Ixia (XXIA) 10-Q 6 Nov 15 2015 Q3 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	9 Months Ended
	Sep. 30, 2015	Oct. 30, 2015
Document and Entity Information [Abstract]
Entity Registrant Name	Ixia
Document Type	10-Q
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		80,085,026
Amendment Flag	false
Entity Central Index Key	1,120,295
Entity Filer Category	Large Accelerated Filer
Document Period End Date	Sep. 30, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	Q3

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 75,751	$ 46,394
Restricted cash	10,000	0
Marketable securities	49,467	79,760
Marketable securities, restricted	40,000	0
Accounts receivable, net of allowances of $862 and $1,011, as of September 30, 2015 and December 31, 2014, respectively	105,663	99,528
Inventories	32,522	44,826
Prepaid expenses and other current assets	53,515	47,077
Total current assets	366,918	317,585
Property and equipment, net	35,965	37,648
Intangible assets, net	113,451	145,108
Goodwill	338,873	338,873
Other assets	28,206	30,697
Total assets	883,413	869,911
Current liabilities:
Accounts payable	12,183	16,902
Accrued expenses and other	58,765	45,271
Deferred revenues	103,760	100,170
Convertible senior notes	135,000	200,000
Term loan	3,000	0
Total current liabilities	312,708	362,343
Deferred revenues	21,930	18,046
Other liabilities	8,769	8,431
Term loan	36,000	0
Total liabilities	$ 379,407	$ 388,820
Commitments and contingencies (Note 11)
Shareholders’ equity:
Common stock, without par value; 200,000 shares authorized at September 30, 2015 and December 31, 2014; 80,084 and 78,575 shares issued and outstanding as of September 30, 2015 and December 31, 2014, respectively	$ 195,959	$ 187,397
Additional paid-in capital	220,990	206,913
Retained earnings	87,774	87,574
Accumulated other comprehensive loss	(717)	(793)
Total shareholders’ equity	504,006	481,091
Total liabilities and shareholders’ equity	$ 883,413	$ 869,911

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Allowance for doubtful accounts receivable	$ 862	$ 1,011
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	80,084,000	78,575,000
Common stock, shares outstanding	80,084,000	78,575,000
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		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Revenues:
Products		$ 85,861	$ 78,697	$ 264,571	$ 236,255
Services		40,026	35,300	113,888	100,997
Total revenues		125,887	113,997	378,459	337,252
Costs and operating expenses:
Cost of revenues – products	[1]	23,872	24,205	72,108	73,207
Cost of revenues – services		3,607	4,008	12,487	12,128
Research and development		28,538	27,612	83,923	87,679
Sales and marketing		37,920	35,642	113,880	114,355
General and administrative		18,486	14,724	54,274	49,296
Amortization of intangible assets		10,378	10,904	32,190	35,986
Acquisition and other related costs		(37)	582	646	3,380
Restructuring		34	4,642	(527)	8,687
Total costs and operating expenses	[2]	122,798	122,319	368,981	384,718
Income (loss) from operations		3,089	(8,322)	9,478	(47,466)
Interest income and other, net		(313)	(99)	(592)	530
Interest expense		(2,270)	(1,943)	(6,852)	(5,829)
Income (loss) before income taxes		506	(10,364)	2,034	(52,765)
Income tax (benefit) expense		(3,502)	(3,035)	1,834	(10,887)
Net income (loss)		$ 4,008	$ (7,329)	$ 200	$ (41,878)
Earnings (loss) per share:
Basic (in dollars per share)		$ 0.05	$ (0.09)	$ 0	$ (0.54)
Diluted (in dollars per share)		$ 0.05	$ (0.09)	$ 0	$ (0.54)
Weighted average number of common and common equivalent shares outstanding:
Basic (in shares)		79,895	77,920	79,336	77,380
Diluted (in shares)		81,929	77,920	81,085	77,380
Cost of revenues - products
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		$ 62	$ 81	$ 233	$ 217
Cost of revenues - services
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		24	31	89	82
Research and development
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		1,345	1,615	5,016	4,918
Sales and marketing
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		1,184	719	3,435	4,140
General and administrative
Weighted average number of common and common equivalent shares outstanding:
Allocated Share-based Compensation Expense		$ 1,816	$ 762	$ 5,548	$ 1,755
[1]	Cost of revenues – products excludes amortization of intangible assets related to purchased technologies of $6.4 million and $19.3 million for the three and nine months ended September 30, 2015, respectively, and $6.4 million and $22.5 million for the three and nine months ended September 30, 2014 , respectively, which are included in Amortization of intangible assets.
[2]	Stock-based compensation included in: Three months ended September 30, Cost of revenues - products: 2015 $62 2014 $81 Cost of revenues - services: 2015 $24 2014 $31 Research and development: 2015 $1,345 2014 $1,615 Sales and marketing: 2015 $1,184 2014 $719 General and administrative: 2015 $1,816 2014 $762Nine months endedSeptember 30, Cost of revenues - products: 2015 $233 2014 $217 Cost of revenues - services: 2015 $89 2014 $82 Research and development: 2015 $5,016 2014 $4,918 Sales and marketing: 2015 $3,435 2014 $4,140 General and administrative: 2015 $5,548 2014 $1,755

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Statement [Abstract]
Cost of revenues - excluded amortization of intangible assets	$ 6.4	$ 6.4	$ 19.3	$ 22.5

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 4,008	$ (7,329)	$ 200	$ (41,878)
Unrealized (loss) gain on investments, net of tax	(37)	(17)	(26)	22
Foreign currency translation adjustment	67	(268)	102	(72)
Other comprehensive income (loss)	30	(285)	76	(50)
Comprehensive income (loss)	$ 4,038	$ (7,614)	$ 276	$ (41,928)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income (loss)	$ 200	$ (41,878)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation	12,629	12,065
Amortization of intangible assets	32,190	35,986
Realized gain on available-for-sale securities	(61)	(65)
Stock-based compensation	14,321	11,112
Deferred income taxes	(1,124)	(1,344)
Amortization of deferred issuance costs	1,237	900
Amortization of investment premiums	54	48
Changes in operating assets and liabilities, net of effect of acquisitions:
Accounts receivable, net	(6,135)	15,354
Inventories	6,948	(7,087)
Prepaid expenses and other current assets	(6,351)	(15,520)
Other assets	3,414	4,549
Accounts payable	(4,380)	(722)
Accrued expenses and other	13,692	(6,770)
Deferred revenues	7,474	16,215
Other liabilities	486	1,496
Net cash provided by operating activities	74,594	24,339
Cash flows from investing activities:
Purchases of property and equipment	(6,025)	(5,361)
Purchases of marketable securities	(188,795)	(77,882)
Proceeds from sale of marketable securities	179,065	58,487
Increase in restricted cash	(10,000)	0
Purchases of other intangible assets	(533)	(517)
Proceeds from purchase price adjustments related to previous acquisitions	0	6,081
Payments in connection with acquisitions, net of cash acquired	0	(3,097)
Net cash used in investing activities	(26,288)	(22,289)
Cash flows from financing activities:
Proceeds from exercise of stock options and employee stock purchase plan options	8,562	6,775
Proceeds from borrowings under term loan	40,000	(393)
Repayments of debt	(66,163)	0
Debt issuance costs	(1,348)	0
Net cash (used in) provided by financing activities	(18,949)	6,382
Net increase in cash and cash equivalents	29,357	8,432
Cash and cash equivalents at beginning of period	46,394	34,189
Cash and cash equivalents at end of period	75,751	42,621
Supplemental disclosure of non-cash investing activities:
Purchased and unpaid property and equipment	550	879
Transfers of inventory to property and equipment	$ 5,356	$ 7,861

Business

Business	9 Months Ended
	Sep. 30, 2015
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. Ixia 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 hardware platforms, such as its chassis, interface cards and appliances, software application tools, and services, including its warranty and maintenance offerings, and professional services. The Company operated within one business segment during the periods presented in the accompanying condensed consolidated financial statements.

