NetScout Systems (NTCT) 10-Q 2 Aug 16 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Jun. 30, 2016	Jul. 27, 2016
Document and Entity Information [Abstract]
Entity Registrant Name	NETSCOUT SYSTEMS INC
Entity Central Index Key	1,078,075
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	NTCT
Amendment Flag	false
Entity Common Stock, Shares Outstanding		91,992,604

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Current assets:
Cash and cash equivalents	$ 210,870	$ 210,711
Marketable securities	108,743	128,003
Accounts receivable and unbilled costs, net of allowance for doubtful accounts of $6,212 and $5,069 at June 30, 2016 and March 31, 2016, respectively	196,227	247,199
Inventories and deferred costs	58,842	58,029
Prepaid income taxes	28,402	18,137
Prepaid expenses and other current assets (related party balances of $38,357 and $44,161, respectively)	65,855	78,399
Total current assets	668,939	740,478
Fixed assets, net	64,058	62,033
Goodwill	1,710,286	1,709,369
Intangible assets, net	1,023,968	1,054,040
Deferred income taxes	5,040	6,206
Long-term marketable securities	15,309	13,361
Other assets	6,858	7,356
Total assets	3,494,458	3,592,843
Current liabilities:
Accounts payable (related party balances of $3,943 and $5,893, respectively)	45,607	43,969
Accrued compensation	68,748	82,303
Accrued other	28,160	32,045
Income taxes payable	2,091	2,091
Deferred revenue and customer deposits	279,974	296,648
Total current liabilities	424,580	457,056
Other long-term liabilities	2,606	2,903
Deferred tax liability	272,763	285,359
Accrued long-term retirement benefits	31,158	31,378
Long-term deferred revenue and customer deposits	67,025	68,129
Long-term debt	300,000	300,000
Contingent liabilities	4,674	4,636
Total liabilities	1,102,806	1,149,461
Commitments and contingencies (Note 12)
Preferred stock, $0.001 par value:
5,000,000 shares authorized; no shares issued or outstanding at June 30, 2016 and March 31, 2016	0	0
Common stock, $0.001 par value:
150,000,000 shares authorized; 114,503,040 and 114,495,614 shares issued and 91,992,604 and 94,088,469 shares outstanding at June 30, 2016 and March 31, 2016, respectively	114	114
Additional paid-in capital	2,650,315	2,642,745
Accumulated other comprehensive loss	(1,735)	(1,501)
Treasury stock at cost, 22,510,436 and 20,407,145 shares at June 30, 2016 and March 31, 2016, respectively	(531,434)	(481,366)
Retained earnings	274,392	283,390
Total stockholders’ equity	2,391,652	2,443,382
Total liabilities and stockholders’ equity	$ 3,494,458	$ 3,592,843

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Related Party Transaction [Line Items]
Accounts receivable, allowance for doubtful accounts	$ 6,212	$ 5,069
Related party prepaid expenses and other current assets	65,855	78,399
Related party accounts payable	$ 45,607	$ 43,969
Preferred stock, par value (in USD per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	114,503,040	114,495,614
Common stock, shares outstanding (in shares)	91,992,604	94,088,469
Treasury stock, shares (in shares)	22,510,436	20,407,145
Affiliated Entity
Related Party Transaction [Line Items]
Related party prepaid expenses and other current assets	$ 38,357	$ 44,161
Related party accounts payable	$ 3,943	$ 5,893

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Revenue:
Product	$ 164,589	$ 53,593
Service	104,363	47,150
Total revenue	268,952	100,743
Cost of revenue:
Product (related party balances of $4,577 and $0, respectively)	59,827	12,498
Service (related party balances of $190 and $0, respectively)	27,207	8,798
Total cost of revenue	87,034	21,296
Gross profit	181,918	79,447
Operating expenses:
Research and development (related party balances of $1,026 and $0, respectively)	60,551	18,058
Sales and marketing (related party balances of $1,600 and $0, respectively)	81,588	38,092
General and administrative (related party balances of $1,504 and $0, respectively)	30,927	10,099
Amortization of acquired intangible assets	17,572	809
Restructuring charges	2,034	0
Total operating expenses	192,672	67,058
Income (loss) from operations	(10,754)	12,389
Interest and other income (expense), net:
Interest income	191	158
Interest expense	(2,331)	(192)
Other expense, net	(764)	(112)
Total interest and other expense, net	(2,904)	(146)
Income (loss) before income tax expense (benefit)	(13,658)	12,243
Income tax expense (benefit)	(4,660)	4,574
Net income (loss)	$ (8,998)	$ 7,669
Basic net income (loss) per share (in USD per share)	$ (0.10)	$ 0.19
Diluted net income (loss) per share (in USD per share)	$ (0.10)	$ 0.19
Weighted average common shares outstanding used in computing:
Net income (loss) per share - basic (in shares)	93,344	40,776
Net income (loss) per share - diluted (in shares)	93,344	41,371

Consolidated Statements of Ope5

Consolidated Statements of Operations (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Related Party Transaction [Line Items]
Related party product	$ 59,827	$ 12,498
Related party service	27,207	8,798
Related party research and development	60,551	18,058
Related party selling and marketing	81,588	38,092
Related party general and administrative expense	30,927	10,099
Affiliated Entity
Related Party Transaction [Line Items]
Related party product	4,577	0
Related party service	190	0
Related party research and development	1,026	0
Related party selling and marketing	1,600	0
Related party general and administrative expense	$ 1,504	$ 0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (8,998)	$ 7,669
Other comprehensive income (loss):
Cumulative translation adjustments	(258)	977
Changes in market value of investments:
Changes in unrealized gains (losses)	41	(59)
Total net change in market value of investments	41	(59)
Changes in market value of derivatives:
Changes in market value of derivatives, net of (benefits) taxes of ($19), and $4, respectively	(31)	6
Reclassification adjustment for net gains included in net income (loss), net of taxes of $8, $460, respectively	14	863
Total net change in market value of derivatives	(17)	869
Other comprehensive income (loss)	(234)	1,787
Total comprehensive income (loss)	$ (9,232)	$ 9,456

Consolidated Statements of Com7

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Changes in market value of derivatives, taxes	$ (19)	$ 4
Reclassification adjustment for net losses included in net income (loss), benefits	$ 8	$ 460

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income (loss)	$ (8,998)	$ 7,669
Adjustments to reconcile net income (loss) to cash provided by operating activities, net of the effects of acquisitions:
Depreciation and amortization	40,174	4,986
Loss on disposal of fixed assets	38	10
Deal-related compensation expense and accretion charges	38	37
Share-based compensation expense associated with equity awards	8,132	4,595
Deferred income taxes	(11,328)	239
Other losses	(17)	42
Changes in assets and liabilities
Accounts receivable and unbilled costs	50,757	23,729
Due from related party	(1,984)	0
Inventories	(3,714)	(1,806)
Prepaid expenses and other assets	(5,429)	6,654
Accounts payable	4,858	(1,629)
Accrued compensation and other expenses	(18,108)	(20,955)
Due to related party	704	0
Income taxes payable	(5)	40
Deferred revenue	(17,385)	(14,321)
Net cash provided by operating activities	37,733	9,290
Cash flows from investing activities:
Purchase of marketable securities	(35,806)	(32,289)
Proceeds from maturity of marketable securities	53,159	19,034
Purchase of fixed assets	(9,218)	(3,415)
Purchase of intangible assets	(20)	(88)
Increase in deposits	(62)	0
Collection of contingently returnable consideration	5,133	0
Capitalized software development costs	(290)	0
Net cash provided by (used in) investing activities	12,896	(16,758)
Cash flows from financing activities:
Treasury stock repurchases	(50,068)	(3,167)
Net cash used in financing activities	(50,068)	(3,167)
Effect of exchange rate changes on cash and cash equivalents	(402)	94
Net increase (decrease) in cash and cash equivalents	159	(10,541)
Cash and cash equivalents, beginning of period	210,711	104,893
Cash and cash equivalents, end of period	210,870	94,352
Non-cash transactions:
Transfers of inventory to fixed assets	2,673	1,229
Additions to property, plant and equipment included in accounts payable	$ 374	$ 245

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION The accompanying unaudited interim consolidated financial statements have been prepared by NetScout Systems, Inc., or NetScout or the Company. Certain information and footnote disclosures normally included in financial statements prepared under United States generally accepted accounting principles (GAAP) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). In the opinion of management, the unaudited interim consolidated financial statements include all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the Company’s financial position, results of operations and cash flows. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The results reported in these unaudited interim consolidated financial statements are not necessarily indicative of results that may be expected for the entire year. All significant intercompany accounts and transactions are eliminated in consolidation. The accompanying unaudited interim consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. On July 14, 2015, or the Closing Date, the Company completed the acquisition of Danaher Corporation’s (Danaher) Communications Business (Communications Business), which included certain assets, liabilities, technology and employees within Tektronix Communications, VSS Monitoring, Arbor Networks and certain portions of the Fluke Networks Enterprise business, which excluded Danaher’s data communications cable installation business and its communication service provider business (the Transaction). The Transaction is more fully described in Note 7 below. The Transaction was recorded using the acquisition method of accounting; accordingly, the financial results of the acquisition are included in the accompanying unaudited interim consolidated financial statements for the periods subsequent to the acquisition. These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements, including the notes thereto, included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2016 filed with the SEC on May 31, 2016. Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09), which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU 2016-09 is effective for the Company beginning April 1, 2017. The Company is currently assessing the potential impact of the adoption of ASU 2016-09 on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Section A - Leases: Amendments to the FASB Accounting Standards Codification (ASU 2016-02), its new standard on accounting for leases. This update requires the recognition of leased assets and lease obligations by lessees for those leases currently classified as operating leases under existing lease guidance. Short term leases with a term of 12 months or less are not required to be recognized. The update also requires disclosure of key information about leasing arrangements to increase transparency and comparability among organizations. ASU 2016-02 is effective for annual reporting periods beginning after December 31, 2018 and interim periods within those fiscal years, and early adoption is permitted. The Company is currently assessing the potential impact of the adoption of ASU 2016-02 on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09) and issued subsequent amendments to the initial guidance in August 2015, March 2016, April 2016 and May 2016 within ASU 2015-04, 2016-08, ASU 2016-10 and ASU 2016-12, respectively ( ASU 2014-09, ASU 2015-04, ASU 2016-08, ASU 2016-10 and ASU 2016-12 collectively, Topic 606). Topic 606 supersedes nearly all existing revenue recognition guidance under GAAP. The core principle of Topic 606 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. Topic 606 defines a five-step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under existing GAAP, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation, among others. Topic 606 will be effective for the Company in the first quarter of its fiscal year 2019. Early adoption is not permitted. The Company is currently assessing the potential impact of the adoption of ASU 2014-09 on its consolidated financial statements.

CONCENTRATION OF CREDIT RISK AN

CONCENTRATION OF CREDIT RISK AND SIGNIFICANT CUSTOMERS	3 Months Ended
	Jun. 30, 2016
Risks and Uncertainties [Abstract]
CONCENTRATION OF CREDIT RISK AND SIGNIFICANT CUSTOMERS	CONCENTRATION OF CREDIT RISK AND SIGNIFICANT CUSTOMERS Financial instruments that potentially subject us to concentration of credit risk consist primarily of investments, trade accounts receivable and accounts payable. The Company's cash, cash equivalents, and marketable securities are placed with financial institutions with high credit standings. At June 30, 2016 , the Company had one direct customer which accounted for more than 10% of the accounts receivable balance, while no indirect channel partner accounted for more than 10% of the accounts receivable balance. At March 31, 2016, the Company had one direct customer which accounted for more than 10% of the accounts receivable balance, while no indirect channel partner accounted for more than 10% of the accounts receivable balance. During the three months ended June 30, 2016 , one direct customer accounted for more than 10% of the Company's total revenue, while no indirect channel partner accounted for more than 10% of total revenue. During the three months ended June 30, 2015 , no direct customer or indirect channel partner accounted for more than 10% of the Company's total revenue. As disclosed parenthetically within the Company's consolidated balance sheet, the Company has a receivable from Danaher in the amount of $38.4 million and $44.2 million that represents a concentration of credit risk at June 30, 2016 and March 31, 2016 , respectively. Historically, the Company has not experienced any significant failure of its customers' ability to meet their payment obligations nor does the Company anticipate material non-performance by its customers in the future; accordingly, the Company does not require collateral from its customers. However, if the Company’s assumptions are incorrect, there could be an adverse impact on its allowance for doubtful accounts.

