Itron Networked Solutions (SSNI) 10-Q 5 Nov 15 2015 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3
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 Common Stock, Shares Outstanding		50,342,582

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 63,455	$ 60,457
Short-term investments	58,460	60,339
Accounts receivable	44,125	54,740
Inventories	3,761	6,722
Deferred cost of revenue	196,602	29,585
Deferred tax assets	357	5,278
Prepaid expenses and other current assets	9,596	5,146
Total current assets	376,356	222,267
Property and equipment, net	12,326	12,860
Goodwill and intangible assets	14,885	8,221
Deferred cost of revenue, non-current	96,128	303,445
Deferred tax assets, non-current	25,033	354
Other long-term assets	5,088	1,047
Total assets	529,816	548,194
Current liabilities:
Accounts payable	28,083	27,530
Deferred revenue	320,241	91,688
Deferred tax liability	24,879	249
Accrued and other liabilities	34,257	24,421
Total current liabilities	407,460	143,888
Deferred revenue, non-current	205,759	517,905
Deferred tax liability, non-current		5,146
Other liabilities	15,850	15,074
Total liabilities	$ 629,069	$ 682,013
Commitments and contingencies (Note 13)
Stockholders’ deficit:
Common stock and additional paid-in capital, $0.001 par value, 1,000,000 shares authorized; 50,316 and 49,062 shares issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	$ 590,614	$ 573,391
Accumulated other comprehensive loss	(1,544)	(779)
Accumulated deficit	(688,323)	(706,431)
Total stockholders’ deficit	(99,253)	(133,819)
Total liabilities and stockholders’ deficit	$ 529,816	$ 548,194

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 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	50,316,000	49,062,000
Common stock, shares outstanding	50,316,000	49,062,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue:
Product revenue	$ 50,093	$ 16,321	$ 209,839	$ 69,299
Service revenue	19,412	11,720	80,473	44,578
Total revenue, net	69,505	28,041	290,312	113,877
Cost of revenue:
Product cost of revenue	21,377	10,791	118,527	42,120
Service cost of revenue	15,141	15,947	47,387	45,598
Total cost of revenue	36,518	26,738	165,914	87,718
Gross profit	32,987	1,303	124,398	26,159
Operating expenses:
Research and development	15,837	16,986	47,581	52,053
Sales and marketing	7,900	10,248	26,109	28,325
General and administrative	9,305	9,601	31,889	33,156
Restructuring	339	1,888	1,611	1,888
Total operating expenses	33,381	38,723	107,190	115,422
Operating (loss) income	(394)	(37,420)	17,208	(89,263)
Other (expense) income, net:
Other (expense) income, net	(99)	7	263	55
(Loss) income before income taxes	(493)	(37,413)	17,471	(89,208)
Provision and (benefit) for income taxes	129	(140)	(637)	463
Net (loss) income	$ (622)	$ (37,273)	$ 18,108	$ (89,671)
Net (loss) income per share
Basic	$ (0.01)	$ (0.77)	$ 0.36	$ (1.86)
Diluted	$ (0.01)	$ (0.77)	$ 0.35	$ (1.86)
Weighted average shares used to compute net (loss) income per share
Basic	50,188	48,551	49,789	48,189
Diluted	50,188	48,551	51,257	48,189

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (622)	$ (37,273)	$ 18,108	$ (89,671)
Other comprehensive (loss) income:
Changes in foreign currency translation adjustment	(109)	75	(882)	63
Net unrealized gain (loss) on available-for-sale investments (net of tax effect of $0 and $0)	28	(74)	117	(129)
Other comprehensive (loss) income:	(81)	1	(765)	(66)
Comprehensive (loss) income	$ (703)	$ (37,272)	$ 17,343	$ (89,737)

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net unrealized gain (loss) on available-for-sale investments, tax effect	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows provided by (used in) operating activities:
Net income (loss)	$ 18,108	$ (89,671)
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities:
Deferred taxes	(935)	917
Depreciation and amortization	5,892	4,704
Stock-based compensation	21,537	31,470
Other non-cash adjustments	354	511
Changes in operating assets and liabilities:
Accounts receivable	11,073	1,795
Inventories	3,043	(161)
Prepaid expenses and other assets	(4,192)	(2,590)
Contingent payments related to Detectent acquisition, held in escrow	(4,000)
Deferred cost of revenue	40,308	(62,510)
Accounts payable	(131)	(3,165)
Customer deposits	151	33
Deferred revenue	(84,190)	92,413
Accrued and other liabilities	6,412	3,865
Net cash provided by (used in) operating activities	13,430	(22,389)
Cash flows used in investing activities:
Business acquisition, net of cash acquired	(7,098)	(8,750)
Proceeds from sales of available-for-sale investments	11,486	42,459
Proceeds from maturities of available-for-sale investments	9,250	6,750
Purchases of available-for-sale investments	(18,910)	(46,621)
Purchases of property and equipment	(3,529)	(4,222)
Net cash used in investing activities	(8,801)	(10,384)
Cash flows (used in) provided by financing activities:
Payments on capital lease obligations	(994)	(1,145)
Proceeds from issuance of common stock, net of repurchases	3,655	6,846
Taxes paid related to net share settlement of equity awards	(3,968)	(5,410)
Net cash (used in) provided by financing activities	(1,307)	291
Effect of exchange rate changes on cash and cash equivalents	(324)
Net increase (decrease) in cash and cash equivalents	2,998	(32,482)
Cash and cash equivalents-beginning of period	60,457	82,596
Cash and cash equivalents-end of period	63,455	50,114
Supplemental cash flow information:
Cash paid for taxes	2,384	544
Cash paid for interest	$ 44	$ 106

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	1. Basis of Presentation The accompanying unaudited condensed consolidated financial statements of Silver Spring Networks, Inc. (the “Company”, “we”, “us” and “our”) have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) for interim financial information as well as the instructions to Form 10-Q and applicable rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments, including normal recurring accruals, considered necessary for a fair presentation have been included. The results of operations for the three and nine months ended September 30, 2015, are not necessarily indicative of the results that may be expected for the year ending December 31, 2015, or any future period. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Risk Factors,” “Quantitative and Qualitative Disclosures About Market Risk,” and the Consolidated Financial Statements and footnotes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2014. The preparation of unaudited condensed consolidated financial statements necessarily requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the condensed consolidated balance sheet dates and the reported amounts of revenues and expenses for the periods presented. Actual results could differ materially from those estimates under different assumptions or conditions. As a result, the quarterly results may not be indicative of the full year results. The condensed consolidated financial statements include the accounts of Silver Spring Networks, Inc. and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. During the three months ended March 31, 2015, the Company recorded an out-of-period correcting adjustment to deferred cost of revenue that was included in total assets in previous period in the condensed consolidated balance sheets. These corrections resulted in a decrease to the Company's net income of $3.2 million for the three months ended March 31, 2015. The Company recorded these corrections in product cost of revenue in the three months ended March 31, 2015. Management assessed the impact of these errors and concluded that the amounts were not material, either individually or in the aggregate, to any prior period, to the three month period ended March 31, 2015, or to the expected full year financial statements.

