Itron Networked Solutions (SSNI) 10-Q 11 May 15 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Mar. 31, 2015	6-May-15
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	31-Mar-15
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q1
Trading Symbol	ssni
Entity Registrant Name	SILVER SPRING NETWORKS INC
Entity Central Index Key	1180079
Current Fiscal Year End Date	-19
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		49,701,343

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$50,695	$60,457
Short-term investments	60,520	60,339
Accounts receivable	47,921	54,740
Inventory	7,337	6,722
Deferred cost of revenue	188,310	29,585
Deferred tax assets	367	5,278
Prepaid expenses and other current assets	7,492	5,146
Total current assets	362,642	222,267
Property and equipment, net	12,598	12,860
Goodwill and intangible assets	15,997	8,221
Deferred cost of revenue, non-current	112,214	303,445
Deferred tax assets, non-current	20,874	354
Other long-term assets	3,887	1,047
Total assets	528,212	548,194
Current liabilities:
Accounts payable	30,408	27,530
Accrued liabilities	24,755	23,258
Deferred revenue	295,960	91,688
Current portion of capital lease obligations	897	1,163
Deferred tax liability	20,778	249
Total current liabilities	372,798	143,888
Deferred revenue, non-current	234,024	517,905
Deferred tax liability, non-current	17	5,146
Other liabilities	15,672	15,074
Total liabilities	622,511	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; 49,694 and 49,062 shares issued and outstanding as of March 31, 2015 and December 31, 2014, respectively	578,776	573,391
Accumulated other comprehensive loss	-1,549	-779
Accumulated deficit	-671,526	-706,431
Total stockholders' deficit	-94,299	-133,819
Total liabilities and stockholders’ deficit	$528,212	$548,194

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Condensed Consolidated Balance Sheets [Abstract]
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	49,694,000	49,062,000
Common stock, shares outstanding	49,694,000	49,062,000

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue:
Product revenue	$105,035	$28,227
Service revenue	38,605	16,002
Total revenue, net	143,640	44,229
Cost of revenue:
Product cost of revenue	56,617	17,915
Service cost of revenue	15,568	14,870
Total cost of revenue	72,185	32,785
Gross profit	71,455	11,444
Operating expenses:
Research and development	15,694	17,725
Sales and marketing	9,297	9,223
General and administrative	12,129	11,667
Restructuring	194
Total operating expenses	37,314	38,615
Operating income (loss)	34,141	-27,171
Other income (expense), net:
Other income (expense), net	288	-37
Income (loss) before income taxes	34,429	-27,208
(Benefit) provision for income taxes	-476	599
Net income (loss)	$34,905	($27,807)
Net income (loss) per share
Basic	$0.71	($0.58)
Diluted	$0.69	($0.58)
Weighted average shares used to compute net loss per share
Basic	49,306	47,693
Diluted	50,899	47,693

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net income (loss)	$34,905	($27,807)
Other comprehensive income (loss):
Change in foreign currency translation adjustment	-948	8
Net unrealized gain (loss) on available-for-sale investments (net of tax effect of $0 and $0)	178	-75
Other comprehensive loss	-770	-67
Comprehensive income (loss)	$34,135	($27,874)

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]
Net unrealized gain (loss) on available-for-sale investments, tax effect	$0	$0

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Cash flows used in operating activities:
Net income (loss)	$34,905	($27,807)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Deferred taxes	-890	407
Depreciation and amortization	1,949	1,466
Stock-based compensation	7,023	11,432
Other non-cash adjustments	53	102
Changes in operating assets and liabilities:
Accounts receivable	7,301	8,301
Inventory	-604	-509
Prepaid expenses and other assets	-904	-1,144
Contingent payments related to Detectent acquisition, held in escrow	-4,000
Deferred cost of revenue	32,516	-20,366
Accounts payable	2,878	-3,124
Customer deposits	-200	107
Deferred revenue	-80,561	27,675
Accrued and other liabilities	79	200
Net cash used in operating activities	-455	-3,260
Cash flows provided by (used in) investing activities:
Business acquisition, net of cash acquired	-7,098
Proceeds from sales of available-for-sale investments		13,966
Proceeds from maturities of available-for-sale investments	4,000	4,500
Purchases of available-for-sale investments	-4,056	-17,354
Purchases of property and equipment	-1,374	-1,742
Net cash used in investing activities	-8,528	-630
Cash flows provided by (used in) financing activities:
Payments on capital lease obligations	-410	-356
Proceeds from issuance of common stock, net of repurchases	1,905	4,555
Taxes paid related to net share settlement of equity awards	-2,057	-4,413
Net cash used in financing activities	-562	-214
Effect of exchange rate changes on cash and cash equivalents	-217
Net decrease in cash and cash equivalents	-9,762	-4,104
Cash and cash equivalents-beginning of period	60,457	82,596
Cash and cash equivalents-end of period	50,695	78,492
Supplemental cash flow information: Cash paid for taxes	970	98
Supplemental cash flow information: Cash paid for interest	$20	$34

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2015
Basis of Presentation [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 months ended March 31, 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.

Significant_Accounting_Policie

Significant Accounting Policies and Estimates	3 Months Ended
	Mar. 31, 2015
Significant Accounting Policies and Estimates [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, in Notes to Consolidated Financial Statements in Item 8 of Part II of our Annual Report on Form 10-K for the year ended December 31, 2014 that have had a material impact on our condensed consolidated financial statements and related notes, except as described below.
	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 quarter ended March 31, 2015 in the Condensed Statements of Operations included revenue of $112.3 million and cost of revenue of $43.6 million, respectively, which otherwise would have been deferred before the change in such assessment, resulting in a $68.7 million increase to net income, $1.40 increase to basic net income per share, and $1.35 increase to diluted net income per share. Receipt of acceptance from the 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 May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance related to revenue from contracts with customers, which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. Under this guidance, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. The new guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract.  The updated standard will replace most existing revenue recognition guidance under GAAP when it becomes effective and permits the use of either the full retrospective or cumulative effect transition method. Early adoption is not permitted. The updated standard will be effective for us in the first quarter of 2017. We have not yet selected a transition method and we are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures.

