | Maximum [Member]
Common Stock [Line Items]
Vesting period				4 years
2012 Equity Incentive Plan [Member] | Performance Stock Units [Member]
Common Stock [Line Items]
Vesting period				3 years
2012 Employee Stock Purchase Plan [Member]
Common Stock [Line Items]
Common stock shares reserved for issuance				4,900,000	4,300,000		400,000
Purchase price of the stock as a percent of price of common stock				85.00%
Increase in shares reserved for issuance					490,622
Number of shares to be increased as percent of total number of shares outstanding				1.00%
Maximum employees contribution				15.00%
Offering period				6 months
Inducement Grants [Member]
Common Stock [Line Items]
Consecutive trading period	45 days
Inducement Grants [Member] | One-Year Anniversary [Member]
Common Stock [Line Items]
Common stock on the date of grant and vest	25.00%
Inducement Grants [Member] | Restricted stock units [Member]
Common Stock [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	250,000
Inducement Grants [Member] | Performance Stock Units [Member]
Common Stock [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	125,000
Inducement Grants [Member] | Inducement Awards [Member]
Common Stock [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	125,000
Subordinated convertible notes [Member]
Common Stock [Line Items]
Interest payable		$ 2,300,000
Shares issued upon conversion of notes		3,764,954
Loss on debt extinguishments						22,900,000
Subordinated convertible notes [Member] | February 2012 Note [Member]
Common Stock [Line Items]
Convertible promissory note		$ 24,000,000
Subordinated convertible notes [Member] | December 2011 Note [Member]
Common Stock [Line Items]
Convertible promissory note		$ 30,000,000
Convertible Preferred Stock [Member]
Common Stock [Line Items]
Outstanding convertible securities converted into common stock		32,406,995
Initial Public Offering [Member]
Common Stock [Line Items]
Issuance of common stock, shares		5,462,500
Share Price		$ 17
Underwriting discounts and commissions						6,500,000
Offering costs		$ 2,200,000
Offering expenses						4,200,000
Initial Public Offering [Member] | Subordinated convertible notes [Member]
Common Stock [Line Items]
Share Price			$ 17
Interest payable			$ 2,300,000
Shares issued upon conversion of notes			3,764,954
Loss on debt extinguishments						$ 22,900,000
Private Placement [Member]
Common Stock [Line Items]
Issuance of common stock, shares		705,881				705,881
Share Price		$ 17				$ 17

Common Stock (Common Stock Warr

Common Stock (Common Stock Warrants Narrative) (Details) - $ / shares	Dec. 31, 2013	Dec. 31, 2015	Mar. 31, 2011
Common Stock [Line Items]
Preferred stock warrants converted to common stock warrants	20,768
Warrant [Member]
Common Stock [Line Items]
Warrants held to purchase preferred stock shares			50,000
Exercise price of common stock warrant	$ 13.91		$ 0.005
Warrant expires on exercisable and non-forfeitable		Mar. 31, 2016
Issuance of common stock upon net exercise of common stock warrants (in shares)	57,370

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 26,479	$ 33,861	$ 52,504
Total cost of revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	6,135	7,610	12,275
Research And Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	8,060	9,677	17,333
Sales And Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	4,104	6,062	7,060
General And Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 8,180	$ 10,512	$ 15,836

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 26,479	$ 33,861	$ 52,504
Cash received from the exercise of stock options	600	1,100	2,900
Intrinsic value of stock options exercised	2,100	3,600	9,500
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of performance stock awards	16,500	17,300	19,500
Corporate Bonus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	5,600	1,900	$ 1,600
Corporate bonus incentive plan liabilities	$ 5,800	$ 1,900