Significant Accounting Policies

Significant Accounting Policies and Estimates	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Significant Accounting Policies and Estimates	2. Significant Accounting Policies and Estimates There have been no material changes to our significant accounting policies described in Note 1, Description of Business, Basis of Presentation and Significant Accounting Policies Revenue Recognition Through December 31, 2014, due to limited historical experience, for arrangements that contain customer-specific acceptance criteria, revenue has historically been recognized only after obtaining written acceptance for each service area. We perform 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. 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 three months ended September 30, 2015 in the condensed statements of operations included revenue of $2.0 million, which otherwise would have been deferred before the change in assessment, and excluded cost of revenue of $3.3 million, which otherwise would have been recognized in the period before the change in such assessment. This resulted in a $5.3 million decrease in net loss and a $0.11 decrease to basic net loss per share during the three months ended September 30, 2015. During the nine months ended September 30, 2015, revenue and cost of revenue recognized in the condensed statements of operations as a result of the above change in assessment included revenue of $131.9 million and cost of revenue of $54.0 million, which otherwise would have been deferred before the change in such assessment. This resulted in a $77.9 million increase in net income, $1.56 increase to basic net income per share, and a $1.52 increase to diluted net income per share during the nine months ended September 30, 2015. 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. Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2015-05 (Subtopic 350-40), Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) Revenue Recognition

Net (Loss) Income per Share

Net (Loss) Income per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Net (Loss) Income per Share	3. Net (loss) income per share Basic net (loss) income per share applicable to common stockholders is computed by dividing the net (loss) income applicable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net loss per share applicable to common stockholders is computed by giving effect to all potential shares of common stock, including stock options and restricted stock units, to the extent dilutive. The following table sets forth the computation of basic and diluted net (loss) income per share applicable to common stockholders (in thousands, except per share data): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Net (loss) income $ (622 ) $ (37,273 ) $ 18,108 $ (89,671 ) Weighted average shares outstanding—basic 50,188 48,551 49,789 48,189 Dilutive effect of employee equity incentive plans — — 1,468 — Weighted average shares outstanding—diluted 50,188 48,551 51,257 48,189 Basic net (loss) income per share $ (0.01 ) $ (0.77 ) $ 0.36 $ (1.86 ) Diluted net (loss) income per share $ (0.01 ) $ (0.77 ) $ 0.35 $ (1.86 ) The following potential common shares outstanding were excluded from the computation of diluted net (loss) income per share because including them would have been anti-dilutive (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Employee equity incentive plans 7,291 7,512 3,873 7,512

Cash, Cash Equivalents, and Sho

Cash, Cash Equivalents, and Short-Term Investments	9 Months Ended
	Sep. 30, 2015
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Short-Term Investments	4. Cash, Cash Equivalents and Short-Term Investments Cash, cash equivalents and short-term investments consisted of the following (in thousands): As of September 30, 2015 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 57,242 $ — $ — $ 57,242 Cash equivalents: Money market mutual funds 6,213 — — 6,213 Total cash equivalents 6,213 — — 6,213 Short-term fixed income securities: U.S. government and agency obligations 37,375 99 — 37,474 U.S. and foreign corporate debt securities 18,971 19 (4 ) 18,986 Foreign governments and multi-national agency obligations 2,000 — — 2,000 Total short-term investments 58,346 118 (4 ) 58,460 Total cash, cash equivalents and short-term investments $ 121,801 $ 118 $ (4 ) $ 121,915 As of December 31, 2014 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 equivalents 6,218 — — 6,218 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 September 30, 2015, approximately 42% and 42% of our cash, cash equivalents and short-term investments were held with two separate financial institutions. As of December 31, 2014, approximately 46% and 42% of our cash, cash equivalents and short-term investments were held with two separate financial institutions. Contractual Maturities The contractual maturities of cash equivalents and short-term investments consisted of the following (in thousands): As of September 30, 2015 As of December 31, 2014 Amortized Aggregate Amortized Aggregate Cost Basis Fair Value Cost Basis Fair Value Due within one year $ 21,846 $ 21,867 $ 20,588 $ 20,599 Due after 1 year through 3 years 42,713 42,805 45,973 45,958 Total cash equivalents & short-term investments $ 64,559 $ 64,672 $ 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 September 30, 2015 and December 31, 2014, aggregated by investment category and the length of time that individual securities have been in a continuous loss position (in thousands): As of September 30, 2015 As of December 31, 2014 Total (Less Than 12 Months) Total (Less Than 12 Months) Fair Unrealized Fair Unrealized Value Loss Value Loss U.S. and foreign corporate debt securities $ 8,983 $ (4 ) $ 14,563 $ (33 ) Foreign governments and multi-national agency obligations - - 1,992 (8 ) U.S. government and agency obligations - - 13,523 (18 ) Total $ 8,983 $ (4 ) $ 30,078 $ (59 ) As of September 30, 2015, 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 September 30, 2015, we anticipate that we will recover the entire amortized cost basis of such available-for-sale debt securities and have determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the three and nine months ended September 30, 2015 and 2014. There were no material gross realized gains or losses from available-for-sale securities during the three and nine months ended September 30, 2015 and 2014.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	5. 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 nine months ended September 30, 2015 and the year ended December 31, 2014. Assets Measured at Fair Value on a Recurring Basis As of September 30, 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 Active Markets Significant Other Significant for Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,213 $ — $ — $ 6,213 Total cash equivalents 6,213 — — 6,213 Short-term investments: U.S. government and agency obligations — 37,474 — 37,474 U.S. and foreign corporate debt securities — 18,986 — 18,986 Foreign governments and multi-national agency obligations — 2,000 — 2,000 Total short-term investments — 58,460 — 58,460 Total assets measured at fair value $ 6,213 $ 58,460 $ — $ 64,673 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 Active Markets Significant Other Significant for 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 September 30, 2015 and December 31, 2014, there were no liabilities that were measured and recorded at fair value on a recurring basis. As of September 30, 2015 and December 31, 2014, there were no assets and liabilities that were measured and recorded at fair value on a nonrecurring basis. Assets and Liabilities Not Measured at Fair Value The carrying amounts of our accounts receivable, accounts payable, and accrued and other liabilities approximate fair value due to their short maturities.

Business Acquisition

Business Acquisition	9 Months Ended
	Sep. 30, 2015
Business Combinations [Abstract]
Business Acquisition	6. Business Acquisition 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 key employees’ retention (“retention period”). Contingent payments associated with future employment conditions will be recorded as compensation expense over the retention period. During the three and nine months ended September 30, 2015, we recorded $0.5 million and $1.4 million, respectively, 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 $0.4 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 Goodwill represents the excess of the purchase consideration over the fair value of the underlying net assets acquired and liabilities assumed. The goodwill arising from the Detectent acquisition is largely attributable to the synergies expected to be realized. None of the goodwill recorded as part of the Detectent acquisition will be deductible for income tax purposes. The following table summarizes the estimated fair value of the assets acquired and liabilities assumed at the acquisition date. The estimated fair value of the identifiable assets acquired and liabilities assumed in the acquisition is based on management’s best estimates. As we finalize certain valuation assumptions, the provisional measurements of certain assets and liabilities, which include accruals, deferred income taxes, and goodwill, are subject to change, and the final purchase price accounting could be different from the amounts presented herein. 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 three months ended September 30, 2015. As a result, the net other tangible assets acquired increased by $0.2 million, offset by an increase in deferred tax liabilities and other fair value adjustment by $0.1 million. The net impact of $0.1 million of these items was accounted for as measurement period adjustments during the three months ended September 30, 2015 with a corresponding adjustment to goodwill. For the nine months ended September 30, 2015, cumulatively, 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, resulting in a net identifiable assets acquired increase of $0.3 million. 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 represented the value of the non-compete and non-solicit agreements signed by key employees. 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 20.1% 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 we expect to amortize these intangible assets on a straight-line basis over their weighted average expected useful lives of approximately one to seven years. Deferred tax assets and liabilities resulting from the acquisition of Detectent have been netted, where applicable. Following the Detectent acquisition, Detectent has become part of our U.S. tax group. Accordingly, 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 of the Company’s valuation allowance which was recorded as a tax benefit during the nine months ended September 30, 2015 financial statements in accordance with ASC 805. In connection with the acquisition, we incurred $2.0 million of acquisition-related costs that were expensed during the nine months ended September 30, 2015. These costs are included primarily as part of general and administration costs in the consolidated statement of operations. Detectent’s financial results have been included in the condensed consolidated financial statements since the acquisition date. Total Detectent revenue represented approximately 1% of the total consolidated revenue recognized during three and nine months ended September 30, 2015. Acquisition of Streetlight.Vision On May 23, 2014, we completed the acquisition of Streetlight.Vision (“SLV”), a company incorporated under the laws of France, which provides street light control and management software, and paid approximately $8.8 million in cash. 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.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	7. Goodwill and Intangible Assets Goodwill: The following table presents goodwill and changes in the carrying amount of goodwill (in thousands): September 30, 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 (381 ) (488 ) Balance, end of period $ 8,845 $ 4,729 During the nine months ended September 30, 2015, we recorded goodwill of $4.5 million in connection with our acquisition of Detectent. During the year ended December 31, 2014, we recorded goodwill of $4.7 million in connection with our acquisition of SLV. 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 (in thousands): Developed Technology and Order Backlog Customer Relationships Trade Name and Non­Compete Agreements In­process R&D Total Amortization Period 1-5 years 2-7 years 3-6 years Indefinite Cost: Balance at December 31, 2014 $ 2,396 $ 2,140 $ 269 $ 269 $ 5,074 Acquired as a part of Detectent acquisition 2,200 1,500 100 — 3,800 Balance at September 30, 2015 $ 4,596 $ 3,640 $ 369 $ 269 $ 8,874 Accumulated Amortization: Balance at December 31, 2014 $ 1,139 $ 417 $ 26 $ — $ 1,582 Amortization expense 782 413 57 — 1,252 Balance at September 30, 2015 $ 1,921 $ 830 $ 83 $ — $ 2,834 Intangible assets, net at September 30, 2015 $ 2,675 $ 2,810 $ 286 $ 269 $ 6,040 Intangible assets, net at December 31, 2014 $ 1,257 $ 1,723 $ 243 $ 269 $ 3,492 Intangible assets subject to amortization are amortized over their useful lives as shown in the table above. During the first quarter of 2015, we recorded intangible assets of $3.8 million in connection with our acquisition of Detectent. The following table illustrates the amortization expense included in the consolidated statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Cost of revenue $ 260 $ 182 $ 782 $ 278 Sales and marketing 153 117 447 117 General and administrative 8 23 Total $ 421 $ 299 $ 1,252 $ 395 The estimated future amortization expense of purchased intangible assets with definite lives for the next five years is as follows (in thousands): Year Ended 2015 $ 421 2016 1,398 2017 1,385 2018 1,144 2019 994 2020 and thereafter 429 $ 5,771