Basis of Presentation, Signific

Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 and for the three and nine months ended September 30, 2015 and 2014 , 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 and nine months ended September 30, 2015 and 2014 are not necessarily indicative of results to be expected for the full year ending December 31, 2015 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 (“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, 2014 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, 2014 (the “ 2014 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 2014 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 2014 Form 10-K; however, in this Form 10-Q the Company is including a new disclosure relating to the classification of cash and investments as restricted as a result of restrictions on their use under the terms of the Company’s amended and restated credit agreement entered into in March 2015, as follows: Restricted cash and restricted marketable securities represent amounts restricted under the terms of the Company's amended and restated credit agreement for use only in the repayment of the Company's unsecured convertible senior notes due December 15, 2015. See Note 4 for additional information regarding the Company's amended and restated credit agreement. Recent Accounting Pronouncements In September 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2015-16, Simplifying the Accounting for Measurement-Period Adjustments , which provides new guidance regarding measurement period adjustments in connection with business combinations by requiring that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The standard will be effective for annual reporting periods beginning after December 15, 2015, including interim periods within those reporting periods. The standard update is to be applied prospectively to adjustments of provisional amounts that occur after the effective date with earlier application permitted for financial statements that have not been issued. The Company does not expect the adoption of this standard to have an impact 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 April 2015, the FASB issued ASU 2015-03, Interest—Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs , and, in August 2015, the FASB issued ASU 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . These ASUs require debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of that debt consistent with debt discounts. The presentation and subsequent measurement of debt issuance costs associated with lines of credit may be presented as an asset and amortized ratably over the term of the line of credit arrangement, regardless of whether there are outstanding borrowings on the arrangement. The recognition and measurement guidance for debt issuance costs are not affected by these ASUs. These ASUs are effective for financial statements issued for fiscal years beginning after December 15, 2015 and interim periods within those years. Early application is permitted. The Company is in the process of evaluating the impact of the adoption of these accounting standard updates on its consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern: Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern , which provides guidance about management's responsibility to evaluate whether or not there is substantial doubt about a company's ability to continue as a going concern and to provide related footnote disclosure. The standard will be effective for annual reporting periods ending after December 15, 2016, and interim periods thereafter. Early application is permitted. The Company is in the process of evaluating the impact of the adoption of this accounting standard update on its consolidated financial statements. In June 2014, the FASB issued ASU 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide that a Performance Target Could Be Achieved after the Requisite Service Period , which provides new guidance regarding share-based compensation. The new guidance clarifies that share-based compensation performance targets that could be achieved after the requisite service period should be treated as performance conditions that affect vesting, rather than as a condition that affects the grant-date fair value of the award. The standard will be effective for annual reporting periods beginning after December 15, 2015, including interim periods within those reporting periods. Early adoption is permitted. The Company is in the process of evaluating 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 sate 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.

Restructuring Costs

Restructuring Costs	9 Months Ended
	Sep. 30, 2015
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Costs During the three and nine months ended September 30, 2015 , the Company recorded net restructuring charges of $34,000 and net restructuring credits of $0.5 million , respectively. During the three and nine months ended September 30, 2014 , the Company recorded restructuring charges of $4.6 million and $8.7 million , respectively. The Company’s restructuring charges include severance and other employee termination costs, lease termination costs, and other restructuring related costs, which are reported in the Restructuring line item on its condensed consolidated statements of operations. Net restructuring credits recorded during the nine months ended September 30, 2015 included a recovery in the amount of $0.4 million relating to a favorable lease buyout and $0.4 million relating to the receipt of proceeds from an insurance settlement related to costs previously charged to the Restructuring line item on the condensed consolidated statements of operations. The timing of cash payments associated with restructuring charges depends upon the type of restructuring charge and can extend over multiple periods. During the first quarter of 2014 , the Company's management approved, committed to and initiated a plan to restructure the Company's operations following its December 5, 2013 acquisition of Net Optics, Inc. (the “Net Optics Restructuring”). The Net Optics Restructuring included a net reduction in force of approximately 45 positions (primarily impacting the Company's research and development team in Israel and Santa Clara, California), which represented approximately 2.3% of our worldwide work force at that time. The Company recognized cumulative restructuring charges of $3.5 million , of which $2.0 million related to employee termination benefits consisting of severance and other related employee costs, $1.1 million related to costs required to terminate its subsidiary's lease in Israel, and approximately $323,000 was for other restructuring related costs. The Net Optics Restructuring was substantially completed during the second quarter of 2014, and no further charges are expected. During the third quarter of 2014 , the Company's management approved, committed to and implemented a company-wide initiative (the “2014 Corporate Restructuring”) to restructure the Company's operations to better align its operating costs with its business opportunities. The 2014 Corporate Restructuring included a reduction in force of approximately 96 positions across multiple business functions, which represented approximately 5% of our then worldwide work force. The Company recognized restructuring charges during 2014 of $6.1 million , of which $4.1 million related to one-time expenses for employee termination benefits, approximately $1.8 million was for facility related charges in India and Romania, and approximately $137,000 was for other restructuring related costs. The 2014 Corporate Restructuring was substantially completed during the fourth quarter of 2014, and no further charges are expected. Activities related to our restructuring plans are as follows (in thousands): 2014 Corporate Net Optics Other Total Accrual at December 31, 2014 1,940 337 246 2,523 Charges, net of recoveries (193 ) (334 ) — (527 ) Payments (1,190 ) (3 ) (140 ) (1,333 ) Non-cash items — — (106 ) (106 ) Accrual at September 30, 2015 $ 557 $ — $ — $ 557 At September 30, 2015 , the remaining accrual related to the Company's restructuring activities totaled $0.6 million and was included in Accrued expenses and other on its condensed consolidated balance sheet. The remaining accrual primarily relates to lease termination costs, which are anticipated to be fully paid by the third quarter of 2020.