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Beginning balance	4,525	4,726	4,616
Number of Shares, Options granted	669	732	1,168
Number of Shares, Options exercised	(234)	(378)	(631)
Number of Shares, Options cancelled or expired	(528)	(555)	(427)
Number of Shares, Ending balance	4,432	4,525	4,726
Number of Shares, Options vested and expected to vest	4,398
Number of Shares, Options exercisable	3,223
Weighted Average Exercise Price per Share, Beginning balance	$ 12.38	$ 11.88	$ 21.73
Weighted Average Exercise Price per Share, Options granted	10.36	14.67	18.36
Weighted Average Exercise Price per Share, Options exercised	2.38	2.94	4.74
Weighted Average Exercise Price per Share, Options cancelled or expired	17.52	17.57	27.52
Weighted Average Exercise Price per Share, Ending balance	11.99	$ 12.38	$ 11.88
Weighted Average Exercise Price per Share, Options vested and expected to vest	11.98
Weighted Average Exercise Price per Share, Options exercisable	$ 11.67
Weighted Average Remaining Contractual Term (years), Ending balance	5 years 4 months 10 days	5 years 8 months 1 day	6 years 5 months 5 days
Weighted Average Remaining Contractual Term (years), Options vested and expected to vest	5 years 3 months 29 days
Weighted Average Remaining Contractual Term (years), Options exercisable	4 years 26 days
Aggregate Intrinsic Value, Ending balance	$ 17,290	$ 8,699	$ 43
Aggregate Intrinsic Value, Options vested and expected to vest	17,225
Aggregate Intrinsic Value, Option exercisable	$ 14,470

Stock-Based Compensation (Sum67

Stock-Based Compensation (Summary of Restricted Stock Units Activity) (Details) - Restricted stock units [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares, Beginning balance	2,198	2,757	231
Number of Shares, Restricted stock units granted	1,713	1,218	3,662
Number of Shares, Restricted stock units vested	(1,407)	(1,280)	(1,020)
Number of Shares, Restricted stock units cancelled	(413)	(497)	(116)
Number of Shares, Ending balance	3,086	2,198	2,757
Number of Shares, Performance restricted stock units granted	995
Weighted Average Grant Date Fair Value per Share, Beginning balance	$ 15.06	$ 19.14	$ 449.51
Weighted Average Grant Date Fair Value per Share, Restricted stock units granted	12.67	10.72	48.41
Weighted Average Grant Date Fair Value per Share, Restricted stock units vested	15.32	18.77	23.36
Weighted Average Grant Date Fair Value per Share, Restricted stock units cancelled	14	17.50	49.69
Weighted Average Grant Date Fair Value per Share, Ending balance	11.11	$ 15.06	$ 19.14
Weighted Average Grant Date Fair Value per Share, Performance restricted stock units granted	$ 6.85
Weighted Average Remaining Contractual Term (years), Ending balance	1 year 8 months 23 days	1 year 29 days	1 year 2 months 5 days
Aggregate Intrinsic Value, Ending balance	$ 44,473	$ 18,532	$ 57,951

Stock-Based Compensation (Sum68

Stock-Based Compensation (Summary of Assumptions Relating to Stock Options, ESPP And Market-Based PSU) (Details) - $ / shares		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	[1]	59.00%	43.00%	47.00%
Expected volatility, maximum	[1]	66.00%	47.00%	52.00%
Expected life in years	[1]		6 years 29 days
Risk-free interest rate, minimum	[1]	1.54%	1.81%	0.87%
Risk-free interest rate, maximum	[1]	1.78%	1.98%	1.96%
Weighted average grant date fair value per share	[1]	$ 5.82	$ 6.60
Performance Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	[2]	60.00%
Expected volatility, maximum	[2]	65.00%
Risk-free interest rate, minimum	[2]	1.02%
Risk-free interest rate, maximum	[2]	1.22%
Weighted average grant date fair value per share	[2]	$ 6.85
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility, minimum	[1]	33.00%	33.00%
Expected volatility, maximum	[1]	62.00%	36.00%
Risk-free interest rate, minimum	[1]	0.05%	0.05%
Risk-free interest rate, maximum	[1]	0.24%	0.08%
Expected volatility	[1]			52.00%
Risk-free interest rate	[1]			0.87%
Minimum [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	[1]	5 years 10 months 6 days		5 years
Maximum [Member] | Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	[1]	6 years 29 days		6 years 29 days
Maximum [Member] | ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life in years	[1]	1 year	1 year	1 year
[1]	The Black-Scholes-Merton option-pricing model is utilized to estimate the fair value of stock options and ESPP.
[2]	The fair value market-based PSUs utilize the Monte Carlo simulation option pricing model. The Company amortizes the fair value of these awards over the derived service period. Provided that the derived service is rendered, the total fair value of the market-based PSUs at the date of grant is recognized as compensation expense even if the market condition is not achieved. However, the number of shares that ultimately vest can vary significantly with the performance of the specified market criteria.