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation Equity Incentive Plan Our Board of Directors adopted the 2012 Equity Incentive Plan, or the 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 and restricted 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, or ISOs, or Nonqualified Stock Options, or 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. Restricted stock units, or RSUs, generally vest between two to four years. As of January 1, 2015, the total shares reserved for issuance under the 2012 Plan were automatically increased by 1,962,491. Employee Stock Purchase Plan 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. As of January 1, 2015, the total shares reserved for issuance under the ESPP were automatically increased by 490,622. Inducement Grants On July 28, 2015, we entered into an employment offer letter with Michael Bell, our President and Chief Executive Officer (“CEO”), pursuant to which we agreed to grant Mr. Bell a stock option to purchase 250,000 shares of our common stock, RSUs that may be settled for 125,000 shares of our common stock, and performance stock units (“PSUs”) that may be settled for 125,000 shares of our common stock as inducement awards (collectively, the “Inducement Grants”). The stock option The fair value of shares of our common stock underlying the stock option, RSUs, and PSUs included in are determined based upon the fair market value of our common stock at the date of grant. Performance Stock Awards In 2015, we granted to our 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 us 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 3-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 $5.7 million which will be recognized over the requisite service period using the accelerated method. As of September 30, 2015 and December 31, 2014, there were 5.0 million and 4.3 million shares, respectively, of common stock reserved for future grants under our 2012 Plan and 2012 Employee Stock Purchase Plan. We recorded stock-based compensation expense as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Cost of revenue $ 1,197 $ 2,770 $ 5,129 $ 7,392 Research and development 1,771 3,042 6,783 8,892 Sales and marketing 914 1,783 3,439 5,582 General and administrative 1,971 2,881 6,186 9,604 Stock-based compensation expense $ 5,853 $ 10,476 $ 21,537 $ 31,470 Of the total stock-based compensation, we recorded $0.8 million and $2.7 million, respectively as stock-based compensation related to our corporate bonus incentive plan during the three months ended September 30, 2015 and 2014. We recorded $6.1 million and $6.0 million, respectively as stock-based compensation related to our corporate bonus incentive plan during the nine months ended September 30, 2015 and 2014. As of September 30, 2015 and December 31, 2014, stock-based bonuses of $6.1 million and $1.9 million, respectively, were recorded as accrued liabilities in the consolidated balance sheets in connection with our corporate bonus incentive plan. The following table summarizes our stock option activity and related information for the nine months ended September 30, 2015 (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, 2014 4,525 $ 12.38 Options granted 419 8.04 Options exercised (155 ) 2.70 Options cancelled or expired (411 ) 17.46 Balance at September 30, 2015 4,378 $ 11.83 5.52 $ 15,592 As of September 30, 2015: Options vested and expected to vest 4,339 $ 11.81 5.50 $ 15,538 Options exercisable 3,327 $ 11.51 4.52 $ 13,499 The aggregate intrinsic value disclosed above represents the total intrinsic value (the difference between the fair value of our common stock as of September 30, 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 September 30, 2015. This amount is subject to change based on changes to the fair value of our common stock. The following table summarizes our restricted stock unit activity and related information for the nine months ended September 30, 2015 (in thousands, except per share data): Restricted Stock Units Outstanding Weighted Average Grant Number of Date Fair Value Shares per Share Balance at December 31, 2014 2,200 $ 15.06 Restricted stock units granted 2,038 $ 9.64 Restricted stock units vested (1,056 ) $ 15.59 Restricted stock units cancelled (323 ) $ 14.18 Balance at September 30, 2015 2,859 $ 10.84 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 is determined using the Black-Scholes-Merton option pricing model. 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 represents 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. As of September 30, 2015, there was $5.9 million and $22.2 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements related to options and RSUs, and PSUs, respectively, which are expected to be recognized over a weighted-average period of 2.5 and 2.4 years, respectively.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2015
Income Tax Disclosure [Abstract]
Income Taxes	9. Income Taxes Our provision and benefit for income taxes for the three months ended September 30, 2015 and 2014 reflects an effective tax rate of (26.2%) and 0.4%, respectively. Our benefit for income taxes for the nine months ended September 30, 2015 and 2014 reflects an effective tax rate of (3.6%) and (0.5%), respectively. Our benefit for income taxes for the three and nine months ended September 30, 2015 consists primarily of a net benefit of $0.1 and $1.1 million, respectively, which was due to the deferred income tax benefits related to the Detectent acquisition. Our provision for income taxes for the three and nine months ended September 30, 2014 consisted primarily of foreign income and withholding taxes.

Segment Information

Segment Information	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Segment Information	10. Segment Information We operate in one reportable segment. Our chief operating decision maker is our CEO, who reviews 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): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Revenue: United States $ 53,113 $ 15,700 $ 248,049 $ 71,561 Australia 14,492 8,828 37,204 22,131 All Other 1,900 3,513 5,059 20,185 Total $ 69,505 $ 28,041 $ 290,312 $ 113,877

Balance Sheet Details

Balance Sheet Details	9 Months Ended
	Sep. 30, 2015
Disclosure Text Block Supplement [Abstract]
Balance Sheet Details	11. Balance Sheet Details Inventories Inventories consisted of the following (in thousands): September 30, December 31, 2015 2014 Component parts $ 1,332 $ 2,843 Finished goods 2,429 3,879 Inventories $ 3,761 $ 6,722 Accrued and other liabilities Accrued and other liabilities consisted of the following (in thousands): September 30, December 31, 2015 2014 Accrued payroll and related expenses $ 14,045 $ 8,912 Accrued operating expenses 3,103 2,548 Warranty obligations, current 7,664 3,838 Sales, property and income taxes 1,012 1,996 Current portion of capital lease obligation 454 1,163 Other deferred revenue 6,794 4,955 Other 1,185 1,009 Accrued and other liabilities $ 34,257 $ 24,421 Other Liabilities Other liabilities consisted of the following (in thousands): September 30, December 31, 2015 2014 Warranty obligations, non-current $ 3,263 $ 3,397 Other deferred revenue 10,652 9,816 Deferred rent long term 994 1,368 Other 941 493 Other liabilities $ 15,850 $ 15,074 Product Warranty Product warranty obligation is presented as follows on the consolidated balance sheets (in thousands): September 30, December 31, 2015 2014 Current warranty obligation—classified in accrued and other liabilities $ 7,664 $ 3,838 Non-current warranty obligation—classified in other liabilities 3,263 3,397 $ 10,927 $ 7,235 Product warranty activity was as follows (in thousands): Nine Months Ended September 30, 2015 2014 Warranty obligation—beginning of period $ 7,235 $ 6,089 Warranty expense for new warranties issued 346 506 Utilization of warranty obligation (1,624 ) (2,101 ) Changes in estimates for pre-existing warranties 4,970 2,789 Warranty obligation—end of period $ 10,927 $ 7,283 Accumulated Other Comprehensive Loss (AOCL) The components of accumulated other comprehensive loss, 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, 2014 $ (724 ) $ (55 ) $ (779 ) Other comprehensive (loss) income before reclassification (882 ) 156 (726 ) Amounts reclassified from AOCI — (39 ) (39 ) Other comprehensive (loss) income (882 ) 117 (765 ) Balance as of September 30, 2015 $ (1,606 ) $ 62 $ (1,544 )