Debt

Debt	9 Months Ended
	Sep. 30, 2015
Debt Disclosure [Abstract]
Debt	Debt Unsecured Convertible Senior Notes On December 7, 2010, the Company issued $200 million in aggregate principal amount of 3.00% Convertible Senior Notes due December 15, 2015 unless earlier repurchased or converted (the “Notes”). The unsecured Notes were offered and sold only to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The Notes are governed by the terms of an indenture dated December 7, 2010 (the “Indenture”), which was filed with the SEC on December 8, 2010. 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 . As a result of the repurchase, the aggregate principal amount of the Notes that remain outstanding is $135 million . The Company paid the purchase price for the repurchased Notes with funds withdrawn from the restricted amounts, which are identified on the Balance Sheet as Restricted cash and Marketable securities, restricted, established by the Company pursuant to the amended and restated credit agreement dated as of March 2, 2015 (as such agreement is described below in this Note 4 under “Senior Secured Credit Agreement - 2015 Credit Agreement”). The Notes bear interest at a rate of 3.00% per year, payable semiannually in arrears on June 15 and December 15 of each year, which payments began on June 15, 2011. The Company may in certain instances be required to pay additional interest in connection with any events of default relating to its failure to comply with its reporting obligations to the trustee under the Indenture and to the SEC. After any such default under the Indenture, if the trustee or the holders of at least 25% in aggregate principal amount of the Notes give the Company notice of, and direct the Company to cure, the default and the default is not cured within 60 days thereafter, then unless a waiver is obtained from the holders of more than 50% in aggregate principal amount of the Notes, an event of default will occur under the Indenture. Upon any such event of default, the Company may elect that for the first 180 days (or such lesser amount of time during which the event of default continues), the sole remedy be the payment of additional interest at an annual rate equal to 0.50% . In the event that such additional interest becomes payable because of the Company's failure to timely file certain reports with the SEC and the trustee, the filing of such reports will cure the event of default and the interest rate will be reduced (so long as no other events of default then exist). If the Company elects to pay such additional interest and the event of default is not cured within the 180 -day period, or if the Company does not make such an election to pay additional interest when the event of default first occurs, the trustee or the holders of at least 25% in aggregate principal amount of the Notes may declare the Notes to be due and payable immediately. Amortization of deferred issuance costs recorded to interest expense was $372,000 and $300,000 for the three months ended September 30, 2015 and September 30, 2014 , respectively, and $972,000 and $900,000 for the nine months ended September 30, 2015 and September 30, 2014 , respectively. Amortization of deferred issuance costs recorded to interest expense for the three and nine months ended September 30, 2015 includes $169,000 of deferred issuance costs related to the repurchased portion of the Notes. The Notes are convertible at any time prior to the close of business on the third business day immediately preceding the maturity date, at the holder’s option, into shares of our common stock at an initial conversion rate of 51.4536 shares per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $19.43 per share. The conversion rate is subject to adjustment for certain events that occur prior to maturity, such as a change in control transaction as defined in the Indenture. The Company may not redeem the Notes prior to the maturity date. If a fundamental change (such as a change in control event or if the Company's Common Stock ceases to be listed or quoted on any of the New York Stock Exchange, the Nasdaq Global Select Market or the Nasdaq Global Market or any of their respective successors) occurs prior to the maturity date, holders may require the Company to repurchase for cash all or part of their Notes at a repurchase price equal to 100% of the principal amount of the Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The Indenture provides for customary events of default (subject in certain cases to grace and cure periods) including, without limitation, (i) the failure to pay amounts due under the Notes, (ii) the failure to deliver the shares of our Common Stock due upon conversion of any Note, (iii) our failure to comply with other agreements contained in the Indenture or in the Notes, including the Company's agreement to timely file certain reports with the trustee, (iv) payment defaults on, or acceleration of, other indebtedness, (v) the failure to pay certain judgments, and (vi) certain events of bankruptcy, insolvency or reorganization with respect to the Company. An event of default under the Indenture (other than an event of default related to certain events of bankruptcy, insolvency or reorganization) will allow either the trustee or the holders of at least 25% in aggregate principal amount of the then outstanding Notes to cause the acceleration of the Notes (subject to the Company’s right to elect to pay additional interest as an alternative remedy under certain circumstances as described above). An event of default related to certain events of bankruptcy, insolvency or reorganization with respect to the Company will automatically cause the acceleration of the Notes. As of September 30, 2015 , the estimated fair value of the Notes then outstanding was approximately $135 million . The fair value of the Notes was estimated using market prices of the Notes, which are based on Level 2 inputs. Senior Secured Credit Agreement 2015 Credit Agreement On March 2, 2015 (the “Closing Date”), the Company entered into an amended and restated credit agreement (as amended by a Corrective Amendment to Credit Agreement dated as of March 20, 2015, 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 hereinafter collectively referred to as the “Lenders”). The Credit Agreement amended and restated our prior credit agreement dated as of December 21, 2012, as amended (the “Prior Credit Agreement”), 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. On September 30, 2015, the Company entered into a Second Amendment to Amended and Restated Credit Agreement which increased the amount of the revolving credit facility provided under the Credit Agreement by $15 million and effected certain other modifications to the Credit Agreement. The Credit Agreement, as amended to date (the “Amended Credit Agreement”), provides for a (i) term loan (the “Term Loan”) in the aggregate principal amount of $40 million , which amount was advanced to the Company on March 3, 2015, and (ii) revolving credit facility (the “Revolving Credit Facility” and, together with the Term Loan, the “Credit Facility”) in an aggregate amount of up to $75 million , with sub-limits of $25 million for the issuance of standby letters of credit and $15 million for swingline loans. The aggregate amount available under the Credit Facility may, upon our request and subject to the receipt of increased commitments from the Lenders or additional lenders, be increased by an aggregate amount of up to $65 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 the Company may not re-borrow amounts that are repaid or prepaid under the Term Loan. The maturity date of the Credit Facility is February 15, 2018; provided, however, that if, at any time before the maturity date for the Notes (i.e., December 15, 2015), the Company does not have total available liquidity (defined as cash, cash equivalents and marketable securities plus availability under the Revolving Credit Facility) of $25 million in excess of the amount then required to repay its Notes in full, all amounts outstanding under the Credit Facility will become due and payable and the Revolving Credit Facility will terminate within two business days after the date the Company fails to have the required total available liquidity. Debt issuance costs were approximately $1.3 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 and nine months ended September 30, 2015 , amortization recorded to interest expense pertaining to deferred issuance costs was approximately $129,000 and $265,000 , respectively. There was no amortization recorded to interest expense pertaining to deferred issuance costs for the Term Loan for the three and the nine months ended September 30, 2014 . As required by the terms of the Amended Credit Agreement, we maintain funds advanced under the Term Loan of $40 million , together with additional cash, cash equivalents and marketable securities, as restricted assets to be utilized for the repayment or repurchase of the Notes (the “Restricted Amounts”). The Company may utilize amounts maintained as Restricted Amounts only for the repurchase or repayment of the Notes. As described above in this Note 4 under “Unsecured Convertible Senior Notes,” in July 2015, the Company repurchased Notes in the aggregate principal amount of $65 million in a privately negotiated transaction. The Company used a portion the Restricted Amounts then maintained by the Company to fund the purchase price for, and the payment of interest on, such repurchased Notes. The repurchase transaction reduced the total amount of the Restricted Amounts required to be maintained under the Amended Credit Agreement from $115 million to $50 million . The $50 million required to be maintained as the Restricted Amounts as of September 30, 2015 consists of $10 million in cash and cash equivalents, which is included in the Restricted cash line item on our condensed consolidated balance sheet at September 30, 2015 , and $40 million in marketable securities, which is included in the Marketable securities, restricted line item on our condensed consolidated balance sheet at September 30, 2015 . The Company may use the proceeds of the Revolving Credit Facility for (i) working capital, capital expenditures and general corporate purposes, (ii) share repurchases, (iii) the partial refinancing of the Notes, and/or (iv) acquisitions, in each case as permitted by applicable law and the Amended Credit Agreement. The restrictions on acquisitions as set forth in the Amended Credit Agreement include a restriction that precludes the Company from funding an acquisition in whole or in part with cash unless the Company will have, after giving effect to the transaction, cash, cash equivalents and marketable securities in an amount not less than $75 million in excess of the amount then required to be maintained as Restricted Amounts. The Company plans to satisfy its repayment obligations under the Notes, and to pay the purchase price for any earlier additional Note repurchases (whether mandatory or negotiated by the Company), using some combination of (i) cash, cash equivalents and marketable securities, including those maintained as Restricted Amounts, (ii) borrowings under the Revolving Credit Facility, and/or (iii) future cash flows from operations. The Term Loan requires quarterly repayments of principal on the last day of the eleven fiscal quarters following the Closing Date, commencing with the fiscal quarter ended June 30, 2015. The first four payments are in the amount of $500,000 each, the following four payments will be in the amount of $1.0 million each, and the next three payments will be in the amount of $1.5 million each. The remaining principal balance of the Term Loan will be due and payable on the maturity date of the Credit Facility. The first and second of the four payments of $500,000 were made on June 30, 2015 and on September 30, 2015 , respectively. The Company’s and the guarantors’ obligations under the Amended 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 our wholly owned domestic subsidiaries), 65% of the outstanding equity securities of Ixia Technologies International Limited, a company organized under the laws of Ireland. Prior to the date of the Second Amendment, interest rates for the Revolving Credit Facility for the first year following the March 2, 2015 effective date of the Credit Facility and for the Term Loan were previously set, at the Company’s option, at a rate per annum of (i) 4.25% above the Eurodollar rate or (ii) 3.25% above a defined base rate. Pursuant to the Amended Credit Agreement, after September 30, 2015, the interest rates for both the Term Loan and for the Revolving Credit Facility are established, at the Company’s option, based on the Eurodollar rate or a defined base rate. Such interest rates 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 our 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 we default under the Credit Facility, 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 three and nine months ended September 30, 2015 was 4.44% and 4.43% , respectively, which was based on the one month Eurodollar rate plus 4.25% . The Amended Credit Agreement requires the Company to comply with certain covenants, including maintaining (i) a fixed charge coverage ratio (as defined in the Amended Credit Agreement) of not less than 1.25 to 1.00, measured quarterly on a trailing 12 months basis, (ii) a consolidated senior leverage ratio (as defined in the Amended Credit Agreement) of not greater than 2.50 to 1.00 through December 31, 2015 and 2.25 to 1.00 thereafter, measured quarterly on a trailing 12 months basis, and (iii) a consolidated total leverage ratio (as defined in the Amended Credit Agreement) of not greater than 3.00 to 1.00, measured quarterly on a trailing 12 months basis. The consolidated funded indebtedness (as defined in the Amended Credit Agreement) used in the calculation of the consolidated leverage ratio is reduced by the Restricted Amounts (except in connection with the calculation of the applicable margin for loans). The Amended Credit Agreement also contains reporting covenants typical for transactions comparable to the Credit Facility provided for therein, 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 Amended 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 Amended 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 Amended 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 of our outstanding obligations under the Amended Credit Agreement and in an increase in the applicable interest rate(s) as described above. Prior Credit Agreement The Company’s Prior Credit Agreement provided for a credit facility (the “Prior Credit Facility”) that originally consisted of a revolving loan commitment of up to $150 million . As a result of the termination of certain lenders’ commitments under the Prior Credit Facility, the aggregate loan amount was reduced to $67.5 million in January 2015 and further reduced to $46.5 million in March 2015 prior to the date of the amendment and restatement of the Prior Credit Agreement on March 2, 2015. Due to our defaults under the Prior Credit Agreement, we were at the time of its amendment and restatement blocked from borrowing and obtaining letters of credit under the Prior Credit Facility. As of December 31, 2014, and immediately prior to the March 2015 amendment and restatement of the Prior Credit Agreement, no amounts were outstanding under the Prior Credit Facility.

