Ixia (XXIA) 10-Q 6 May 16 2016 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	3 Months Ended
	Mar. 31, 2016	May. 02, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	Ixia
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		81,752,978
Amendment Flag	false
Entity Central Index Key	1,120,295
Entity Filer Category	Large Accelerated Filer
Document Period End Date	Mar. 31, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q1

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 61,378	$ 52,472
Marketable securities	19,521	14,504
Accounts receivable, net of allowances of $1,131 and $1,107, as of March 31, 2016 and December 31, 2015, respectively	95,727	121,932
Inventories	31,164	33,289
Prepaid expenses and other current assets	41,911	44,384
Total current assets	249,701	266,581
Property and equipment, net	37,706	36,536
Intangible assets, net	93,976	103,660
Goodwill	338,873	338,873
Other assets	35,883	34,227
Total assets	756,139	779,877
Current liabilities:
Accounts payable	9,711	15,346
Accrued expenses and other	45,698	70,029
Deferred revenues	112,283	108,436
Term loan, net	3,548	3,045
Total current liabilities	171,240	196,856
Deferred revenues	22,592	22,117
Other liabilities	6,814	7,406
Term loan, net	32,697	34,487
Total liabilities	$ 233,343	$ 260,866
Commitments and contingencies (Note 10)
Shareholders’ equity:
Common stock, without par value; 200,000 shares authorized at March 31, 2016 and December 31, 2015; 81,233 and 80,805 shares issued and outstanding as of March 31, 2016 and December 31, 2015, respectively	$ 202,681	$ 201,087
Additional paid-in capital	230,073	225,432
Retained earnings	90,838	93,525
Accumulated other comprehensive loss	(796)	(1,033)
Total shareholders’ equity	522,796	519,011
Total liabilities and shareholders’ equity	$ 756,139	$ 779,877

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 1,131	$ 1,107
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	81,233,000	80,805,000
Common stock, shares outstanding	81,233,000	80,805,000
Common stock, without par value (in dollars per share)	$ 0	$ 0

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Revenues:
Products		$ 71,973	$ 85,904
Services		40,700	35,058
Total revenues		112,673	120,962
Costs and operating expenses:
Cost of revenues – products	[1]	21,041	24,051
Cost of revenues – services		4,185	4,516
Research and development		27,462	27,626
Sales and marketing		39,031	37,521
General and administrative		15,888	18,371
Amortization of intangible assets		9,979	10,923
Acquisition and other related costs		26	582
Restructuring		(184)	(210)
Total costs and operating expenses	[2]	117,428	123,380
Loss from operations		(4,755)	(2,418)
Interest income and other, net		300	(481)
Interest expense		(514)	(2,147)
Loss before income taxes		(4,969)	(5,046)
Income tax (benefit) expense		(2,282)	4,565
Net loss		$ (2,687)	$ (9,611)
Loss per share:
Basic (in dollars per share)		$ (0.03)	$ (0.12)
Diluted (in dollars per share)		$ (0.03)	$ (0.12)
Weighted average number of common and common equivalent shares outstanding:
Basic (in shares)		81,015	78,706
Diluted (in shares)		81,015	78,706
Cost of revenues - products
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		$ 87	$ 95
Cost of revenues - services
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		33	36
Research and development
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		1,693	2,093
Sales and marketing
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		1,648	1,049
General and administrative
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		$ 1,480	$ 1,874
[1]	Cost of revenues – products excludes amortization of intangible assets related to purchased technologies of $6.4 million for each of the three months ended March 31, 2016 and 2015, which are included in Amortization of intangible assets.
[2]	Stock-based compensation included in: Three months ended March 31, Cost of revenues - products: 2016 $87 2015 $95 Cost of revenues - services: 2016 $33 2015 $36 Research and development: 2016 $1,693 2015 $2,093 Sales and marketing: 2016 $1,648 2015 $1,049 General and administrative: 2016 $1,480 2015 $1,874

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Income Statement [Abstract]
Cost of revenues - excluded amortization of intangible assets	$ 6.4	$ 6.4

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net loss	$ (2,687)	$ (9,611)
Unrealized gain on investments, net of tax	18	75
Foreign currency translation adjustment	219	(5)
Other comprehensive income	237	70
Comprehensive loss	$ (2,450)	$ (9,541)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Cash flows from operating activities:
Net loss	$ (2,687)	$ (9,611)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation	4,329	4,161
Amortization of intangible assets	9,979	10,923
Realized gain on available-for-sale securities	(2)	(29)
Stock-based compensation	4,941	5,147
Deferred income taxes	(418)	(849)
Excess tax benefits from stock-based compensation	(139)	0
Amortization of deferred issuance costs	111	335
Amortization of investment premiums	(4)	12
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net	26,205	8,773
Inventories	(797)	5,429
Prepaid expenses and other current assets	881	(636)
Other assets	(1,550)	3,921
Accounts payable	(6,108)	(4,453)
Accrued expenses and other	(22,196)	1,797
Deferred revenues	4,322	6,777
Other liabilities	(200)	1,705
Net cash provided by operating activities	16,667	33,402
Cash flows from investing activities:
Purchases of property and equipment	(2,810)	(2,955)
Purchases of marketable securities	(5,403)	(89,869)
Proceeds from sale of marketable securities	411	55,980
Increase in restricted cash	0	(10,000)
Purchases of other intangible assets	(295)	(226)
Net cash used in investing activities	(8,097)	(47,070)
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan options	1,758	651
Proceeds from borrowings under term loan	0	40,000
Repayments of debt	(500)	0
Debt issuance costs	(897)	(1,237)
Cash paid for shares withheld for taxes	(164)	0
Excess tax benefits from stock-based compensation	139	0
Net cash provided by financing activities	336	39,414
Net increase in cash and cash equivalents	8,906	25,746
Cash and cash equivalents at beginning of period	52,472	46,394
Cash and cash equivalents at end of period	61,378	72,140
Supplemental disclosure of non-cash investing activities:
Purchased and unpaid property and equipment	988	509
Transfers of inventory to property and equipment	$ 2,922	$ 2,586

Business

Business	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business	Business Ixia ("Ixia" or the "Company") was incorporated on May 27, 1997 as a California corporation. The Company provides application performance and security resilience solutions so that organizations can validate, secure and optimize their physical and virtual networks. Enterprises, service providers, network equipment manufacturers, and governments worldwide rely on Ixia’s solutions to deploy new technologies and achieve efficient, secure ongoing operation of their networks. Ixia's product solutions consist of its high performance hardware platforms, software applications and services, including warranty and maintenance offerings and professional services. The Company operates within one business segment.