SHARE-BASED COMPENSATION

SHARE-BASED COMPENSATION	3 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
SHARE-BASED COMPENSATION	SHARE-BASED COMPENSATION The following is a summary of share-based compensation expense including restricted stock units and employee stock purchases made under the Company's 2011 Employee Stock Purchase Plan (ESPP) based on estimated fair values within the applicable cost and expense lines identified below (in thousands): Three Months Ended June 30, 2016 2015 Cost of product revenue $ 195 $ 102 Cost of service revenue 798 373 Research and development 2,633 1,490 Sales and marketing 2,611 1,403 General and administrative 1,895 1,227 $ 8,132 $ 4,595 Employee Stock Purchase Plan – The Company maintains the ESPP for all eligible employees as described in the Company’s Annual Report on Form 10-K for the year ended March 31, 2016 . Under the ESPP, shares of the Company’s common stock may be purchased on the last day of each bi-annual offering period at 85% of the fair value on the last day of such offering period. The offering periods run from March 1st through August 31st and from September 1st through the last day of February each year.

CASH, CASH EQUIVALENTS AND MARK

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES	3 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES	CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents and those investments with original maturities greater than three months to be marketable securities. Cash and cash equivalents consisted of money market instruments and cash maintained with various financial institutions at June 30, 2016 and March 31, 2016 . Marketable Securities The following is a summary of marketable securities held by NetScout at June 30, 2016 , classified as short-term and long-term (in thousands): Amortized Cost Unrealized Gains Fair Value Type of security: U.S. government and municipal obligations $ 82,005 $ 24 $ 82,029 Commercial paper 26,714 — 26,714 Total short-term marketable securities 108,719 24 108,743 U.S. government and municipal obligations 15,276 33 15,309 Total long-term marketable securities 15,276 33 15,309 Total marketable securities $ 123,995 $ 57 $ 124,052 The following is a summary of marketable securities held by NetScout at March 31, 2016 , classified as short-term and long-term (in thousands): Amortized Cost Unrealized Gains Fair Value Type of security: U.S. government and municipal obligations $ 109,963 $ 4 $ 109,967 Commercial paper 16,172 — 16,172 Corporate bonds 1,864 — 1,864 Total short-term marketable securities 127,999 4 128,003 U.S. government and municipal obligations 13,349 12 13,361 Total long-term marketable securities 13,349 12 13,361 Total marketable securities $ 141,348 $ 16 $ 141,364 Contractual maturities of the Company’s marketable securities held at June 30, 2016 and March 31, 2016 were as follows (in thousands): June 30, March 31, Available-for-sale securities: Due in 1 year or less $ 108,743 $ 128,003 Due after 1 year through 5 years 15,309 13,361 $ 124,052 $ 141,364

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	3 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	FAIR VALUE MEASUREMENTS The fair value hierarchy has three levels based on the reliability of the inputs used to determine fair value. Level 1 refers to fair values determined based on quoted prices in active markets for identical assets. Level 2 refers to fair values estimated using significant other observable inputs, and Level 3 includes fair values estimated using significant non-observable inputs. The following tables present the Company’s financial assets and liabilities measured on a recurring basis using the fair value hierarchy at June 30, 2016 and March 31, 2016 (in thousands): Fair Value Measurements at June 30, 2016 Level 1 Level 2 Level 3 Total ASSETS: Cash and cash equivalents $ 210,870 $ — $ — $ 210,870 U.S. government and municipal obligations 25,611 71,727 — 97,338 Commercial paper — 26,714 — 26,714 Derivative financial instruments — 116 — 116 Contingently returnable consideration — — 8,341 $ 8,341 $ 236,481 $ 98,557 $ 8,341 $ 343,379 LIABILITIES: Contingent purchase consideration $ — $ — $ (4,674 ) $ (4,674 ) Derivative financial instruments — (93 ) — (93 ) $ — $ (93 ) $ (4,674 ) $ (4,767 ) Fair Value Measurements at March 31, 2016 Level 1 Level 2 Level 3 Total ASSETS: Cash and cash equivalents $ 210,711 $ — $ — $ 210,711 U.S. government and municipal obligations 41,116 82,212 — 123,328 Commercial paper — 16,172 — 16,172 Corporate bonds 1,864 — — 1,864 Derivative financial instruments — 191 — 191 Contingently returnable consideration 16,131 16,131 $ 253,691 $ 98,575 $ 16,131 $ 368,397 LIABILITIES: Contingent purchase consideration $ — $ — $ (7,293 ) $ (7,293 ) Derivative financial instruments — (158 ) — (158 ) $ — $ (158 ) $ (7,293 ) $ (7,451 ) This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. On a recurring basis, the Company measures certain financial assets and liabilities at fair value, including marketable securities and derivative financial instruments. The Company’s Level 1 investments are classified as such because they are valued using quoted market prices or alternative pricing sources with reasonable levels of price transparency. The Company’s Level 2 investments are classified as such because fair value is being calculated using data from similar but not identical sources, or a discounted cash flow model using the contractual interest rate as compared to the underlying interest yield curve. The Company's derivative financial instruments consist of forward foreign exchange contracts and are classified as Level 2 because the fair values of these derivatives are determined using models based on market observable inputs, including spot prices for foreign currencies and credit derivatives, as well as an interest rate factor. The Company classifies municipal obligations as level 2 because the fair values are determined using quoted prices from markets the Company considers to be inactive. Commercial paper is classified as Level 2 because the Company uses market information from similar but not identical instruments and discounted cash flow models based on interest rate yield curves to determine fair value. For further information on the Company's derivative instruments refer to Note 9. The Company's Level 3 asset and liabilities consist of contingently returnable consideration and contingent purchase consideration, respectively. The Company's contingently returnable consideration represents a contingent right of return from Danaher to reimburse NetScout for cash awards to be paid by NetScout to employees of the Communications Business transferred to Newco (as defined below) for post-combination services on various dates through August 4, 2016 as part of the Transaction. The contingently returnable consideration is classified as Level 3 because the fair value of the asset was determined using assumptions developed by management in determining the estimated cash awards expected to be paid on August 4, 2016 after applying an assumed forfeiture rate. The contingently returnable consideration of $8.4 million , net of taxes as of June 30, 2016 is included as prepaid expenses and other current assets in the Company’s consolidated balance sheet. For additional information, see Note 7 of the Company's Notes to Consolidated Financial Statements. The fair value of contingent purchase consideration of $4.7 million is related to the acquisition of Simena LLC (Simena) in November 2011 for future consideration to be paid to the former seller. The following table sets forth a reconciliation of changes in the fair value of the Company’s Level 3 financial assets and liabilities for the three months ended June 30, 2016 (in thousands): Contingent Purchase Consideration Contingently Returnable Consideration Balance at beginning of period $ (7,293 ) $ 16,131 Increase in fair value and accretion expense (included within research and development expense) (38 ) — Payment received — (7,790 ) Payments made 2,657 — Balance at end of period $ (4,674 ) $ 8,341 Deal-related compensation expense and accretion charges related to the contingent consideration for the three months ended June 30, 2016 was $38 thousand and was included as part of earnings.

INVENTORIES

INVENTORIES	3 Months Ended
	Jun. 30, 2016
Inventory Disclosure [Abstract]
INVENTORIES	INVENTORIES Inventories are stated at the lower of actual cost or net realizable value. Cost is determined by using the first in, first out (FIFO) method. Inventories consist of the following (in thousands): June 30, March 31, Raw materials $ 20,497 $ 18,617 Work in process 1,315 651 Finished goods 37,030 38,761 $ 58,842 $ 58,029