Selected Balance Sheet Data

Selected Balance Sheet Data	9 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Selected Balance Sheet Data	Selected Balance Sheet Data Investments in Marketable Securities Investments in marketable securities as of September 30, 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 $ 50,384 $ 22 $ (7 ) $ 50,399 Corporate debt securities 39,116 21 (69 ) 39,068 Total $ 89,500 $ 43 $ (76 ) $ 89,467 Investments in marketable securities as of December 31, 2014 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 $ 42,289 $ 9 $ (17 ) $ 42,281 Corporate debt securities 37,476 41 (38 ) 37,479 Total $ 79,765 $ 50 $ (55 ) $ 79,760 As of September 30, 2015 , $40 million of our marketable securities were restricted under the terms of the Amended Credit Agreement for use only in the repayment of or satisfaction of other obligations relating to the Notes due December 15, 2015 and are classified as Marketable securities, restricted on the Company's condensed consolidated balance sheet as of September 30, 2015 . See Note 4 for additional information regarding the restrictions under our Amended Credit Agreement relating to these marketable securities. As of September 30, 2015 and December 31, 2014 , the Company's available-for-sale securities had a weighted remaining contractual maturity of 1.25 and 1.69 years, respectively. For the three and nine months ended September 30, 2015 and 2014 , gross realized gains and losses were not significant. See Note 7 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 September 30, 2015 , by contractual years-to-maturity, are as follows (in thousands): Amortized Cost Fair Value Due in less than 1 year $ 44,243 $ 44,246 Due within 1-2 years 25,751 25,737 Due within 2-5 years 19,506 19,484 Total $ 89,500 $ 89,467 Inventories Inventories consist of the following (in thousands): September 30, 2015 December 31, 2014 Raw materials $ 4,360 $ 5,502 Work in process 10,108 18,047 Finished goods 18,054 21,277 $ 32,522 $ 44,826 Accrued expenses and other As of September 30, 2015 and December 31, 2014 , accrued compensation and related expenses totaled $12.6 million and $9.9 million , respectively, accrued bonus expenses totaled $13.5 million and $3.9 million , respectively, and accrued vacation totaled $8.5 million and $7.5 million , respectively.

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	9 Months Ended
	Sep. 30, 2015
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 and nine months ended September 30, 2015 . We have not had any historical goodwill impairment charges. The following table presents the Company's purchased intangible assets (in thousands) as of September 30, 2015 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (123,870 ) $ 61,795 Customer relationships 6.0 71,700 (49,362 ) 22,338 Service agreements 6.4 30,100 (12,099 ) 18,001 Trademarks 5.1 11,300 (6,508 ) 4,792 Non-compete agreements 4.0 8,000 (5,141 ) 2,859 Other 4.5 5,416 (1,750 ) 3,666 $ 312,181 $ (198,730 ) $ 113,451 The following table presents the Company's purchased intangible assets (in thousands) as of December 31, 2014 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (106,953 ) $ 78,712 Customer relationships 6.0 71,700 (40,938 ) 30,762 Service agreements 6.4 30,100 (8,577 ) 21,523 Trademarks 5.1 11,300 (5,033 ) 6,267 Non-compete agreements 4.0 8,000 (3,641 ) 4,359 Other 4.2 4,883 (1,398 ) 3,485 $ 311,648 $ (166,540 ) $ 145,108 The estimated future amortization expense of purchased intangible assets as of September 30, 2015 is as follows (in thousands): Remaining in 2015 $ 10,101 2016 37,867 2017 31,876 2018 20,606 2019 7,374 2020 3,839 Thereafter 1,788 $ 113,451

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2015
Stockholders' Equity Note [Abstract]
Shareholders' Equity	Shareholders’ Equity The following table summarizes the changes in Accumulated other comprehensive loss , by component, net of income taxes (in thousands): Gains and Losses on Available-for- Sale Securities (a) Foreign Currency Items Total Beginning balance, December 31, 2014 $ (32 ) $ (761 ) $ (793 ) Other comprehensive income before reclassifications 11 102 113 Amounts reclassified from accumulated other comprehensive loss (b) (37 ) — (37 ) Net current period other comprehensive income (26 ) 102 76 Ending balance, September 30, 2015 $ (58 ) $ (659 ) $ (717 ) (a) All amounts are net-of-tax. Amounts in parentheses indicate reductions. (b) Amount represents gain on the sale of securities and is included as a component of Interest income and other, net in the condensed consolidated statements of operations.

Earnings (loss) Per Share

Earnings (loss) Per Share	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Earnings (loss) Per Share	Earnings (loss) Per Share Basic earnings (loss) per common share is computed by dividing net income (loss) by the weighted average number of common shares outstanding during the period. Diluted income (loss) per common share is computed by giving effect to all potential dilutive common shares, including stock-based awards. The following table sets forth the computation of basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2015 and 2014 (in thousands, except per share data): Three months ended Nine months ended 2015 2014 2015 2014 Basic presentation: Numerator for basic earnings (loss) per share: Net income (loss) $ 4,008 $ (7,329 ) $ 200 $ (41,878 ) Denominator for basic earnings (loss) per share: Weighted average common shares outstanding 79,895 77,920 79,336 77,380 Basic earnings (loss) per share $ 0.05 $ (0.09 ) $ 0.00 $ (0.54 ) Diluted presentation: Numerator for diluted earnings (loss) per share: Net income (loss) $ 4,008 $ (7,329 ) $ 200 $ (41,878 ) Denominator for diluted earnings (loss) per share: Weighted average common shares outstanding 79,895 77,920 79,336 77,380 Effect of dilutive securities: Stock options and other share-based awards 2,034 — 1,749 — Diluted weighted average common shares outstanding 81,929 77,920 81,085 77,380 Diluted earnings (loss) per share $ 0.05 $ (0.09 ) $ 0.00 $ (0.54 ) The diluted earnings per share computation for the three and nine months ended September 30, 2015 excludes (i) the weighted average number of shares underlying our Notes of 7.2 million shares and 9.3 million shares, respectively, as such shares are considered anti-dilutive because the related interest expense on a per common share "if converted" basis exceeds basic earnings per share, and (ii) the weighted average number of shares underlying the Company's employee stock options and other share-based awards of 2.1 million shares and 2.9 million shares, respectively, which are anti-dilutive because, in general, the exercise prices of these awards (to the extent such awards have exercise prices) exceed the average closing sales price per share of the Company's common stock during the applicable period. The diluted loss per share computation for the three and nine months ended September 30, 2014 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 4.2 million shares and 4.5 million shares, respectively, which were anti-dilutive because the Company reported net losses for the applicable periods.