Basis of Presentation, Signific

Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements	Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements Basis of Presentation The accompanying condensed consolidated financial statements as of March 31, 2016 and for the three months ended March 31, 2016 and 2015 , are unaudited and reflect all adjustments (consisting only of normal recurring adjustments) which are, in the opinion of the Company's management, necessary for a fair statement of its financial position, operating results and cash flows for the interim periods presented. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of results to be expected for the full year ending December 31, 2016 or any other future period. These condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting . Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet as of December 31, 2015 has been derived from the Company's audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2015 (the “ 2015 Form 10-K"), but does not include all disclosures required by GAAP. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in our 2015 Form 10-K. Significant Accounting Policies The Company’s significant accounting policies are set forth in Note 1 to the audited consolidated financial statements included in its 2015 Form 10-K. Recent Accounting Pronouncements In April 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing. ASU 2016-10 clarifies the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). The amendments in this update affect the guidance in ASU 2014-09, Revenue from Contracts with Customers, which is not yet effective. The effective date and transition requirements for the amendments in this update are the same as the effective date and transition requirements of ASU 2014-09. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Stock Compensation: Improvements to Employee Share-Based Payment. ASU 2016-09 involves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Under the new standard, income tax benefits and deficiencies are to be recognized as income tax expense or benefit in the income statement and the tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity should also recognize excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. Excess tax benefits should be classified along with other income tax cash flows as an operating activity. In regards to forfeitures, the entity may make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early adoption is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers: Principal Versus Agent Considerations. ASU 2016-08 clarifies the implementation guidance for what the FASB calls principal-versus-agent considerations in the board's revenue recognition standard by instructing the participants in the sale to determine whether they control the good or service and are entitled to the gross amount of the transaction or are acting as an agent and should collect only a fee or commission for arranging the sale. The amendments in this update affect the guidance in ASU 2014-09, Revenue from Contracts with Customers, which is not yet effective. The effective date and transition requirements for the amendments in this update are the same as the effective date and transition requirements of ASU 2014-09. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases , which requires that lessees recognize assets and liabilities for leases with lease terms greater than twelve months in the statement of financial position. ASU 2016-02 also requires improved disclosures to help users of financial statements better understand the amount, timing and uncertainty of cash flows arising from leases . The standard will be effective for annual reporting periods beginning after December 15, 2018, including interim periods within those reporting periods. Early adoption is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which provides updated guidance that enhances the reporting model for financial instruments, which includes amendments to address aspects of recognition, measurement, presentation, and disclosure. The standard will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those reporting periods. Except for the early application guidance, early adoption of the amendments is not permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred taxes in the statement of financial position. The updated guidance requires that deferred tax assets and liabilities be classified as noncurrent in a classified balance sheet. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early application is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory , which provides new guidance regarding the measurement of inventory. The new guidance requires most inventory to be measured at the lower of cost and net realizable value. The standard defines net realizable value as estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The standard applies to companies other than those that measure inventory using last-in, first-out (LIFO) or the retail inventory method. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early application is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which provides new guidance on the recognition of revenue and states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard was originally set to become effective in annual periods beginning after December 15, 2016 and for interim and annual reporting periods thereafter. In August 2015, the FASB issued ASU 2015-14 Revenue from Contracts with Customers; Deferral of the Effective Date, which defers the effective date of ASU 2014-09 for all entities by one year, thereby delaying the effective date of the standard to January 1, 2018, with an option that would permit companies to adopt the standard as early as the original effective date. Early adoption prior to the original effective date is not permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements.

Debt

Debt	3 Months Ended
	Mar. 31, 2016
Debt Disclosure [Abstract]
Debt	Debt Senior Secured Credit Agreements 2015 Credit Agreement On March 2, 2015 , the Company entered into an amended and restated credit agreement (as amended to date, the “Credit Agreement”) by and among the Company, as borrower, certain of the Company’s wholly owned direct and indirect subsidiaries, as guarantors, Silicon Valley Bank, as administrative agent, swingline lender and letter of credit issuer, and the other lenders party thereto (Silicon Valley Bank and the other lenders from time to time party thereto hereinafter collectively referred to as the “Lenders”). The Credit Agreement amended and restated the Company's prior credit agreement dated as of December 21, 2012 , as amended, by and among the Company, the guarantors, Silicon Valley Bank, as administrative agent, swingline lender, and letter of credit issuer (as successor to Bank of America, N.A. in such capacities), and the other lenders party thereto. The Credit Agreement originally provided for a (i) term loan (the “Term Loan”) in the aggregate principal amount of $40 million and (ii) a revolving credit facility (the “Revolving Credit Facility” and, together with the Term Loan, the “Credit Facility”) in an aggregate amount of up to $60 million , with sub-limits of $25 million for the issuance of standby letters of credit and $15 million for swingline loans. On September 30, 2015 , the Company entered into an amendment to the Credit Agreement which, among other modifications, increased the commitments under the Revolving Credit Facility to an aggregate amount of up to $75 million . On January 25, 2016 , the Company entered into an amendment to the Credit Agreement which, among other modifications, (i) increased the commitments under the Revolving Credit Facility to $150 million and (ii) extended the maturity date of the Revolving Credit Facility from February 15, 2018 to February 15, 2020 . The maturity date of the Term Loan is February 15, 2018 . The aggregate amount available under the Revolving Credit Facility is, upon the Company's request and subject to the receipt of increased commitments from the Lenders or additional lenders, subject to increase by an aggregate amount of up to $100 million . The Company is permitted to voluntarily prepay outstanding loans under the Credit Facility at any time without premium or penalty. Prior to the maturity of the Credit Facility, the Company may re-borrow amounts under the Revolving Credit Facility, but it may not re-borrow amounts that are repaid or prepaid under the Term Loan. Debt issuance costs were approximately $2.2 million , which were capitalized to deferred issuance costs and are being amortized to interest expense over the three -year term of the Credit Facility. During the three months ended March 31, 2016 and 2015 , amortization recorded to interest expense pertaining to deferred issuance costs was approximately $111,000 and $35,000 , respectively. The Term Loan requires quarterly repayments ranging from $1.0 million to $1.5 million through December 31, 2017 . The remaining principal balance will be due and payable on the maturity date of the Term Loan (i.e., February 15, 2018 ). The Company’s and the guarantors’ obligations under the Credit Agreement are secured by (i) a first priority perfected security interest in substantially all existing and after acquired tangible and intangible personal property of the Company and the guarantors and (ii) the pledge by the Company and the guarantors of (a) all outstanding equity securities of their existing and future domestic subsidiaries, including, in the case of the Company, the outstanding equity securities of each of the guarantors, and (b) 65% of the outstanding equity securities of their existing and future respective first-tier foreign subsidiaries, including, in the case of Catapult Communications Corporation (one of the Company's wholly owned domestic subsidiaries), 65% of the outstanding equity securities of Ixia Technologies International Limited, a company organized under the laws of Ireland. Interest rates for the Revolving Credit Facility and for the Term Loan are set, at the Company’s option, at a rate per annum based on the Eurodollar rate or a defined base rate. Prior to September 30, 2015, the interest rates were 4.25% above the Eurodollar rate or 3.25% above a defined base rate. After September 30, 2015 , the interest rates for both the Term Loan and the Revolving Credit Facility range from 2.0% to 3.0% above the Eurodollar rate for Eurodollar-based borrowings and from 1.0% to 2.0% above the defined base rate for base rate borrowings, in each case depending on the Company’s leverage ratio. The Company is also required to pay a quarterly commitment fee, ranging from 0.30% to 0.50% per annum, on the undrawn portion of the Revolving Credit Facility. Letter of credit fees accrue based on the daily amount available to be drawn under outstanding letters of credit and range from 2.0% to 3.0% , depending on the Company’s leverage ratio. Swingline loans bear interest at the defined base rate plus the applicable margin for loans under the Revolving Credit Facility based on the defined base rate. If the Company defaults under the Credit Agreement, the Lenders may increase the interest rate(s) to 2.0% more than the rate(s) otherwise applicable. The weighted average interest rate applicable to the Term Loan for the fiscal quarter ended March 31, 2016 was 2.77 %. As of March 31, 2016 , the interest rate applicable to the amount outstanding under our Term Loan was 2.43 %. The Credit Agreement requires the Company to comply with certain covenants, including maintaining (i) a fixed charge coverage ratio (as defined in the Credit Agreement) of not less than 1.25 to 1.00 , (ii) a consolidated senior leverage ratio (as defined in the Credit Agreement) of not greater than 2.50 to 1.00 through December 31, 2015 and (iii) a consolidated total leverage ratio (as defined in the Credit Agreement), of not greater than 3.00 to 1.00 through December 31, 2015 , 3.25 to 1.00 through June 30, 2018 , and 3.00 to 1.00 thereafter, in each case measured quarterly on a trailing 12 month basis. The Credit Agreement contains reporting covenants typical for transactions comparable to the Credit Facility, including covenants to furnish the lenders with financial statements, business plans, annual budgets, and other financial and business information and with notice of certain material events and information regarding collateral. The Credit Agreement also contains customary affirmative covenants, including covenants relating to the payment of obligations, preservation of the existence of and registrations for patents, trademarks, trade names, and copyrights, maintenance of properties and insurance, compliance with laws and material contractual obligations, books and records, inspection rights, use of proceeds, addition of subsidiary guarantors, and security for the Credit Facility. The Credit Agreement contains customary negative covenants, including restrictions relating to liens and additional indebtedness, investments, mergers, liquidations and other fundamental changes, the sale and other disposition of properties and assets, restricted payments, changes in lines of business, transactions with affiliates, entering into certain burdensome agreements, and use of proceeds. The Credit Agreement permits the Company to fund cash acquisitions in an aggregate amount of up to $200 million , subject to certain limitations, including the requirement that, after giving effect to an acquisition, the Company’s available liquidity, as defined in the Credit Agreement, exceeds $50 million . The Credit Agreement provides for customary events of default, including the non-payment of amounts due, failure to perform under covenants, breaches of representations and warranties, cross-defaults relating to certain indebtedness, institution of insolvency proceedings, inability to pay debts as they become due, entry of certain judgments, events relating to the Employee Retirement Income Security Act of 1974, as amended, invalidity of loan documents, change of control events, and ineffectiveness of subordination provisions. The occurrence of an event of default may result in the acceleration of all outstanding obligations under the Credit Agreement and in an increase in the applicable interest rate(s) as described above. Unsecured Convertible Senior Notes On December 7, 2010 , the Company issued $200 million in aggregate principal amount of 3.00% Convertible Senior Notes (the “Notes”) due December 15, 2015 unless earlier repurchased or converted. The unsecured Notes were governed by the terms of an indenture dated December 7, 2010 between the Company and Wells Fargo Bank, N.A., as trustee (the “Indenture”). In July 2015, the Company repurchased $65.0 million in aggregate principal amount of the Notes in a privately negotiated transaction for an aggregate cash purchase price of approximately $65.2 million plus accrued interest up to the date of repurchase in the aggregate amount of approximately $119,000 . In December 2015 , the remaining outstanding Notes in the aggregate principal amount of $135.0 million matured, and the Company repaid the Notes, together with accrued interest in the aggregate amount of approximately $2.0 million , in full. Amortization of deferred issuance costs recorded to interest expense was $300,000 for the three months ended March 31, 2015 .