Net_Income_Loss_Per_Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2015
Net Income (Loss) Per Share [Abstract]
Net Income (Loss) Per Share	3. Net income (loss) per share
	Basic net income (loss) per share applicable to common stockholders is computed by dividing the net income (loss) applicable to common stockholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net 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 income (loss) per share applicable to common stockholders (in thousands, except per share data):
		Three Months Ended
		March 31,
		2015		2014
	Net income (loss)	$	34,905	$	-27,807
	Weighted average shares outstanding—basic		49,306		47,693
	Dilutive effect of employee equity incentive plans		1,593		-
	Weighted average shares outstanding—diluted		50,899		47,693
	Basic net income (loss) per share	$	0.71	$	-0.58
	Diluted net income (loss) per share	$	0.69	$	-0.58
	The following potential common shares outstanding were excluded from the computation of diluted net income (loss) per share because including them would have been anti-dilutive (in thousands):
		March 31,
		2015		2014
	Employee equity incentive plans		4,405		6,725

Cash_Cash_Equivalents_and_Shor

Cash, Cash Equivalents, and Short-Term Investments	3 Months Ended
	Mar. 31, 2015
Cash, Cash Equivalents, and Short-Term Investments [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 March 31, 2015
		Amortized		Unrealized		Unrealized		Estimated
		Cost		Gains		Losses		Fair Value
	Current assets:
	Cash	$	44,318	$	—	$	—	$	44,318
	Cash equivalents:
	Money market mutual funds		6,377		—		—		6,377
	Total cash equivalents		6,377		—		—		6,377
	Short-term fixed income securities:
	U.S. government and agency obligations		39,006		133		—		39,139
	U.S. and foreign corporate debt securities		19,340		48		-4		19,384
	Foreign governments and multi-national agency obligations		2,000		—		-3		1,997
	Total short-term investments		60,346		181		-7		60,520
	Total cash, cash equivalents and short-term investments	$	111,041	$	181	$	-7	$	111,215
		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 March 31, 2015, approximately 45% and 40% 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):
		31-Mar-15				31-Dec-14
		Amortized		Aggregate		Amortized		Aggregate
		Cost Basis		Fair Value		Cost Basis		Fair Value
	Due within one year	$	17,745	$	17,759	$	20,588	$	20,599
	Due after 1 year through 3 years		48,978		49,138		45,973		45,958
	Total cash equivalents & short-term investments	$	66,723	$	66,897	$	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 March 31, 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 March 31, 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	$	3,723	$	-4	$	14,563	$	-33
	Foreign governments and multi-national agency obligations		1,997		-3		1,992		-8
	U.S. government and agency obligations		-		-		13,523		-18
	Total	$	5,720	$	-7	$	30,078	$	-59
	As of March 31, 2015 and December 31, 2014, there were no investments with unrealized losses for a period in excess of 12 months.
	We periodically review our marketable debt securities for other-than-temporary impairment. We consider factors such as the duration, severity and the reason for the decline in value, the potential recovery period and our intent to sell. We also consider whether it is more likely than not that we will be required to (i) sell the debt securities before recovery of their amortized cost basis, and (ii) the amortized cost basis cannot be recovered as a result of credit losses. As of March 31, 2015, we anticipate that we will recover the entire amortized cost basis of such available-for-sale debt securities and has determined that no other-than-temporary impairments associated with credit losses were required to be recognized during the three months ended March 31, 2015 and 2014. There were no material gross realized gains or losses from available-for-sale securities during the three months ended March 31, 2015 and 2014.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2015
Fair Value Measurements [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, the fair value hierarchy prioritizes the inputs into three levels that may be used to measure fair value. The fair value framework requires the categorization of assets and liabilities into three levels based upon the assumptions (inputs) used to price the assets or liabilities. The guidance for fair value measurements requires that assets and liabilities carried at fair value be classified and disclosed in one of the following categories:
	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 three months ended March 31, 2015 and year ended December 31, 2014.
	Assets Measured at Fair Value on a Recurring Basis
	As of March 31, 2015, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands):
		Fair Value Measurement Using
		Quoted Prices in
		Active Markets		Significant Other		Significant
		for Identical		Observable		Unobservable
		Instruments		Inputs		Inputs
		(Level 1)		(Level 2)		(Level 3)		Total
	Cash equivalents:
	Money-market funds	$	6,377	$	—	$	—	$	6,377
	Total cash equivalents		6,377		—		—		6,377
	Short-term investments:
	U.S. government and agency obligations		—		39,139		—		39,139
	U.S. and foreign corporate debt securities		—		19,384		—		19,384
	Foreign governments and multi-national agency obligations		—		1,997		—		1,997
	Total short-term investments		—		60,520		—		60,520
	Total assets measured at fair value	$	6,377	$	60,520	$	—	$	66,897
	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 March 31, 2015 and December 31, 2014, there were no liabilities that were measured and recorded at fair value on a recurring basis.
	As of March 31, 2015 and December 31, 2014, there were no assets and liabilities that are 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 other accrued liabilities approximate fair value due to their short maturities.

Business_Acquisition

Business Acquisition	3 Months Ended
	Mar. 31, 2015
Business Acquisition [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 months ended March 31, 2015, we recorded 0.4 million in compensation expense in the consolidated statement of operations with a corresponding liability included in the accrued liability in the consolidated balance sheets.
	In accordance with ASC Topic 805, Business Combinations (“ASC 805”), the acquisition of Detectent was accounted for under the acquisition method of accounting. Under the acquisition method of accounting, the total purchase consideration, assets acquired and the liabilities assumed are measured at fair value as of the date of acquisition when control is obtained. The fair value of the consideration transferred and the assets acquired and liabilities assumed was determined by us and in doing so relied in part upon a third-party valuation report to measure the identifiable intangible assets acquired and obligations related to deferred revenue. The following table summarizes the fair value of total consideration transferred for the Detectent acquisition, the total fair value of net identifiable assets acquired and the resulting goodwill recorded (in thousands):
	[
		Cash consideration	$	7,616
		Less: Fair value of net identifiable assets acquired		-2,824
		Goodwill	$	4,792
	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		-604
	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		-890
	Total fair value of net identifiable assets acquired	$	2,824
	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 $0.9 million which was recognized in the purchase price accounting has been netted with our existing deferred tax assets. As a result, there was a $0.9 million reversal of the Company’s valuation allowance which was recorded as a tax benefit in the 2015 first quarter financial statements in accordance with ASC 805.
	We recognized $0.7 million of acquisition-related costs that were expensed during the three months ended March 31, 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 less than 1% of the total revenue recognized during the period ended March 31, 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 recorded a 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.