Concentrations

Concentrations	9 Months Ended
	Sep. 30, 2015
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 Nine months ended 2015 2014 2015 2014 Network Test Solutions $ 92,504 $ 84,110 $ 280,652 $ 257,309 Network Visibility Solutions 33,383 29,887 97,807 79,943 $ 125,887 $ 113,997 $ 378,459 $ 337,252 Significant Customers No customer accounted for more than 10% of total revenues for the three and nine months ended September 30, 2015 . As of September 30, 2015 and December 31, 2014 , no customer accounted for more than 10% of the Company's total receivables. No customer accounted for more than 10% of total revenues for the three and nine months ended September 30, 2014 , and one customer accounted for more than 10% of total receivables as of September 30, 2014 . International Data For the three and nine months ended September 30, 2015 and 2014 , the percentages of total revenues consisting of international revenues based on customer location consisted of the following: Three months ended Nine months ended 2015 2014 2015 2014 International revenues 36.1 % 42.5 % 37.6 % 41.1 % As of September 30, 2015 and December 31, 2014 , the Company's property and equipment, net were geographically located as follows (in thousands): September 30, 2015 December 31, 2014 United States $ 22,881 $ 24,697 Romania 6,536 6,035 India 3,660 3,857 Other 2,888 3,059 Total $ 35,965 $ 37,648

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 are classified in the table below in one of the three categories described above (in thousands): September 30, 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 $ 500 $ 500 $ — $ — U.S. Treasury, government and agency debt securities 7,999 — 7,999 — Corporate debt securities 18,793 — 18,793 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 50,399 — 50,399 — Corporate debt securities 39,068 — 39,068 — Total financial assets $ 116,759 $ 500 $ 116,259 $ — Financial assets carried at fair value as of December 31, 2014 are classified in the table below in one of the three categories described above (in thousands): December 31, 2014 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 $ 267 $ 267 $ — $ — Corporate debt securities 5,349 — 5,349 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 42,281 — 42,281 — Corporate debt securities 37,479 — 37,479 — Total financial assets $ 85,376 $ 267 $ 85,109 $ — 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 and nine month periods ended September 30, 2015 , and there were no Level 3 assets held at September 30, 2015 .

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2015
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. The settlement will not become effective until the parties agree on a formal Stipulation of Settlement and such Stipulation is approved by the Court. The settlement terms include 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 settlement will 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, the settlement will resolve the claims asserted against all of the defendants in the purported class action and will include a full release of all defendants in connection with the allegations made in the purported securities class action. 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. The settlement will not become effective until the parties agree on a formal Stipulation of Settlement and such Stipulation is approved by the Court. The settlement will require that the Company implement certain corporate governance measures and will also provide that the plaintiffs' counsel may apply to the Court for an award of attorneys’ fees and expenses in the amount of $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 settlement will not include any admission of wrongdoing or liability on the part of the Company or the individual defendants and will include a full release of all defendants in connection with the allegations made in the derivative action. 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 , for which the Company has established a reserve in its financial statements for the quarter ended September 30, 2015. 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. 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	9 Months Ended
	Sep. 30, 2015
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. A final decision has yet to be issued by the U.S. Tax Court due to other outstanding procedural issues. At this time, the U.S. Department of the Treasury has not withdrawn the requirement from its regulations to include stock-based compensation. The I.R.S. has the right to appeal the U.S. Tax Court decision. 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 September 30, 2015 and December 31, 2014 , current deferred tax assets totaled $16.5 million and $15.5 million , respectively, and were included within Prepaid expenses and other current assets on the Company's condensed consolidated balance sheets. As of September 30, 2015 and December 31, 2014 , long-term deferred tax assets totaled $11.9 million at each date and were included within Other assets on the Company's condensed consolidated balance sheets. As of September 30, 2015 and December 31, 2014 , long-term deferred tax liabilities totaling $1.1 million and $1.4 million , respectively, were included within Other liabilities on the Company's condensed consolidated balance sheets.

Basis of Presentation, Signif20

Basis of Presentation, Significant Accounting Policies and Recent Accounting Pronouncements (Policies)	9 Months Ended
	Sep. 30, 2015
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements as of September 30, 2015 and for the three and nine months ended September 30, 2015 and 2014 , 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 and nine months ended September 30, 2015 and 2014 are not necessarily indicative of results to be expected for the full year ending December 31, 2015 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 (“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, 2014 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, 2014 (the “ 2014 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 2014 Form 10-K.
Restricted Cash and Cash Equivalents	Restricted cash and restricted marketable securities represent amounts restricted under the terms of the Company's amended and restated credit agreement for use only in the repayment of the Company's unsecured convertible senior notes due December 15, 2015. See Note 4 for additional information regarding the Company's amended and restated credit agreement.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In September 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update (“ASU”) 2015-16, Simplifying the Accounting for Measurement-Period Adjustments , which provides new guidance regarding measurement period adjustments in connection with business combinations by requiring that an acquirer recognize adjustments to provisional amounts that are identified during the measurement period in the reporting period in which the adjustment amounts are determined. The standard will be effective for annual reporting periods beginning after December 15, 2015, including interim periods within those reporting periods. The standard update is to be applied prospectively to adjustments of provisional amounts that occur after the effective date with earlier application permitted for financial statements that have not been issued. The Company does not expect the adoption of this standard to have an impact 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 April 2015, the FASB issued ASU 2015-03, Interest—Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs , and, in August 2015, the FASB issued ASU 2015-15, Presentation and Subsequent Measurement of Debt Issuance Costs Associated with Line-of-Credit Arrangements . These ASUs require debt issuance costs related to a recognized debt liability to be presented in the balance sheet as a direct deduction from the carrying amount of that debt consistent with debt discounts. The presentation and subsequent measurement of debt issuance costs associated with lines of credit may be presented as an asset and amortized ratably over the term of the line of credit arrangement, regardless of whether there are outstanding borrowings on the arrangement. The recognition and measurement guidance for debt issuance costs are not affected by these ASUs. These ASUs are effective for financial statements issued for fiscal years beginning after December 15, 2015 and interim periods within those years. Early application is permitted. The Company is in the process of evaluating the impact of the adoption of these accounting standard updates on its consolidated financial statements. In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements-Going Concern: Disclosure of Uncertainties about an Entity's Ability to Continue as a Going Concern , which provides guidance about management's responsibility to evaluate whether or not there is substantial doubt about a company's ability to continue as a going concern and to provide related footnote disclosure. The standard will be effective for annual reporting periods ending after December 15, 2016, and interim periods thereafter. Early application is permitted. The Company is in the process of evaluating the impact of the adoption of this accounting standard update on its consolidated financial statements. In June 2014, the FASB issued ASU 2014-12, Accounting for Share-Based Payments When the Terms of an Award Provide that a Performance Target Could Be Achieved after the Requisite Service Period , which provides new guidance regarding share-based compensation. The new guidance clarifies that share-based compensation performance targets that could be achieved after the requisite service period should be treated as performance conditions that affect vesting, rather than as a condition that affects the grant-date fair value of the award. The standard will be effective for annual reporting periods beginning after December 15, 2015, including interim periods within those reporting periods. Early adoption is permitted. The Company is in the process of evaluating 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 sate 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.