ACQUISITIONS

ACQUISITIONS	3 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
ACQUISITIONS	ACQUISITIONS On July 14, 2015 (Closing Date), the Company completed the Transaction, which was structured as a Reverse Morris Trust transaction whereby Danaher contributed its Communications Business to a new subsidiary, Potomac Holding LLC (Newco). The total equity consideration was approximately $2.3 billion based on issuing approximately 62.5 million new shares of NetScout common stock to the existing common unit holders of Newco, based on the July 13, 2015 NetScout common stock closing share price of $36.89 per share. On the Closing Date, the Company did not gain control over certain foreign entities due to regulatory and other compliance requirements (Delayed Close Entities). The Company closed on the acquisition of these Delayed Close Entities on October 7, 2015. The Transaction was accounted for under the acquisition method of accounting with the operations of the Communications Business included in the Company’s operating results from the relevant date of acquisition. The acquisition method of accounting requires, among other things, that assets acquired and liabilities assumed be recognized at their fair values as of the acquisition date. The preliminary determination of the fair value of assets acquired and liabilities assumed has been recognized based on management's estimates and assumptions using the information about facts and circumstances that existed at the acquisition date. While the Company uses its best estimates and assumptions as part of the purchase price allocation process to value the assets acquired and liabilities assumed on the acquisition date, its estimates and assumptions are subject to refinement. Fair value estimates are based on a complex series of judgments about future events and uncertainties and rely heavily on estimates and assumptions. The judgments used to determine the estimated fair value assigned to each class of assets acquired and liabilities assumed, as well as asset lives, can materially impact the Company's results of operations. The finalization of the purchase accounting assessment will result in a change in the valuation of assets acquired and liabilities assumed and may have a material impact on the Company's results of operations and financial position. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company records adjustments to the assets acquired and liabilities assumed with a corresponding offset to goodwill to reflect additional information received about facts and circumstances which existed at the date of acquisition. The Company records adjustments to the assets acquired and liabilities assumed subsequent to the purchase price allocation period in the Company’s operating results in the period in which the adjustments were determined. The size and breadth of the Transaction will necessitate the use of this measurement period to adequately analyze and assess a number of the factors used in establishing the fair value of certain tangible and intangible assets acquired and liabilities assumed as of the acquisition date and the related tax impacts of any changes made. Any potential adjustments made could be material in relation to the preliminary values presented below. The primary areas of the purchase price allocation that are not yet finalized are related to the valuation of deferred income taxes and residual goodwill. In connection with the Transaction, under the Employee Matters Agreement dated July 14, 2015 by and among the Company, Danaher and Newco, Danaher will fund certain contracts under which employees will provide post-combination services to the Company. 1) For any outstanding Danaher restricted stock units or stock options held by employees of the Communications Business transferred to Newco (Newco Employees) that vested from July 14, 2015 through August 4, 2015, the awards continued to vest in Danaher shares. These awards met the definition of a derivative under ASC 815 and as such, the Company determined the fair value of these awards on July 14, 2015 and recorded them separate from the business combination as prepaid compensation. The derivative was amortized into compensation expense through August 4, 2015, the post-combination requisite settlement date. 2) All outstanding Danaher restricted stock units or stock options held by Newco Employees that were due to vest after August 4, 2015 were cancelled and replaced by NetScout with a cash retention award equal to one half of the value of the employee’s cancelled Danaher equity award and up to an aggregate of $15 million of restricted stock units relating to shares of NetScout common stock equal to the remaining one half of the value of the employee’s cancelled Danaher equity award. The restricted stock units issued are considered new share-based payment awards granted by NetScout to the former employees of Danaher. NetScout accounted for these new awards separately from the business combination. The Company recognized share-based compensation net of an estimated forfeiture rate and only recognized compensation cost for those shares expected to vest on a straight-line basis over the requisite service period of the award. The cash retention award will become payable on August 4, 2016, subject to the employee’s continued employment with NetScout through the applicable vesting date of August 4, 2016. Danaher will reimburse NetScout for the amount of the cash retention payments (net of any applicable employment taxes and tax deductions). The cash retention award liability will be accounted for separately from the business combination as the cash retention award is automatically forfeited upon termination of employment. NetScout will record the cash retention award liability over the period it is earned as compensation expense for post-combination services. The reimbursement by Danaher to NetScout of the estimated cash retention award payment represents contingently returnable consideration, which will be accounted for separately from the business combination on the date of the acquisition. At June 30, 2016 , the Company has recorded a receivable from Danaher in the amount of $8.4 million , net of tax and is included as prepaid expenses and other current assets in Company’s consolidated balance sheet. At June 30, 2016 , the Company has recorded a cash retention award liability of $9.7 million and is included as accrued compensation in Company’s consolidated balance sheet. For the three months ended June 30, 2016 , $1.7 million has been recorded as compensation expense for post-combination services. 3) Newco Employees that were entitled to receive an incentive bonus under the Danaher annual bonus plan and who continued to be employed by NetScout through December 31, 2015 received a cash incentive bonus payment. The cash incentive bonus liability was accounted for separately from the business combination as the cash incentive bonus is automatically forfeited upon termination of employment. NetScout recorded the liability over the period it was earned as compensation expense for post-combination services. The payment of the cash retention award, which was reimbursed by Danaher to NetScout, was accounted for separately from the business combination on the date of the acquisition. 4) Certain Newco Employees received cash retention payments that were subject to the employee’s continued employment with NetScout through October 16, 2015, ninety ( 90 ) days after the close of the acquisition. The cash retention payment liability was accounted for separately from the business combination as the cash retention payment was automatically forfeited upon termination of employment. NetScout recorded the liability over the period it was earned as compensation expense for post-combination services. The payment of the cash retention award, which was reimbursed by Danaher to NetScout, was accounted for separately from the business combination on the date of the acquisition. The following table summarizes the allocation of the purchase price for the entities acquired on July 14, 2015 (in thousands): Purchase Price Allocation: Total equity consideration $ 2,299,911 (1) Less: Equity consideration for replacement awards (29,355 ) (2) Estimated Purchase Price 2,270,556 Estimated fair value of assets acquired and liabilities assumed: Cash 27,701 Accounts receivable 140,586 Inventories 80,719 Prepaid expenses and other assets 6,715 Property, plant and equipment 36,825 Deferred income taxes 13,067 Intangible assets 1,080,700 Other assets 999 Accounts payable (21,311 ) Accrued compensation (24,316 ) Accrued other (12,916 ) Deferred revenue (187,882 ) Other long-term liabilities (3,615 ) Accrued retirement benefits (29,917 ) Deferred tax liabilities (344,646 ) Goodwill $ 1,507,847 (1) Represents approximately 62.5 million new shares (plus cash in lieu of fractional shares) of NetScout common stock issued to the existing common unit holders of Newco based on the July 13, 2015 NetScout common stock closing share price of $36.89 per share, less the fair value attributable to the foreign entities that the Company did not obtain control over on July 14, 2015 due to regulatory and other compliance requirements. (2) Represents the value of certain outstanding Danaher equity awards held by Newco Employees for which continuing employees received, or will receive value after the Closing Date. A portion of this amount relates to awards that will continue to vest in Danaher shares after the Closing Date. These future compensation amounts will be settled in shares other than shares of the acquired business. The balance of this amount also represents future compensation expense and relates to cash awards to be paid by NetScout to acquired Newco employees on August 4, 2016. The cash payments by NetScout will be reimbursed by Danaher. These items are further described in the Employee Matters Agreement dated July 14, 2015 by and among NetScout Systems, Inc., Danaher Corporation and Potomac Holding LLC and have been accounted for separately from the Communications Business Acquisition. The following table summarizes the allocation of the purchase price for the Delayed Close Entities acquired on October 7, 2015 (in thousands): Purchase Price Allocation: Total equity consideration $ 5,700 (1) Estimated Purchase Price $ 5,700 Estimated fair value of assets acquired and liabilities assumed: Accounts receivable $ 110 Inventories 78 Prepaid expenses and other assets 35 Property, plant and equipment 1,254 Other assets 281 Accounts payable (8 ) Accrued compensation (824 ) Accrued other (176 ) Deferred revenue (65 ) Other long-term liabilities (126 ) Goodwill $ 5,141 (1 ) Represents the fair value attributable to the Delayed Close Entities that the Company obtained control over on October 7, 2015. The Transaction was aimed at extending the Company's reach into growth-oriented adjacent markets, including cyber security, with a broader range of market-leading products and capabilities; strengthening the Company's go-to-market resources to better support a larger, more diverse and more global customer base; and increasing scale and elevating the Company's strategic position within key accounts. Goodwill was recognized for the excess purchase price over the fair value of the assets acquired. Goodwill of $1.5 billion from the acquisition was included within the following operating segments: $534.8 million in cybersecurity (Arbor Networks), $794.4 million for the service assurance product lines focused on the service provider market (formerly known as Tektronix Communications), $57.0 million in the network visibility product lines (formerly known as VSS Monitoring), and $125.1 million in the service assurance product lines primarily focused on the enterprise market (formerly known as FNET) as of March 31, 2016. There were no measurement period adjustments during the three months ended June 30, 2016. All reporting units resulting from the Transaction will be included in the Company’s annual goodwill impairment review. Goodwill and intangible assets recorded as part of the acquisition are not deductible for tax purposes. The fair values of intangible assets were based on valuations using an income approach. These assumptions include estimates of future revenues associated with the technology purchased as part of the acquisition and the migration of the current technology to more advanced version of the software. This fair value measurement was based on significant inputs not observable in the market and thus represents Level 3 fair value measurements. The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives (in thousands): Fair Value Useful Life (Years) Developed technology $ 221,900 9 - 13 Customer relationships 794,100 13 - 18 Backlog 18,200 1 - 3 Definite lived trademark and trade names 43,900 3 - 9 Leasehold interest 2,600 4 - 6 $ 1,080,700 The weighted average useful life of identifiable intangible assets acquired in the Transaction is 14.7 years . Developed technology is amortized using an accelerated amortization method and has a weighted average useful life of 11.7 years . Customer relationships are amortized using an accelerated amortization method and have a weighted average useful life of 16.3 years . Backlog is amortized using an accelerated amortization method and has a weighted average useful life of 2.0 years . Trademarks and trade names are amortized using an accelerated amortization method and have a weighted average useful life of 8.5 years . Leasehold interests are amortized on a straight-line basis and have a weighted average useful life of 5.6 years . The Company incurred approximately $0 and $3.4 million of acquisition-related costs related to the Transaction during the three months ended June 30, 2016 and 2015, respectively. During the three months ended June 30, 2016 , the Company has recorded $173.8 million of revenue and a net loss of $3.7 million directly attributable to the entities acquired as part of the Transaction within its consolidated financial statements. The following table presents unaudited pro forma results of the historical Consolidated Statements of Operations of the Company and the Communications Business of Danaher for the three months ended June 30, 2015, giving effect to the Transaction as if they occurred on April 1, 2014 (in thousands, except per share data): Three Months Ended June 30, 2015 (unaudited) Pro forma revenue $ 290,113 Pro forma net loss $ (4,763 ) Pro forma net loss per share: Basic $ (0.05 ) Diluted $ (0.05 ) Pro forma shares outstanding Basic 103,560 Diluted 103,560 The pro forma results for the three months ended June 30, 2015 primarily include adjustments for amortization of intangibles. This pro forma information does not purport to indicate the results that would have actually been obtained had the acquisitions been completed on the assumed date, or which may be realized in the future.

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS	3 Months Ended
	Jun. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS Goodwill The Company has five reporting units: (1) legacy NetScout, (2) cybersecurity (Arbor Networks), (3) service assurance product lines focused on the service provider market (formerly known as Tektronix Communications), (4) network visibility product lines (formerly known as VSS Monitoring) and (5) service assurance product lines primarily focused on the enterprise market (formerly known as FNET). At June 30, 2016 , goodwill attributable to the legacy NetScout, cybersecurity, service assurance line focused on the service provider market, network visibility product lines and service assurance product lines focused on the enterprise market reporting units was $197.8 million , $534.9 million , $795.5 million , $57.0 million , and $125.1 million , respectively. At March 31, 2016, goodwill attributable to the legacy NetScout, cybersecurity, service assurance line focused on the service provider market, network visibility product lines and service assurance product lines focused on the enterprise market reporting units was $198.1 million , $534.8 million , $794.4 million , $57.0 million and $125.1 million , respectively. Goodwill is tested for impairment at a reporting unit level at least annually, or on an interim basis if an event occurs or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value. The change in the carrying amount of goodwill for the three months ended June 30, 2016 is due to the impact of foreign currency translation adjustments related to asset balances that are recorded in currencies other than the U.S. Dollar. The changes in the carrying amount of goodwill for the three months ended June 30, 2016 are as follows (in thousands): Balance at March 31, 2016 $ 1,709,369 Foreign currency translation impact 917 Balance at June 30, 2016 $ 1,710,286 Intangible Assets The net carrying amounts of intangible assets were $1.0 billion and $ 1.1 billion at June 30, 2016 and March 31, 2016 , respectively. Intangible assets acquired in a business combination are recorded under the acquisition method of accounting at their estimated fair values at the date of acquisition. The Company amortizes intangible assets over their estimated useful lives, except for the acquired trade name which resulted from the Network General Central Corporation (Network General) acquisition, which has an indefinite life and thus is not amortized. The carrying value of the indefinite-lived trade name is evaluated for potential impairment annually or more frequently if events or changes in circumstances indicate that the asset might be impaired. Intangible assets include the indefinite-lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at June 30, 2016 (in thousands): Cost Accumulated Amortization Net Developed technology $ 253,036 $ (79,949 ) $ 173,087 Customer relationships 833,129 (58,248 ) $ 774,881 Distributor relationships 7,364 (1,927 ) $ 5,437 Definite lived trademark and trade names 43,922 (7,156 ) $ 36,766 Core technology 7,152 (4,866 ) $ 2,286 Net beneficial leases 336 (336 ) $ — Non-compete agreements 285 (285 ) $ — Leasehold interest 2,600 (562 ) $ 2,038 Backlog 18,216 (9,610 ) $ 8,606 Capitalized Software 1,915 (62 ) $ 1,853 Other 1,204 (790 ) $ 414 $ 1,169,159 $ (163,791 ) $ 1,005,368 Intangible assets include the indefinite-lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at March 31, 2016 (in thousands): Cost Accumulated Amortization Net Developed technology $ 253,249 $ (69,810 ) $ 183,439 Customer relationships 834,091 (42,526 ) 791,565 Distributor relationships 5,348 (1,633 ) 3,715 Definite-lived trademark and trade name 43,964 (5,511 ) 38,453 Core technology 7,169 (4,659 ) 2,510 Net beneficial leases 336 (336 ) — Non-compete agreements 288 (288 ) — Leasehold interest 2,600 (416 ) 2,184 Backlog 18,245 (6,750 ) 11,495 Capitalized Software 1,625 — 1,625 Other 1,191 (737 ) 454 $ 1,168,106 $ (132,666 ) $ 1,035,440 Amortization of backlog included as product revenue was $2.9 million and $0 for the three months ended June 30, 2016 and 2015, respectively. Amortization of developed technology, distributor relationships, core technology and software included as cost of product revenue was $10.7 million and $758 thousand for the three months ended June 30, 2016 and 2015, respectively. Amortization of other intangible assets included as operating expense was $17.6 million and $847 thousand for the three months ended June 30, 2016 and 2015, respectively. The following is the expected future amortization expense at June 30, 2016 for the fiscal years ending March 31 (in thousands): 2017 (remaining nine months) $ 93,541 2018 111,121 2019 105,575 2020 97,407 2021 85,349 Thereafter 512,375 $ 1,005,368 The weighted average amortization period of developed technology and core technology is 11.5 years . The weighted average amortization period for customer and distributor relationships is 16.1 years . The weighted average amortization period for trademarks and trade names is 8.5 years . The weighted average amortization period for leasehold interests is 5.6 years . The weighted average amortization period for backlog is 2.0 years . The weighted average amortization period for capitalized software is 4.0 years . The weighted average amortization period for amortizing all intangible assets is 14.6 years .

DERIVATIVE INSTRUMENTS AND HEDG

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	3 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES	DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES NetScout operates internationally and, in the normal course of business, is exposed to fluctuations in foreign currency exchange rates. The exposures result from costs that are denominated in currencies other than the U.S. Dollar, primarily the Euro, British Pound, Canadian Dollar, and Indian Rupee. The Company manages its foreign cash flow risk by hedging forecasted cash flows for operating expenses denominated in foreign currencies for up to twelve months, within specified guidelines through the use of forward contracts. The Company enters into foreign currency exchange contracts to hedge cash flow exposures from costs that are denominated in currencies other than the U.S. Dollar. These hedges are designated as cash flow hedges at inception. All of the Company’s derivative instruments are utilized for risk management purposes, and the Company does not use derivatives for speculative trading purposes. These contracts will mature over the next twelve months and are expected to impact earnings on or before maturity. The notional amounts and fair values of derivative instruments in the consolidated balance sheets at June 30, 2016 and March 31, 2016 were as follows (in thousands): Notional Amounts (a) Prepaid Expenses and Other Current Assets Accrued Other June 30, March 31, June 30, March 31, June 30, March 31, Derivatives Designated as Hedging Instruments: Forward contracts $ 10,736 $ 17,490 $ 116 $ 191 $ 93 $ 158 (a) Notional amounts represent the gross contract/notional amount of the derivatives outstanding. The following table provides the effect foreign exchange forward contracts had on other comprehensive income (loss) (OCI) and results of operations for the three months ended June 30, 2016 and 2015 (in thousands): Derivatives in Cash Flow Hedging Relationships Effective Portion Ineffective Portion Gain (Loss) Recognized in OCI on Derivative (a) Gain (Loss) Reclassified from Accumulated OCI into Income (b) Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing) (c) June 30, 2016 June 30, 2015 Location June 30, 2016 June 30, 2015 Location June 30, 2016 June 30, 2015 Forward contracts $ (50 ) $ 10 Research and development $ (12 ) $ 47 Research and development $ 13 $ 34 Sales and marketing 34 1,276 Sales and marketing (35 ) (14 ) $ (50 ) $ 10 $ 22 $ 1,323 $ (22 ) $ 20 (a) The amount represents the change in fair value of derivative contracts due to changes in spot rates. (b) The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings. (c) The amount represents the change in fair value of derivative contracts due to changes in the difference between the spot price and forward price that is excluded from the assessment of hedge effectiveness and therefore recognized in earnings. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.