Stock-Based Compensation - Unre

Stock-Based Compensation - Unrecognized Compensation Cost, Recognized over a Weighted Average Period (Details) $ in Millions	12 Months Ended
	Dec. 31, 2015USD ($)
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 6.9
Weighted Average Period	2 years 7 months 6 days
ESPP, RSUs, and PSUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs	$ 24.9
Weighted Average Period	2 years 7 months 6 days

Income Taxes (Schedule Of Compo

Income Taxes (Schedule Of Components of Income (Loss) Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
United States									$ 116,530	$ (57,125)	$ (28,774)
Foreign									(33,473)	(30,623)	(37,809)
Income (loss) before income taxes	$ 65,586	$ (493)	$ (16,465)	$ 34,429	$ 1,460	$ (37,413)	$ (24,587)	$ (27,208)	$ 83,057	$ (87,748)	$ (66,583)

Income Taxes (Schedule Of Provi

Income Taxes (Schedule Of Provision For Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
State, Current									$ 4,488	$ 1,191	$ (115)
Foreign, Current									192	613	452
Total current provision for income taxes									4,680	1,804	337
United States federal, Deferred									(1,091)		(47)
State, Deferred									(37)		123
Foreign, Deferred									(481)	(382)	(189)
Total deferred provision (benefit) for income taxes									(1,609)	(382)	(113)
Provision for income taxes	$ 3,708	$ 129	$ (290)	$ (476)	$ 959	$ (140)	$ 4	$ 599	$ 3,071	$ 1,422	$ 224

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Line Items]
Federal statutory income tax rate	35.00%
Income tax benefits resulting from stock awards	$ 200	$ 100
Undistributed earnings of foreign subsidiaries	3,800
Gross unrecognized tax benefits	12,110	10,645	$ 8,715	$ 5,586
Unrecognized tax benefits that would reduce the effective income tax rate	$ 9,800	$ 8,700
Earliest Tax Year
Income Taxes [Line Items]
Open tax year	2,003
Latest Tax Year
Income Taxes [Line Items]
Open tax year	2,015
Long Term Liabilities [Member]
Income Taxes [Line Items]
Gross unrecognized tax benefits	$ 300
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 175,900
Net operating loss carryforwards expiration year	2,029
State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 276,800
Net operating loss carryforwards expiration year	2,016
Research Tax Credit [Member] | Federal [Member]
Income Taxes [Line Items]
Research tax credit carryforwards	$ 10,400
Tax credit carryforwards expiration year	Dec. 31, 2023
Research Tax Credit [Member] | California [Member] | State [Member]
Income Taxes [Line Items]
Research tax credit carryforwards	$ 12,800

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Federal Statutory Income Tax Rate To Effective Income Tax Rate) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Federal statutory tax expense (benefit)									$ 29,070	$ (30,031)	$ (23,304)
Research tax credit									(548)	(574)	(884)
Effect of non-U.S. operations									11,331	10,754	13,320
Change in valuation allowance									(40,521)	18,166	(925)
Stock-based compensation expense									573	1,982	3,455
Loss on debt extinguishments											8,287
State taxes									2,937	792	8
Other									229	333	267
Provision for income taxes	$ 3,708	$ 129	$ (290)	$ (476)	$ 959	$ (140)	$ 4	$ 599	$ 3,071	$ 1,422	$ 224