Restructuring Costs (Tables)

Restructuring Costs (Tables)	9 Months Ended
	Sep. 30, 2015
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	Activities related to our restructuring plans are as follows (in thousands): 2014 Corporate Net Optics Other Total Accrual at December 31, 2014 1,940 337 246 2,523 Charges, net of recoveries (193 ) (334 ) — (527 ) Payments (1,190 ) (3 ) (140 ) (1,333 ) Non-cash items — — (106 ) (106 ) Accrual at September 30, 2015 $ 557 $ — $ — $ 557

Selected Balance Sheet Data (Ta

Selected Balance Sheet Data (Tables)	9 Months Ended
	Sep. 30, 2015
Balance Sheet Related Disclosures [Abstract]
Available-for-sale Securities	Investments in marketable securities as of September 30, 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 $ 50,384 $ 22 $ (7 ) $ 50,399 Corporate debt securities 39,116 21 (69 ) 39,068 Total $ 89,500 $ 43 $ (76 ) $ 89,467 Investments in marketable securities as of December 31, 2014 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 $ 42,289 $ 9 $ (17 ) $ 42,281 Corporate debt securities 37,476 41 (38 ) 37,479 Total $ 79,765 $ 50 $ (55 ) $ 79,760
Investments Classified by Contractual Maturity Date	The amortized cost and fair value of our marketable securities at September 30, 2015 , by contractual years-to-maturity, are as follows (in thousands): Amortized Cost Fair Value Due in less than 1 year $ 44,243 $ 44,246 Due within 1-2 years 25,751 25,737 Due within 2-5 years 19,506 19,484 Total $ 89,500 $ 89,467
Schedule of Inventory, Current	Inventories consist of the following (in thousands): September 30, 2015 December 31, 2014 Raw materials $ 4,360 $ 5,502 Work in process 10,108 18,047 Finished goods 18,054 21,277 $ 32,522 $ 44,826

Goodwill and Other Intangible23

Goodwill and Other Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2015
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 September 30, 2015 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (123,870 ) $ 61,795 Customer relationships 6.0 71,700 (49,362 ) 22,338 Service agreements 6.4 30,100 (12,099 ) 18,001 Trademarks 5.1 11,300 (6,508 ) 4,792 Non-compete agreements 4.0 8,000 (5,141 ) 2,859 Other 4.5 5,416 (1,750 ) 3,666 $ 312,181 $ (198,730 ) $ 113,451 The following table presents the Company's purchased intangible assets (in thousands) as of December 31, 2014 : Weighted Average Useful Life (in years) Gross Accumulated Amortization Net Technology 5.5 $ 185,665 $ (106,953 ) $ 78,712 Customer relationships 6.0 71,700 (40,938 ) 30,762 Service agreements 6.4 30,100 (8,577 ) 21,523 Trademarks 5.1 11,300 (5,033 ) 6,267 Non-compete agreements 4.0 8,000 (3,641 ) 4,359 Other 4.2 4,883 (1,398 ) 3,485 $ 311,648 $ (166,540 ) $ 145,108
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The estimated future amortization expense of purchased intangible assets as of September 30, 2015 is as follows (in thousands): Remaining in 2015 $ 10,101 2016 37,867 2017 31,876 2018 20,606 2019 7,374 2020 3,839 Thereafter 1,788 $ 113,451

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2015
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 and Losses on Available-for- Sale Securities (a) Foreign Currency Items Total Beginning balance, December 31, 2014 $ (32 ) $ (761 ) $ (793 ) Other comprehensive income before reclassifications 11 102 113 Amounts reclassified from accumulated other comprehensive loss (b) (37 ) — (37 ) Net current period other comprehensive income (26 ) 102 76 Ending balance, September 30, 2015 $ (58 ) $ (659 ) $ (717 ) (a) All amounts are net-of-tax. Amounts in parentheses indicate reductions. (b) Amount represents gain on the sale of securities and is included as a component of Interest income and other, net in the condensed consolidated statements of operations.

Earnings (loss) Per Share (Tabl

Earnings (loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2015
Earnings Per Share [Abstract]
Schedule of Earnings (Loss) Per Share, Basic and Diluted	The following table sets forth the computation of basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2015 and 2014 (in thousands, except per share data): Three months ended Nine months ended 2015 2014 2015 2014 Basic presentation: Numerator for basic earnings (loss) per share: Net income (loss) $ 4,008 $ (7,329 ) $ 200 $ (41,878 ) Denominator for basic earnings (loss) per share: Weighted average common shares outstanding 79,895 77,920 79,336 77,380 Basic earnings (loss) per share $ 0.05 $ (0.09 ) $ 0.00 $ (0.54 ) Diluted presentation: Numerator for diluted earnings (loss) per share: Net income (loss) $ 4,008 $ (7,329 ) $ 200 $ (41,878 ) Denominator for diluted earnings (loss) per share: Weighted average common shares outstanding 79,895 77,920 79,336 77,380 Effect of dilutive securities: Stock options and other share-based awards 2,034 — 1,749 — Diluted weighted average common shares outstanding 81,929 77,920 81,085 77,380 Diluted earnings (loss) per share $ 0.05 $ (0.09 ) $ 0.00 $ (0.54 )

Concentrations (Tables)

Concentrations (Tables)	9 Months Ended
	Sep. 30, 2015
Risks and Uncertainties [Abstract]
Reconciliation of Revenue from Segments to Consolidated	The following table presents revenue by product line (in thousands): Three months ended Nine months ended 2015 2014 2015 2014 Network Test Solutions $ 92,504 $ 84,110 $ 280,652 $ 257,309 Network Visibility Solutions 33,383 29,887 97,807 79,943 $ 125,887 $ 113,997 $ 378,459 $ 337,252
Schedule of Revenue from External Customers Attributed to Foreign Countries by Geographic Area	For the three and nine months ended September 30, 2015 and 2014 , the percentages of total revenues consisting of international revenues based on customer location consisted of the following: Three months ended Nine months ended 2015 2014 2015 2014 International revenues 36.1 % 42.5 % 37.6 % 41.1 %
Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country	As of September 30, 2015 and December 31, 2014 , the Company's property and equipment, net were geographically located as follows (in thousands): September 30, 2015 December 31, 2014 United States $ 22,881 $ 24,697 Romania 6,536 6,035 India 3,660 3,857 Other 2,888 3,059 Total $ 35,965 $ 37,648

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value, Assets Measured on Recurring Basis	Financial assets carried at fair value as of September 30, 2015 are classified in the table below in one of the three categories described above (in thousands): September 30, 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 $ 500 $ 500 $ — $ — U.S. Treasury, government and agency debt securities 7,999 — 7,999 — Corporate debt securities 18,793 — 18,793 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 50,399 — 50,399 — Corporate debt securities 39,068 — 39,068 — Total financial assets $ 116,759 $ 500 $ 116,259 $ — Financial assets carried at fair value as of December 31, 2014 are classified in the table below in one of the three categories described above (in thousands): December 31, 2014 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 $ 267 $ 267 $ — $ — Corporate debt securities 5,349 — 5,349 — Short-term marketable securities: U.S. Treasury, government and agency debt securities 42,281 — 42,281 — Corporate debt securities 37,479 — 37,479 — Total financial assets $ 85,376 $ 267 $ 85,109 $ —

Business (Details)

Business (Details)	9 Months Ended
	Sep. 30, 2015segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of business segments	1