LONG-TERM DEBT

LONG-TERM DEBT	3 Months Ended
	Jun. 30, 2016
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT On July 14, 2015, the Company entered into a certain credit facility with a syndicate of lenders pursuant to a Credit Agreement (Credit Agreement), dated as of July 14, 2015, by and among: the Company; JPMorgan Chase Bank, N.A. (JPMorgan), as administrative agent and collateral agent; J.P. Morgan Securities LLC, KeyBanc Capital Markets, Merrill Lynch, Pierce, Fenner & Smith Incorporated, RBC Capital Markets and Wells Fargo Securities, LLC, as joint lead arrangers and joint bookrunners; Santander Bank, N.A., SunTrust Bank, N.A. and U.S. Bank National Association, as co-documentation agents; and the lenders party thereto. The Credit Agreement provides for a five -year, $800 million senior secured revolving credit facility, including a letter of credit sub-facility of up to $50 million . The Company may elect to use the new credit facility for working capital purposes or repurchase of up to 20 million shares of common stock under the Company's common stock repurchase plan. The commitments under the Credit Agreement will expire on July 14, 2020, and any outstanding loans will be due on that date. At June 30, 2016 , $300 million was outstanding under this credit facility. At the Company’s election, revolving loans under the Credit Agreement bear interest at either (a) an Alternate Base Rate per annum equal to the greatest of (1) JPMorgan’s prime rate, (2) 0.50% in excess of the Federal Funds effective rate, or (3) an adjusted one month LIBO rate plus 1% ; or (b) such adjusted LIBO rate (for the interest period selected by the Company), in each case plus an applicable margin. For the period from the delivery of the Company's financial statements for the quarter ended March 31, 2016 until the Company has delivered financial statements for the quarter ended June 30, 2016, the applicable margin will be 1.50% per annum for LIBOR loans and 0.50% per annum for Alternate Base Rate loans, and thereafter the applicable margin will vary depending on the Company’s leverage ratio, ranging from 1.00% per annum for Base Rate loans and 2.00% per annum for LIBOR loans if the Company’s consolidated leverage ratio is greater than 2.50 to 1.00, down to 0.25% per annum for Alternate Base Rate loans and 1.25% per annum for LIBOR loans if the Company’s consolidated leverage ratio is equal to or less than 1.00 to 1.00. The Company’s consolidated leverage ratio is the ratio of its total funded debt compared to its consolidated adjusted EBITDA. Consolidated adjusted EBITDA includes certain adjustments, including, without limitation, adjustments relating to extraordinary, unusual or non-recurring charges, certain restructuring charges, non-cash charges, certain transaction costs and expenses and certain pro forma adjustments in connection with material acquisitions and dispositions, all as set forth in detail in the definition of Consolidated EBITDA in the Credit Agreement. Commitment fees will accrue on the daily unused amount of the credit facility. For the period from the delivery of the Company's financial statements for the quarter ended March 31, 2016 until the Company has delivered financial statements for the quarter ended June 30, 2016 , the commitment fee will be 0.25% per annum, and thereafter the commitment fee will vary depending on the Company’s consolidated leverage ratio, ranging from 0.35% per annum if the Company’s consolidated leverage ratio is greater than 2.50 to 1.00, down to 0.20% per annum if the Company’s consolidated leverage ratio is equal to or less than 1.00 to 1.00. Letter of credit participation fees are payable to each lender on the amount of such lender’s letter of credit exposure, during the period from the closing date of the Credit Agreement to but excluding the date which is the later of (i) the date on which such lender’s commitment terminates or (ii) the date on which such lender ceases to have any letter of credit exposure, at a rate per annum equal to the applicable margin for LIBOR loans. Additionally, the Company will pay a fronting fee to each issuing bank in amounts to be agreed to between the Company and the applicable issuing bank. Interest on Alternate Base Rate loans is payable at the end of each calendar quarter. Interest on LIBOR loans is payable at the end of each interest rate period or at the end of each three-month interval within an interest rate period if the period is longer than three months. The Company may also prepay loans under the Credit Agreement at any time, without penalty, subject to certain notice requirements. Debt is recorded at the amount drawn on the revolving credit facility plus interest based on floating rates reflective of changes in the market which approximates fair value. The loans and other obligations under the credit facility are (a) guaranteed by each of the Company’s wholly owned material domestic restricted subsidiaries, subject to certain exceptions, and (b) are secured by substantially all of the assets of the Company and the subsidiary guarantors, including a pledge of all the capital stock of material subsidiaries held directly by the Company and the subsidiary guarantors (which pledge, in the case of any foreign subsidiary, is limited to 65% of the voting stock), subject to certain customary exceptions and limitations. The Credit Agreement generally prohibits any other liens on the assets of the Company and its restricted subsidiaries, subject to certain exceptions as described in the Credit Agreement. The Credit Agreement contains certain covenants applicable to the Company and its restricted subsidiaries, including, without limitation, limitations on additional indebtedness, liens, various fundamental changes, dividends and distributions, investments (including acquisitions), transactions with affiliates, asset sales, including sale-leaseback transactions, speculative hedge agreements, payment of junior financing, changes in business and other limitations customary in senior secured credit facilities. In addition, the Company is required to maintain certain consolidated leverage and interest coverage ratios. These covenants and limitations are more fully described in the Credit Agreement. At June 30, 2016 , the Company was in compliance with all of these covenants. The Credit Agreement provides that events of default will exist in certain circumstances, including failure to make payment of principal or interest on the loans when required, failure to perform certain obligations under the Credit Agreement and related documents, defaults under certain other indebtedness, certain insolvency events, certain events arising under ERISA, a change of control and certain other events. Upon an event of default, the administrative agent with the consent of, or at the request of, the holders of more than 50% in principal amount of the loans and commitments may terminate the commitments and accelerate the maturity of the loans and enforce certain other remedies under the Credit Agreement and the other loan documents. In connection with the Company’s new revolving credit facility described above, effective as of the Closing Date, the Company terminated its existing term loan and revolving credit facility pursuant to the Credit and Security Agreement, dated as of November 22, 2011, by and among the Company, KeyBank National Association, as joint lead arranger, sole book runner and administrative agent, Wells Fargo Bank, National Association, as joint lead arranger and co-syndication agent, Merrill Lynch, Pierce, Fenner & Smith Incorporated, as joint lead arranger, Bank of America, N.A., as co-syndication agent, and Silicon Valley Bank and Comerica Bank, as co-documentation agents, and the Lenders party thereto. The Company capitalized $6.6 million of debt issuance costs associated with the origination of the Credit Agreement, which are being amortized over the life of the revolving credit facility. The unamortized balance was $5.4 million as of June 30, 2016 . A balance of $1.3 million is included as prepaid expenses and other current assets and a balance of $4.1 million was included as other assets in Company’s consolidated balance sheet.

RESTRUCTURING CHARGES

RESTRUCTURING CHARGES	3 Months Ended
	Jun. 30, 2016
Restructuring and Related Activities [Abstract]
RESTRUCTURING CHARGES	RESTRUCTURING CHARGES During the fiscal year ended March 31, 2016, the Company recorded a restructuring charge of $500 thousand related to one-time termination benefits to be paid to one employee. During the quarter ended June 30, 2016, the Company restructured certain departments to better align functions related to the Transaction. As a result of the restructuring program, the Company recorded $2.0 million of restructuring charges related to one-time termination benefits to be paid to nineteen employees. The following table provides a summary of the activity related to the restructuring plans and the related restructuring liability (in thousands): Q3 FY2016 Plan Q1 FY2017 Plan Employee-Related Employee-Related Total Balance at March 31, 2016 $ 272 $ — $ 272 Restructuring charges to operations — 2,034 2,034 Cash payments (114 ) (373 ) (487 ) Other adjustments (2 ) (6 ) (8 ) Balance at June 30, 2016 $ 156 $ 1,655 $ 1,811 The accrual for employee-related severance is included as accrued compensation in the Company's consolidated balance sheet. The balance is expected to be paid in full during the quarter ended September 30, 2016.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	3 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Acquisition related – The Company has one contingent liability related to the acquisition of Simena, LLC (Simena) in November 2011 for future consideration to be paid to the former seller which had an initial fair value of $8.0 million at the time of acquisition. At June 30, 2016 , the present value of the future consideration was $4.7 million . Legal – From time to time, NetScout is subject to legal proceedings and claims in the ordinary course of business. In the opinion of management, the amount of ultimate expense with respect to any current legal proceedings and claims, if determined adversely, will not have a significant adverse effect on the Company’s financial condition, results of operations or cash flows.

PENSION BENEFIT PLANS

PENSION BENEFIT PLANS	3 Months Ended
	Jun. 30, 2016
Compensation and Retirement Disclosure [Abstract]
PENSION BENEFIT PLANS	PENSION BENEFIT PLANS Certain of the Company's non-U.S. employees participate in certain noncontributory defined benefit pension plans acquired in the Transaction. None of the Company's employees in the U.S. participate in any noncontributory defined benefit pension plans. In general, these plans are funded based on considerations relating to legal requirements, underlying asset returns, the plan’s funded status, the anticipated deductibility of the contribution, local practices, market conditions, interest rates and other factors. The following sets forth the components of the Company's net periodic pension cost of the noncontributory defined benefit pension plans for the three months ended June 30, 2016 and 2015 (in thousands): Three Months Ended June 30, 2016 2015 Service cost $ 84 $ — Interest cost 164 — Net periodic pension cost $ 248 $ — Expected Contributions During the three months ended June 30, 2016 , the Company did no t make any contributions to its defined benefit pension plans. During the fiscal year ending March 31, 2017, the Company's cash contribution requirements for its defined benefit pension plans are expected to be less than $1.0 million . As a majority of the participants within the Company's plans are all active employees, the benefit payments are not expected to be material in the foreseeable future. Other Matters Substantially all employees not covered by defined benefit plans are covered by defined contribution plans, which generally provide for company funding based on a percentage of compensation. Expense for all defined contribution plans amounted to $2.9 million and $1.1 million for the three months ended June 30, 2016 and 2015, respectively.

TREASURY STOCK

TREASURY STOCK	3 Months Ended
	Jun. 30, 2016
Equity [Abstract]
TREASURY STOCK	TREASURY STOCK On April 22, 2014, the Company's board of directors approved a stock repurchase program. This program authorized management to make repurchases of NetScout outstanding common stock of up to $100 million . The Company repurchased 67,752 shares for $2.8 million under this program during the three months ended June 30, 2015. Through March 31, 2016, the Company had repurchased 824,452 shares totaling $34.3 million in the open market under this stock repurchase plan. At March 31, 2016, there were no shares of common stock that remained available to be purchased under this plan due to the approval of a new share repurchase program approved on May 19, 2015. On May 19, 2015, the Company’s board of directors approved a new share repurchase program, conditional upon the completion of the Transaction. This program enables the Company to repurchase up to 20 million shares of its common stock. This plan became effective on July 14, 2015 upon the completion of the Transaction and replaced the Company's previously existing open market stock repurchase program described above. The Company is not obligated to acquire any specific amount of common stock within any particular timeframe under this program. For additional information regarding the Transaction, see Note 7. Through June 30, 2016 , the Company has repurchased 12,178,518 shares totaling $350.0 million in the open market under this stock repurchase plan. At June 30, 2016 , 7,821,482 shares of common stock remained available to be purchased under the plan. The Company repurchased 2,100,382 shares for $50.0 million under the program during the three months ended June 30, 2016. In connection with the vesting and release of the restriction on previously vested shares of restricted stock units, the Company withheld 2,909 shares at a cost of $68 thousand related to minimum statutory tax withholding requirements on these restricted stock units during the three months ended June 30, 2016 . These withholding transactions do not fall under the repurchase program described above, and therefore do not reduce the amount that is available for repurchase under that program.

NET INCOME (LOSS) PER SHARE

NET INCOME (LOSS) PER SHARE	3 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME (LOSS) PER SHARE Calculations of the basic and diluted net income (loss) per share and potential common shares are as follows (in thousands, except for per share data): Three Months Ended June 30, 2016 2015 Numerator: Net income (loss) $ (8,998 ) $ 7,669 Denominator: Denominator for basic net income (loss) per share - weighted average common shares outstanding 93,344 40,776 Dilutive common equivalent shares: Weighted average stock options — — Weighted average restricted stock units — 595 Denominator for diluted net income (loss) per share - weighted average shares outstanding 93,344 41,371 Net income (loss) per share: Basic net income (loss) per share $ (0.10 ) $ 0.19 Diluted net income (loss) per share $ (0.10 ) $ 0.19 The following table sets forth restricted stock units excluded from the calculation of diluted net income (loss) per share, since their inclusion would be antidilutive (in thousands): Three Months Ended June 30, 2016 2015 Restricted stock units 2,282 19 Basic net income (loss) per share is calculated by dividing net income (loss) by the weighted average number of shares outstanding during the period. Unvested restricted shares, although legally issued and outstanding, are not considered outstanding for purposes of calculating basic earnings per share. Diluted net income (loss) per share is calculated by dividing net income (loss) by the weighted average number of shares outstanding plus the dilutive effect, if any, of outstanding stock options, restricted shares and restricted stock units using the treasury stock method. The calculation of the dilutive effect of outstanding equity awards under the treasury stock method includes consideration of proceeds from the assumed exercise of stock options, unrecognized compensation expense and any tax benefits as additional proceeds. As we incurred a net loss in the three months ended June 30, 2016 , all outstanding restricted stock units have an anti-dilutive effect and are therefore excluded from the computation of diluted weighted average share outstanding.