Selected Balance Sheet Data

Selected Balance Sheet Data	3 Months Ended
	Mar. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Selected Balance Sheet Data	Selected Balance Sheet Data Investments in Marketable Securities Investments in marketable securities as of March 31, 2016 consisted of the following (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale – short-term: U.S. Treasury, government and agency debt securities $ 9,603 $ 2 $ — $ 9,605 Corporate debt securities 9,962 1 (47 ) 9,916 Total $ 19,565 $ 3 $ (47 ) $ 19,521 Investments in marketable securities as of December 31, 2015 consisted of the following (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale – short-term: U.S. Treasury, government and agency debt securities $ 4,301 $ — $ (13 ) $ 4,288 Corporate debt securities 10,265 — (49 ) 10,216 Total $ 14,566 $ — $ (62 ) $ 14,504 As of March 31, 2016 and December 31, 2015 , the Company's available-for-sale securities had a weighted remaining contractual maturity of 1.25 and 1.58 years, respectively. For the three months ended March 31, 2016 and 2015 , gross realized gains and losses were not significant. See Note 6 for information on the unrealized holding gains (losses) on available-for-sale securities reclassified out of accumulated other comprehensive loss into the condensed consolidated statements of operations. The amortized cost and fair value of our marketable securities at March 31, 2016 , by contractual years-to-maturity, are as follows (in thousands): Amortized Cost Fair Value Due in less than 1 year $ 8,655 $ 8,649 Due within 1-2 years 8,721 8,704 Due within 2-5 years 2,189 2,168 Total $ 19,565 $ 19,521 Inventories Inventories consist of the following (in thousands): March 31, 2016 December 31, 2015 Raw materials $ 1,984 $ 3,864 Work in process 7,820 11,253 Finished goods 21,360 18,172 $ 31,164 $ 33,289 Accrued expenses and other As of March 31, 2016 and December 31, 2015 , accrued bonus expenses totaled $3.6 million and $20.4 million , respectively, accrued compensation and related expenses totaled $12.2 million and $12.8 million , respectively, and accrued vacation totaled $9.4 million and $8.0 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets There was no activity related to goodwill for the three months ended March 31, 2016 . We have not had any historical goodwill impairment charges. The following table presents the Company's purchased intangible assets (in thousands) as of March 31, 2016 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (135,147 ) $ 50,518 Customer relationships 6.0 71,700 (53,564 ) 18,136 Service agreements 6.4 30,100 (14,446 ) 15,654 Trademarks 5.1 11,300 (7,491 ) 3,809 Non-compete agreements 4.0 8,000 (6,141 ) 1,859 Other 4.5 6,045 (2,045 ) 4,000 $ 312,810 $ (218,834 ) $ 93,976 The following table presents the Company's purchased intangible assets (in thousands) as of December 31, 2015 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (129,509 ) $ 56,156 Customer relationships 6.0 71,700 (51,533 ) 20,167 Service agreements 6.4 30,100 (13,272 ) 16,828 Trademarks 5.1 11,300 (7,000 ) 4,300 Non-compete agreements 4.0 8,000 (5,641 ) 2,359 Other 4.5 5,750 (1,900 ) 3,850 $ 312,515 $ (208,855 ) $ 103,660 The estimated future amortization expense of purchased intangible assets as of March 31, 2016 is as follows (in thousands): Remaining in 2016 $ 29,059 2017 31,919 2018 20,664 2019 7,444 2020 3,922 2021 672 Thereafter 296 $ 93,976

Shareholders' Equity

Shareholders' Equity	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity Accumulated Other Comprehensive Loss The following table summarizes the changes in Accumulated other comprehensive loss , by component, net of income taxes (in thousands): Gains (Losses) on Available-for- Sale Securities (a) Foreign Currency Items Total Beginning balance, December 31, 2015 $ (88 ) $ (945 ) $ (1,033 ) Other comprehensive income before reclassifications 18 219 237 Amounts reclassified from accumulated other comprehensive loss — — — Net current period other comprehensive income 18 219 237 Ending balance, March 31, 2016 $ (70 ) $ (726 ) $ (796 ) (a) All amounts are net-of-tax. Amounts in parentheses indicate reductions. Share Repurchase Program In February 2016, the Company’s board of directors approved a share repurchase program (the "Program") under which the Company may, over the 12 months following the date of announcement, acquire up to $25 million of its common stock. Under the Program, the Company may, from time to time, and subject to general business and market conditions, alternative investment opportunities, and other factors, repurchase shares in open market purchases, privately negotiated transactions and/or through other means, and may include repurchases pursuant to a Rule 10b5-1 trading plan. There is no guarantee as to the exact number of shares that will be repurchased by the Company, and the Company may discontinue or suspend repurchases at any time in the Company’s discretion. As of March 31, 2016, the Company has not repurchased any shares under the Program.

Loss Per Share

Loss Per Share	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share Basic loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the period. Diluted loss per common share is computed by giving effect to all potential dilutive common shares, including stock-based awards, using the treasury stock method. The following table sets forth the computation of basic and diluted loss per share for the three months ended March 31, 2016 and 2015 (in thousands, except per share data): Three months ended 2016 2015 Basic presentation: Numerator for basic loss per share: Net loss $ (2,687 ) $ (9,611 ) Denominator for basic loss per share: Weighted average common shares outstanding 81,015 78,706 Basic loss per share $ (0.03 ) $ (0.12 ) Diluted presentation: Numerator for diluted loss per share: Net loss $ (2,687 ) $ (9,611 ) Denominator for dilutive loss per share: Weighted average common shares outstanding 81,015 78,706 Diluted loss per share $ (0.03 ) $ (0.12 ) The diluted earnings per share computation for the three months ended March 31, 2016 excludes the weighted average number of shares underlying the Company's employee stock options and other share-based awards of 4.9 million shares, which were anti-dilutive because the Company reported a net loss for the period. The diluted loss per share computation for the three months ended March 31, 2015 excludes the weighted average number of shares underlying our Notes of 10.3 million shares and the weighted average number of shares underlying the Company's employee stock options and other share-based awards of 4.8 million shares, which were anti-dilutive because the Company reported a net loss for the period.