Restructuring Charges

Restructuring Charges	9 Months Ended
	Sep. 30, 2015
Restructuring And Related Activities [Abstract]
Restructuring Charges	12. Restructuring 2014 Restructuring Plan In September 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 $1.9 million in severance costs as restructuring charges during the third quarter of 2014. We recorded $0.3 million and $1.6 million in severance and other related costs as restructuring charges during the three and nine months ended September 30, 2015 under the 2014 Restructuring Plan. In connection with the 2014 Restructuring Plan, we expect to record aggregate future charges up to approximately $0.4 million. The remaining restructuring costs under the 2014 Restructuring Plan are expected to be incurred in the fourth quarter of 2015. Accrued liabilities related to restructuring actions during nine months ended September 30, 2015 consisted of the following (in thousands): Balance December 31, 2014 Additions Utilization Balance September 30, 2015 (1) Fiscal 2014 Plan Severance costs $ 235 $ 1,153 $ (1,206 ) $ 182 Professional fees — 458 (458 ) — Total $ 235 $ 1,611 $ (1,664 ) $ 182 (1) Included under Accrued and other liabilities in the condensed consolidated balance sheets.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. Commitments and contingencies Operating and Capital Leases Our primary operating lease commitment as of September 30, 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. Rent expense for all facility leases was $1.4 million and $1.4 million for the three months ended September 30, 2015 and 2014, respectively, and $3.9 million and $4.0 million for nine months ended September 30, 2015 and 2014, respectively. On October 27, 2015, we entered into new lease agreements with CF Tasman SV LLC (the”Landlord”). See Note 14, Subsequent Event Notes to Condensed Consolidated Financial Statements The future minimum commitments under our operating and capital leases were as follows (in thousands): September 30, 2015 Operating Capital Leases 2015 $ 1,394 $ 175 2016 2,962 112 2017 722 — 2018 641 — 2019 548 — 2020 and thereafter 1,435 — Net minimum lease payments $ 7,702 $ 287 Less amount representing interest (10 ) Present value of net minimum capital lease payments $ 277 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 (the “’101 Patent”), 5,481,546 (the “’546 Patent”), and 5,592,491 (the “’491 Patent,” and together with the ‘101 Patent and the ‘546 Patent, the “EON Patents”) by certain networking technology and services that we and the other defendants provide. Other defendants included Landis+Gyr AG, 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 described below in “ Customer Performance and Other Commitments We continue to believe that the evidence and the law do not support the jury’s findings of infringement, validity, and the award of damages, and intend to continue vigorously defending the action, including exercising all available appeals. However, given the inherent uncertainty in predicting the ultimate outcome of the appeals process, we believe it is reasonably possible that a material loss of up to $14.7 million, the amount of the amended final judgment, may result from these proceedings. In continuing to assess the impact of the jury verdict and the judgment on our financial statements, we will continue to evaluate the jury verdict, the court’s rulings on the post-trial motions and the likelihood of a successful appeal. 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 have 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”). 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. We believe that OG&E has meritorious defenses to TransData’s allegations, and that OG&E will continue to vigorously defend itself. 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 Technoogy, 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 these claims under the terms of our master agreements with them. We have not agreed to indemnify GE, and we have not yet responded to L+G’s request. To our knowledge, no answers have yet been filed by GE or L+G. 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, 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 have agreed to indemnify, assume control of the defense and resolve the claim against Pepco Holdings. We and Pepco Holdings waived service of the complaint, and our answer is due in November 2015. 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 September 30, 2015 and December 31, 2014, we had a total of $21.0 million, including $13.0 million related to the EON patent litigation mentioned above, and $17.0 million, respectively, of standby letters of credit issued under the credit facility with a financial institution, of which $4.4 million (AUD$6.1 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 September 30, 2015, we had a $20.3 million unsecured surety bond. 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 coverage policies, 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. Historically, payments made by us under these indemnification provisions have not had a material effect on our results of operations, financial position or cash flows.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2015
Subsequent Events [Abstract]
Subsequent Event	14. Subsequent Event 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 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 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 $3.9 million to $7.5 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.

Significant Accounting Polici22

Significant Accounting Policies and Estimates (Policies)	9 Months Ended
	Sep. 30, 2015
Accounting Policies [Abstract]
Revenue Recognition	Revenue Recognition Through December 31, 2014, due to limited historical experience, for arrangements that contain customer-specific acceptance criteria, revenue has historically been recognized only after obtaining written acceptance for each service area. We perform 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. 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 three months ended September 30, 2015 in the condensed statements of operations included revenue of $2.0 million, which otherwise would have been deferred before the change in assessment, and excluded cost of revenue of $3.3 million, which otherwise would have been recognized in the period before the change in such assessment. This resulted in a $5.3 million decrease in net loss and a $0.11 decrease to basic net loss per share during the three months ended September 30, 2015. During the nine months ended September 30, 2015, revenue and cost of revenue recognized in the condensed statements of operations as a result of the above change in assessment included revenue of $131.9 million and cost of revenue of $54.0 million, which otherwise would have been deferred before the change in such assessment. This resulted in a $77.9 million increase in net income, $1.56 increase to basic net income per share, and a $1.52 increase to diluted net income per share during the nine months ended September 30, 2015. 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.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2015-05 (Subtopic 350-40), Customer's Accounting for Fees Paid in a Cloud Computing Arrangement In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) Revenue Recognition

Net (Loss) Income per Share (Ta

Net (Loss) Income per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net (Loss) Income per Share	The following table sets forth the computation of basic and diluted net (loss) income per share applicable to common stockholders (in thousands, except per share data): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Net (loss) income $ (622 ) $ (37,273 ) $ 18,108 $ (89,671 ) Weighted average shares outstanding—basic 50,188 48,551 49,789 48,189 Dilutive effect of employee equity incentive plans — — 1,468 — Weighted average shares outstanding—diluted 50,188 48,551 51,257 48,189 Basic net (loss) income per share $ (0.01 ) $ (0.77 ) $ 0.36 $ (1.86 ) Diluted net (loss) income per share $ (0.01 ) $ (0.77 ) $ 0.35 $ (1.86 )
Common Shares Outstanding Excluded from Computation of Diluted Net (Loss) Income per Share	The following potential common shares outstanding were excluded from the computation of diluted net (loss) income per share because including them would have been anti-dilutive (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Employee equity incentive plans 7,291 7,512 3,873 7,512