INCOME TAXES

INCOME TAXES	3 Months Ended
	Jun. 30, 2016
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company's effective income tax rates were 34.1% and 37.4% for the three months ended June 30, 2016 and 2015 , respectively. Generally, the effective tax rate differs from the statutory tax rate due to the impact of the domestic production activities deduction, research and development credit, the impact of state taxes and income generated in jurisdictions that have a different tax rate than the U.S. statutory rate. The effective tax rate for the three months ended June 30, 2016 is lower than the effective rate for the three months ended June 30, 2015 , primarily due to an increase in research and development credits (the research and development tax credit was not enacted in the prior period), an increase in the domestic production activities deduction and the expansion of its international footprint from recent acquisitions.

SEGMENT AND GEOGRAPHIC INFORMAT

SEGMENT AND GEOGRAPHIC INFORMATION	3 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
SEGMENT AND GEOGRAPHIC INFORMATION	SEGMENT AND GEOGRAPHIC INFORMATION The Company reports revenues and income under five operating segments that aggregate under one reportable segment. The Company manages its business in the following geographic areas: United States, Europe, Asia and the rest of the world. In accordance with United States export control regulations, the Company does not sell or do business with countries subject to economic sanctions and export controls. Total revenue by geography is as follows (in thousands): Three Months Ended June 30, 2016 2015 United States $ 172,772 $ 78,273 Europe 41,855 12,607 Asia 26,843 3,532 Rest of the world 27,482 6,331 $ 268,952 $ 100,743 The United States revenue includes sales to resellers in the United States. These resellers fulfill customer orders and may subsequently ship the Company’s products to international locations. The Company reports these shipments as United States revenue since the Company ships the products to a United States location. A majority of revenue attributable to locations outside of the United States is a result of export sales. Substantially all of the Company’s identifiable assets are located in the United States.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Jun. 30, 2016
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS During our fiscal year ended March 31, 2016 and the three months ended June 30, 2016, a member of the Company’s Board of Directors served as an executive officer (under Section 16 of the Securities Exchange Act of 1934, as amended (the Exchange Act)) of Danaher. As part of the split off of Danaher’s Communications Business and the Company’s subsequent acquisition of that business from Newco's shareholders, NetScout has entered into multiple transactions with Danaher which include: transitions services agreements, lease agreements, closing agreements, and compensation for post-combination services provisions within the separation and distribution agreement. The Company has disclosed these transactions parenthetically within the financial statements. This board member is now the founding President and CEO of Fortive Corporation, which spun out of Danaher in July 2016. As part of the spin out of Fortive Corporation the transition services agreement was amended to, among other things assign Danaher's rights, duties, obligations and liabilities under the transition services agreement to Fluke Corporation, a subsidiary of Fortive Corporation. A member of the Company’s Board of Directors serves as a member of the board of directors for EMC, Corporation (EMC) and therefore, the Company considers sales to EMC to be a related party transaction. The Company recognized $57 thousand and $79 thousand in revenue from EMC during the three months ended June 30, 2016 and 2015 in the ordinary course of business. A member of the Company’s Board of Directors also serves as a member of the board of directors for The MITRE Corporation (MITRE) and therefore, the Company considers sales to MITRE to be a related party transaction. The Company generated $11 thousand and $0 in revenue from MITRE during the three months ended ended June 30, 2016 and 2015 in the ordinary course of business. During our fiscal year ended March 31, 2016, the Company had a member of the Board of Directors who served as a Section 16 officer of State Street Corporation (State Street) and therefore, the Company considered sales to State Street to be a related party transaction. The Company recognized $60 thousand in revenue from State Street during the three months ended June 30, 2015 in the ordinary course of business. This board member is no longer a section 16 officer of State Street, as such State Street is no longer considered a related party in the Company's fiscal year ended March 31, 2017.

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	3 Months Ended
	Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited interim consolidated financial statements have been prepared by NetScout Systems, Inc., or NetScout or the Company. Certain information and footnote disclosures normally included in financial statements prepared under United States generally accepted accounting principles (GAAP) have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (SEC). In the opinion of management, the unaudited interim consolidated financial statements include all adjustments, consisting of normal recurring adjustments, necessary for a fair statement of the Company’s financial position, results of operations and cash flows. The year-end consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. The results reported in these unaudited interim consolidated financial statements are not necessarily indicative of results that may be expected for the entire year. All significant intercompany accounts and transactions are eliminated in consolidation. The accompanying unaudited interim consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. On July 14, 2015, or the Closing Date, the Company completed the acquisition of Danaher Corporation’s (Danaher) Communications Business (Communications Business), which included certain assets, liabilities, technology and employees within Tektronix Communications, VSS Monitoring, Arbor Networks and certain portions of the Fluke Networks Enterprise business, which excluded Danaher’s data communications cable installation business and its communication service provider business (the Transaction). The Transaction is more fully described in Note 7 below. The Transaction was recorded using the acquisition method of accounting; accordingly, the financial results of the acquisition are included in the accompanying unaudited interim consolidated financial statements for the periods subsequent to the acquisition. These unaudited interim consolidated financial statements should be read in conjunction with the audited consolidated financial statements, including the notes thereto, included in the Company’s Annual Report on Form 10-K for the fiscal year ended March 31, 2016 filed with the SEC on May 31, 2016.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting (ASU 2016-09), which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures and statutory tax withholding requirements, as well as classification in the statement of cash flows. ASU 2016-09 is effective for the Company beginning April 1, 2017. The Company is currently assessing the potential impact of the adoption of ASU 2016-09 on its consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) Section A - Leases: Amendments to the FASB Accounting Standards Codification (ASU 2016-02), its new standard on accounting for leases. This update requires the recognition of leased assets and lease obligations by lessees for those leases currently classified as operating leases under existing lease guidance. Short term leases with a term of 12 months or less are not required to be recognized. The update also requires disclosure of key information about leasing arrangements to increase transparency and comparability among organizations. ASU 2016-02 is effective for annual reporting periods beginning after December 31, 2018 and interim periods within those fiscal years, and early adoption is permitted. The Company is currently assessing the potential impact of the adoption of ASU 2016-02 on its consolidated financial statements. In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers: Topic 606 (ASU 2014-09) and issued subsequent amendments to the initial guidance in August 2015, March 2016, April 2016 and May 2016 within ASU 2015-04, 2016-08, ASU 2016-10 and ASU 2016-12, respectively ( ASU 2014-09, ASU 2015-04, ASU 2016-08, ASU 2016-10 and ASU 2016-12 collectively, Topic 606). Topic 606 supersedes nearly all existing revenue recognition guidance under GAAP. The core principle of Topic 606 is to recognize revenues when promised goods or services are transferred to customers in an amount that reflects the consideration that is expected to be received for those goods or services. Topic 606 defines a five-step process to achieve this core principle and, in doing so, it is possible more judgment and estimates may be required within the revenue recognition process than required under existing GAAP, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation, among others. Topic 606 will be effective for the Company in the first quarter of its fiscal year 2019. Early adoption is not permitted. The Company is currently assessing the potential impact of the adoption of ASU 2014-09 on its consolidated financial statements.

SHARE-BASED COMPENSATION (Table

SHARE-BASED COMPENSATION (Tables)	3 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Share-Based Compensation Expense	The following is a summary of share-based compensation expense including restricted stock units and employee stock purchases made under the Company's 2011 Employee Stock Purchase Plan (ESPP) based on estimated fair values within the applicable cost and expense lines identified below (in thousands): Three Months Ended June 30, 2016 2015 Cost of product revenue $ 195 $ 102 Cost of service revenue 798 373 Research and development 2,633 1,490 Sales and marketing 2,611 1,403 General and administrative 1,895 1,227 $ 8,132 $ 4,595

CASH, CASH EQUIVALENTS AND MA29

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES (Tables)	3 Months Ended
	Jun. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Summary of Marketable Securities	The following is a summary of marketable securities held by NetScout at June 30, 2016 , classified as short-term and long-term (in thousands): Amortized Cost Unrealized Gains Fair Value Type of security: U.S. government and municipal obligations $ 82,005 $ 24 $ 82,029 Commercial paper 26,714 — 26,714 Total short-term marketable securities 108,719 24 108,743 U.S. government and municipal obligations 15,276 33 15,309 Total long-term marketable securities 15,276 33 15,309 Total marketable securities $ 123,995 $ 57 $ 124,052 The following is a summary of marketable securities held by NetScout at March 31, 2016 , classified as short-term and long-term (in thousands): Amortized Cost Unrealized Gains Fair Value Type of security: U.S. government and municipal obligations $ 109,963 $ 4 $ 109,967 Commercial paper 16,172 — 16,172 Corporate bonds 1,864 — 1,864 Total short-term marketable securities 127,999 4 128,003 U.S. government and municipal obligations 13,349 12 13,361 Total long-term marketable securities 13,349 12 13,361 Total marketable securities $ 141,348 $ 16 $ 141,364
Summary of Contractual Maturities of Marketable Securities	Contractual maturities of the Company’s marketable securities held at June 30, 2016 and March 31, 2016 were as follows (in thousands): June 30, March 31, Available-for-sale securities: Due in 1 year or less $ 108,743 $ 128,003 Due after 1 year through 5 years 15,309 13,361 $ 124,052 $ 141,364

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	3 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities	The following tables present the Company’s financial assets and liabilities measured on a recurring basis using the fair value hierarchy at June 30, 2016 and March 31, 2016 (in thousands): Fair Value Measurements at June 30, 2016 Level 1 Level 2 Level 3 Total ASSETS: Cash and cash equivalents $ 210,870 $ — $ — $ 210,870 U.S. government and municipal obligations 25,611 71,727 — 97,338 Commercial paper — 26,714 — 26,714 Derivative financial instruments — 116 — 116 Contingently returnable consideration — — 8,341 $ 8,341 $ 236,481 $ 98,557 $ 8,341 $ 343,379 LIABILITIES: Contingent purchase consideration $ — $ — $ (4,674 ) $ (4,674 ) Derivative financial instruments — (93 ) — (93 ) $ — $ (93 ) $ (4,674 ) $ (4,767 ) Fair Value Measurements at March 31, 2016 Level 1 Level 2 Level 3 Total ASSETS: Cash and cash equivalents $ 210,711 $ — $ — $ 210,711 U.S. government and municipal obligations 41,116 82,212 — 123,328 Commercial paper — 16,172 — 16,172 Corporate bonds 1,864 — — 1,864 Derivative financial instruments — 191 — 191 Contingently returnable consideration 16,131 16,131 $ 253,691 $ 98,575 $ 16,131 $ 368,397 LIABILITIES: Contingent purchase consideration $ — $ — $ (7,293 ) $ (7,293 ) Derivative financial instruments — (158 ) — (158 ) $ — $ (158 ) $ (7,293 ) $ (7,451 )
Schedule of Reconciliation of Changes in Fair Value of Level III Financial Assets	The following table sets forth a reconciliation of changes in the fair value of the Company’s Level 3 financial assets and liabilities for the three months ended June 30, 2016 (in thousands): Contingent Purchase Consideration Contingently Returnable Consideration Balance at beginning of period $ (7,293 ) $ 16,131 Increase in fair value and accretion expense (included within research and development expense) (38 ) — Payment received — (7,790 ) Payments made 2,657 — Balance at end of period $ (4,674 ) $ 8,341

INVENTORIES (Tables)

INVENTORIES (Tables)	3 Months Ended
	Jun. 30, 2016
Inventory Disclosure [Abstract]
Schedule of Inventories	Inventories consist of the following (in thousands): June 30, March 31, Raw materials $ 20,497 $ 18,617 Work in process 1,315 651 Finished goods 37,030 38,761 $ 58,842 $ 58,029