Concentrations

Concentrations	3 Months Ended
	Mar. 31, 2016
Risks and Uncertainties [Abstract]
Concentrations	Concentrations Revenue by Product Line The Company has two product lines: Network Test Solutions and Network Visibility Solutions. The Company's Network Test Solutions products include its multi-slot test chassis and appliances, traffic generation interface cards, and suite of test applications, and the related technical support, warranty and software maintenance services, including its Application and Threat Intelligence (ATI) service. The Company's Network Visibility Solutions products include its network packet brokers, bypass switches, virtual and physical taps, and the related technical support, warranty and software maintenance services. The following table presents revenue by product line (in thousands): Three months ended 2016 2015 Network Test Solutions $ 83,505 $ 85,347 Network Visibility Solutions 29,168 35,615 $ 112,673 $ 120,962 Significant Customers No customer accounted for more than 10% of total revenues for the three months ended March 31, 2016 . Two customers each accounted for more than 10% of total revenues for the three months ended March 31, 2015 . As of March 31, 2016 and December 31, 2015 , no customer accounted for more than 10% of the Company's total receivables. International Data For the three months ended March 31, 2016 and 2015 , the percentages of total revenues consisting of international revenues based on customer location consisted of the following: Three months ended 2016 2015 International revenues 48.4 % 38.4 % The percentage of total revenues from customers located in Japan for the three months ended March 31, 2016 was 11.1% . As of March 31, 2016 and December 31, 2015 , the Company's property and equipment, net were geographically located as follows (in thousands): March 31, 2016 December 31, 2015 United States $ 24,657 $ 23,654 Romania 6,700 6,542 India 3,410 3,576 Other 2,939 2,764 Total $ 37,706 $ 36,536