Goodwill_and_Intangible_Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets [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):
			March 31,			December 31,
			2015			2014
	Balance, beginning of period		$	4,729		$	447
	Goodwill acquired during the period			4,792			4,685
	Goodwill measurement period adjustment			45			85
	Currency translation adjustment			-453			-488
	Balance, end of period		$	9,113		$	4,729
	During the three months ended March 31, 2015, we recorded goodwill of $4.8 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. In addition, we also adjusted goodwill by $0.1 million in connection with our acquisition of SLV as a measurement period adjustment during the year ended December 31, 2014 and three months ended March 31, 2015. 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:
		Developed Technology and Order Backlog			Customer Relationships			Trade Name and Non-Compete Agreements		In-process 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 March 31, 2015	$	4,596		$	3,640		$	369	$	269	$	8,874
	Accumulated Amortization:
	Balance at December 31, 2014	$	1,139		$	417		$	26	$	—	$	1,582
	Amortization expense		262			128			18		—		408
	Balance at March 31, 2015	$	1,401		$	545		$	44	$	—	$	1,990
	Intangible assets, net at March 31, 2015	$	3,195		$	3,095		$	325	$	269	$	6,884
	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 first quarter ended March 31, 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 for the three months ended March 31, 2015 (in thousand):
		Three Months Ended
		31-Mar-15
	Cost of revenue	$	262
	Sales and marketing		139
	General and administrative		7
	Total	$	408
	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		$	1,266
	2016			1,398
	2017			1,385
	2018			1,144
	2019			994
	2020 and thereafter			428
			$	6,615

StockBased_Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [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 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 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 at 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 and 2014, the total shares reserved for issuance under the 2012 Plan were automatically increased by 1,962,491 and 1,895,371, respectively.
	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 the Company’s Common Stock reserved for issuance under the Plan shall be increased automatically by the number of shares equal to 1% of the total number of outstanding shares of the Company 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 and 2014, the total shares reserved for issuance under the ESPP were automatically increased by 490,622 and 473,843, respectively.
	Performance Stock Award
	On February 10, 2015, we granted to our Chief Executive Officer, performance restricted stock units (“PSUs”) to acquire up to a maximum of 250,000 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 his continued services to the Company as a director, officer, employee or consultant. The PSUs become eligible to vest when the average closing price during the 45 consecutive trading days’ reaches the share price thresholds specified in the grant between the grant date and the 3-year anniversary. We determined the value of these RSUs using a Monte-Carlo simulation due to the path-dependency of the award. The fair value of the PSUs is determined to be $1.1 million which will be recognized over the requisite service period using the accelerated method.
	As of March 31, 2015 and December 31, 2014, there were 6.4  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
		March 31,
		2015			2014
	Cost of revenue	$	1,723		$	2,692
	Research and development		2,180			3,155
	Sales and marketing		1,238			2,045
	General and administrative		1,882			3,540
	Stock-based compensation expense	$	7,023		$	11,432
	Of the total stock-based compensation, we recorded $1.5 million and $2.7 million, respectively as stock-based compensation related to our corporate bonus incentive plan during the three months ended March 31, 2015 and 2014. As of March 31, 2015 and December 31, 2014, stock-based bonus of $3.4 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 three months ended March 31, 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	405			7.99
	Options exercised	-95			2.52
	Options cancelled or expired	-176			16.88
	Balance at March 31, 2015	4,659		$	12.03		6.00	$	9,286
	As of March 31, 2015:
	Options vested and expected to vest	4,590		$	11.99		5.95	$	9,272
	Options exercisable	3,230		$	11.25		4.66	$	8,815
	The aggregate intrinsic value disclosed above represents the total intrinsic value (the difference between the fair value of our common stock as of March 31, 2015 and the exercise price, multiplied by the number of in-the-money options) that would have been received by the option holders had all option holders exercised their options on March 31, 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 three months ended March 31, 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	284			4.81
	Restricted stock units vested	-539			17.75
	Restricted stock units cancelled	-115			14.80
	Balance at March 31, 2015	1,830		$	12.69
	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 March 31, 2015, there was $8.3 million and $17.1 million of total unrecognized compensation cost related to non-vested stock-based compensation arrangements related to options and RSUs, respectively, which are expected to be recognized over a weighted-average period of 2.9 and 2.1 years, respectively.

Income_Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2015
Income Taxes [Abstract]
Income Taxes	9. Income Taxes
	Our benefit for income taxes for the three months ended March 31, 2015 reflects an effective tax rate of (1.4%). Our provision for income taxes for the three months ended March 31, 2014 reflects an effective tax rate of (2.2%).  Our benefit for income taxes for the three months ended March 31, 2015 consists primarily of a net benefit of $0.9 million, which was due to the deferred income tax benefits related to the Detectent acquisition. Our provision for income taxes for the three months ended March 31, 2014 consisted primarily of foreign income and withholding taxes.

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2015
Segment Information [Abstract]
Segment Information	10. Segment Information
	We operate in one reportable segment. Our chief operating decision maker is our Chief Executive Officer, 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 March 31,
		2015		2014
	Revenue:
	United States	$	122,582	$	21,842
	Australia		19,176		9,775
	All Other		1,882		12,612
	Total	$	143,640	$	44,229

Balance_Sheet_Details

Balance Sheet Details	3 Months Ended
	Mar. 31, 2015
Balance Sheet Details [Abstract]
Balance Sheet Details	11. Balance Sheet Details
	Inventory
	Inventory consisted of the following (in thousands):
		March 31,		December 31,
		2015		2014
	Component parts	$	2,385	$	2,843
	Finished goods		4,952		3,879
	Inventory	$	7,337	$	6,722
	Accrued Liabilities
	Accrued liabilities consisted of the following (in thousands):
		March 31,		December 31,
		2015		2014
	Accrued payroll and related expenses	$	10,206	$	8,912
	Accrued operating expenses		3,278		2,548
	Warranty obligations, current		4,365		3,838
	Sales, property and income taxes		1,036		1,996
	Other deferred revenue		4,968		4,955
	Other		902		1,009
	Accrued liabilities	$	24,755	$	23,258
	Other Liabilities
	Other liabilities consisted of the following (in thousands):
		March 31,		December 31,
		2015		2014
	Warranty obligations, non-current	$	3,647	$	3,397
	Other deferred revenue		10,089		9,816
	Other		1,936		1,861
	Other liabilities	$	15,672	$	15,074
	Product Warranty
	Product warranty obligation is presented as follows on the consolidated balance sheets (in thousands):
		March 31,		December 31,
		2015		2014
	Current warranty obligation—classified in accrued liabilities	$	4,365	$	3,838
	Non-current warranty obligation—classified in other liabilities		3,647		3,397
		$	8,012	$	7,235
	Product warranty activity was as follows (in thousands):
		Three Months Ended
		March 31,
		2015		2014
	Warranty obligation—beginning of period	$	7,235	$	6,089
	Warranty expense for new warranties issued		304		224
	Utilization of warranty obligation		-639		-851
	Changes in estimates for pre-existing warranties		1,112		1,371
	Warranty obligation—end of period	$	8,012	$	6,833
	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 income (loss) before reclassification		-948		178		-770
	Balance as of March 31, 2015	$	-1,672	$	123	$	-1,549

Restructuring_Charges

Restructuring Charges	3 Months Ended
	Mar. 31, 2015
Restructuring Charges [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 $1.8 million in severance costs as restructuring charges during third quarter 2014. We recorded $0.2 million in severance and other related costs as restructuring charges during first quarter 2015 under the 2014 Restructuring Plan.
	In connection with the 2014 Restructuring Plan, we expect to record aggregate future charges of approximately $1.4 million to $1.9 million.  The remaining restructuring costs under the 2014 Restructuring Plan are expected to be incurred by the first half of 2015.
	Accrued liabilities related to restructuring actions during three months ending March 31, 2015 consist of the following (in thousands):
			Balance		Additions		Utilization		Balance
			31-Dec-14						March 31, 2015 (1)
	Fiscal 2014 Plan
	Severance costs	$	235	$	61	$	-179	$	117
	Professional fees		—		133		—		133
	Total	$	235	$	194	$	-179	$	250
	(1)   Included under accounts payable and accrued liabilities in the condensed consolidated balance sheets