Income Taxes (Schedule Of Com74

Income Taxes (Schedule Of Components Of Deferred Tax Assets and Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Net operating loss and tax credit carryforwards	$ 84,060	$ 129,471
Deferred revenue	119,440	159,523
Stock-based compensation expense	12,434	12,241
Accruals and reserves	12,551	7,452
Intangible assets	1,696	1,434
Other	333	355
Gross deferred tax assets	230,514	310,476
Valuation allowance	(142,635)	(186,273)	$ (168,092)	$ (166,995)
Deferred tax assets	87,879	124,203
Property and equipment, net	(1,552)	(1,612)
Deferred cost of revenue	(85,258)	(122,116)
Deferred tax liabilities	(86,810)	(123,728)
Net deferred tax assets	$ 1,069	$ 475

Income Taxes (Summary Of Deferr

Income Taxes (Summary Of Deferred Tax Assets Valuation Allowance) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Balance at Beginning of Period	$ 186,273	$ 168,092	$ 166,995
Reversal of valuation allowance	(43,638)	18,181	1,097
Balance at End of Period	$ 142,635	$ 186,273	$ 168,092

Income Taxes (Reconciliation 76

Income Taxes (Reconciliation of Beginning and Ending Amounts of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Unrecognized tax benefits—beginning of period	$ 10,645	$ 8,715	$ 5,586
Gross increase for tax positions of prior years	85	165	1,216
Gross decrease for tax positions of prior years	(34)	(13)
Gross increase for tax positions of current year	1,414	1,778	1,913
Unrecognized tax benefits balance—end of period	$ 12,110	$ 10,645	$ 8,715

Segment Information (Narrative)

Segment Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2015segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Total revenue, net	$ 199,247	$ 69,505	$ 77,167	$ 143,640	$ 77,411	$ 28,041	$ 41,607	$ 44,229	$ 489,559	$ 191,288	$ 326,858
United States [Member]
Revenue:
Total revenue, net									425,951	101,579	285,430
Australia [Member]
Revenue:
Total revenue, net									45,247	62,745	40,939
All Other [Member]
Revenue:
Total revenue, net									$ 18,361	$ 26,964	$ 489

Balance Sheet Details (Schedule

Balance Sheet Details (Schedule Of Deferred Revenue) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Deferred revenue, beginning of period	$ 609,593	$ 524,653
Revenue deferred in the period	281,779	276,228
Revenue recognized in the period	(489,559)	(191,288)
Deferred revenue, end of period	$ 401,813	$ 609,593

Balance Sheet Details (Schedu80

Balance Sheet Details (Schedule Of Deferred Cost Of Revenue) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Deferred cost of revenue, beginning of period	$ 333,030	$ 276,123
Costs deferred related to revenue deferred in the period	91,044	123,001
Cost of revenue recognized in the period	(188,324)	(66,094)
Deferred cost of revenue, end of period	$ 235,750	$ 333,030

Balance Sheet Details (Schedu81

Balance Sheet Details (Schedule of Inventories) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Inventory Disclosure [Abstract]
Component parts	$ 1,201	$ 2,843
Finished goods	3,344	3,879
Inventory	$ 4,545	$ 6,722

Balance Sheet Details (Narrativ

Balance Sheet Details (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Balance Sheet Details [Line Items]
Depreciation and amortization expense	$ 6.1	$ 5.9	$ 6.5
Machinery and equipment [Member]
Balance Sheet Details [Line Items]
Assets held under capital leases	4.8	4.8
Accumulated amortization for assets held under capital leases	4.4	3.5
Software [Member]
Balance Sheet Details [Line Items]
Assets held under capital leases	3.5	3.5
Accumulated amortization for assets held under capital leases	3.3	2.9
Consigned inventory [Member]
Balance Sheet Details [Line Items]
Inventory	$ 2	$ 3