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in the principal or most advantageous market for an asset or liability in an orderly transaction between market participants at the measurement date. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. The Company categorizes each of our fair value measurements in one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. This hierarchy prioritizes the inputs into three broad levels as follows: Level 1. Observable inputs such as quoted prices in active markets; Level 2. Inputs, other than quoted prices in active markets, that are observable either directly or indirectly; and Level 3. Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions. Financial assets carried at fair value as of March 31, 2016 are classified in the table below in one of the three categories described above (in thousands): March 31, 2016 Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents: Money market funds $ 117 $ 117 $ — $ — U.S. Treasury, government and agency debt securities 10,196 — 10,196 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 9,605 — 9,605 — Corporate debt securities 9,916 — 9,916 — Total financial assets $ 29,834 $ 117 $ 29,717 $ — Financial assets carried at fair value as of December 31, 2015 are classified in the table below in one of the three categories described above (in thousands): December 31, 2015 Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents: Money market funds $ 284 $ 284 $ — $ — Short-term marketable securities: U.S. Treasury, government and agency debt securities 4,288 — 4,288 — Corporate debt securities 10,216 — 10,216 — Total financial assets $ 14,788 $ 284 $ 14,504 $ — The Company's cash and investment instruments are classified within Level 1 or Level 2 of the fair value hierarchy based on quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. The fair values of the Company's money market funds, U.S. treasury, government and agency debt securities, and corporate debt securities are based on quoted market prices as shown in its investment brokerage/custodial statements. To the extent deemed necessary, the Company may also obtain non-binding dealer quotes to corroborate the estimated fair values reflected in its investment brokerage/custodial statements. There were no transfers of assets between levels within the fair value hierarchy for the three month period ended March 31, 2016 , and there were no Level 3 assets held at March 31, 2016 . The carrying value of the Company's Term Loan at March 31, 2016 and December 31, 2015 was $38.0 million and $38.5 million , respectively. The carrying value of the Term Loan approximates fair value as the interest rate is variable over the selected interest period and is similar to current rates at which we can borrow funds.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Securities Class Action On November 14, 2013, a purported securities class action complaint captioned Felix Santore v. Ixia, Victor Alston, Atul Bhatnagar, Thomas B. Miller, and Errol Ginsberg was filed against us and certain of our current and former officers and directors in the U.S. District Court for the Central District of California. The lawsuit purports to be a class action brought on behalf of purchasers of the Company’s securities during the period from April 10, 2010 through October 14, 2013. The initial complaint alleged that the defendants violated the Securities Exchange Act of 1934, as amended (the “Exchange Act”), by making materially false and misleading statements concerning the Company’s recognition of revenues related to its warranty and software maintenance contracts and the academic credentials and employment history of the Company’s former President and Chief Executive Officer, Victor Alston. The complaint also alleged that the defendants made false and misleading statements, and failed to make certain disclosures, regarding the Company’s business, operations and prospects, including regarding the financial statements and internal financial controls that were the subject of the Company’s April 2013 restatement of certain of its prior period financial statements. The complaint further alleged that the Company lacked adequate internal financial controls and issued materially false and misleading financial statements for the fiscal years ended December 31, 2010 and 2011, and the fiscal quarters ended March 31, 2011, June 30, 2011, September 30, 2011, March 31, 2012, June 30, 2012, and September 30, 2012. The complaint, which purported to assert claims for violations of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder, sought, on behalf of the purported class, an unspecified amount of monetary damages, interest, fees and expenses of attorneys and experts, and other relief. On March 24, 2014, following a proceeding to select a lead plaintiff in the matter, the court issued an order appointing Oklahoma Firefighters Pension & Retirement System and Oklahoma Law Enforcement Retirement System (the “Oklahoma Group”) as lead plaintiffs. On June 11, 2014, the Oklahoma Group filed a first amended complaint, which asserted claims against the same defendants under the same legal theories set forth in the initial complaint. The first amended complaint also contained allegations that certain of the individual defendants increased their trading in the Company’s stock during February, March, April and May of 2011 and during February and March of 2013, and that the defendants sought to inflate the Company’s reported deferred revenues during the period of February 4, 2011 through April 3, 2013. On July 18, 2014, all named defendants moved to dismiss the first amended complaint for failure to state a claim under the Federal Rules of Civil Procedure and the Private Securities Law Reform Act of 1995 (“PSLRA”). After briefing and a hearing on October 6, 2014, the court issued an order dismissing the first amended complaint in its entirety without prejudice. The court gave the Oklahoma Group 30 days in which to file an amended complaint. On November 5, 2014, the Oklahoma Group filed a second amended complaint. On January 6, 2015, the named defendants moved to dismiss the second amended complaint. After briefing and a hearing on April 13, 2015, the court issued an order dismissing the second amended complaint in its entirety without prejudice. The court gave the Oklahoma Group 30 days in which to file an amended complaint. On April 24, 2015, the court issued an order staying the class action until July 31, 2015, pending the outcome of a voluntary, non-binding mediation scheduled for July 23, 2015 to explore a possible settlement of both the purported securities class action and the shareholder derivative action discussed below. On July 23, 2015, the parties conducted the scheduled mediation with respect to the purported class action but did not reach an agreement to resolve and settle the litigation. However, settlement discussions continued after the mediation session, and on August 14, 2015, the parties agreed in principle to settle the purported securities class action litigation. On November 17, 2015 , the Company entered into a Stipulation and Agreement of Settlement, dated November 11, 2015 relating to the proposed settlement of the class action (the “Class Action Settlement Agreement”). This Class Action Settlement Agreement would resolve all of the claims asserted against the defendants in the Class Action and was entered into subject to the Court’s preliminary and final approval. The Class Action Settlement Agreement provides, among other terms, for a settlement payment of $3.5 million , which the Company expects will be paid in full by one of the Company’s insurance carriers. The Class Action Settlement Agreement does not include any admission of wrongdoing or liability on the part of the Company or the individual defendants, and upon final approval of the settlement by the Court, provides for a dismissal of, and a release of all claims asserted against the defendants in, the class action. In February 2016, the Court granted preliminary approval of the Class Action Settlement Agreement and scheduled a hearing for July 29, 2016 to consider final approval of the Class Action Settlement Agreement. In March 2016, the Company's insurer funded the payment of $3.5 million into an escrow account established pursuant to the Class Action Settlement Agreement. The funds are being held in the escrow account pending the Court's final approval of the Class Action Settlement Agreement. The Company has accrued a liability of $3.5 million related to this matter as a component of Accrued expenses and other in the accompanying consolidated balance sheets as of March 31, 2016 . The Company has also recorded an offsetting receivable for $3.5 million in Prepaid expenses and other current assets in the accompanying consolidated balance sheets as of March 31, 2016 , as the Company deems recovery of the related insurance proceeds probable. Shareholder Derivative Action A consolidated shareholder derivative action, captioned In re Ixia Shareholder Derivative Litigation , is pending in the U.S. District Court for the Central District of California. This action is the consolidation of two lawsuits, namely: (i) Erie County Employees' Retirement System, Derivatively on behalf of Nominal Defendant Ixia v. Victor Alston, Errol Ginsberg, Laurent Asscher, Jonathan Fram, Gail Hamilton, Jon Rager, Atul Bhatnagar, and Thomas B. Miller, defendants, and Ixia, nominal defendant and (ii) Colleen Witmer, derivatively on behalf of Ixia v. Victor Alston, Atul Bhatnagar, Thomas B. Miller, Errol Ginsberg, Jonathan Fram, Laurent Asscher, Gail Hamilton, Jon F. Rager, Christopher Lee Williams, Alan Grahame, Raymond De Graaf, Walker H. Colston II, and Ronald W. Buckly, defendants, and Ixia, nominal defendant . Both were filed in the U.S. District Court for the Central District of California in May 2014. Co-lead plaintiffs Erie County Employees’ Retirement System and Colleen Witmer filed a consolidated complaint on September 2, 2014. The consolidated complaint includes many allegations similar to those made in the purported class action complaint described above. Among other things, the complaint alleges that some or all (depending upon the claim) of the individual defendants breached their fiduciary duties to the Company by causing or allowing the Company to disseminate misleading financial statements, ignoring problems with the Company’s financial controls, making stock sales on the basis of material non-public information, and violating the Company’s code of conduct. As relief, among other things, the complaint seeks an unspecified amount of monetary damages, disgorgement and restitution of stock sale proceeds and an award under California Corporations Code Sections 24502 and 25502.5, as well as unspecified equitable and declaratory relief. On October 15, 2014, the Company, on whose behalf the derivative action claims are purportedly brought, moved to dismiss the consolidated complaint on the grounds that the derivative plaintiffs did not file the claims in accordance with applicable laws governing the filing of derivative actions. The individual defendants joined in that motion and also filed motions to dismiss the claims against them for failure to state a claim. Before any ruling by the court on those motions, the plaintiffs filed an amended consolidated complaint on January 26, 2015. On March 12, 2015, the Company filed a motion to dismiss the amended consolidated complaint on the same grounds as it had set forth with respect to the first consolidated complaint, and the individual defendants joined in that motion and also filed motions to dismiss the claims against them for failure to state a claim. On April 24, 2015, before the scheduled hearing on the motion to dismiss, the Court issued an order staying the shareholder derivative action until July 31, 2015, pending the outcome of a voluntary, non-binding mediation scheduled for July 23, 2015 in connection with both the derivative action and the purported securities class action discussed above. On July 23, 2015, the parties participated in the scheduled voluntary, non-binding mediation with respect to the derivative action and agreed in principle to resolve and settle the litigation. On November 17, 2015 , the Company entered into a Stipulation and Agreement of Settlement, dated November 17, 2015, relating to the proposed settlement of the derivative action (the “Derivative Action Settlement Agreement”). The Derivative Action Settlement Agreement would resolve all of the claims asserted against the defendants in the derivative action and was entered into subject to preliminary and final approval by the Court. The Derivative Action Settlement Agreement provides, among other terms, for the Company to implement certain corporate governance measures and for the plaintiffs' counsel to apply to the Court for an award of attorneys’ fees and expenses in an amount of up to $575,000 . The Company expects that any fees and expenses awarded by the Court to the plaintiffs' counsel will be paid by one of the Company’s insurance carriers. The Derivative Action Settlement Agreement does not include any admission of wrongdoing or liability on the part of the Company or the individual defendants and provides for a dismissal of, and a release of all claims asserted against the defendants in, the derivative action. In February 2016, the Court granted preliminary approval of the Derivative Action Settlement Agreement and scheduled a hearing for May 27, 2016 to consider final approval of the Derivative Action Settlement Agreement. The Company has accrued a liability of $575,000 related to this matter as a component of Accrued expenses and other in the accompanying condensed consolidated balance sheets as of March 31, 2016 . The Company has also recorded an offsetting receivable for $575,000 in Prepaid expenses and other current assets in the accompanying condensed consolidated balance sheets as of March 31, 2016 , as the Company deems recovery of the related insurance proceeds probable. SEC Investigation In July 2014, the Staff of the SEC’s Division of Enforcement (the “Staff”) requested that the Company produce certain documents and information in connection with an investigation of the Company. The SEC subsequently issued subpoenas to the Company seeking certain additional documents and to certain of the Company’s current and former employees seeking certain documents and their testimony. Based on the documents requested by the Staff, the Company believes that the SEC’s investigation relates to the matters addressed by (i) the previously disclosed accounting-related investigation conducted by the Audit Committee of the Company’s Board of Directors (the “Board”) that was completed in February 2014, and (ii) a separate internal investigation conducted by a Special Committee of the Board of stock sales during February and March 2013 by then current executive officers and directors of the Company. The Special Committee, which completed its investigation in June 2014, did not find with respect to such sales that there had been any insider trading based upon material non-public information. The Special Committee, however, made no finding with respect to the Company's former President and Chief Executive Officer, Victor Alston, because he declined to be interviewed by the Special Committee's counsel (both the Special Committee and the Audit Committee were assisted by independent counsel in their investigations). The Company is continuing to cooperate fully with the SEC in its investigation and is in discussions with the Staff concerning a proposed settlement of the investigation as it pertains to the Company. Based on oral communications with the Staff, the Company understands that the proposed settlement would require the Company, without admitting or denying any allegations by the SEC, to consent to the SEC’s issuance of an administrative order with non-fraud charges involving violations of Section 13 of the Exchange Act and rules promulgated by the SEC thereunder. The Company understands that the charges would relate to the Company’s books and records, internal controls, and disclosures (not including financial statements) for the year ended December 31, 2012, and books and records, internal controls, and disclosures (including financial statements) for the first and second quarters of 2013. The Company would be required to pay a civil penalty in the amount of $750,000 . The proposed settlement is subject to the Company’s receipt of, and agreement to, written settlement documentation from the Staff. In the event the Company and the Staff agree on such documentation, the settlement would then be subject to approval by the SEC Commissioners, and there can be no assurance that the SEC Commissioners would approve the proposed settlement. The proposed settlement would resolve Ixia’s potential liability with respect to the SEC investigation. Current or former employees, officers, and/or directors of the Company are not addressed by this proposed settlement. The Company has accrued a liability of $750,000 related to this matter as a component of Accrued expenses and other in the accompanying condensed consolidated balance sheets as of March 31, 2016 . Indemnifications In the normal course of business, the Company provides certain indemnifications, commitments and guarantees of varying scope to customers, including against claims of intellectual property infringement made by third parties arising from the use of the Company's products. The Company also has certain obligations to indemnify its officers, directors and employees for certain events or occurrences while the officers, directors or employees are or were serving at the Company's request in such capacity. The duration of these indemnifications, commitments and guarantees varies and in certain cases is indefinite. Many of these indemnifications, commitments and guarantees do not provide for any limitation of the maximum potential future payments that the Company could be obligated to make. However, the Company's director and officer insurance policy may enable it to recover a portion of any future payments related to its officer, director or employee indemnifications. Historically, costs related to these indemnifications, commitments and guarantees have not been significant. With the exception of the product warranty accrual associated with the Company's initial standard warranty, no liabilities have been recorded for these indemnifications, commitments and guarantees.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company accounts for its provision for income taxes in accordance with Accounting Standard Codification (“ASC”) 740, Income Taxes. In accordance with ASC 740, the Company uses an estimate of its annual effective rate for the full fiscal year in computing the year-to-date provision for income taxes for the interim periods, including federal, foreign, state, and local income taxes. On July 27, 2015, the U.S. Tax Court issued an opinion in Altera Corp. v. Commissioner related to the treatment of stock-based compensation expense in an intercompany cost-sharing arrangement. On February 19, 2016, the I.R.S. filed a notice of appeal with respect to such opinion in the U.S Ninth Circuit Court of Appeals. We concluded that no adjustment to our consolidated financial statements is appropriate at this time due to the uncertainties with respect to the ultimate resolution of this case. As of March 31, 2016 and December 31, 2015 , current deferred tax assets totaled $14.7 million and $14.5 million , respectively, and were included within Prepaid expenses and other current assets on the Company's condensed consolidated balance sheets. At each of March 31, 2016 and December 31, 2015 , long-term deferred tax assets totaled $18.9 million and were included within Other assets on the Company's condensed consolidated balance sheets. At each of March 31, 2016 and December 31, 2015 , long-term deferred tax liabilities totaling $0.4 million are included within Other liabilities on the Company's condensed consolidated balance sheets.