Commitments_and_Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Abstract]
Commitments and Contingencies	13. Commitments and contingencies
	Operating and Capital Leases
	Our primary operating lease commitment at March 31, 2015, related to our headquarters in Redwood City, California, requires monthly lease payments through April 2016. We recognize rent expense on a straight-line basis over the lease period. Rent expense for all facility leases was $1.2 million and $1.3 million for the three months ended March 31, 2015 and 2014, respectively.
	The future minimum commitments under our operating and capital leases were as follows (in thousands):
		31-Mar-15
		Operating Leases		Capital Leases
	2015	$	4,126	$	754
	2016		2,843		112
	2017		597		—
	2018		608		—
	2019		545		—
	2020 and thereafter		1,425		—
	Net minimum lease payments	$	10,144	$	866
	Less amount representing interest				-31
	Present value of net minimum capital lease payments			$	835
	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.”  Upon completion of the appeal process, both the surety bond and standby letter of credit will be released.  In January 2015, the District Court accepted the bond and entered the stay of execution of the judgment.  EON filed a notice of cross appeal in January 2015.  We filed our opening appellate brief in March 2015.  EON’s principal brief is due in May 2015. We expect the appeal process to take place during 2015 and perhaps into early 2016.
	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 (“GE”) meters with our wireless modules.  We have agreed with GE 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, GE filed reexamination requests on the TransData patents at issue with the U.S. Patent and Trademark Office (the “USPTO”).    In August and September 2014, GE 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. Pre-trial proceedings in the matter are ongoing, and each side has filed pre-trial motions.  The court has not yet set any hearing date. We believe that OG&E has meritorious defenses to TransData’s allegations, and that OG&E will continue to vigorously defend itself.
	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 reexamination, and we filed an answer responding to the complaint and raising additional defenses.  The trial has been scheduled for November 2015.  We believe that we have meritorious defenses to Linex’s allegations and intend to continue vigorously defending against the action.
	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 March 31, 2015 and December 31, 2014, we had a total of $17.0 million, including $13.0 million related to 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 $0.5 million (AUD$0.6 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 March 31, 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. As of December 31, 2014, 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.

Significant_Accounting_Policie1

Significant Accounting Policies and Estimates (Policies)	3 Months Ended
	Mar. 31, 2015
Significant Accounting Policies and Estimates [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 quarter ended March 31, 2015 in the Condensed Statements of Operations included revenue of $112.3 million and cost of revenue of $43.6 million, respectively, which otherwise would have been deferred before the change in such assessment, resulting in a $68.7 million increase to net income, $1.40 increase to basic net income per share, and $1.35 increase to diluted net income per share. Receipt of acceptance from the 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 May 2014, the Financial Accounting Standards Board (“FASB”) issued guidance related to revenue from contracts with customers, which supersedes the revenue recognition requirements in ASC 605, Revenue Recognition. Under this guidance, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. The new guidance also requires additional disclosure about the nature, amount, timing and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract.  The updated standard will replace most existing revenue recognition guidance under GAAP when it becomes effective and permits the use of either the full retrospective or cumulative effect transition method. Early adoption is not permitted. The updated standard will be effective for us in the first quarter of 2017. We have not yet selected a transition method and we are currently evaluating the effect that the updated standard will have on our consolidated financial statements and related disclosures.

Net_Income_Loss_Per_Share_Tabl

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2015
Net Income (Loss) Per Share [Abstract]
Computation of Basic and Diluted Net Income (Loss) Per Share
		Three Months Ended
		March 31,
		2015		2014
	Net income (loss)	$	34,905	$	-27,807
	Weighted average shares outstanding—basic		49,306		47,693
	Dilutive effect of employee equity incentive plans		1,593		-
	Weighted average shares outstanding—diluted		50,899		47,693
	Basic net income (loss) per share	$	0.71	$	-0.58
	Diluted net income (loss) per share	$	0.69	$	-0.58
Common Shares Outstanding Excluded from Computation of Diluted Net Income (Loss) Per Share
		March 31,
		2015		2014
	Employee equity incentive plans		4,405		6,725

Cash_Cash_Equivalents_and_Shor1

Cash, Cash Equivalents, and Short-Term Investments (Tables)	3 Months Ended
	Mar. 31, 2015
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Cash, Cash Equivalents, and Short-Term Investments
		As of March 31, 2015
		Amortized		Unrealized		Unrealized		Estimated
		Cost		Gains		Losses		Fair Value
	Current assets:
	Cash	$	44,318	$	—	$	—	$	44,318
	Cash equivalents:
	Money market mutual funds		6,377		—		—		6,377
	Total cash equivalents		6,377		—		—		6,377
	Short-term fixed income securities:
	U.S. government and agency obligations		39,006		133		—		39,139
	U.S. and foreign corporate debt securities		19,340		48		-4		19,384
	Foreign governments and multi-national agency obligations		2,000		—		-3		1,997
	Total short-term investments		60,346		181		-7		60,520
	Total cash, cash equivalents and short-term investments	$	111,041	$	181	$	-7	$	111,215
		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
		31-Mar-15				31-Dec-14
		Amortized		Aggregate		Amortized		Aggregate
		Cost Basis		Fair Value		Cost Basis		Fair Value
	Due within one year	$	17,745	$	17,759	$	20,588	$	20,599
	Due after 1 year through 3 years		48,978		49,138		45,973		45,958
	Total cash equivalents & short-term investments	$	66,723	$	66,897	$	66,561	$	66,557
Schedule of Gross Unrealized Losses and Fair Values of Investments
		As of March 31, 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	$	3,723	$	-4	$	14,563	$	-33
	Foreign governments and multi-national agency obligations		1,997		-3		1,992		-8
	U.S. government and agency obligations		-		-		13,523		-18
	Total	$	5,720	$	-7	$	30,078	$	-59