Balance Sheet Details (Schedu83

Balance Sheet Details (Schedule Of Property And Equipment) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Property and equipment	$ 49,886	$ 42,606
Less: Accumulated depreciation and amortization	(35,780)	(29,746)
Property and equipment, net	14,106	12,860
Computer and network equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	16,568	14,708
Software [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	13,719	13,460
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	15,141	10,538
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	1,543	1,335
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment	$ 2,915	$ 2,565

Balance Sheet Details (Schedu84

Balance Sheet Details (Schedule of Accrued and Other Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Accrued payroll and related expenses	$ 14,249	$ 8,912
Accrued operating expenses	5,937	2,548
Warranty obligations, current	8,601	3,838
Sales, property and income taxes	4,850	1,996
Current portion of capital lease obligation	285	1,163
Other deferred revenue	8,326	4,955
Other	503	1,009
Accrued and other liabilities	$ 42,751	$ 24,421

Balance Sheet Details (Schedu85

Balance Sheet Details (Schedule Of Other Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Other Liabilities Disclosure [Abstract]
Warranty obligations, non-current	$ 2,898	$ 3,397
Other deferred revenue	11,099	9,816
Deferred rent long term	944	1,368
Other	1,462	493
Other liabilities	$ 16,403	$ 15,074

Balance Sheet Details (Schedu86

Balance Sheet Details (Schedule of Product Warranty Obligation) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Product Warranties Disclosures [Abstract]
Warranty obligation, current - classified in accrued and other liabilities	$ 8,601	$ 3,838
Warranty obligation, non-current - classified in other liabilities	2,898	3,397
Warranty obligation	$ 11,499	$ 7,235	$ 6,089	$ 6,089	$ 6,316

Balance Sheet Details (Schedu87

Balance Sheet Details (Schedule of Product Warranty Activity) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2012
Product Warranties Disclosures [Abstract]
Warranty obligation—beginning of period	$ 7,235	$ 6,089	$ 6,316
Warranty expense for new warranties issued	450	669	1,406
Utilization of warranty obligation	(2,131)	(2,562)	(1,767)
Changes in estimates for pre-existing warranties	5,945	3,039	134
Warranty obligation—end of period	$ 11,499	$ 7,235	$ 6,089

Balance Sheet Details (Accumula

Balance Sheet Details (Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	$ (779)	$ 130
Other comprehensive (loss) income before reclassification	(947)	(781)
Amounts reclassified from AOCI	(46)	(128)
Other comprehensive (loss) income	(993)	(909)	$ 266
Ending balance	(1,772)	(779)	130
Foreign Currency Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(724)	46
Other comprehensive (loss) income before reclassification	(837)	(770)
Other comprehensive (loss) income	(837)	(770)
Ending balance	(1,561)	(724)	46
Unrealized Gains (Losses) On Available For Sale Securities [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning balance	(55)	84
Other comprehensive (loss) income before reclassification	(110)	(11)
Amounts reclassified from AOCI	(46)	(128)
Other comprehensive (loss) income	(156)	(139)
Ending balance	$ (211)	$ (55)	$ 84