Restructuring Costs (Details)

Restructuring Costs (Details) $ in Thousands	3 Months Ended			9 Months Ended		21 Months Ended
	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)position	Mar. 31, 2014position	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Dec. 31, 2014USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring	$ 34	$ 4,642		$ (527)	$ 8,687
Favorable lease buyout				400
Insurance gain				400
Restructuring reserve	$ 557			$ 557		$ 557	$ 2,523
Corporate Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 6,100
Number of positions eliminated | position		96
Workforce reduction (as a percent)		5.00%
Employee Severance | Corporate Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Restructuring						3,500
Facility Closing | Corporate Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 1,800
Other | Corporate Restructuring 2014
Restructuring Cost and Reserve [Line Items]
Restructuring		137
Net Optics, Inc.
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | position			45
Workforce reduction (as a percent)			2.30%
Net Optics, Inc. | Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring		$ 4,100				2,000
Net Optics, Inc. | Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring						1,100
Net Optics, Inc. | Other
Restructuring Cost and Reserve [Line Items]
Restructuring						$ 323

Restructuring Costs - Activity

Restructuring Costs - Activity Related to Restructuring Plan (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2015USD ($)
Restructuring Reserve [Roll Forward]
Accrual at beginning of period	$ 2,523
Charges, net of recoveries	(527)
Payments	(1,333)
Non-cash items	(106)
Accrual at end of period	557
2014 Corporate Restructuring
Restructuring Reserve [Roll Forward]
Accrual at beginning of period	1,940
Charges, net of recoveries	(193)
Payments	(1,190)
Non-cash items	0
Accrual at end of period	557
Net Optics Restructuring
Restructuring Reserve [Roll Forward]
Accrual at beginning of period	337
Charges, net of recoveries	(334)
Payments	(3)
Non-cash items	0
Accrual at end of period	0
Other
Restructuring Reserve [Roll Forward]
Accrual at beginning of period	246
Charges, net of recoveries	0
Payments	(140)
Non-cash items	(106)
Accrual at end of period	$ 0

Debt - Convertible Senior Notes

Debt - Convertible Senior Notes (Details)	Dec. 07, 2010USD ($)$ / shares	Jul. 31, 2015USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)
Debt Instrument [Line Items]
Amortization					$ 1,237,000	$ 900,000
Convertible Notes Payable | Senior Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 200,000,000		$ 135,000,000		135,000,000
Stated rate (as a percent)	3.00%
Minimum aggregate principal amount of outstanding notes threshold (as a percent)	25.00%
Default period (in days)	60 days
Waiver on notes outstanding (as a percent)	50.00%
Remedy period (in days)	180 days
Interest rate change (as a percent)	0.50%
Amortization			372,000	$ 300,000	972,000	$ 900,000
Conversion ratio	51.4536
Convertible principal amount	$ 1,000
Conversion price (in dollars per share) | $ / shares	$ 19.43
Redemption percentage	100.00%
Convertible Notes Payable | Senior Notes | Fair Value, Inputs, Level 2
Debt Instrument [Line Items]
Estimated fair value			$ 135,000,000		135,000,000
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
Repurchased Notes Payable | Senior Notes
Debt Instrument [Line Items]
Amortization					$ 169,000

Debt - 2015 Amended Credit Agre

Debt - 2015 Amended Credit Agreement (Details)	Sep. 30, 2015USD ($)	Mar. 02, 2015USD ($)quarterd	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Sep. 30, 2015USD ($)	Sep. 30, 2014USD ($)	Jul. 31, 2015USD ($)	Mar. 03, 2015USD ($)	Dec. 07, 2010USD ($)
Debt Instrument [Line Items]
Amortization					$ 1,237,000	$ 900,000
Notes Payable to Banks | 2015 Credit Agreement
Debt Instrument [Line Items]
Aggregate principal amount								$ 40,000,000
Collateral amounts	$ 50,000,000		$ 50,000,000		$ 50,000,000		$ 115,000,000
Minimum available liquidity in case of business acquisition		$ 75,000,000
Number of quarters | quarter		11
Fixed charge coverage ratio					1.25
Consolidated total leverage ratio					3
Notes Payable to Banks | 2015 Credit Agreement | Restricted Cash
Debt Instrument [Line Items]
Collateral amounts	10,000,000		10,000,000		$ 10,000,000
Notes Payable to Banks | 2015 Credit Agreement | Marketable Securities
Debt Instrument [Line Items]
Collateral amounts	40,000,000		40,000,000		40,000,000
Notes Payable to Banks | 2015 Credit Agreement | Minimum
Debt Instrument [Line Items]
Commitment fee (as a percent)		0.30%
Notes Payable to Banks | 2015 Credit Agreement | Maximum
Debt Instrument [Line Items]
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 | First Four Quarters
Debt Instrument [Line Items]
Number of quarters | quarter		4
Quarterly principal payments	500,000	$ 500,000	$ 500,000		$ 500,000
Notes Payable to Banks | 2015 Credit Agreement | Next Four Quarters
Debt Instrument [Line Items]
Quarterly principal payments		$ 1,000,000
Notes Payable to Banks | 2015 Credit Agreement | Last Three Quarters
Debt Instrument [Line Items]
Number of quarters | quarter		3
Quarterly principal payments		$ 1,500,000
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					2.25
Notes Payable to Banks | 2015 Credit Agreement | Eurodollar
Debt Instrument [Line Items]
Effective average interest rate (as a percent)			4.44%		4.43%
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%
Notes Payable to Banks | 2015 Credit Agreement | One-month Eurodollar
Debt Instrument [Line Items]
Basis spread on variable rate (as a percent)			4.25%		4.25%
Notes Payable to Banks | Second Amended Agreement
Debt Instrument [Line Items]
Increase in credit facility	15,000,000
Senior Notes | Convertible Notes Payable
Debt Instrument [Line Items]
Aggregate principal amount	135,000,000		$ 135,000,000		$ 135,000,000				$ 200,000,000
Amortization			372,000	$ 300,000	972,000	900,000
Line of Credit | Revolving Credit Facility | Silicon Valley Bank
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	$ 75,000,000		75,000,000		75,000,000
Increased commitments		$ 65,000,000
Minimum total available liquidity		$ 25,000,000
Minimum total available liquidity, number of days | d		2
Capitalized debt issuance cost		$ 1,300,000
Amortization period (in years)		3 years
Amortization			$ 129,000	$ 0	$ 265,000	$ 0
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
Convertible Debt | Senior Notes | Convertible Notes Payable
Debt Instrument [Line Items]
Principal amount repurchased							$ 65,000,000

Debt - Prior Credit Facility (D

Debt - Prior Credit Facility (Details) - USD ($)	Mar. 31, 2015	Jan. 31, 2015	Dec. 31, 2014
Prior Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit maximum borrowing capacity	$ 46,500,000	$ 67,500,000	$ 150,000,000

Selected Balance Sheet Data - I

Selected Balance Sheet Data - Investments in Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Available-for-sale – short-term:
Amortized Cost	$ 89,500	$ 79,765
Gross Unrealized Gains	43	50
Gross Unrealized Losses	(76)	(55)
Fair Value	89,467	79,760
Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Available-for-sale – short-term:
Amortized Cost	50,384	42,289
Gross Unrealized Gains	22	9
Gross Unrealized Losses	(7)	(17)
Fair Value	50,399	42,281
Short-term marketable securities: | Corporate debt securities
Available-for-sale – short-term:
Amortized Cost	39,116	37,476
Gross Unrealized Gains	21	41
Gross Unrealized Losses	(69)	(38)
Fair Value	$ 39,068	$ 37,479

Selected Balance Sheet Data - A

Selected Balance Sheet Data - Amortized Cost and Fair Value of Investments (Details) $ in Thousands	Sep. 30, 2015USD ($)
Amortized Cost
Due in less than 1 year	$ 44,243
Due within 1-2 years	25,751
Due within 2-5 years	19,506
Total	89,500
Fair Value
Due in less than 1 year	44,246
Due within 1-2 years	25,737
Due within 2-5 years	19,484
Total	$ 89,467