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2015
Fair Value Measurements [Abstract]
Fair Value of Financial Assets Recorded on Recurring Basis	As of March 31, 2015, financial assets recorded at fair value on a recurring basis were determined using the following inputs (in thousands):
		Fair Value Measurement Using
		Quoted Prices in
		Active Markets		Significant Other		Significant
		for Identical		Observable		Unobservable
		Instruments		Inputs		Inputs
		(Level 1)		(Level 2)		(Level 3)		Total
	Cash equivalents:
	Money-market funds	$	6,377	$	—	$	—	$	6,377
	Total cash equivalents		6,377		—		—		6,377
	Short-term investments:
	U.S. government and agency obligations		—		39,139		—		39,139
	U.S. and foreign corporate debt securities		—		19,384		—		19,384
	Foreign governments and multi-national agency obligations		—		1,997		—		1,997
	Total short-term investments		—		60,520		—		60,520
	Total assets measured at fair value	$	6,377	$	60,520	$	—	$	66,897
	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])	3 Months Ended
	Mar. 31, 2015
Detectent Inc. [Member]
Business Acquisition [Line Items]
Schedule of Business Acquisition
		Cash consideration	$	7,616
		Less: Fair value of net identifiable assets acquired		-2,824
		Goodwill	$	4,792
Assets Acquired and Liabilities Assumed
	Cash	$	518
	Net other tangible liabilities		-604
	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		-890
	Total fair value of net identifiable assets acquired	$	2,824

Goodwill_and_Intangible_Assets1

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2015
Goodwill and Intangible Assets [Abstract]
Schedule of Goodwill
			March 31,			December 31,
			2015			2014
	Balance, beginning of period		$	4,729		$	447
	Goodwill acquired during the period			4,792			4,685
	Goodwill measurement period adjustment			45			85
	Currency translation adjustment			-453			-488
	Balance, end of period		$	9,113		$	4,729
Schedule of Intangible Assets
		Developed Technology and Order Backlog			Customer Relationships			Trade Name and Non-Compete Agreements		In-process 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 March 31, 2015	$	4,596		$	3,640		$	369	$	269	$	8,874
	Accumulated Amortization:
	Balance at December 31, 2014	$	1,139		$	417		$	26	$	—	$	1,582
	Amortization expense		262			128			18		—		408
	Balance at March 31, 2015	$	1,401		$	545		$	44	$	—	$	1,990
	Intangible assets, net at March 31, 2015	$	3,195		$	3,095		$	325	$	269	$	6,884
	Intangible assets, net at December 31, 2014	$	1,257		$	1,723		$	243	$	269	$	3,492
Schedule of Amortization Expense
		Three Months Ended
		31-Mar-15
	Cost of revenue	$	262
	Sales and marketing		139
	General and administrative		7
	Total	$	408
Schedule of Estimated Future Amortization Expense
			Year Ended
	2015		$	1,266
	2016			1,398
	2017			1,385
	2018			1,144
	2019			994
	2020 and thereafter			428
			$	6,615

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Stock-Based Compensation Expense
		Three Months Ended
		March 31,
		2015			2014
	Cost of revenue	$	1,723		$	2,692
	Research and development		2,180			3,155
	Sales and marketing		1,238			2,045
	General and administrative		1,882			3,540
	Stock-based compensation expense	$	7,023		$	11,432
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	405			7.99
	Options exercised	-95			2.52
	Options cancelled or expired	-176			16.88
	Balance at March 31, 2015	4,659		$	12.03		6.00	$	9,286
	As of March 31, 2015:
	Options vested and expected to vest	4,590		$	11.99		5.95	$	9,272
	Options exercisable	3,230		$	11.25		4.66	$	8,815
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	284			4.81
	Restricted stock units vested	-539			17.75
	Restricted stock units cancelled	-115			14.80
	Balance at March 31, 2015	1,830		$	12.69

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2015
Segment Information [Abstract]
Schedule of Revenue by Geographic Region
		Three Months Ended March 31,
		2015		2014
	Revenue:
	United States	$	122,582	$	21,842
	Australia		19,176		9,775
	All Other		1,882		12,612
	Total	$	143,640	$	44,229

Balance_Sheet_Details_Tables

Balance Sheet Details (Tables)	3 Months Ended
	Mar. 31, 2015
Balance Sheet Details [Abstract]
Schedule of Inventory
		March 31,		December 31,
		2015		2014
	Component parts	$	2,385	$	2,843
	Finished goods		4,952		3,879
	Inventory	$	7,337	$	6,722
Schedule of Accrued Liabilities
		March 31,		December 31,
		2015		2014
	Accrued payroll and related expenses	$	10,206	$	8,912
	Accrued operating expenses		3,278		2,548
	Warranty obligations, current		4,365		3,838
	Sales, property and income taxes		1,036		1,996
	Other deferred revenue		4,968		4,955
	Other		902		1,009
	Accrued liabilities	$	24,755	$	23,258
Schedule of Other Liabilities
		March 31,		December 31,
		2015		2014
	Warranty obligations, non-current	$	3,647	$	3,397
	Other deferred revenue		10,089		9,816
	Other		1,936		1,861
	Other liabilities	$	15,672	$	15,074
Schedule of Product Warranty Obligation
		March 31,		December 31,
		2015		2014
	Current warranty obligation—classified in accrued liabilities	$	4,365	$	3,838
	Non-current warranty obligation—classified in other liabilities		3,647		3,397
		$	8,012	$	7,235
Schedule of Product Warranty Activity
		Three Months Ended
		March 31,
		2015		2014
	Warranty obligation—beginning of period	$	7,235	$	6,089
	Warranty expense for new warranties issued		304		224
	Utilization of warranty obligation		-639		-851
	Changes in estimates for pre-existing warranties		1,112		1,371
	Warranty obligation—end of period	$	8,012	$	6,833
Schedule of Accumulated Other Comprehensive Income (AOCI)
				Unrealized Gains
		Foreign Currency		(Losses) on Available
		Adjustment		for Sale Securities		Total
	Balance as of December 31, 2014	$	-724	$	-55	$	-779
	Other comprehensive income (loss) before reclassification		-948		178		-770
	Balance as of March 31, 2015	$	-1,672	$	123	$	-1,549

Restructuring_Charges_Tables

Restructuring Charges (Tables)	3 Months Ended
	Mar. 31, 2015
Restructuring Charges [Abstract]
Accrued Liabilities Related to Restructuring Actions
			Balance		Additions		Utilization		Balance
			31-Dec-14						March 31, 2015 (1)
	Fiscal 2014 Plan
	Severance costs	$	235	$	61	$	-179	$	117
	Professional fees		—		133		—		133
	Total	$	235	$	194	$	-179	$	250
	(1)   Included under accounts payable and accrued liabilities in the condensed consolidated balance sheets

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2015
Commitments and Contingencies [Abstract]
Future Minimum Commitments Under Operating and Capital Leases
		31-Mar-15
		Operating Leases		Capital Leases
	2015	$	4,126	$	754
	2016		2,843		112
	2017		597		—
	2018		608		—
	2019		545		—
	2020 and thereafter		1,425		—
	Net minimum lease payments	$	10,144	$	866
	Less amount representing interest				-31
	Present value of net minimum capital lease payments			$	835