Basis of Presentation, Signif19

Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	3 Months Ended
	Mar. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements as of March 31, 2016 and for the three months ended March 31, 2016 and 2015 , are unaudited and reflect all adjustments (consisting only of normal recurring adjustments) which are, in the opinion of the Company's management, necessary for a fair statement of its financial position, operating results and cash flows for the interim periods presented. The results of operations for the three months ended March 31, 2016 are not necessarily indicative of results to be expected for the full year ending December 31, 2016 or any other future period. These condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations of the Securities and Exchange Commission (the “SEC”) regarding interim financial reporting . Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet as of December 31, 2015 has been derived from the Company's audited consolidated financial statements included in its Annual Report on Form 10-K for the year ended December 31, 2015 (the “ 2015 Form 10-K"), but does not include all disclosures required by GAAP. These condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements and related notes included in our 2015 Form 10-K.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In April 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing. ASU 2016-10 clarifies the implementation guidance on identifying performance obligations and licensing. Specifically, the amendments reduce the cost and complexity of identifying promised goods or services and improve the guidance for determining whether promises are separately identifiable. The amendments also provide implementation guidance on determining whether an entity's promise to grant a license provides a customer with either a right to use the entity's intellectual property (which is satisfied at a point in time) or a right to access the entity's intellectual property (which is satisfied over time). The amendments in this update affect the guidance in ASU 2014-09, Revenue from Contracts with Customers, which is not yet effective. The effective date and transition requirements for the amendments in this update are the same as the effective date and transition requirements of ASU 2014-09. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-09, Stock Compensation: Improvements to Employee Share-Based Payment. ASU 2016-09 involves several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. Under the new standard, income tax benefits and deficiencies are to be recognized as income tax expense or benefit in the income statement and the tax effects of exercised or vested awards should be treated as discrete items in the reporting period in which they occur. An entity should also recognize excess tax benefits regardless of whether the benefit reduces taxes payable in the current period. Excess tax benefits should be classified along with other income tax cash flows as an operating activity. In regards to forfeitures, the entity may make an entity-wide accounting policy election to either estimate the number of awards that are expected to vest or account for forfeitures when they occur. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early adoption is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard on its consolidated financial statements. In March 2016, the FASB issued ASU 2016-08, Revenue from Contracts with Customers: Principal Versus Agent Considerations. ASU 2016-08 clarifies the implementation guidance for what the FASB calls principal-versus-agent considerations in the board's revenue recognition standard by instructing the participants in the sale to determine whether they control the good or service and are entitled to the gross amount of the transaction or are acting as an agent and should collect only a fee or commission for arranging the sale. The amendments in this update affect the guidance in ASU 2014-09, Revenue from Contracts with Customers, which is not yet effective. The effective date and transition requirements for the amendments in this update are the same as the effective date and transition requirements of ASU 2014-09. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases , which requires that lessees recognize assets and liabilities for leases with lease terms greater than twelve months in the statement of financial position. ASU 2016-02 also requires improved disclosures to help users of financial statements better understand the amount, timing and uncertainty of cash flows arising from leases . The standard will be effective for annual reporting periods beginning after December 15, 2018, including interim periods within those reporting periods. Early adoption is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard on its consolidated financial statements. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities , which provides updated guidance that enhances the reporting model for financial instruments, which includes amendments to address aspects of recognition, measurement, presentation, and disclosure. The standard will be effective for annual reporting periods beginning after December 15, 2017, including interim periods within those reporting periods. Except for the early application guidance, early adoption of the amendments is not permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred taxes in the statement of financial position. The updated guidance requires that deferred tax assets and liabilities be classified as noncurrent in a classified balance sheet. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early application is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory , which provides new guidance regarding the measurement of inventory. The new guidance requires most inventory to be measured at the lower of cost and net realizable value. The standard defines net realizable value as estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal and transportation. The standard applies to companies other than those that measure inventory using last-in, first-out (LIFO) or the retail inventory method. The standard will be effective for annual reporting periods beginning after December 15, 2016, including interim periods within those reporting periods. Early application is permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which provides new guidance on the recognition of revenue and states that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard was originally set to become effective in annual periods beginning after December 15, 2016 and for interim and annual reporting periods thereafter. In August 2015, the FASB issued ASU 2015-14 Revenue from Contracts with Customers; Deferral of the Effective Date, which defers the effective date of ASU 2014-09 for all entities by one year, thereby delaying the effective date of the standard to January 1, 2018, with an option that would permit companies to adopt the standard as early as the original effective date. Early adoption prior to the original effective date is not permitted. The Company has not yet evaluated the impact of the adoption of this accounting standard update on its consolidated financial statements.

Selected Balance Sheet Data (Ta

Selected Balance Sheet Data (Tables)	3 Months Ended
	Mar. 31, 2016
Balance Sheet Related Disclosures [Abstract]
Available-for-sale Securities	Investments in marketable securities as of March 31, 2016 consisted of the following (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale – short-term: U.S. Treasury, government and agency debt securities $ 9,603 $ 2 $ — $ 9,605 Corporate debt securities 9,962 1 (47 ) 9,916 Total $ 19,565 $ 3 $ (47 ) $ 19,521 Investments in marketable securities as of December 31, 2015 consisted of the following (in thousands): Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Available-for-sale – short-term: U.S. Treasury, government and agency debt securities $ 4,301 $ — $ (13 ) $ 4,288 Corporate debt securities 10,265 — (49 ) 10,216 Total $ 14,566 $ — $ (62 ) $ 14,504
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of our marketable securities at March 31, 2016 , by contractual years-to-maturity, are as follows (in thousands): Amortized Cost Fair Value Due in less than 1 year $ 8,655 $ 8,649 Due within 1-2 years 8,721 8,704 Due within 2-5 years 2,189 2,168 Total $ 19,565 $ 19,521
Schedule of Inventory, Current	Inventories consist of the following (in thousands): March 31, 2016 December 31, 2015 Raw materials $ 1,984 $ 3,864 Work in process 7,820 11,253 Finished goods 21,360 18,172 $ 31,164 $ 33,289

Goodwill and Other Intangible21

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following table presents the Company's purchased intangible assets (in thousands) as of March 31, 2016 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (135,147 ) $ 50,518 Customer relationships 6.0 71,700 (53,564 ) 18,136 Service agreements 6.4 30,100 (14,446 ) 15,654 Trademarks 5.1 11,300 (7,491 ) 3,809 Non-compete agreements 4.0 8,000 (6,141 ) 1,859 Other 4.5 6,045 (2,045 ) 4,000 $ 312,810 $ (218,834 ) $ 93,976 The following table presents the Company's purchased intangible assets (in thousands) as of December 31, 2015 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (129,509 ) $ 56,156 Customer relationships 6.0 71,700 (51,533 ) 20,167 Service agreements 6.4 30,100 (13,272 ) 16,828 Trademarks 5.1 11,300 (7,000 ) 4,300 Non-compete agreements 4.0 8,000 (5,641 ) 2,359 Other 4.5 5,750 (1,900 ) 3,850 $ 312,515 $ (208,855 ) $ 103,660
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated future amortization expense of purchased intangible assets as of March 31, 2016 is as follows (in thousands): Remaining in 2016 $ 29,059 2017 31,919 2018 20,664 2019 7,444 2020 3,922 2021 672 Thereafter 296 $ 93,976

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2016
Stockholders' Equity Note [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	The following table summarizes the changes in Accumulated other comprehensive loss , by component, net of income taxes (in thousands): Gains (Losses) on Available-for- Sale Securities (a) Foreign Currency Items Total Beginning balance, December 31, 2015 $ (88 ) $ (945 ) $ (1,033 ) Other comprehensive income before reclassifications 18 219 237 Amounts reclassified from accumulated other comprehensive loss — — — Net current period other comprehensive income 18 219 237 Ending balance, March 31, 2016 $ (70 ) $ (726 ) $ (796 ) (a) All amounts are net-of-tax. Amounts in parentheses indicate reductions.