Cash, Cash Equivalents, and S24

Cash, Cash Equivalents, and Short-Term Investments (Tables)	9 Months Ended
	Sep. 30, 2015
Cash And Cash Equivalents [Abstract]
Cash, Cash Equivalents, and Short-Term Investments	As of September 30, 2015 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Current assets: Cash $ 57,242 $ — $ — $ 57,242 Cash equivalents: Money market mutual funds 6,213 — — 6,213 Total cash equivalents 6,213 — — 6,213 Short-term fixed income securities: U.S. government and agency obligations 37,375 99 — 37,474 U.S. and foreign corporate debt securities 18,971 19 (4 ) 18,986 Foreign governments and multi-national agency obligations 2,000 — — 2,000 Total short-term investments 58,346 118 (4 ) 58,460 Total cash, cash equivalents and short-term investments $ 121,801 $ 118 $ (4 ) $ 121,915 As of December 31, 2014 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 equivalents 6,218 — — 6,218 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	As of September 30, 2015 As of December 31, 2014 Amortized Aggregate Amortized Aggregate Cost Basis Fair Value Cost Basis Fair Value Due within one year $ 21,846 $ 21,867 $ 20,588 $ 20,599 Due after 1 year through 3 years 42,713 42,805 45,973 45,958 Total cash equivalents & short-term investments $ 64,559 $ 64,672 $ 66,561 $ 66,557
Schedule of Gross Unrealized Losses and Fair Values of Investments	As of September 30, 2015 As of December 31, 2014 Total (Less Than 12 Months) Total (Less Than 12 Months) Fair Unrealized Fair Unrealized Value Loss Value Loss U.S. and foreign corporate debt securities $ 8,983 $ (4 ) $ 14,563 $ (33 ) Foreign governments and multi-national agency obligations - - 1,992 (8 ) U.S. government and agency obligations - - 13,523 (18 ) Total $ 8,983 $ (4 ) $ 30,078 $ (59 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets Recorded on Recurring Basis	As of September 30, 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 Active Markets Significant Other Significant for Identical Observable Unobservable Instruments Inputs Inputs (Level 1) (Level 2) (Level 3) Total Cash equivalents: Money-market funds $ 6,213 $ — $ — $ 6,213 Total cash equivalents 6,213 — — 6,213 Short-term investments: U.S. government and agency obligations — 37,474 — 37,474 U.S. and foreign corporate debt securities — 18,986 — 18,986 Foreign governments and multi-national agency obligations — 2,000 — 2,000 Total short-term investments — 58,460 — 58,460 Total assets measured at fair value $ 6,213 $ 58,460 $ — $ 64,673 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 Active Markets Significant Other Significant for 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 Acquisition (Tables)

Business Acquisition (Tables) - Detectent Inc. [Member]	9 Months Ended
	Sep. 30, 2015
Business Acquisition [Line Items]
Schedule of Business Acquisition	Cash consideration $ 7,616 Less: Fair value of net identifiable assets acquired (3,164 ) Goodwill $ 4,452
Assets Acquired and Liabilities Assumed	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)	9 Months Ended
	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	September 30, 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 (381 ) (488 ) Balance, end of period $ 8,845 $ 4,729
Schedule of Intangible Assets	Developed Technology and Order Backlog Customer Relationships Trade Name and Non­Compete Agreements In­process R&D Total Amortization Period 1-5 years 2-7 years 3-6 years Indefinite Cost: Balance at December 31, 2014 $ 2,396 $ 2,140 $ 269 $ 269 $ 5,074 Acquired as a part of Detectent acquisition 2,200 1,500 100 — 3,800 Balance at September 30, 2015 $ 4,596 $ 3,640 $ 369 $ 269 $ 8,874 Accumulated Amortization: Balance at December 31, 2014 $ 1,139 $ 417 $ 26 $ — $ 1,582 Amortization expense 782 413 57 — 1,252 Balance at September 30, 2015 $ 1,921 $ 830 $ 83 $ — $ 2,834 Intangible assets, net at September 30, 2015 $ 2,675 $ 2,810 $ 286 $ 269 $ 6,040 Intangible assets, net at December 31, 2014 $ 1,257 $ 1,723 $ 243 $ 269 $ 3,492
Schedule of Amortization Expense	Three Months Ended September 30, Nine Months Ended September 30, 2015 2014 2015 2014 Cost of revenue $ 260 $ 182 $ 782 $ 278 Sales and marketing 153 117 447 117 General and administrative 8 23 Total $ 421 $ 299 $ 1,252 $ 395
Schedule of Estimated Future Amortization Expense	Year Ended 2015 $ 421 2016 1,398 2017 1,385 2018 1,144 2019 994 2020 and thereafter 429 $ 5,771

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation Expense	Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Cost of revenue $ 1,197 $ 2,770 $ 5,129 $ 7,392 Research and development 1,771 3,042 6,783 8,892 Sales and marketing 914 1,783 3,439 5,582 General and administrative 1,971 2,881 6,186 9,604 Stock-based compensation expense $ 5,853 $ 10,476 $ 21,537 $ 31,470
Summary of Stock Option Activity	Options Outstanding Weighted Weighted Average Average Exercise Remaining Aggregate Number of Price per Contractual Intrinsic Shares Share Term (years) Value Balance at December 31, 2014 4,525 $ 12.38 Options granted 419 8.04 Options exercised (155 ) 2.70 Options cancelled or expired (411 ) 17.46 Balance at September 30, 2015 4,378 $ 11.83 5.52 $ 15,592 As of September 30, 2015: Options vested and expected to vest 4,339 $ 11.81 5.50 $ 15,538 Options exercisable 3,327 $ 11.51 4.52 $ 13,499
Summary of Restricted Stock Unit Activity	Restricted Stock Units Outstanding Weighted Average Grant Number of Date Fair Value Shares per Share Balance at December 31, 2014 2,200 $ 15.06 Restricted stock units granted 2,038 $ 9.64 Restricted stock units vested (1,056 ) $ 15.59 Restricted stock units cancelled (323 ) $ 14.18 Balance at September 30, 2015 2,859 $ 10.84

Segment Information (Tables)

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2015
Segment Reporting [Abstract]
Schedule of Revenue by Geographic Region	Three Months Ended Nine Months Ended September 30, September 30, 2015 2014 2015 2014 Revenue: United States $ 53,113 $ 15,700 $ 248,049 $ 71,561 Australia 14,492 8,828 37,204 22,131 All Other 1,900 3,513 5,059 20,185 Total $ 69,505 $ 28,041 $ 290,312 $ 113,877

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	9 Months Ended
	Sep. 30, 2015
Disclosure Text Block Supplement [Abstract]
Schedule of Inventories	September 30, December 31, 2015 2014 Component parts $ 1,332 $ 2,843 Finished goods 2,429 3,879 Inventories $ 3,761 $ 6,722
Schedule of Accrued and Other Liabilities	September 30, December 31, 2015 2014 Accrued payroll and related expenses $ 14,045 $ 8,912 Accrued operating expenses 3,103 2,548 Warranty obligations, current 7,664 3,838 Sales, property and income taxes 1,012 1,996 Current portion of capital lease obligation 454 1,163 Other deferred revenue 6,794 4,955 Other 1,185 1,009 Accrued and other liabilities $ 34,257 $ 24,421
Schedule of Other Liabilities	September 30, December 31, 2015 2014 Warranty obligations, non-current $ 3,263 $ 3,397 Other deferred revenue 10,652 9,816 Deferred rent long term 994 1,368 Other 941 493 Other liabilities $ 15,850 $ 15,074
Schedule of Product Warranty Obligation	September 30, December 31, 2015 2014 Current warranty obligation—classified in accrued and other liabilities $ 7,664 $ 3,838 Non-current warranty obligation—classified in other liabilities 3,263 3,397 $ 10,927 $ 7,235
Schedule of Product Warranty Activity	Nine Months Ended September 30, 2015 2014 Warranty obligation—beginning of period $ 7,235 $ 6,089 Warranty expense for new warranties issued 346 506 Utilization of warranty obligation (1,624 ) (2,101 ) Changes in estimates for pre-existing warranties 4,970 2,789 Warranty obligation—end of period $ 10,927 $ 7,283
Schedule of Accumulated Other Comprehensive Loss (AOCL)	Unrealized Gains Foreign Currency (Losses) on Available Adjustment for Sale Securities Total Balance as of December 31, 2014 $ (724 ) $ (55 ) $ (779 ) Other comprehensive (loss) income before reclassification (882 ) 156 (726 ) Amounts reclassified from AOCI — (39 ) (39 ) Other comprehensive (loss) income (882 ) 117 (765 ) Balance as of September 30, 2015 $ (1,606 ) $ 62 $ (1,544 )

Restructuring Charges (Tables)

Restructuring Charges (Tables)	9 Months Ended
	Sep. 30, 2015
Restructuring And Related Activities [Abstract]
Accrued Liabilities Related to Restructuring Actions	Balance December 31, 2014 Additions Utilization Balance September 30, 2015 (1) Fiscal 2014 Plan Severance costs $ 235 $ 1,153 $ (1,206 ) $ 182 Professional fees — 458 (458 ) — Total $ 235 $ 1,611 $ (1,664 ) $ 182 (1) Included under Accrued and other liabilities in the condensed consolidated balance sheets.