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	3 Months Ended
	Jun. 30, 2016
Business Combinations [Abstract]
Summary of Purchase Price Allocation	The following table summarizes the allocation of the purchase price for the entities acquired on July 14, 2015 (in thousands): Purchase Price Allocation: Total equity consideration $ 2,299,911 (1) Less: Equity consideration for replacement awards (29,355 ) (2) Estimated Purchase Price 2,270,556 Estimated fair value of assets acquired and liabilities assumed: Cash 27,701 Accounts receivable 140,586 Inventories 80,719 Prepaid expenses and other assets 6,715 Property, plant and equipment 36,825 Deferred income taxes 13,067 Intangible assets 1,080,700 Other assets 999 Accounts payable (21,311 ) Accrued compensation (24,316 ) Accrued other (12,916 ) Deferred revenue (187,882 ) Other long-term liabilities (3,615 ) Accrued retirement benefits (29,917 ) Deferred tax liabilities (344,646 ) Goodwill $ 1,507,847 (1) Represents approximately 62.5 million new shares (plus cash in lieu of fractional shares) of NetScout common stock issued to the existing common unit holders of Newco based on the July 13, 2015 NetScout common stock closing share price of $36.89 per share, less the fair value attributable to the foreign entities that the Company did not obtain control over on July 14, 2015 due to regulatory and other compliance requirements. (2) Represents the value of certain outstanding Danaher equity awards held by Newco Employees for which continuing employees received, or will receive value after the Closing Date. A portion of this amount relates to awards that will continue to vest in Danaher shares after the Closing Date. These future compensation amounts will be settled in shares other than shares of the acquired business. The balance of this amount also represents future compensation expense and relates to cash awards to be paid by NetScout to acquired Newco employees on August 4, 2016. The cash payments by NetScout will be reimbursed by Danaher. These items are further described in the Employee Matters Agreement dated July 14, 2015 by and among NetScout Systems, Inc., Danaher Corporation and Potomac Holding LLC and have been accounted for separately from the Communications Business Acquisition. The following table summarizes the allocation of the purchase price for the Delayed Close Entities acquired on October 7, 2015 (in thousands): Purchase Price Allocation: Total equity consideration $ 5,700 (1) Estimated Purchase Price $ 5,700 Estimated fair value of assets acquired and liabilities assumed: Accounts receivable $ 110 Inventories 78 Prepaid expenses and other assets 35 Property, plant and equipment 1,254 Other assets 281 Accounts payable (8 ) Accrued compensation (824 ) Accrued other (176 ) Deferred revenue (65 ) Other long-term liabilities (126 ) Goodwill $ 5,141 (1 ) Represents the fair value attributable to the Delayed Close Entities that the Company obtained control over on October 7, 2015.
Schedule of Fair value of Acquired Identifiable Intangible Assets and Related Estimates of Useful Lives	The following table reflects the fair value of the acquired identifiable intangible assets and related estimates of useful lives (in thousands): Fair Value Useful Life (Years) Developed technology $ 221,900 9 - 13 Customer relationships 794,100 13 - 18 Backlog 18,200 1 - 3 Definite lived trademark and trade names 43,900 3 - 9 Leasehold interest 2,600 4 - 6 $ 1,080,700
Schedule of Pro Forma Results of Consolidated Statement of Operations	The following table presents unaudited pro forma results of the historical Consolidated Statements of Operations of the Company and the Communications Business of Danaher for the three months ended June 30, 2015, giving effect to the Transaction as if they occurred on April 1, 2014 (in thousands, except per share data): Three Months Ended June 30, 2015 (unaudited) Pro forma revenue $ 290,113 Pro forma net loss $ (4,763 ) Pro forma net loss per share: Basic $ (0.05 ) Diluted $ (0.05 ) Pro forma shares outstanding Basic 103,560 Diluted 103,560

GOODWILL AND INTANGIBLE ASSETS

GOODWILL AND INTANGIBLE ASSETS (Tables)	3 Months Ended
	Jun. 30, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The changes in the carrying amount of goodwill for the three months ended June 30, 2016 are as follows (in thousands): Balance at March 31, 2016 $ 1,709,369 Foreign currency translation impact 917 Balance at June 30, 2016 $ 1,710,286
Schedule of Intangible Assets	Intangible assets include the indefinite-lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at June 30, 2016 (in thousands): Cost Accumulated Amortization Net Developed technology $ 253,036 $ (79,949 ) $ 173,087 Customer relationships 833,129 (58,248 ) $ 774,881 Distributor relationships 7,364 (1,927 ) $ 5,437 Definite lived trademark and trade names 43,922 (7,156 ) $ 36,766 Core technology 7,152 (4,866 ) $ 2,286 Net beneficial leases 336 (336 ) $ — Non-compete agreements 285 (285 ) $ — Leasehold interest 2,600 (562 ) $ 2,038 Backlog 18,216 (9,610 ) $ 8,606 Capitalized Software 1,915 (62 ) $ 1,853 Other 1,204 (790 ) $ 414 $ 1,169,159 $ (163,791 ) $ 1,005,368 Intangible assets include the indefinite-lived trade name with a carrying value of $18.6 million and the following amortizable intangible assets at March 31, 2016 (in thousands): Cost Accumulated Amortization Net Developed technology $ 253,249 $ (69,810 ) $ 183,439 Customer relationships 834,091 (42,526 ) 791,565 Distributor relationships 5,348 (1,633 ) 3,715 Definite-lived trademark and trade name 43,964 (5,511 ) 38,453 Core technology 7,169 (4,659 ) 2,510 Net beneficial leases 336 (336 ) — Non-compete agreements 288 (288 ) — Leasehold interest 2,600 (416 ) 2,184 Backlog 18,245 (6,750 ) 11,495 Capitalized Software 1,625 — 1,625 Other 1,191 (737 ) 454 $ 1,168,106 $ (132,666 ) $ 1,035,440
Schedule of Expected Future Amortization Expense	e following is the expected future amortization expense at June 30, 2016 for the fiscal years ending March 31 (in thousands): 2017 (remaining nine months) $ 93,541 2018 111,121 2019 105,575 2020 97,407 2021 85,349 Thereafter 512,375 $ 1,005,368

DERIVATIVE INSTRUMENTS AND HE34

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES (Tables)	3 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Notional Amounts and Fair Values of Derivative Instruments on Consolidated Balance Sheet	The notional amounts and fair values of derivative instruments in the consolidated balance sheets at June 30, 2016 and March 31, 2016 were as follows (in thousands): Notional Amounts (a) Prepaid Expenses and Other Current Assets Accrued Other June 30, March 31, June 30, March 31, June 30, March 31, Derivatives Designated as Hedging Instruments: Forward contracts $ 10,736 $ 17,490 $ 116 $ 191 $ 93 $ 158 (a) Notional amounts represent the gross contract/notional amount of the derivatives outstanding.
Summary of Effect of Foreign Exchange Forward Contracts on OCI and Results of Operations	The following table provides the effect foreign exchange forward contracts had on other comprehensive income (loss) (OCI) and results of operations for the three months ended June 30, 2016 and 2015 (in thousands): Derivatives in Cash Flow Hedging Relationships Effective Portion Ineffective Portion Gain (Loss) Recognized in OCI on Derivative (a) Gain (Loss) Reclassified from Accumulated OCI into Income (b) Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing) (c) June 30, 2016 June 30, 2015 Location June 30, 2016 June 30, 2015 Location June 30, 2016 June 30, 2015 Forward contracts $ (50 ) $ 10 Research and development $ (12 ) $ 47 Research and development $ 13 $ 34 Sales and marketing 34 1,276 Sales and marketing (35 ) (14 ) $ (50 ) $ 10 $ 22 $ 1,323 $ (22 ) $ 20 (a) The amount represents the change in fair value of derivative contracts due to changes in spot rates. (b) The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings. (c) The amount represents the change in fair value of derivative contracts due to changes in the difference between the spot price and forward price that is excluded from the assessment of hedge effectiveness and therefore recognized in earnings. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.

RESTRUCTURING CHARGES (Tables)

RESTRUCTURING CHARGES (Tables)	3 Months Ended
	Jun. 30, 2016
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Liability	The following table provides a summary of the activity related to the restructuring plans and the related restructuring liability (in thousands): Q3 FY2016 Plan Q1 FY2017 Plan Employee-Related Employee-Related Total Balance at March 31, 2016 $ 272 $ — $ 272 Restructuring charges to operations — 2,034 2,034 Cash payments (114 ) (373 ) (487 ) Other adjustments (2 ) (6 ) (8 ) Balance at June 30, 2016 $ 156 $ 1,655 $ 1,811

PENSION BENEFIT PLANS (Tables)

PENSION BENEFIT PLANS (Tables)	3 Months Ended
	Jun. 30, 2016
Compensation and Retirement Disclosure [Abstract]
Schedule of Net Periodic Pension Costs of Noncontributory Defined Benefit Pension Plans	he following sets forth the components of the Company's net periodic pension cost of the noncontributory defined benefit pension plans for the three months ended June 30, 2016 and 2015 (in thousands): Three Months Ended June 30, 2016 2015 Service cost $ 84 $ — Interest cost 164 — Net periodic pension cost $ 248 $ —

NET INCOME (LOSS) PER SHARE (Ta

NET INCOME (LOSS) PER SHARE (Tables)	3 Months Ended
	Jun. 30, 2016
Earnings Per Share [Abstract]
Schedule of Calculations of the Basic and Diluted Net Income (Loss) Per Share and Potential Common Shares	Calculations of the basic and diluted net income (loss) per share and potential common shares are as follows (in thousands, except for per share data): Three Months Ended June 30, 2016 2015 Numerator: Net income (loss) $ (8,998 ) $ 7,669 Denominator: Denominator for basic net income (loss) per share - weighted average common shares outstanding 93,344 40,776 Dilutive common equivalent shares: Weighted average stock options — — Weighted average restricted stock units — 595 Denominator for diluted net income (loss) per share - weighted average shares outstanding 93,344 41,371 Net income (loss) per share: Basic net income (loss) per share $ (0.10 ) $ 0.19 Diluted net income (loss) per share $ (0.10 ) $ 0.19
Summary of Antidilutive Securities Excluded from Computation of Diluted EPS	The following table sets forth restricted stock units excluded from the calculation of diluted net income (loss) per share, since their inclusion would be antidilutive (in thousands): Three Months Ended June 30, 2016 2015 Restricted stock units 2,282 19

SEGMENT AND GEOGRAPHIC INFORM38

SEGMENT AND GEOGRAPHIC INFORMATION (Tables)	3 Months Ended
	Jun. 30, 2016
Segment Reporting [Abstract]
Summary of Total Revenue by Geography	Total revenue by geography is as follows (in thousands): Three Months Ended June 30, 2016 2015 United States $ 172,772 $ 78,273 Europe 41,855 12,607 Asia 26,843 3,532 Rest of the world 27,482 6,331 $ 268,952 $ 100,743

CONCENTRATION OF CREDIT RISK 39

CONCENTRATION OF CREDIT RISK AND SIGNIFICANT CUSTOMERS - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2016USD ($)Customer	Jun. 30, 2015Customer	Mar. 31, 2016USD ($)Customer
Concentration Risk [Line Items]
Related party prepaid expenses and other current assets | $	$ 65,855		$ 78,399
Affiliated Entity
Concentration Risk [Line Items]
Related party prepaid expenses and other current assets | $	$ 38,357		$ 44,161
Customer Concentration Risk | Indirect Customer | Accounts receivable
Concentration Risk [Line Items]
Number of customers contributing to more than 10%	0		0
Customer Concentration Risk | Indirect Customer | Sales Revenue
Concentration Risk [Line Items]
Number of customers contributing to more than 10%	0	0
Customer Concentration Risk | Direct Customer | Accounts receivable
Concentration Risk [Line Items]
Number of customers contributing to more than 10%	1		1
Customer Concentration Risk | Direct Customer | Sales Revenue
Concentration Risk [Line Items]
Number of customers contributing to more than 10%	1	0
Credit Concentration Risk | Danaher | Affiliated Entity
Concentration Risk [Line Items]
Related party prepaid expenses and other current assets | $	$ 38,400		$ 44,200

SHARE-BASED COMPENSATION - Summ

SHARE-BASED COMPENSATION - Summary of Share-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 8,132	$ 4,595
Cost of product revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	195	102
Cost of service revenue
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	798	373
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	2,633	1,490
Sales and marketing
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	2,611	1,403
General and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Share-based compensation expense	$ 1,895	$ 1,227

SHARE-BASED COMPENSATION - Narr

SHARE-BASED COMPENSATION - Narrative (Details)	3 Months Ended
	Jun. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Percentage of common stock price for employees	85.00%

CASH, CASH EQUIVALENTS AND MA42

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 123,995	$ 141,348
Unrealized Gains	57	16
Fair Value	124,052	141,364
U.S. government and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Fair Value	97,338	123,328
Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Fair Value	26,714	16,172
Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Fair Value		1,864
Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	108,719	127,999
Unrealized Gains	24	4
Fair Value	108,743	128,003
Short-term marketable securities | U.S. government and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	82,005	109,963
Unrealized Gains	24	4
Fair Value	82,029	109,967
Short-term marketable securities | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	26,714	16,172
Unrealized Gains	0	0
Fair Value	26,714	16,172
Short-term marketable securities | Corporate bonds
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost		1,864
Unrealized Gains		0
Fair Value		1,864
Long-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,276	13,349
Unrealized Gains	33	12
Fair Value	15,309	13,361
Long-term marketable securities | U.S. government and municipal obligations
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,276	13,349
Unrealized Gains	33	12
Fair Value	$ 15,309	$ 13,361