Loss Per Share (Tables)

Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2016
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted loss per share for the three months ended March 31, 2016 and 2015 (in thousands, except per share data): Three months ended 2016 2015 Basic presentation: Numerator for basic loss per share: Net loss $ (2,687 ) $ (9,611 ) Denominator for basic loss per share: Weighted average common shares outstanding 81,015 78,706 Basic loss per share $ (0.03 ) $ (0.12 ) Diluted presentation: Numerator for diluted loss per share: Net loss $ (2,687 ) $ (9,611 ) Denominator for dilutive loss per share: Weighted average common shares outstanding 81,015 78,706 Diluted loss per share $ (0.03 ) $ (0.12 )

Concentrations (Tables)

Concentrations (Tables)	3 Months Ended
	Mar. 31, 2016
Risks and Uncertainties [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following table presents revenue by product line (in thousands): Three months ended 2016 2015 Network Test Solutions $ 83,505 $ 85,347 Network Visibility Solutions 29,168 35,615 $ 112,673 $ 120,962
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	For the three months ended March 31, 2016 and 2015 , the percentages of total revenues consisting of international revenues based on customer location consisted of the following: Three months ended 2016 2015 International revenues 48.4 % 38.4 %
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country	As of March 31, 2016 and December 31, 2015 , the Company's property and equipment, net were geographically located as follows (in thousands): March 31, 2016 December 31, 2015 United States $ 24,657 $ 23,654 Romania 6,700 6,542 India 3,410 3,576 Other 2,939 2,764 Total $ 37,706 $ 36,536

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2016
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis	Financial assets carried at fair value as of March 31, 2016 are classified in the table below in one of the three categories described above (in thousands): March 31, 2016 Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents: Money market funds $ 117 $ 117 $ — $ — U.S. Treasury, government and agency debt securities 10,196 — 10,196 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 9,605 — 9,605 — Corporate debt securities 9,916 — 9,916 — Total financial assets $ 29,834 $ 117 $ 29,717 $ — Financial assets carried at fair value as of December 31, 2015 are classified in the table below in one of the three categories described above (in thousands): December 31, 2015 Fair Value Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Cash equivalents: Money market funds $ 284 $ 284 $ — $ — Short-term marketable securities: U.S. Treasury, government and agency debt securities 4,288 — 4,288 — Corporate debt securities 10,216 — 10,216 — Total financial assets $ 14,788 $ 284 $ 14,504 $ —

Business (Details)

Business (Details)	3 Months Ended
	Mar. 31, 2016segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments	1

Debt - 2015 Credit Agreement (D

Debt - 2015 Credit Agreement (Details) - USD ($)	Mar. 02, 2015	Mar. 31, 2016	Mar. 31, 2015	Jan. 25, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 07, 2010
Debt Instrument [Line Items]
Amortization		$ 111,000	$ 335,000
Notes Payable to Banks | 2015 Credit Agreement
Debt Instrument [Line Items]
Aggregate principal amount		$ 40,000,000
Fixed charge coverage ratio		1.25
Consolidated total leverage ratio		3.25
Notes Payable to Banks | 2015 Credit Agreement | Minimum
Debt Instrument [Line Items]
Quarterly principal payments		$ 1,000,000
Commitment fee (as a percent)	0.30%
Notes Payable to Banks | 2015 Credit Agreement | Maximum
Debt Instrument [Line Items]
Quarterly principal payments		$ 1,500,000
Commitment fee (as a percent)	0.50%
Notes Payable to Banks | 2015 Credit Agreement | First-tier Foreign Subsidiaries
Debt Instrument [Line Items]
Outstanding equity (as a percent)	65.00%
Notes Payable to Banks | 2015 Credit Agreement | Ixia Technologies International Limited
Debt Instrument [Line Items]
Outstanding equity (as a percent)	65.00%
Notes Payable to Banks | 2015 Credit Agreement | Through December 31, 2015
Debt Instrument [Line Items]
Consolidated senior leverage ratio		2.50
Notes Payable to Banks | 2015 Credit Agreement | After December 31, 2015
Debt Instrument [Line Items]
Consolidated senior leverage ratio		3
Notes Payable to Banks | 2015 Credit Agreement | Eurodollar
Debt Instrument [Line Items]
Effective average interest rate (as a percent)		2.77%
Effective percentage		2.43%
Notes Payable to Banks | 2015 Credit Agreement | Eurodollar | After September 30, 2015
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	4.25%
Notes Payable to Banks | 2015 Credit Agreement | Eurodollar | After First Anniversary of Closing Date | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
Notes Payable to Banks | 2015 Credit Agreement | Eurodollar | After First Anniversary of Closing Date | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	3.00%
Notes Payable to Banks | 2015 Credit Agreement | Base Rate | After September 30, 2015
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	3.25%
Notes Payable to Banks | 2015 Credit Agreement | Base Rate | After First Anniversary of Closing Date | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	1.00%
Notes Payable to Banks | 2015 Credit Agreement | Base Rate | After First Anniversary of Closing Date | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
Senior Notes | Convertible Notes Payable
Debt Instrument [Line Items]
Aggregate principal amount					$ 135,000,000		$ 200,000,000
Amortization			300,000
Line of Credit | Revolving Credit Facility | Silicon Valley Bank
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity		$ 60,000,000		$ 150,000,000		$ 75,000,000
Increased commitments				100,000,000
Capitalized debt issuance cost	$ 2,200,000
Amortization period (in years)	3 years
Amortization		$ 111,000	$ 35,000
Maximum amount of acquisition funding				$ 200,000,000
Line of Credit | Revolving Credit Facility | Silicon Valley Bank | Leverage Ratio | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
Line of Credit | Revolving Credit Facility | Silicon Valley Bank | Leverage Ratio | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	3.00%
Line of Credit | Revolving Credit Facility | Silicon Valley Bank | Upon Default
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)	2.00%
Line of Credit | Standby Letter of Credit | Silicon Valley Bank
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	$ 25,000,000
Line of Credit | Swingline Loans | Silicon Valley Bank
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	15,000,000
Collateral A | Credit Facility
Debt Instrument [Line Items]
Collateral amounts	$ 50,000,000

Debt - Convertible Senior Notes

Debt - Convertible Senior Notes (Details) - USD ($)	1 Months Ended	3 Months Ended		12 Months Ended
	Jul. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 07, 2010
Debt Instrument [Line Items]
Amortization		$ 111,000	$ 335,000
Convertible Notes Payable | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount				$ 135,000,000	$ 200,000,000
Stated rate (as a percent)					3.00%
Repayments				$ 2,000,000
Amortization			$ 300,000
Convertible Notes Payable | Senior Notes | Convertible Debt
Debt Instrument [Line Items]
Principal amount repurchased	$ 65,000,000
Aggregate cash purchase price	65,200,000
Accrued interest	$ 119,000