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2015
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Commitments Under Operating and Capital Leases	September 30, 2015 Operating Capital Leases 2015 $ 1,394 $ 175 2016 2,962 112 2017 722 — 2018 641 — 2019 548 — 2020 and thereafter 1,435 — Net minimum lease payments $ 7,702 $ 287 Less amount representing interest (10 ) Present value of net minimum capital lease payments $ 277

Basis of Presentation (Details)

Basis of Presentation (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basis Of Presentation [Line Items]
Net income (loss)	$ (622)		$ (37,273)	$ 18,108	$ (89,671)
Out-Of-Period Correcting Adjustment [Member]
Basis Of Presentation [Line Items]
Net income (loss)		$ (3,200)

Significant Accounting Polici34

Significant Accounting Policies and Estimates (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue	$ 69,505	$ 28,041	$ 290,312	$ 113,877
Cost of revenue	36,518	26,738	165,914	87,718
Net (loss) income	$ (622)	$ (37,273)	$ 18,108	$ (89,671)
Basic net (loss) income per share	$ (0.01)	$ (0.77)	$ 0.36	$ (1.86)
Diluted net (loss) income per share	$ (0.01)	$ (0.77)	$ 0.35	$ (1.86)
Customer-Specific Acceptance Criteria [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue	$ 2,000		$ 131,900
Cost of revenue	3,300		54,000
Net (loss) income	$ 5,300		$ 77,900
Basic net (loss) income per share	$ 0.11		$ 1.56
Diluted net (loss) income per share			$ 1.52

Net (Loss) Income per Share (Co

Net (Loss) Income per Share (Computation of Basic and Diluted Net (Loss) Income per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share [Abstract]
Net (loss) income	$ (622)	$ (37,273)	$ 18,108	$ (89,671)
Weighted average shares outstanding—basic	50,188	48,551	49,789	48,189
Dilutive effect of employee equity incentive plans			1,468
Weighted average shares outstanding—diluted	50,188	48,551	51,257	48,189
Basic net (loss) income per share	$ (0.01)	$ (0.77)	$ 0.36	$ (1.86)
Diluted net (loss) income per share	$ (0.01)	$ (0.77)	$ 0.35	$ (1.86)

Net (Loss) Income per Share (36

Net (Loss) Income per Share (Common Shares Outstanding Excluded from Computation of Diluted Net (Loss) Income per Share) (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee Equity Incentive Plans [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total common stock equivalents	7,291	7,512	3,873	7,512

Cash, Cash Equivalents, and S37

Cash, Cash Equivalents, and Short-Term Investments (Cash, Cash Equivalents, and Short-Term Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 121,801	$ 120,800
Unrealized Gains	118	55
Unrealized Losses	(4)	(59)
Estimated Fair Value	121,915	120,796
Cash [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	57,242	54,239
Estimated Fair Value	57,242	54,239
Cash Equivalents [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	6,213	6,218
Estimated Fair Value	6,213	6,218
Cash Equivalents [Member] | Money Market Mutual Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	6,213	6,218
Estimated Fair Value	6,213	6,218
Short-Term Fixed Income Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	58,346	60,343
Unrealized Gains	118	55
Unrealized Losses	(4)	(59)
Estimated Fair Value	58,460	60,339
Short-Term Fixed Income Securities [Member] | U.S. Government And Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	37,375	38,718
Unrealized Gains	99	46
Unrealized Losses		(18)
Estimated Fair Value	37,474	38,746
Short-Term Fixed Income Securities [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	18,971	19,625
Unrealized Gains	19	9
Unrealized Losses	(4)	(33)
Estimated Fair Value	18,986	19,601
Short-Term Fixed Income Securities [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	2,000	2,000
Unrealized Losses		(8)
Estimated Fair Value	$ 2,000	$ 1,992

Cash, Cash Equivalents, and S38

Cash, Cash Equivalents, and Short-Term Investments (Narrative) (Details)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)FinancialInstitution	Sep. 30, 2014USD ($)	Dec. 31, 2014FinancialInstitution
Cash and Cash Equivalents [Line Items]
Number of financial institutions | FinancialInstitution			2		2
Unrealized losses on investments			$ 0
Gross realized gains (losses) from available-for-sale securities	$ 0	$ 0	$ 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	42.00%		42.00%		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	42.00%		42.00%		42.00%

Cash, Cash Equivalents, and S39

Cash, Cash Equivalents, and Short-Term Investments (Contractual Maturities of Cash Equivalents and Short-Term Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Abstract]
Due within one year, Amortized Cost Basis	$ 21,846	$ 20,588
Due after 1 year through 3 years, Amortized Cost Basis	42,713	45,973
Total cash equivalents & short-term investments, Amortized Cost Basis	64,559	66,561
Due within one year, Aggregate Fair Value	21,867	20,599
Due after 1 year through 3 years, Aggregate Fair Value	42,805	45,958
Total cash equivalents & short-term investments, Aggregate Fair Value	$ 64,672	$ 66,557

Cash, Cash Equivalents, and S40

Cash, Cash Equivalents, and Short-Term Investments (Schedule of Gross Unrealized Losses and Fair Values of Investments) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	$ 8,983	$ 30,078
Unrealized Loss Total (Less Than 12 Months)	(4)	(59)
U.S. And Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	8,983	14,563
Unrealized Loss Total (Less Than 12 Months)	$ (4)	(33)
Foreign Governments And Multi-National Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)		1,992
Unrealized Loss Total (Less Than 12 Months)		(8)
U.S. Government And Agency Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)		13,523
Unrealized Loss Total (Less Than 12 Months)		$ (18)

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
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
Fair Value On A Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	64,673	66,557
Fair Value On A Recurring Basis [Member] | U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	37,474	38,746
Fair Value On A Recurring Basis [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	18,986	19,601
Fair Value On A Recurring Basis [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	2,000	1,992
Fair Value On A Recurring Basis [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]
Fair value of financial assets	6,213	6,218
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	58,460	60,339
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	37,474	38,746
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	18,986	19,601
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	2,000	1,992
Fair Value On A Recurring Basis [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	6,213	6,218
Fair Value On A Recurring Basis [Member] | Cash Equivalents [Member] | Money Market Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	6,213	6,218
Fair Value On A Recurring Basis [Member] | 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]
Fair value of financial assets	6,213	6,218
Fair Value On A Recurring Basis [Member] | Cash Equivalents [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Money Market Mutual Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	6,213	6,218
Fair Value On A Recurring Basis [Member] | Short-Term Fixed Income Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	58,460	60,339
Fair Value On A Recurring Basis [Member] | 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]
Fair value of financial assets	$ 58,460	$ 60,339

Business Acquisition (Narrative

Business Acquisition (Narrative) (Details) - USD ($) $ in Thousands	Jan. 16, 2015	May. 23, 2014	Sep. 30, 2015	Mar. 31, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill measurement period adjustment					$ (295)	$ 85
Goodwill			$ 8,845		$ 8,845	$ 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			500		$ 1,400
Increase in other tangible assets acquired			200
Increase in net identifiable assets acquired					300
Goodwill measurement period adjustment			100
Decrease in other tangible liabilities					500
Deferred tax liabilities and other fair value adjustment			100		200
Deferred tax liabilities	1,128		$ 1,100		1,100
Reversal of valuation allowance					(1,000)
Acquisition-related costs					$ 2,000
Subsidiary revenue of the total revenue			1.00%		1.00%
Goodwill	$ 4,452
Detectent Inc. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Discount rate	18.60%
Detectent Inc. [Member] | Order Backlog [Member]
Business Acquisition [Line Items]
Discount rate	20.10%
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					7 years
StreetLight Vision [Member]
Business Acquisition [Line Items]
Cash consideration		$ 8,800
Goodwill		$ 4,700
Decrease in net assets acquired				$ (100)
Short Term [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Compensation expense			$ 1,000
Long Term [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Compensation expense					$ 400