CASH, CASH EQUIVALENTS AND MA43

CASH, CASH EQUIVALENTS AND MARKETABLE SECURITIES - Summary of Contractual Maturities of Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Available-for-sale securities:
Due in 1 year or less	$ 108,743	$ 128,003
Due after 1 year through 5 years	15,309	13,361
Fair Value	$ 124,052	$ 141,364

FAIR VALUE MEASUREMENTS - Sched

FAIR VALUE MEASUREMENTS - Schedule of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
ASSETS:
Cash and cash equivalents	$ 210,870	$ 210,711
Marketable securities	124,052	141,364
Derivative financial instruments	116	191
Contingently returnable consideration	8,341	16,131
Total assets	343,379	368,397
LIABILITIES:
Contingent purchase consideration	(4,674)	(7,293)
Derivative financial instruments	(93)	(158)
Total liabilities	(4,767)	(7,451)
U.S. government and municipal obligations
ASSETS:
Marketable securities	97,338	123,328
Commercial paper
ASSETS:
Marketable securities	26,714	16,172
Corporate bonds
ASSETS:
Marketable securities		1,864
Level 1
ASSETS:
Cash and cash equivalents	210,870	210,711
Derivative financial instruments	0	0
Contingently returnable consideration	0
Total assets	236,481	253,691
LIABILITIES:
Contingent purchase consideration	0	0
Derivative financial instruments	0	0
Total liabilities	0	0
Level 1 | U.S. government and municipal obligations
ASSETS:
Marketable securities	25,611	41,116
Level 1 | Commercial paper
ASSETS:
Marketable securities	0	0
Level 1 | Corporate bonds
ASSETS:
Marketable securities		1,864
Level 2
ASSETS:
Cash and cash equivalents	0	0
Derivative financial instruments	116	191
Contingently returnable consideration	0
Total assets	98,557	98,575
LIABILITIES:
Contingent purchase consideration	0	0
Derivative financial instruments	(93)	(158)
Total liabilities	(93)	(158)
Level 2 | U.S. government and municipal obligations
ASSETS:
Marketable securities	71,727	82,212
Level 2 | Commercial paper
ASSETS:
Marketable securities	26,714	16,172
Level 2 | Corporate bonds
ASSETS:
Marketable securities		0
Level 3
ASSETS:
Cash and cash equivalents	0	0
Derivative financial instruments	0	0
Contingently returnable consideration	8,341	16,131
Total assets	8,341	16,131
LIABILITIES:
Contingent purchase consideration	(4,674)	(7,293)
Derivative financial instruments	0	0
Total liabilities	(4,674)	(7,293)
Level 3 | U.S. government and municipal obligations
ASSETS:
Marketable securities	0	0
Level 3 | Commercial paper
ASSETS:
Marketable securities	$ 0	0
Level 3 | Corporate bonds
ASSETS:
Marketable securities		$ 0

FAIR VALUE MEASUREMENTS - Narra

FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Nov. 30, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingently returnable consideration	$ 8,341	$ 16,131
Contingent purchase consideration	4,674	7,293
Fair value, measurements, recurring | Contingent Purchase Consideration
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Deal related compensation expense, accretion charges and changes related to settlements of contractual non-compliance liabilities	38
Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingently returnable consideration	8,341	16,131
Contingent purchase consideration	4,674	$ 7,293
Level 3 | Prepaid expenses and other current assets
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingently returnable consideration	8,400
Simena
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent purchase consideration			$ 8,000
Simena | Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Contingent purchase consideration	$ 5,000

FAIR VALUE MEASUREMENTS - Sch46

FAIR VALUE MEASUREMENTS - Schedule of Reconciliation of Changes in Fair Value of Level III Financial Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Payment received	$ (5,133)	$ 0
Fair value, measurements, recurring | Contingent Purchase Consideration
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	(7,293)
Increase in fair value and accretion expense (included within research and development expense)	(38)
Payments made	2,657
Balance at end of period	(4,674)
Fair value, measurements, recurring | Contingently Returnable Consideration
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	16,131
Payment received	(7,790)
Balance at end of period	$ 8,341

INVENTORIES - Schedule of Inven

INVENTORIES - Schedule of Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Inventory Disclosure [Abstract]
Raw materials	$ 20,497	$ 18,617
Work in process	1,315	651
Finished goods	37,030	38,761
Total inventories	$ 58,842	$ 58,029

ACQUISITIONS - Narrative (Detai

ACQUISITIONS - Narrative (Details) - USD ($)	Oct. 07, 2015	Jul. 14, 2015	Jun. 30, 2016	Oct. 07, 2015	Jun. 30, 2015	Mar. 31, 2016	Jul. 13, 2015
Business Acquisition [Line Items]
Goodwill			$ 1,710,286,000			$ 1,709,369,000
Weighted average useful life of acquired intangible assets			14 years 7 months
Backlog
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			2 years
Trademarks and trade names
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			8 years 6 months
Leasehold interest
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			5 years 7 months 6 days
Arbor Networks
Business Acquisition [Line Items]
Goodwill			$ 534,900,000			534,800,000
Service assurance for service provider
Business Acquisition [Line Items]
Goodwill			795,500,000			794,400,000
Network visibility
Business Acquisition [Line Items]
Goodwill			57,000,000			57,000,000
Service assurance for enterprise
Business Acquisition [Line Items]
Goodwill			$ 125,100,000			125,100,000
Cash retention award | Vesting after August 4, 2015
Business Acquisition [Line Items]
Percent of cancelled Danaher equity awards replaced			50.00%
Restricted stock units | Vesting after August 4, 2015
Business Acquisition [Line Items]
Shares issued in business acquisition (in shares)			15,000,000
Percent of cancelled Danaher equity awards replaced			50.00%
Post combination compensation expense, Danaher equity awards | Vesting after August 4, 2015
Business Acquisition [Line Items]
Post combination compensation expense			$ 1,700,000
Contingently returnable consideration, cash retention award | Vesting after August 4, 2015 | Prepaid expenses and other current assets
Business Acquisition [Line Items]
Receivable from Danaher			8,400,000
Cash retention award | Vesting after August 4, 2015 | Accrued compensation
Business Acquisition [Line Items]
Cash liability			$ 9,700,000
Common stock
Business Acquisition [Line Items]
Share price (in dollars per share)							$ 36.89
Communications Business
Business Acquisition [Line Items]
Total equity consideration	$ 5,700,000	$ 2,299,911,000		$ 2,300,000,000
Increase (decrease) in accounts receivable	110,000	140,586,000		110,000
Increase in inventory	78,000	80,719,000		78,000
Decrease in prepaid expenses and other assets	(35,000)	(6,715,000)		(35,000)
Increase in property, plant and equipment	1,254,000	36,825,000		1,254,000
Increase (decrease) in accounts payable	8,000	21,311,000		8,000
Increase (decrease) in accrued expenses	176,000	12,916,000		176,000
Increase (decrease) in deferred revenue	65,000	187,882,000		65,000
Goodwill	$ 5,141,000	$ 1,507,847,000		$ 5,141,000		1,500,000,000
Weighted average useful life of acquired intangible assets			14 years 8 months
Revenues			$ 173,800,000
Net loss			3,700,000
Communications Business | General and administrative
Business Acquisition [Line Items]
Acquisition related costs			$ 0		$ 3,400,000
Communications Business | Developed technology
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			11 years 8 months 12 days
Communications Business | Customer relationships
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			16 years 3 months 18 days
Communications Business | Backlog
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			2 years
Communications Business | Trademarks and trade names
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			8 years 6 months
Communications Business | Leasehold interest
Business Acquisition [Line Items]
Weighted average useful life of acquired intangible assets			5 years 7 months 6 days
Communications Business | Arbor Networks
Business Acquisition [Line Items]
Goodwill						534,800,000
Communications Business | Service assurance for service provider
Business Acquisition [Line Items]
Goodwill						794,400,000
Communications Business | Network visibility
Business Acquisition [Line Items]
Goodwill						57,000,000
Communications Business | Service assurance for enterprise
Business Acquisition [Line Items]
Goodwill						$ 125,100,000
Communications Business | Common stock | Newco
Business Acquisition [Line Items]
Shares issued in business acquisition (in shares)		62,500,000

ACQUISITIONS - Summary of Purch

ACQUISITIONS - Summary of Purchase Price Allocation (Details) - USD ($) $ in Thousands	Oct. 07, 2015	Jul. 14, 2015	Oct. 07, 2015	Jun. 30, 2016	Mar. 31, 2016
Estimated fair value of assets acquired and liabilities assumed:
Goodwill				$ 1,710,286	$ 1,709,369
Communications Business
Business Acquisition [Line Items]
Total equity consideration	$ (5,700)	$ (2,299,911)	$ (2,300,000)
Estimated Purchase Price	5,700	2,270,556
Estimated fair value of assets acquired and liabilities assumed:
Cash		27,701
Accounts receivable	110	140,586	110
Inventories	78	80,719	78
Prepaid expenses and other assets	35	6,715	35
Property, plant and equipment	1,254	36,825	1,254
Deferred income taxes		13,067
Intangible assets		1,080,700
Other assets	281	999	281
Accounts payable	(8)	(21,311)	(8)
Accrued compensation	(824)	(24,316)	(824)
Accrued other	(176)	(12,916)	(176)
Deferred revenue	(65)	(187,882)	(65)
Other long-term liabilities	(126)	(3,615)	(126)
Accrued retirement benefits		(29,917)
Deferred tax liabilities		(344,646)
Goodwill	$ 5,141	1,507,847	$ 5,141		$ 1,500,000
Communications Business | Replacement Awards
Business Acquisition [Line Items]
Total equity consideration		$ (29,355)

ACQUISITIONS - Summary of Pur50

ACQUISITIONS - Summary of Purchase Price Allocation (Footnote) (Details) - Common stock - $ / shares shares in Millions	Jul. 14, 2015	Jul. 13, 2015
Business Acquisition [Line Items]
Share price (in dollars per share)		$ 36.89
Newco | Communications Business
Business Acquisition [Line Items]
Shares issued in business acquisition (in shares)	62.5

ACQUISITIONS - Schedule of Fair

ACQUISITIONS - Schedule of Fair value of Acquired Identifiable Intangible Assets and Related Estimates of Useful Lives (Details) - Communications Business $ in Thousands	3 Months Ended
	Jun. 30, 2016USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 1,080,700
Developed technology
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 221,900
Developed technology | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	9 years
Developed technology | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	13 years
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 794,100
Customer relationships | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	13 years
Customer relationships | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	18 years
Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 18,200
Backlog | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	1 year
Backlog | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	3 years
Definite lived trademark and trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 43,900
Definite lived trademark and trade names | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	3 years
Definite lived trademark and trade names | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	9 years
Leasehold interest
Acquired Finite-Lived Intangible Assets [Line Items]
Fair value of finite-lived intangible assets	$ 2,600
Leasehold interest | Minimum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	4 years
Leasehold interest | Maximum
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life of identifiable finite-lived intangible assets	6 years

ACQUISITIONS - Schedule of Pro

ACQUISITIONS - Schedule of Pro Forma Results of Consolidated Statement of Operations (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2015USD ($)$ / sharesshares
Business Acquisition, Pro Forma Information [Abstract]
Pro forma revenue | $	$ 290,113
Pro forma net loss | $	$ (4,763)
Pro forma net loss per share:
Basic (in dollars per share) | $ / shares	$ (0.05)
Diluted (in dollars per share) | $ / shares	$ (0.05)
Pro forma shares outstanding
Basic (in shares) | shares	103,560
Diluted (in shares) | shares	103,560

GOODWILL AND INTANGIBLE ASSET53

GOODWILL AND INTANGIBLE ASSETS - Narrative (Details)	3 Months Ended
	Jun. 30, 2016USD ($)Segment	Jun. 30, 2015USD ($)	Mar. 31, 2016USD ($)
Acquired Finite-Lived Intangible Assets [Line Items]
Number of operating segments | Segment	5
Goodwill	$ 1,710,286,000		$ 1,709,369,000
Carrying value of intangible assets	1,023,968,000		1,054,040,000
Amortization expenses	$ 17,572,000	$ 809,000
Weighted average useful life of acquired intangible assets	14 years 7 months
Acquired software and core technology | Included as cost of product revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	$ 10,700,000	758,000
Other acquired intangible assets | Included as operating expense
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	$ 17,600,000	847,000
Developed and core technology
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	11 years 6 months
Customer and distributor relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	16 years 1 month
Trademarks and trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	8 years 6 months
Leasehold interest
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	5 years 7 months 6 days
Backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	2 years
Backlog | Product revenue
Acquired Finite-Lived Intangible Assets [Line Items]
Amortization expenses	$ 2,900,000	$ 0
Capitalized Software
Acquired Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of acquired intangible assets	4 years
Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 18,600,000		18,600,000
Legacy NetScout
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	197,800,000		198,100,000
Arbor Networks
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	534,900,000		534,800,000
Service assurance for service provider
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	795,500,000		794,400,000
Network visibility
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	57,000,000		57,000,000
Service assurance for enterprise
Acquired Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 125,100,000		$ 125,100,000