Selected Balance Sheet Data - I

Selected Balance Sheet Data - Investments in Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Available-for-sale – short-term:
Amortized Cost	$ 19,565	$ 14,566
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(47)	(62)
Fair Value	19,521	14,504
Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Available-for-sale – short-term:
Amortized Cost	9,603	4,301
Gross Unrealized Gains	2	0
Gross Unrealized Losses	0	(13)
Fair Value	9,605	4,288
Short-term marketable securities: | Corporate debt securities
Available-for-sale – short-term:
Amortized Cost	9,962	10,265
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(47)	(49)
Fair Value	$ 9,916	$ 10,216

Selected Balance Sheet Data - A

Selected Balance Sheet Data - Amortized Cost and Fair Value of Investments (Details) $ in Thousands	Mar. 31, 2016USD ($)
Amortized Cost
Due in less than 1 year	$ 8,655
Due within 1-2 years	8,721
Due within 2-5 years	2,189
Total	19,565
Fair Value
Due in less than 1 year	8,649
Due within 1-2 years	8,704
Due within 2-5 years	2,168
Total	$ 19,521

Selected Balance Sheet Data -31

Selected Balance Sheet Data - Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 1,984	$ 3,864
Work in process	7,820	11,253
Finished goods	21,360	18,172
Inventories	$ 31,164	$ 33,289

Selected Balance Sheet Data (De

Selected Balance Sheet Data (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Weighted average contractual maturity (in years)	1 year 3 months	1 year 6 months 29 days
Accrued compensation and related expenses	$ 3.6	$ 20.4
Accrued bonus expense	12.2	12.8
Accrued vacation	$ 9.4	$ 8

Goodwill and Other Intangible33

Goodwill and Other Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2016	Dec. 31, 2015
Other intangible assets:
Gross	$ 312,810	$ 312,515
Accumulated Amortization	(218,834)	(208,855)
Net	$ 93,976	$ 103,660
Technology
Other intangible assets:
Weighted Average Useful Life (in years)	5 years 6 months	5 years 6 months
Gross	$ 185,665	$ 185,665
Accumulated Amortization	(135,147)	(129,509)
Net	$ 50,518	$ 56,156
Customer relationships
Other intangible assets:
Weighted Average Useful Life (in years)	6 years	6 years
Gross	$ 71,700	$ 71,700
Accumulated Amortization	(53,564)	(51,533)
Net	$ 18,136	$ 20,167
Service agreements
Other intangible assets:
Weighted Average Useful Life (in years)	6 years 146 days	6 years 146 days
Gross	$ 30,100	$ 30,100
Accumulated Amortization	(14,446)	(13,272)
Net	$ 15,654	$ 16,828
Trademarks
Other intangible assets:
Weighted Average Useful Life (in years)	5 years 36 days	5 years 36 days
Gross	$ 11,300	$ 11,300
Accumulated Amortization	(7,491)	(7,000)
Net	$ 3,809	$ 4,300
Non-compete agreements
Other intangible assets:
Weighted Average Useful Life (in years)	4 years	4 years
Gross	$ 8,000	$ 8,000
Accumulated Amortization	(6,141)	(5,641)
Net	$ 1,859	$ 2,359
Other
Other intangible assets:
Weighted Average Useful Life (in years)	4 years 6 months	4 years 6 months
Gross	$ 6,045	$ 5,750
Accumulated Amortization	(2,045)	(1,900)
Net	$ 4,000	$ 3,850

Goodwill and Other Intangible34

Goodwill and Other Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining in 2016	$ 29,059
2,017	31,919
2,018	20,664
2,019	7,444
2,020	3,922
2,021	672
Thereafter	296
Net	$ 93,976	$ 103,660

Shareholders' Equity - Summary

Shareholders' Equity - Summary of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Feb. 29, 2016
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income	$ 237	$ 70
Share repurchase authorized amount			$ 25,000
Gains and Losses on Available-for- Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(88)
Other comprehensive income before reclassifications	18
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	18
Balance at end of period	(70)
Foreign Currency Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(945)
Other comprehensive income before reclassifications	219
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	219
Balance at end of period	(726)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period	(1,033)
Other comprehensive income before reclassifications	237
Amounts reclassified from accumulated other comprehensive loss	0
Other comprehensive income	237
Balance at end of period	$ (796)

Loss Per Share - Computation of

Loss Per Share - Computation of Basic and Diluted Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Basic presentation:
Net loss	$ (2,687)	$ (9,611)
Weighted average common shares outstanding	81,015	78,706
Basic loss per share (in dollars per share)	$ (0.03)	$ (0.12)
Diluted presentation:
Net loss	$ (2,687)	$ (9,611)
Denominator for dilutive loss per share:
Diluted weighted average common shares outstanding (in shares)	81,015	78,706
Diluted loss per share (in dollars per share)	$ (0.03)	$ (0.12)
Equity Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	4,900	4,800
Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)		10,300

Concentrations (Details)

Concentrations (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016USD ($)customerproduct_line	Mar. 31, 2015USD ($)customer
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of product lines | product_line	2
Revenues	$ 112,673	$ 120,962
Network Test Solutions
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	83,505	85,347
Network Visibility Solutions
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 29,168	$ 35,615
Customer Concentration Risk | Sales Revenue, Net
Segment Reporting, Revenue Reconciling Item [Line Items]
Number of customers | customer	0	2
JAPAN | Geographic Concentration Risk | Sales Revenue, Net
Segment Reporting, Revenue Reconciling Item [Line Items]
Concentration risk percentage		11.10%
International revenues | Geographic Concentration Risk | Sales Revenue, Net
Segment Reporting, Revenue Reconciling Item [Line Items]
Concentration risk percentage	48.40%	38.40%

Concentrations - Geographical L

Concentrations - Geographical Locations of Property, Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	$ 37,706	$ 36,536
United States
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	24,657	23,654
Romania
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	6,700	6,542
India
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	3,410	3,576
Other
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	$ 2,939	$ 2,764

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets Carried at Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Note 11 - Fair Value Measurements (Details) - Financial Assets Carried at Fair Value [Line Items]
Long-term Debt, Fair Value	$ 38,000	$ 38,500
Short-term marketable securities:
Investments	19,521	14,504
Total financial assets	29,834	14,788
Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	117	284
Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	10,196
Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	9,605	4,288
Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	9,916	10,216
Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term marketable securities:
Total financial assets	117	284
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	117	284
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	0	0
Significant Other Observable Inputs (Level 2)
Short-term marketable securities:
Total financial assets	29,717	14,504
Significant Other Observable Inputs (Level 2) | Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	0	0
Significant Other Observable Inputs (Level 2) | Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	10,196
Significant Other Observable Inputs (Level 2) | Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	9,605	4,288
Significant Other Observable Inputs (Level 2) | Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	9,916	10,216
Significant Unobservable Inputs (Level 3)
Short-term marketable securities:
Total financial assets	0	0
Significant Unobservable Inputs (Level 3) | Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	0	0
Significant Unobservable Inputs (Level 3) | Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	0
Significant Unobservable Inputs (Level 3) | Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	0	0
Significant Unobservable Inputs (Level 3) | Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Jul. 18, 2014	Mar. 31, 2016USD ($)lawsuit	Jul. 23, 2015USD ($)
Securities Class Action | Pending Litigation
Loss Contingencies [Line Items]
Number of days to respond	30 days
Settlement amount		$ 3,500
Receivable amount		3,500
Loss contingency accrual		$ 3,500
Shareholder Derivative Action | Pending Litigation
Loss Contingencies [Line Items]
Number of lawsuits | lawsuit		2
Legal Fees | Shareholder Derivative Action | Pending Litigation
Loss Contingencies [Line Items]
Receivable amount		$ 575
Loss contingency accrual		575	$ 575
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Civil penalty		$ 750

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Mar. 31, 2016	Dec. 31, 2015
Prepaid Expenses and Other Current Assets
Income Taxes (Details) [Line Items]
Current deferred tax assets	$ 14.7	$ 14.5
Other Assets
Income Taxes (Details) [Line Items]
Noncurrent deferred tax assets	18.9	18.9
Other Liabilities
Income Taxes (Details) [Line Items]
Noncurrent deferred tax liabilities	$ 0.4	$ 0.4