Business Acquisition (Schedule

Business Acquisition (Schedule of Business Acquisition) (Details) - USD ($) $ in Thousands	Jan. 16, 2015	Sep. 30, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$ 8,845	$ 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 Acquisition (Assets Ac

Business Acquisition (Assets Acquired and Liabilities Assumed) (Details) - Detectent Inc. [Member] - USD ($) $ in Thousands	Sep. 30, 2015	Jan. 16, 2015
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	$ (1,100)	(1,128)
Total fair value of net identifiable assets acquired		3,164
Developed Technology [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 Asset45

Goodwill and Intangible Assets (Schedule of Goodwill) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Organization Consolidation And Presentation Of Financial Statements [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	(381)	(488)
Balance, end of period	$ 8,845	$ 4,729

Goodwill and Intangible Asset46

Goodwill and Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill acquired during the period	$ 4,792	$ 4,685
Disclosure - Goodwill and Intangible Assets (Narrative) (Details) [Line Items]
Intangible assets acquired as a part of Detectent acquisition	3,800
StreetLight Vision [Member]
Goodwill [Line Items]
Goodwill acquired during the period		$ 4,700
Detectent Inc. [Member]
Goodwill [Line Items]
Goodwill acquired during the period	$ 4,500

Goodwill and Intangible Asset47

Goodwill and Intangible Assets (Schedule of Intangible Assets) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Schedule Of Intangible Assets [Line Items]
Cost, Beginning balance			$ 5,074
Cost, Acquired as a part of Detectent acquisition			3,800
Cost, Ending balance	$ 8,874		8,874		$ 5,074
Accumulated Amortization, Beginning balance			1,582
Accumulated Amortization, Amortization expense	421	$ 299	1,252	$ 395
Accumulated Amortization, Ending balance	2,834		2,834		1,582
Intangible assets, net			6,040		3,492
In-Process Research And Development (IPR&D) [Member]
Schedule Of Intangible Assets [Line Items]
Intangible assets, net			269		269
Indefinite-lived Cost, Beginning balance			269
Indefinite-lived Cost, Ending balance	269		269		269
Developed Technology And Order Backlog [Member]
Schedule Of Intangible Assets [Line Items]
Finite-lived Cost, Beginning balance			2,396
Finite-lived Cost, Acquired as a part of Detectent acquisition			2,200
Finite-lived Cost, Ending balance	4,596		4,596		2,396
Accumulated Amortization, Beginning balance			1,139
Accumulated Amortization, Amortization expense			782
Accumulated Amortization, Ending balance	1,921		1,921		1,139
Intangible assets, net			2,675		1,257
Customer Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Finite-lived Cost, Beginning balance			2,140
Finite-lived Cost, Acquired as a part of Detectent acquisition			1,500
Finite-lived Cost, Ending balance	3,640		3,640		2,140
Accumulated Amortization, Beginning balance			417
Accumulated Amortization, Amortization expense			413
Accumulated Amortization, Ending balance	830		830		417
Intangible assets, net			2,810		1,723
Trade Name And Non-Compete Agreements [Member]
Schedule Of Intangible Assets [Line Items]
Finite-lived Cost, Beginning balance			269
Finite-lived Cost, Acquired as a part of Detectent acquisition			100
Finite-lived Cost, Ending balance	369		369		269
Accumulated Amortization, Beginning balance			26
Accumulated Amortization, Amortization expense			57
Accumulated Amortization, Ending balance	$ 83		83		26
Intangible assets, net			$ 286		$ 243
Minimum [Member] | Developed Technology And Order Backlog [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			1 year
Minimum [Member] | Customer Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			2 years
Minimum [Member] | Trade Name And Non-Compete Agreements [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			3 years
Maximum [Member] | Developed Technology And Order Backlog [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			5 years
Maximum [Member] | Customer Relationships [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			7 years
Maximum [Member] | Trade Name And Non-Compete Agreements [Member]
Schedule Of Intangible Assets [Line Items]
Amortization Period			6 years

Goodwill and Intangible Asset48

Goodwill and Intangible Assets (Schedule of Amortization Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 421	$ 299	$ 1,252	$ 395
Cost Of Revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	260	182	782	278
Sales And Marketing [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	153	$ 117	447	$ 117
General And Administrative [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization expense	$ 8		$ 23

Goodwill and Intangible Asset49

Goodwill and Intangible Assets (Schedule of Estimated Future Amortization Expense) (Details) $ in Thousands	Sep. 30, 2015USD ($)
Goodwill And Intangible Assets Disclosure [Abstract]
2,015	$ 421
2,016	1,398
2,017	1,385
2,018	1,144
2,019	994
2020 and thereafter	429
Net carrying amount	$ 5,771

Stock-Based Compensation (Narra

Stock-Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	Jul. 28, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014	Mar. 12, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 5,853	$ 10,476	$ 21,537	$ 31,470
Accrued liabilities		$ 14,045		$ 14,045		$ 8,912
2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [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
ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares reserved for issuance							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%		15.00%
Offering period				6 months
Inducement Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
common stock on the date of grant and vest	twenty-five
Consecutive trading period	45 days
2012 Equity Incentive Plan and 2012 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares reserved for issuance		5,000,000		5,000,000		4,300,000
Corporate Bonus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense		$ 800	$ 2,700	$ 6,100	$ 6,000
Accrued liabilities		6,100		$ 6,100		$ 1,900
Incentive Stock Options (ISOs) [Member] | 2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [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
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs		5,900		$ 5,900
Weighted-average period of recognized stock-based compensation expenses				2 years 6 months
Stock Options [Member] | 2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Contractual term				10 years
Vesting period				4 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation costs		$ 22,200		$ 22,200
Weighted-average period of recognized stock-based compensation expenses				2 years 4 months 24 days
Restricted Stock Units [Member] | Inducement Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	250,000
Performance Stock Units | Inducement Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	125,000
Inducement Grants[Member] | Inducement Grants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, shares purchased for award	125,000
Performance Stock Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Consecutive trading period				45 days
Requisite service period				3 years
Fair value of performance stock awards				$ 5,700
Minimum [Member] | Restricted Stock Units [Member] | 2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				2 years
Maximum [Member] | Restricted Stock Units [Member] | 2012 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period				4 years

Stock-Based Compensation (Stock

Stock-Based Compensation (Stock-Based Compensation Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 5,853	$ 10,476	$ 21,537	$ 31,470
Cost Of Revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,197	2,770	5,129	7,392
Research And Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,771	3,042	6,783	8,892
Sales And Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	914	1,783	3,439	5,582
General And Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,971	$ 2,881	$ 6,186	$ 9,604

Stock-Based Compensation (Summa

Stock-Based Compensation (Summary of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Balance at December 31, 2014	4,525
Number of Shares, Options granted	419
Number of Shares, Options exercised	(155)
Number of Shares, Options cancelled or expired	(411)
Number of Shares, Balance at September 30, 2015	4,378
Number of Shares, Options vested and expected to vest	4,339
Number of Shares, Options exercisable	3,327
Weighted Average Exercise Price per Share, Balance at December 31, 2014 | $ / shares	$ 12.38
Weighted Average Exercise Price per Share, Options granted | $ / shares	8.04
Weighted Average Exercise Price per Share, Options exercised | $ / shares	2.70
Weighted Average Exercise Price per Share, Options cancelled or expired | $ / shares	17.46
Weighted Average Exercise Price per Share, Balance at September 30, 2015 | $ / shares	11.83
Weighted Average Exercise Price per Share, Options vested and expected to vest | $ / shares	11.81
Weighted Average Exercise Price per Share, Options exercisable | $ / shares	$ 11.51
Weighted Average Remaining Contractual Term (years), Balance at September 30, 2015	5 years 6 months 7 days
Weighted Average Remaining Contractual Term (years), Options vested and expected to vest	5 years 6 months
Weighted Average Remaining Contractual Term (years), Options exercisable	4 years 6 months 7 days
Aggregate Intrinsic Value, Balance at September 30, 2015 | $	$ 15,592
Aggregate Intrinsic Value, Options vested and expected to vest | $	15,538
Aggregate Intrinsic Value, Option exercisable | $	$ 13,499