Borrowings - (Narrative) (Detai

Borrowings - (Narrative) (Details) - USD ($)	1 Months Ended				12 Months Ended
	Mar. 31, 2013	Mar. 18, 2013	Feb. 28, 2012	Dec. 31, 2011	Dec. 31, 2015	Dec. 31, 2013	Dec. 18, 2015	Dec. 31, 2014	May. 08, 2013
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity									$ 50,000,000
Line of Credit Facility Termination Date					2015-12
Line of credit, outstanding borrowings					$ 0
Outstanding letters of credit					22,700,000			$ 17,000,000
Additional letters of credit					52,300,000
Initial Public Offering [Member]
Debt Instrument [Line Items]
Share Price	$ 17
EON Patent Litigation [Member]
Debt Instrument [Line Items]
Outstanding letters of credit					$ 13,000,000
Senior secured credit facility [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity							$ 75,000,000
Line of credit facility terms					The revolving loans and any swingline loans made pursuant to the Credit Facility bear interest at a rate per annum equal to (i) the higher of (a) the prime rate in effect on such day, and (b) the federal funds effective rate plus 0.5%, but in any case at a minimum rate of 0.0% per annum, plus (ii) 0.75%, and mature in December 2017.
Debt instrument interest rate, minimum					0.75%
Maturity date					Dec. 31, 2017
Senior secured credit facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate					0.00%
Senior secured credit facility [Member] | Letter of credit sub-facility [Member]
Debt Instrument [Line Items]
Line of credit facility current borrowing capacity							75,000,000
Senior secured credit facility [Member] | Swingline sub-facility [Member]
Debt Instrument [Line Items]
Line of credit facility current borrowing capacity							$ 5,000,000
Subordinated convertible notes [Member]
Debt Instrument [Line Items]
Debt instrument interest rate, minimum			3.00%	3.00%
Maturity date			Feb. 21, 2015	Dec. 6, 2014
Debt instrument, face amount			$ 30,000,000	$ 24,000,000
Percentage of increase in accrued interest			1.00%	1.00%
Percentage of accrued interest, maximum			6.00%	6.00%
Shares issued upon conversion of notes	3,764,954
Loss on debt extinguishments						$ 22,900,000
Interest payable	$ 2,300,000
Subordinated convertible notes [Member] | Initial Public Offering [Member]
Debt Instrument [Line Items]
Percentage of convertible stock		88.00%
Shares issued upon conversion of notes		3,764,954
Share Price		$ 17
Loss on debt extinguishments						$ 22,900,000
Interest payable		$ 2,300,000
Federal fund effective Rate [Member] | Senior secured credit facility [Member]
Debt Instrument [Line Items]
Debt instrument basis spread on variable rate					0.50%

Benefit Plans (Details)

Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2015USD ($)
Compensation And Retirement Disclosure [Abstract]
Discretionary profit sharing contributions	$ 0

Restructuring (Narrative) (Deta

Restructuring (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 1,671	$ 1,789
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	1,671	1,888
Severance Costs [Member] | 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 1,213	$ 1,888

Restructuring (Accrued Liabilit

Restructuring (Accrued Liabilities Related to Restructuring Actions) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Additions		$ 1,671	$ 1,789
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	[1]	235
Additions		1,671	1,888
Utilizations		(1,845)	(1,653)
Ending Balance	[1]	61	235
2014 Restructuring Plan [Member] | Severance Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	[1]	235
Additions		1,213	1,888
Utilizations		(1,387)	(1,653)
Ending Balance	[1]	61	$ 235
2014 Restructuring Plan [Member] | Professional Fees [Member]
Restructuring Cost and Reserve [Line Items]
Additions		458
Utilizations		$ (458)
[1]	Included under accrued and other liabilities in the consolidated balance sheets