Significant_Accounting_Policie2

Significant Accounting Policies and Estimates (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue	$143,640	$44,229
Cost of revenue	72,185	32,785
Net Income Loss	34,905	-27,807
Basic loss per common share	$0.71	($0.58)
Diluted loss per common share	$0.69	($0.58)
Customer-Specific Acceptance Criteria [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Revenue	112,300
Cost of revenue	43,600
Net Income Loss	$68,700
Basic loss per common share	$1.40
Diluted loss per common share	$1.35

Net_Income_Loss_Per_Share_Comp

Net Income (Loss) Per Share (Computation of Basic and Diluted Net Income (Loss) Per Share) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Net Income (Loss) Per Share [Abstract]
Net income (loss)	$34,905	($27,807)
Weighted average shares outstanding-basic	49,306	47,693
Dilutive effect of employee equity incentive plans	1,593
Weighted average shares outstanding-diluted	50,899	47,693
Basic net income (loss) per share	$0.71	($0.58)
Diluted net income (loss) per share	$0.69	($0.58)

Net_Income_Loss_Per_Share_Comm

Net Income (Loss) Per Share (Common Shares Outstanding Excluded from Computation of Diluted Net Income (Loss) Per Share) (Details) (Employee Equity Incentive Plans [Member])	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Employee Equity Incentive Plans [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total common stock equivalents	4,405	6,725

Cash_Cash_Equivalents_and_Shor2

Cash, Cash Equivalents, and Short-Term Investments (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
	item		item
Cash and Cash Equivalents [Line Items]
Number of financial institutions	2		2
Unrealized losses on investments	$0		$0
Gross realized gains (losses) from available-for-sale securities	$0	$0
Financial Institution One [Member]
Cash and Cash Equivalents [Line Items]
Percentage of cash and cash equivalents held in financial institutions	45.00%		46.00%
Financial Institution Two [Member]
Cash and Cash Equivalents [Line Items]
Percentage of cash and cash equivalents held in financial institutions	40.00%		42.00%

Cash_Cash_Equivalents_and_Shor3

Cash, Cash Equivalents, and Short-Term Investments (Cash, Cash Equivalents, and Short-Term Investments) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$111,041	$120,800
Unrealized Gains	181	55
Unrealized Losses	-7	-59
Estimated Fair Value	111,215	120,796
Cash [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	44,318	54,239
Estimated Fair Value	44,318	54,239
Cash Equivalents [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	6,377	6,218
Estimated Fair Value	6,377	6,218
Cash Equivalents [Member] | Money Market Mutual Funds [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	6,377	6,218
Estimated Fair Value	6,377	6,218
Short-Term Fixed Income Securities [Member]
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	60,346	60,343
Unrealized Gains	181	55
Unrealized Losses	-7	-59
Estimated Fair Value	60,520	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	39,006	38,718
Unrealized Gains	133	46
Unrealized Losses		-18
Estimated Fair Value	39,139	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	19,340	19,625
Unrealized Gains	48	9
Unrealized Losses	-4	-33
Estimated Fair Value	19,384	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	-3	-8
Estimated Fair Value	$1,997	$1,992

Cash_Cash_Equivalents_and_Shor4

Cash, Cash Equivalents, and Short-Term Investments (Contractual Maturities of Cash Equivalents and Short-Term Investments) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Cash, Cash Equivalents, and Short-Term Investments [Abstract]
Due within one year, Amortized Cost Basis	$17,745	$20,588
Due after 1 year through 3 years, Amortized Cost Basis	48,978	45,973
Total cash equivalents & short-term investments, Amortized Cost Basis	66,723	66,561
Due within one year, Aggregate Fair Value	17,759	20,599
Due after 1 year through 3 years, Aggregate Fair Value	49,138	45,958
Total cash equivalents & short-term investments, Aggregate Fair Value	$66,897	$66,557

Cash_Cash_Equivalents_and_Shor5

Cash, Cash Equivalents, and Short-Term Investments (Schedule of Gross Unrealized Losses and Fair Values of Investments) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	$5,720	$30,078
Unrealized Loss Total (Less Than 12 Months)	-7	-59
U.S. And Foreign Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value Total (Less Than 12 Months)	3,723	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)	1,997	1,992
Unrealized Loss Total (Less Than 12 Months)	-3	-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_Fair_V

Fair Value Measurements (Fair Value of Financial Assets Recorded on Recurring Basis) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
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	66,897	66,557
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	6,377	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	6,377	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	60,520	60,339
Fair Value On A Recurring Basis [Member] | Short-Term Fixed Income Securities [Member] | U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	39,139	38,746
Fair Value On A Recurring Basis [Member] | Short-Term Fixed Income Securities [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	19,384	19,601
Fair Value On A Recurring Basis [Member] | Short-Term Fixed Income Securities [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	1,997	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	6,377	6,218
Fair Value On A Recurring Basis [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [Member] | Cash Equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	6,377	6,218
Fair Value On A Recurring Basis [Member] | Quoted Prices In Active Markets For Identical Instruments (Level 1) [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	6,377	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	60,520	60,339
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [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	60,520	60,339
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Short-Term Fixed Income Securities [Member] | U.S. Government And Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	39,139	38,746
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Short-Term Fixed Income Securities [Member] | U.S. And Foreign Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	19,384	19,601
Fair Value On A Recurring Basis [Member] | Significant Other Observable Inputs (Level 2) [Member] | Short-Term Fixed Income Securities [Member] | Foreign Governments And Multi-National Agency Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of financial assets	$1,997	$1,992

Business_Acquisition_Narrative

Business Acquisition (Narrative) (Details) (USD $)	3 Months Ended	0 Months Ended	1 Months Ended	3 Months Ended
	Mar. 31, 2015	Jan. 16, 2015	23-May-14	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$9,113,000			$4,729,000	$447,000
Amortization expenses for intangible assets	408,000
General And Administrative [Member]
Business Acquisition [Line Items]
Amortization expenses for intangible assets	7,000
Customer Relationships [Member]
Business Acquisition [Line Items]
Amortization expenses for intangible assets	128,000
Detectent Inc. [Member]
Business Acquisition [Line Items]
Total consideration		11,600,000
Cash consideration		7,616,000
Contingent payments		4,000,000
Retention period	2 years
Subsidiary revenue of the total revenue	1.00%
Deferred tax liability		890,000
Reversal of valuation allowance	-900,000
Goodwill		4,792,000
Detectent Inc. [Member] | General And Administrative [Member]
Business Acquisition [Line Items]
Compensation expense	400,000
Acquisition-related costs	700,000
Detectent Inc. [Member] | Developed Technology [Member]
Business Acquisition [Line Items]
Discount rate		18.60%
Intangible assets		1,900,000
Detectent Inc. [Member] | Order Backlog [Member]
Business Acquisition [Line Items]
Discount rate		20.10%
Intangible assets		300,000
Detectent Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Discount rate		20.10%
Intangible assets		1,500,000
Detectent Inc. [Member] | Non-Compete Agreements [Member]
Business Acquisition [Line Items]
Discount rate		20.10%
Intangible assets		100,000
StreetLight Vision [Member]
Business Acquisition [Line Items]
Cash consideration			8,800,000
Goodwill			4,700,000
Increase (decrease) in net assets				($100,000)
Minimum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	2 years
Minimum [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	1 year
Maximum [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	7 years
Maximum [Member] | Detectent Inc. [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	7 years