Stock-Based Compensation (Sum53

Stock-Based Compensation (Summary of Restricted Stock Unit Activity) (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2015$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Number of Shares, Balance at December 31, 2014	2,200
Number of Shares, Restricted stock units granted	2,038
Number of Shares, Restricted stock units vested	(1,056)
Number of Shares, Restricted stock units cancelled	(323)
Number of Shares, Balance at September 30, 2015	2,859
Weighted Average Grant Date Fair Value per Share, Balance at December 31, 2014 | $ / shares	$ 15.06
Weighted Average Grant Date Fair Value per Share, Restricted stock units granted | $ / shares	9.64
Weighted Average Grant Date Fair Value per Share, Restricted stock units vested | $ / shares	15.59
Weighted Average Grant Date Fair Value per Share, Restricted stock units cancelled | $ / shares	14.18
Weighted Average Grant Date Fair Value per Share, Balance at September 30, 2015 | $ / shares	$ 10.84

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Taxes [Line Items]
Effective tax rate	(26.20%)	0.40%	(3.60%)	(0.50%)
Detectent Inc. [Member]
Income Taxes [Line Items]
Deferred income tax benefits	$ 1.1		$ 1.1

Segment Information (Details)

Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)segment	Sep. 30, 2014USD ($)
Revenue:
Number of reportable segments | segment			1
Total revenue, net	$ 69,505	$ 28,041	$ 290,312	$ 113,877
United States [Member]
Revenue:
Total revenue, net	53,113	15,700	248,049	71,561
Australia [Member]
Revenue:
Total revenue, net	14,492	8,828	37,204	22,131
All Other [Member]
Revenue:
Total revenue, net	$ 1,900	$ 3,513	$ 5,059	$ 20,185

Balance Sheet Details (Schedule

Balance Sheet Details (Schedule of Inventories) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Disclosure Text Block Supplement [Abstract]
Component parts	$ 1,332	$ 2,843
Finished goods	2,429	3,879
Inventories	$ 3,761	$ 6,722

Balance Sheet Details (Schedu57

Balance Sheet Details (Schedule of Accrued and Other Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Disclosure Text Block Supplement [Abstract]
Accrued payroll and related expenses	$ 14,045	$ 8,912
Accrued operating expenses	3,103	2,548
Warranty obligations, current	7,664	3,838
Sales, property and income taxes	1,012	1,996
Current portion of capital lease obligation	454	1,163
Other deferred revenue	6,794	4,955
Other	1,185	1,009
Accrued and other liabilities	$ 34,257	$ 24,421

Balance Sheet Details (Schedu58

Balance Sheet Details (Schedule Of Other Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Disclosure Text Block Supplement [Abstract]
Warranty obligations, non-current	$ 3,263	$ 3,397
Other deferred revenue	10,652	9,816
Deferred rent long term	994	1,368
Other	941	493
Other liabilities	$ 15,850	$ 15,074

Balance Sheet Details (Schedu59

Balance Sheet Details (Schedule of Product Warranty Obligation) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Product Warranty Liability [Line Items]
Warranty obligation	$ 10,927	$ 7,235	$ 7,283	$ 6,089
Accrued And Other Liabilities [Member]
Product Warranty Liability [Line Items]
Warranty obligation	7,664	3,838
Other Liabilities [Member]
Product Warranty Liability [Line Items]
Warranty obligation	$ 3,263	$ 3,397

Balance Sheet Details (Schedu60

Balance Sheet Details (Schedule of Product Warranty Activity) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Disclosure Text Block Supplement [Abstract]
Warranty obligation—beginning of period	$ 7,235	$ 6,089
Warranty expense for new warranties issued	346	506
Utilization of warranty obligation	(1,624)	(2,101)
Changes in estimates for pre-existing warranties	4,970	2,789
Warranty obligation—end of period	$ 10,927	$ 7,283

Balance Sheet Details (Schedu61

Balance Sheet Details (Schedule of Accumulated Other Comprehensive Loss (AOCL)) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			$ (779)
Other comprehensive (loss) income before reclassification			(726)
Amounts reclassified from AOCI			(39)
Other comprehensive (loss) income	$ (81)	$ 1	(765)	$ (66)
Ending balance	(1,544)		(1,544)
Foreign Currency Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(724)
Other comprehensive (loss) income before reclassification			(882)
Other comprehensive (loss) income			(882)
Ending balance	(1,606)		(1,606)
Unrealized Gains (Losses) On Available For Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance			(55)
Other comprehensive (loss) income before reclassification			156
Amounts reclassified from AOCI			(39)
Other comprehensive (loss) income			117
Ending balance	$ 62		$ 62

Restructuring Charges (Narrativ

Restructuring Charges (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 339	$ 1,888	$ 1,611	$ 1,888
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring			1,611
Severance Costs [Member] | 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 1,900	1,153
Severance Costs [Member] | 2014 Restructuring Plan [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Future charges	$ 400		$ 400

Restructuring Charges (Accrued

Restructuring Charges (Accrued Liabilities Related to Restructuring Actions) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Additions		$ 339	$ 1,888	$ 1,611	$ 1,888
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance				235
Additions				1,611
Utilization				(1,664)
Ending Balance	[1]	182		182
2014 Restructuring Plan [Member] | Severance Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance				235
Additions			$ 1,900	1,153
Utilization				(1,206)
Ending Balance	[1]	$ 182		182
2014 Restructuring Plan [Member] | Professional Fees [Member]
Restructuring Cost and Reserve [Line Items]
Additions				458
Utilization				$ (458)
[1]	Included under Accrued and other liabilities in the condensed consolidated balance sheets.

Commitments and Contingencies64

Commitments and Contingencies (Narrative) (Details) AUD in Millions, $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
	Dec. 31, 2014USD ($)	Jun. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015AUD	Dec. 31, 2014AUD
Commitments and Contingencies [Line Items]
Rent expense facility leases			$ 1.4	$ 1.4	$ 3.9	$ 4
Standby letters of credit	$ 17		21		21
Unsecured surety bond			20.3		20.3
Australian Dollars [Member]
Commitments and Contingencies [Line Items]
Standby letters of credit	0.5		4.4		4.4		AUD 6.1	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		13
Possible estimated loss			$ 14.7		$ 14.7

Commitments and Contingencies65

Commitments and Contingencies (Future Minimum Commitments Under Operating and Capital Leases) (Details) $ in Thousands	Sep. 30, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
Operating Leases, 2015	$ 1,394
Operating Leases, 2016	2,962
Operating Leases, 2017	722
Operating Leases, 2018	641
Operating Leases, 2019	548
Operating Leases, 2020 and thereafter	1,435
Net minimum operating lease payments	7,702
Capital Leases, 2015	175
Capital Leases, 2016	112
Net minimum capital lease payments	287
Less amount representing interest	(10)
Present value of net minimum capital lease payments	$ 277

Subsequent Event (Narrative) (D

Subsequent Event (Narrative) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Jan. 01, 2017ft²	Jan. 01, 2016ft²	Oct. 27, 2015ft²Ageement
Subsequent Event [Line Items]
Initial lease term			10 years 6 months
Extension of lease term			5 years
Rent expense facility leases	$ 1.4	$ 1.4	$ 3.9	$ 4
Aggregate base rent obligation			60.8
Minimum [Member]
Subsequent Event [Line Items]
Rent expense facility leases			3.9
Maximum [Member]
Subsequent Event [Line Items]
Rent expense facility leases			$ 7.5
Scenario, Forecast [Member]
Subsequent Event [Line Items]
Lease agreement space | ft²					47,900	143,900
Subsequent Event [Member] | Landlord [Member]
Subsequent Event [Line Items]
Number of lease agreements | Ageement							2
Lease agreement space | ft²							191,800