Commitments and Contingencies93

Commitments and Contingencies (Narrative) (Details) AUD in Millions, $ in Millions	1 Months Ended			12 Months Ended
	Feb. 29, 2016USD ($)	Dec. 31, 2014USD ($)	Jun. 30, 2014USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Jan. 01, 2017ft²	Jan. 01, 2016ft²	Dec. 31, 2015AUD	Oct. 27, 2015ft²Ageement	Dec. 31, 2014AUD
Commitments And Contingencies [Line Items]
Rent expense facility leases				$ 5.3	$ 5.3	$ 4.9
Number of lease agreements | Ageement										2
Lease agreement space | ft²										191,800
Initial lease term				10 years 6 months
Extension of lease term				5 years
Aggregate base rent obligation				$ 60.8
Standby letters of credit		$ 17		22.7	17
Surety Bond [Member]
Commitments And Contingencies [Line Items]
Financial guarantee		20.3		20.3	20.3
Australian Dollars [Member]
Commitments And Contingencies [Line Items]
Standby letters of credit		0.5		4.4	0.5				AUD 6.2		AUD 0.6
EON Patent Litigation [Member]
Commitments And Contingencies [Line Items]
Litigation settlement amount		13	$ 18.8
Pre-judgment interest		1.5
Additional costs		0.2
Surety bond		$ 17.6
Surety bond percent of final judgment		20.00%
Standby letters of credit				13
EON Patent Litigation [Member] | Standby Letter of Credit [Member]
Commitments And Contingencies [Line Items]
Standby letters of credit		$ 13			$ 13
Atlas/ComEd & Exelon and Atlas/PG&E Patent Litigation [Member]
Commitments And Contingencies [Line Items]
Charges related to legal proceedings				3.6
Subsequent Event [Member]
Commitments And Contingencies [Line Items]
Lease agreement space | ft²								143,900
Subsequent Event [Member] | EON Patent Litigation [Member]
Commitments And Contingencies [Line Items]
Litigation settlement amount	$ 0
Minimum [Member]
Commitments And Contingencies [Line Items]
Rent expense facility leases				1
Maximum [Member]
Commitments And Contingencies [Line Items]
Rent expense facility leases				$ 7.1
Scenario Forecast [Member]
Commitments And Contingencies [Line Items]
Lease agreement space | ft²							47,900

Commitments and Contingencies94

Commitments and Contingencies (Future Minimum Commitments Under Operating and Capital Leases) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, 2016	$ 3,928
Operating Leases, 2017	4,687
Operating Leases, 2018	5,750
Operating Leases, 2019	6,351
Operating Leases, 2020	6,364
Operating Leases, 2021 and thereafter	39,997
Net minimum operating lease payments	67,077
Capital Leases, 2016	112
Net minimum capital lease payments	112
Less amount representing interest	(4)
Present value of net minimum capital lease payments	$ 108

Selected Quarterly Financial 95

Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 199,247	$ 69,505	$ 77,167	$ 143,640	$ 77,411	$ 28,041	$ 41,607	$ 44,229	$ 489,559	$ 191,288	$ 326,858
Cost of revenue	97,902	36,518	57,211	72,185	47,233	26,738	28,195	32,785	263,816	134,951	211,504
Gross profit	101,345	32,987	19,956	71,455	30,178	1,303	13,412	11,444	225,743	56,337	115,354
Operating expenses	35,600	33,381	36,495	37,314	28,786	38,723	38,084	38,615	142,790	144,208	157,109
Operating income (loss)	65,745	(394)	(16,539)	34,141	1,392	(37,420)	(24,672)	(27,171)	82,953	(87,871)	(41,755)
Other income (expense), net	(159)	(99)	74	288	68	7	85	(37)	104	123	(24,828)
Income (loss) before income taxes	65,586	(493)	(16,465)	34,429	1,460	(37,413)	(24,587)	(27,208)	83,057	(87,748)	(66,583)
Provision for income taxes	3,708	129	(290)	(476)	959	(140)	4	599	3,071	1,422	224
Net income (loss)	$ 61,878	$ (622)	$ (16,175)	$ 34,905	$ 501	$ (37,273)	$ (24,591)	$ (27,807)	$ 79,986	$ (89,170)	$ (66,807)
Net income (loss) per share attributable to common stockholders
Basic	$ 1.23	$ (0.01)	$ (0.32)	$ 0.71	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)	$ 1.60	$ (1.84)	$ (4.54)
Diluted	$ 1.19	$ (0.01)	$ (0.32)	$ 0.69	$ 0.01	$ (0.77)	$ (0.51)	$ (0.58)	$ 1.55	$ (1.84)	$ (4.54)
Weighted average shares used to compute net income (loss) per share attributable to common stockholders
Basic	50,481	50,188	49,862	49,306	48,929	48,551	48,315	47,693	49,963	48,377	37,877
Diluted	52,167	50,188	49,862	50,899	50,191	48,551	48,315	47,693	51,524	48,377	37,877