Business_Acquisition_Schedule_

Business Acquisition (Schedule of Business Acquisition) (Details) (USD $)	0 Months Ended
In Thousands, unless otherwise specified	Jan. 16, 2015	Mar. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill		$9,113	$4,729	$447
Detectent Inc. [Member]
Business Acquisition [Line Items]
Cash consideration	7,616
Less: Fair value of net identifiable assets acquired	-2,824
Goodwill	$4,792

Business_Acquisition_Assets_Ac

Business Acquisition (Assets Acquired and Liabilities Assumed) (Details) (Detectent Inc. [Member], USD $)	Jan. 16, 2015
In Thousands, unless otherwise specified
Business Acquisition [Line Items]
Cash	$518
Net other tangible assets, excluding deferred revenue	-604
Deferred tax liabilities in connection with acquired intangible assets and other fair value adjustments, net	-890
Total fair value of net identifiable assets acquired	2,824
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

Recovered_Sheet1

Goodwill And Intangible Assets (Narrative) (Details) (USD $)	3 Months Ended	12 Months Ended	15 Months Ended
	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2015
Goodwill and Intangible Assets [Abstract]
Goodwill acquired during the period	$4,792,000	$4,685,000
Increase (decrease) in goodwill			100,000
Goodwill measurement period adjustment	45,000	85,000
Intangible assets acquired as a part of Detectent acquisition	$3,800,000

Recovered_Sheet2

Goodwill And Intangible Assets (Schedule of Goodwill) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Basis of Presentation [Abstract]
Balance, beginning of period	$4,729	$447
Goodwill acquired during the period	4,792	4,685
Goodwill measurement period adjustment	45	85
Currency translation adjustment	-453	-488
Balance, end of period	$9,113	$4,729

Goodwill_And_Intangible_Assets2

Goodwill And Intangible Assets (Schedule of Intangible Assets) (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	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	5,074
Accumulated Amortization, Beginning Balance	1,582
Accumulated Amortization, Amortization expense	408
Accumulated Amortization, Ending Balance	1,990	1,582
Intangible assets, net	6,884	3,492
In-Process Research And Development (IPR&D) [Member]
Schedule Of Intangible Assets [Line Items]
Indefinite-lived Cost, Beginning Balance	269
Indefinite-lived Cost, Ending Balance	269	269
Intangible assets, net	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	2,396
Accumulated Amortization, Beginning Balance	1,139
Accumulated Amortization, Amortization expense	262
Accumulated Amortization, Ending Balance	1,401	1,139
Intangible assets, net	3,195	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	2,140
Accumulated Amortization, Beginning Balance	417
Accumulated Amortization, Amortization expense	128
Accumulated Amortization, Ending Balance	545	417
Intangible assets, net	3,095	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	269
Accumulated Amortization, Beginning Balance	26
Accumulated Amortization, Amortization expense	18
Accumulated Amortization, Ending Balance	44	26
Intangible assets, net	$325	$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_Assets3

Goodwill And Intangible Assets (Schedule of Amortization Expense) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization, Amortization expense	$408
Cost Of Revenue [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization, Amortization expense	262
Sales And Marketing [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization, Amortization expense	139
General And Administrative [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization, Amortization expense	$7

Goodwill_And_Intangible_Assets4

Goodwill And Intangible Assets (Schedule of Estimated Future Amortization Expense) (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Goodwill and Intangible Assets [Abstract]
2015	$1,266
2016	1,398
2017	1,385
2018	1,144
2019	994
2020 and thereafter	428
Net Carrying Amount	$6,615

StockBased_Compensation_Narrat

Stock-Based Compensation (Narrative) (Details) (USD $)	3 Months Ended		12 Months Ended		0 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Feb. 10, 2015	Mar. 12, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares reserved for issuance	6,400,000		4,300,000
Shares available for grant increase percent	4.00%
Stock-based compensation expense	$7,023,000	$11,432,000
Accrued liabilities	10,206,000		8,912,000
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
Increase in shares reserved for issuance			1,895,371	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%
Maximum employees contribution	15.00%
Corporate Bonus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,500,000	2,700,000
Accrued liabilities	3,400,000		1,900,000
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	8,300,000
Weighted-average period of recognized stock-based compensation expenses	2 years 10 months 24 days
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	17,100,000
Weighted-average period of recognized stock-based compensation expenses	2 years 1 month 6 days
Performance Stock Award [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum common stock to be earned based on common stock price					250,000
Requisite service period	3 years
Fair value of performance stock award	$1,100,000
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

StockBased_Compensation_StockB

Stock-Based Compensation (Stock-Based Compensation Expense) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$7,023	$11,432
Cost Of Revenue [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,723	2,692
Research And Development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	2,180	3,155
Sales And Marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	1,238	2,045
General And Administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$1,882	$3,540

StockBased_Compensation_Summar

Stock-Based Compensation (Summary of Stock Option Activity) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Number of Shares, Beginning Balance	4,525
Number of Shares, Options granted	405
Number of Shares, Options exercised	-95
Number of Shares, Options cancelled or expired	-176
Number of Shares, Ending Balance	4,659
Number of Shares, Options vested and expected to vest	4,590
Number of Shares, Options exercisable	3,230
Weighted Average Exercise Price per Share, Beginning Balance	$12.38
Weighted Average Exercise Price per Share, Options granted	$7.99
Weighted Average Exercise Price per Share, Options exercised	$2.52
Weighted Average Exercise Price per Share, Options cancelled or expired	$16.88
Weighted Average Exercise Price per Share, Ending Balance	$12.03
Weighted Average Exercise Price per Share, Options vested and expected to vest	$11.99
Weighted Average Exercise Price per Share, Options exercisable	$11.25
Weighted Average Remaining Contractual Term (years), Ending Balance	6 years
Weighted Average Remaining Contractual Term (years), Options vested and expected to vest	5 years 11 months 12 days
Weighted Average Remaining Contractual Term (years), Options exercisable	4 years 7 months 28 days
Aggregate Intrinsic Value, Ending Balance	$9,286
Aggregate Intrinsic Value, Options vested and expected to vest	9,272
Aggregate Intrinsic Value, Option exercisable	$8,815