Selected Balance Sheet Data -36

Selected Balance Sheet Data - Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Raw materials	$ 4,360	$ 5,502
Work in process	10,108	18,047
Finished goods	18,054	21,277
Inventories	$ 32,522	$ 44,826

Selected Balance Sheet Data (De

Selected Balance Sheet Data (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
Marketable securities, restricted	$ 40,000	$ 0
Weighted average contractual maturity (in years)	1 year 3 months	1 year 252 days
Accrued compensation and related expenses	$ 12,600	$ 9,900
Accrued bonus expense	13,500	3,900
Accrued vacation	$ 8,500	$ 7,500

Goodwill and Other Intangible38

Goodwill and Other Intangible Assets - Purchased Intangible Assets (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2015	Dec. 31, 2014
Other intangible assets:
Gross	$ 312,181	$ 311,648
Accumulated Amortization	(198,730)	(166,540)
Net	$ 113,451	$ 145,108
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	(123,870)	(106,953)
Net	$ 61,795	$ 78,712
Customer relationships
Other intangible assets:
Weighted Average Useful Life (in years)	6 years	6 years
Gross	$ 71,700	$ 71,700
Accumulated Amortization	(49,362)	(40,938)
Net	$ 22,338	$ 30,762
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	(12,099)	(8,577)
Net	$ 18,001	$ 21,523
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	(6,508)	(5,033)
Net	$ 4,792	$ 6,267
Non-compete agreements
Other intangible assets:
Weighted Average Useful Life (in years)	4 years	4 years
Gross	$ 8,000	$ 8,000
Accumulated Amortization	(5,141)	(3,641)
Net	$ 2,859	$ 4,359
Other
Other intangible assets:
Weighted Average Useful Life (in years)	4 years 200 days	4 years 73 days
Gross	$ 5,416	$ 4,883
Accumulated Amortization	(1,750)	(1,398)
Net	$ 3,666	$ 3,485

Goodwill and Other Intangible39

Goodwill and Other Intangible Assets - Estimated Future Amortization Expense of Purchased Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Remaining in 2015	$ 10,101
2,016	37,867
2,017	31,876
2,018	20,606
2,019	7,374
2,020	3,839
Thereafter	1,788
Net	$ 113,451	$ 145,108

Shareholders' Equity - Summary

Shareholders' Equity - Summary of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income (loss)	$ 30	$ (285)	$ 76	$ (50)
Gains and Losses on Available-for- Sale Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(32)
Other comprehensive income before reclassifications			11
Amounts reclassified from accumulated other comprehensive loss			(37)
Other comprehensive income (loss)			(26)
Balance at end of period	(58)		(58)
Foreign Currency Items
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(761)
Other comprehensive income before reclassifications			102
Amounts reclassified from accumulated other comprehensive loss			0
Other comprehensive income (loss)			102
Balance at end of period	(659)		(659)
Total
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at beginning of period			(793)
Other comprehensive income before reclassifications			113
Amounts reclassified from accumulated other comprehensive loss			(37)
Other comprehensive income (loss)			76
Balance at end of period	$ (717)		$ (717)

Earnings (loss) Per Share - Com

Earnings (loss) Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Basic presentation:
Net income (loss)	$ 4,008	$ (7,329)	$ 200	$ (41,878)
Weighted average common shares outstanding	79,895	77,920	79,336	77,380
Basic earnings (loss) per share (in dollars per share)	$ 0.05	$ (0.09)	$ 0	$ (0.54)
Diluted presentation:
Net income (loss)	$ 4,008	$ (7,329)	$ 200	$ (41,878)
Denominator for dilutive (loss) earnings per share: (in shares)
Stock options and other share-based awards (in shares)	2,034	0	1,749	0
Diluted weighted average common shares outstanding (in shares)	81,929	77,920	81,085	77,380
Diluted earnings (loss) per share (in dollars per share)	$ 0.05	$ (0.09)	$ 0	$ (0.54)

Earnings (loss) Per Share (Deta

Earnings (loss) Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Convertible Debt Securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded (in shares)	7.2	10.3	9.3	10.3
Equity Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Securities excluded (in shares)	2.1	4.2	2.9	4.5

Concentrations - Revenue Concen

Concentrations - Revenue Concentration, Product Lines (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 125,887	$ 113,997	$ 378,459	$ 337,252
Network Test Solutions
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	92,504	84,110	280,652	257,309
Network Visibility Solutions
Segment Reporting, Revenue Reconciling Item [Line Items]
Revenues	$ 33,383	$ 29,887	$ 97,807	$ 79,943

Concentrations - Revenue and Re

Concentrations - Revenue and Receivables Concentration, Customers (Details) - customer	9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers	0	1	0

Concentrations - Geographic Con

Concentrations - Geographic Concentration (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Sales Revenue, Net | Geographic Concentration Risk | International
Note 10 - Concentrations (Details) - Geographic Concentration [Line Items]
International revenues	36.10%	42.50%	37.60%	41.10%

Concentrations - Geographical L

Concentrations - Geographical Locations of Property, Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	$ 35,965	$ 37,648
United States
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	22,881	24,697
Romania
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	6,536	6,035
India
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	3,660	3,857
Other
Note 10 - Concentrations (Details) - Geographical Locations of Property, Equipment, Net [Line Items]
Property and equipment, net	$ 2,888	$ 3,059

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets Carried at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Short-term marketable securities:
Investments	$ 89,467	$ 79,760
Total financial assets	116,759	85,376
Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	500	267
Cash equivalents: | Corporate debt securities
Cash equivalents:
Cash equivalents:	18,793	5,349
Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	7,999
Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	39,068	37,479
Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	50,399	42,281
Quoted Prices in Active Markets for Identical Assets (Level 1)
Short-term marketable securities:
Total financial assets	500	267
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents: | Money market funds
Cash equivalents:
Cash equivalents:	500	267
Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash equivalents: | Corporate debt securities
Cash equivalents:
Cash equivalents:	0	0
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: | Corporate debt securities
Short-term marketable securities:
Investments	0	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
Significant Other Observable Inputs (Level 2)
Short-term marketable securities:
Total financial assets	116,259	85,109
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: | Corporate debt securities
Cash equivalents:
Cash equivalents:	18,793	5,349
Significant Other Observable Inputs (Level 2) | Cash equivalents: | U.S. Treasury, government and agency debt securities
Cash equivalents:
Cash equivalents:	7,999
Significant Other Observable Inputs (Level 2) | Short-term marketable securities: | Corporate debt securities
Short-term marketable securities:
Investments	39,068	37,479
Significant Other Observable Inputs (Level 2) | Short-term marketable securities: | U.S. Treasury, government and agency debt securities
Short-term marketable securities:
Investments	50,399	42,281
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: | Corporate debt securities
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: | Corporate debt securities
Short-term marketable securities:
Investments	0	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

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	Nov. 05, 2014	Jul. 18, 2014	Sep. 30, 2015USD ($)lawsuit	Jul. 23, 2015USD ($)
Securities Class Action | Pending Litigation
Loss Contingencies [Line Items]
Number of days to respond	30 days	30 days
Settlement amount			$ 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]
Loss contingency accrual				$ 575
Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Civil penalty			$ 750

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Sep. 30, 2015	Dec. 31, 2014
Prepaid Expenses and Other Current Assets
Income Taxes (Details) [Line Items]
Current deferred tax assets	$ 16.5	$ 15.5
Other Assets
Income Taxes (Details) [Line Items]
Noncurrent deferred tax assets	11.9	11.9
Other Liabilities
Income Taxes (Details) [Line Items]
Noncurrent deferred tax liabilities	$ 1.1	$ 1.4