StockBased_Compensation_Summar1

Stock-Based Compensation (Summary of Restricted Stock Unit Activity) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2015
Stock-Based Compensation [Abstract]
Number of Shares, Beginning Balance	2,200
Number of Shares, Restricted stock units granted	284
Number of Shares, Restricted stock units vested	-539
Number of Shares, Restricted stock units cancelled	-115
Number of Shares, Ending Balance	1,830
Weighted Average Grant Date Fair Value per Share, Beginning Balance	$15.06
Weighted Average Grant Date Fair Value per Share, Restricted stock units granted	$4.81
Weighted Average Grant Date Fair Value per Share, Restricted stock units vested	$17.75
Weighted Average Grant Date Fair Value per Share, Restricted stock units cancelled	$14.80
Weighted Average Grant Date Fair Value per Share, Ending Balance	$12.69

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended
In Millions, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Income Taxes [Line Items]
Effective tax rate	-1.40%	-2.20%
Detectent Inc. [Member]
Income Taxes [Line Items]
Deferred income tax benefits	-0.9

Segment_Information_Details

Segment Information (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
	segment
Revenue:
Number of reportable segments	1
Total revenue, net	$143,640	$44,229
United States [Member]
Revenue:
Total revenue, net	122,582	21,842
Australia [Member]
Revenue:
Total revenue, net	19,176	9,775
All Other [Member]
Revenue:
Total revenue, net	$1,882	$12,612

Balance_Sheet_Details_Schedule

Balance Sheet Details (Schedule of Inventory) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Balance Sheet Details [Abstract]
Component parts	$2,385	$2,843
Finished goods	4,952	3,879
Inventory	$7,337	$6,722

Balance_Sheet_Details_Schedule1

Balance Sheet Details (Schedule of Accrued Liabilities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Balance Sheet Details [Abstract]
Accrued payroll and related expenses	$10,206	$8,912
Accrued operating expenses	3,278	2,548
Warranty obligations, current	4,365	3,838
Sales, property and income taxes	1,036	1,996
Other deferred revenue	4,968	4,955
Other	902	1,009
Accrued liabilities	$24,755	$23,258

Balance_Sheet_Details_Schedule2

Balance Sheet Details (Schedule Of Other Liabilities) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014
In Thousands, unless otherwise specified
Balance Sheet Details [Abstract]
Warranty obligations, non-current	$3,647	$3,397
Other deferred revenue	10,089	9,816
Other	1,936	1,861
Other Liabilities, Noncurrent, Total	$15,672	$15,074

Balance_Sheet_Details_Schedule3

Balance Sheet Details (Schedule of Product Warranty Obligation) (Details) (USD $)	Mar. 31, 2015	Dec. 31, 2014	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Guarantee Obligations [Line Items]
Warranty obligation	$8,012	$7,235	$6,833	$6,089
Accrued Liabilities [Member]
Guarantee Obligations [Line Items]
Warranty obligation	4,365	3,838
Other Liabilities [Member]
Guarantee Obligations [Line Items]
Warranty obligation	$3,647	$3,397

Balance_Sheet_Details_Schedule4

Balance Sheet Details (Schedule of Product Warranty Activity) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Mar. 31, 2014
Balance Sheet Details [Abstract]
Warranty obligation-beginning of period	$7,235	$6,089
Warranty expense for new warranties issued	304	224
Utilization of warranty obligation	-639	-851
Changes in estimates for pre-existing warranties	1,112	1,371
Warranty obligation-end of period	$8,012	$6,833

Balance_Sheet_Details_Schedule5

Balance Sheet Details (Schedule of Accumulated Other Comprehensive Income (AOCI)) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2014	($779)
Other comprehensive income before reclassification	-770
Balance as of March 31, 2015	-1,549
Foreign Currency Adjustment [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2014	-724
Other comprehensive income before reclassification	-948
Balance as of March 31, 2015	-1,672
Unrealized Gains (Losses) On Available For Sale Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance as of December 31, 2014	-55
Other comprehensive income before reclassification	178
Balance as of March 31, 2015	$123

Restructuring_Charges_Narrativ

Restructuring Charges (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring	$194,000
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	194,000
Severance Costs [Member] | 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring	61,000	1,800,000
Minimum [Member] | Severance Costs [Member] | 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Future charges	1,400,000
Maximum [Member] | Severance Costs [Member] | 2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Future charges	$1,900,000

Restructuring_Charges_Accrued_

Restructuring Charges (Accrued Liabilities Related to Restructuring Actions) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2015	Sep. 30, 2014
Restructuring Cost and Reserve [Line Items]
Additions	$194
2014 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	235
Additions	194
Utilization	-179
Ending Balance	250
2014 Restructuring Plan [Member] | Severance Costs [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance	235
Additions	61	1,800
Utilization	-179
Ending Balance	117
2014 Restructuring Plan [Member] | Professional Fees [Member]
Restructuring Cost and Reserve [Line Items]
Additions	133
Ending Balance	$133

Commitments_and_Contingencies_1

Commitments and Contingencies (Narrative) (Details)

3 Months Ended

1 Months Ended

In Millions, unless otherwise specified

Mar. 31, 2015

Mar. 31, 2014

Dec. 31, 2014

Dec. 31, 2014

Jun. 30, 2014

Mar. 31, 2015

Mar. 31, 2015

Dec. 31, 2014

Mar. 31, 2015

Mar. 31, 2015

Dec. 31, 2014

Dec. 31, 2014

USD ($)

USD ($)

USD ($)

EON Patent Litigation [Member]

EON Patent Litigation [Member]

EON Patent Litigation [Member]

Standby Letters Of Credit [Member]

Standby Letters Of Credit [Member]

Standby Letters Of Credit [Member]

Standby Letters Of Credit [Member]

Standby Letters Of Credit [Member]

Standby Letters Of Credit [Member]

USD ($)

USD ($)

USD ($)

USD ($)

USD ($)

Australian Dollars [Member]

Australian Dollars [Member]

Australian Dollars [Member]

Australian Dollars [Member]

USD ($)

AUD

USD ($)

AUD

Loss Contingencies [Line Items]

Rent expense facility leases

$1.20

$1.30

Litigation settlement amount

13

18.8

Pre-judgment interest

1.5

Litigation costs

0.2

Surety bond

17.6

Surety bond percent of additional judgment, percent

20.00%

Outstanding letters of credit

13

Possible estimated loss

14.7

Credit facility with financial institution

17

17

0.5

0.6

0.5

0.6

Unsecured surety bond

$20.30

$20.30

Commitments_and_Contingencies_2

Commitments and Contingencies (Future Minimum Commitments Under Operating and Capital Leases) (Details) (USD $)	Mar. 31, 2015
In Thousands, unless otherwise specified
Commitments and Contingencies [Abstract]
Operating Leases, 2015	$4,126
Operating Leases, 2016	2,843
Operating Leases, 2017	597
Operating Leases, 2018	608
Operating Leases, 2019	545
Operating Leases, 2020 and thereafter	1,425
Net minimum operating lease payments	10,144
Capital Leases, 2015	754
Capital Leases, 2016	112
Net minimum capital lease payments	866
Less amount representing interest	-31
Present value of net minimum capital lease payments	$835