GOODWILL AND INTANGIBLE ASSET54

GOODWILL AND INTANGIBLE ASSETS - Schedule of Changes in Carrying Amount of Goodwill (Details) $ in Thousands	3 Months Ended
	Jun. 30, 2016USD ($)
Goodwill [Roll Forward]
Balance at March 31, 2016	$ 1,709,369
Foreign currency translation impact	917
Balance at June 30, 2016	$ 1,710,286

GOODWILL AND INTANGIBLE ASSET55

GOODWILL AND INTANGIBLE ASSETS - Schedule of Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,169,159	$ 1,168,106
Accumulated Amortization	(163,791)	(132,666)
Net	1,005,368	1,035,440
Developed technology
Finite-Lived Intangible Assets [Line Items]
Cost	253,036	253,249
Accumulated Amortization	(79,949)	(69,810)
Net	173,087	183,439
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	833,129	834,091
Accumulated Amortization	(58,248)	(42,526)
Net	774,881	791,565
Distributor relationships
Finite-Lived Intangible Assets [Line Items]
Cost	7,364	5,348
Accumulated Amortization	(1,927)	(1,633)
Net	5,437	3,715
Definite lived trademark and trade names
Finite-Lived Intangible Assets [Line Items]
Cost	43,922	43,964
Accumulated Amortization	(7,156)	(5,511)
Net	36,766	38,453
Core technology
Finite-Lived Intangible Assets [Line Items]
Cost	7,152	7,169
Accumulated Amortization	(4,866)	(4,659)
Net	2,286	2,510
Net beneficial leases
Finite-Lived Intangible Assets [Line Items]
Cost	336	336
Accumulated Amortization	(336)	(336)
Net	0	0
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Cost	285	288
Accumulated Amortization	(285)	(288)
Net	0	0
Leasehold interest
Finite-Lived Intangible Assets [Line Items]
Cost	2,600	2,600
Accumulated Amortization	(562)	(416)
Net	2,038	2,184
Backlog
Finite-Lived Intangible Assets [Line Items]
Cost	18,216	18,245
Accumulated Amortization	(9,610)	(6,750)
Net	8,606	11,495
Capitalized Software
Finite-Lived Intangible Assets [Line Items]
Cost	1,915	1,625
Accumulated Amortization	(62)	0
Net	1,853	1,625
Other
Finite-Lived Intangible Assets [Line Items]
Cost	1,204	1,191
Accumulated Amortization	(790)	(737)
Net	$ 414	$ 454

GOODWILL AND INTANGIBLE ASSET56

GOODWILL AND INTANGIBLE ASSETS - Schedule of Expected Future Amortization Expense (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Mar. 31, 2016
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2017 (remaining nine months)	$ 93,541
2,018	111,121
2,019	105,575
2,020	97,407
2,021	85,349
Thereafter	512,375
Net	$ 1,005,368	$ 1,035,440

DERIVATIVE INSTRUMENTS AND HE57

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Narrative (Details)	3 Months Ended
	Jun. 30, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Managing period of hedging forecasted cash flows for operating expenses denominated in foreign currencies	12 months
Contract maturity period	12 months

DERIVATIVE INSTRUMENTS AND HE58

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Summary of Notional Amounts and Fair Values of Derivative Instruments on Consolidated Balance Sheet (Details) - Forward contracts - Cash flow hedges - Designated as hedging instrument - USD ($) $ in Thousands		Jun. 30, 2016	Mar. 31, 2016
Derivatives, Fair Value [Line Items]
Notional Amounts	[1]	$ 10,736	$ 17,490
Prepaid Expenses and Other Current Assets
Derivatives, Fair Value [Line Items]
Prepaid Expenses and Other Current Assets		116	191
Accrued Other
Derivatives, Fair Value [Line Items]
Accrued Other		$ 93	$ 158
[1]	Notional amounts represent the gross contract/notional amount of the derivatives outstanding.

DERIVATIVE INSTRUMENTS AND HE59

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Summary of Effect of Foreign Exchange Forward Contracts on Other Comprehensive Income and Results of Operations (Details) - Forward contracts - Cash flow hedges - Designated as hedging instrument - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2016	Jun. 30, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	[1]	$ (50)	$ 10
Gain (Loss) Reclassified from Accumulated OCI into Income	[2]	22	1,323
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	[3]	(22)	20
Research and development
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income	[2]	(12)	47
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	[3]	13	34
Sales and marketing
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Reclassified from Accumulated OCI into Income	[2]	34	1,276
Gain (Loss) Recognized in Income (Amount Excluded from Effectiveness Testing)	[3]	$ (35)	$ (14)
[1]	The amount represents the change in fair value of derivative contracts due to changes in spot rates.
[2]	The amount represents reclassification from other comprehensive income to earnings that occurs when the hedged item affects earnings.
[3]	The amount represents the change in fair value of derivative contracts due to changes in the difference between the spot price and forward price that is excluded from the assessment of hedge effectiveness and therefore recognized in earnings. No gains or losses were reclassified as a result of discontinuance of cash flow hedges.

DERIVATIVE INSTRUMENTS AND HE60

DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES - Summary of Effect of Foreign Exchange Forward Contracts on Other Comprehensive Income and Results of Operations (Footnote) (Details) - USD ($)	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Reclassified gain (loss) as a result of discontinuance of cash flow hedges	$ 0	$ 0

LONG-TERM DEBT - Narrative (Det

LONG-TERM DEBT - Narrative (Details)	Jul. 14, 2015USD ($)shares	Jun. 30, 2016USD ($)
Maximum
Debt Instrument [Line Items]
Leverage ratio	2.50	2.50
Minimum
Debt Instrument [Line Items]
Leverage ratio	1	1
Common Stock Repurchase Plan
Debt Instrument [Line Items]
Stock authorized to repurchase under stock repurchase program (in shares) | shares	20,000,000
Senior secured revolving credit facility | Line of credit
Debt Instrument [Line Items]
Debt term	5 years
Credit facility	$ 800,000,000
Amount outstanding under credit facility		$ 300,000,000
Commitment fee percentage		0.25%
Debt default, acceleration clause, required consent percentage	50.00%
Unamortized debt issuance costs	$ 6,600,000	$ 5,400,000
Senior secured revolving credit facility | Line of credit | Prepaid expenses and other current assets
Debt Instrument [Line Items]
Unamortized debt issuance costs		1,300,000
Senior secured revolving credit facility | Line of credit | Other assets
Debt Instrument [Line Items]
Unamortized debt issuance costs		$ 4,100,000
Senior secured revolving credit facility | Line of credit | Maximum
Debt Instrument [Line Items]
Commitment fee percentage		0.35%
Senior secured revolving credit facility | Line of credit | Maximum | Foreign Subsidiaries
Debt Instrument [Line Items]
Voting stock pledge limit for any foreign subsidiary	65.00%
Senior secured revolving credit facility | Line of credit | Minimum
Debt Instrument [Line Items]
Commitment fee percentage		0.20%
Senior secured revolving credit facility | Line of credit | Federal funds effective rate
Debt Instrument [Line Items]
Interest rate in excess of effective rate	0.50%
Senior secured revolving credit facility | Line of credit | LIBOR
Debt Instrument [Line Items]
Interest rate in excess of effective rate	1.00%
Senior secured revolving credit facility | Line of credit | LIBOR | LIBOR loans
Debt Instrument [Line Items]
Interest rate in excess of effective rate	1.50%
Senior secured revolving credit facility | Line of credit | LIBOR | LIBOR loans | Maximum
Debt Instrument [Line Items]
Interest rate in excess of effective rate	2.00%
Senior secured revolving credit facility | Line of credit | LIBOR | LIBOR loans | Minimum
Debt Instrument [Line Items]
Interest rate in excess of effective rate	1.25%
Senior secured revolving credit facility | Line of credit | Base rate | Base rate loans
Debt Instrument [Line Items]
Interest rate in excess of effective rate	0.50%
Senior secured revolving credit facility | Line of credit | Base rate | Base rate loans | Maximum
Debt Instrument [Line Items]
Interest rate in excess of effective rate	1.00%
Senior secured revolving credit facility | Line of credit | Base rate | Base rate loans | Minimum
Debt Instrument [Line Items]
Interest rate in excess of effective rate	0.25%
Letter of credit sub-facility | Line of credit
Debt Instrument [Line Items]
Credit facility	$ 50,000,000

RESTRUCTURING CHARGES - Narrati

RESTRUCTURING CHARGES - Narrative (Details) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2016USD ($)Employee	Jun. 30, 2015USD ($)	Mar. 31, 2016USD ($)Employee
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,034	$ 0
Severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,034		$ 500
Restructuring and Related Cost, Number of Employees Terminated | Employee	19		1

RESTRUCTURING CHARGES - Schedul

RESTRUCTURING CHARGES - Schedule of Restructuring Liability (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges to operations	$ 2,034	$ 0
Severance
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2016	272
Restructuring charges to operations	2,034		$ 500
Cash payments	(487)
Other adjustments	(8)
Balance at June 30, 2016	1,811		272
Q3 FY2016 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges to operations	0
Q3 FY2016 Plan | Severance
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2016	272
Cash payments	(114)
Other adjustments	(2)
Balance at June 30, 2016	156		272
Q1 FY2017 Plan | Severance
Restructuring Cost and Reserve [Line Items]
Balance at March 31, 2016	0
Restructuring charges to operations	2,034
Cash payments	(373)
Other adjustments	(6)
Balance at June 30, 2016	$ 1,655		$ 0

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Narrative (Details) $ in Thousands	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Nov. 30, 2011USD ($)liability
Commitments and Contingencies Disclosure [Line Items]
Fair value of contingent liability	$ 4,674	$ 7,293
Simena
Commitments and Contingencies Disclosure [Line Items]
Number of contingent liabilities recorded | liability			1
Fair value of contingent liability			$ 8,000
Present value of future consideration
Commitments and Contingencies Disclosure [Line Items]
Fair value of contingent liability	$ 4,700

PENSION BENEFIT PLANS - Narrati

PENSION BENEFIT PLANS - Narrative (Details)	3 Months Ended
	Jun. 30, 2016USD ($)Employee	Jun. 30, 2015USD ($)
Defined Benefit Plan Disclosure [Line Items]
Expense for all defined benefit pension and defined contribution plans	$ 2,900,000	$ 1,100,000
Danaher | United States
Defined Benefit Plan Disclosure [Line Items]
Number of employees participating in noncontributory defined benefit pension plans | Employee	0
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Contributions to defined benefit pension plans	$ 0
Expected cash contribution requirements for defined benefit pension plans, less than	$ 1,000,000

PENSION BENEFIT PLANS - Schedul

PENSION BENEFIT PLANS - Schedule of Net Periodic Pension Costs of Noncontributory Defined Benefit Pension Plans (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 84	$ 0
Interest cost	164	0
Net periodic pension cost	$ 248	$ 0

TREASURY STOCK - Narrative (Det

TREASURY STOCK - Narrative (Details) - USD ($)	3 Months Ended		13 Months Ended	23 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Mar. 31, 2016	May 19, 2015	Apr. 22, 2014
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period, value	$ 50,068,000	$ 3,167,000
Share Repurchase Program, April 2014
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount up to						$ 100,000,000
Shares repurchased during the period (in shares)		67,752		824,452
Shares repurchased during the period, value		$ 2,800,000		$ 34,300,000
Stock remaining to be purchased (in shares)	0		0
Share Repurchase Program, May 2015
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period (in shares)	2,100,382		12,178,518
Shares repurchased during the period, value	$ 50,000,000		$ 350,000,000
Stock remaining to be purchased (in shares)	7,821,482		7,821,482
Stock authorized to repurchase under stock repurchase program (in shares)					20,000,000
Restricted stock units
Equity, Class of Treasury Stock [Line Items]
Shares repurchased during the period (in shares)	2,909
Shares repurchased during the period, value	$ 68,000

NET INCOME (LOSS) PER SHARE - S

NET INCOME (LOSS) PER SHARE - Schedule of Calculations of Basic and Diluted Net Income (Loss) Per Share and Potential Common Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Numerator:
Net income (loss)	$ (8,998)	$ 7,669
Denominator:
Denominator for basic net income per share - weighted average common shares outstanding (in shares)	93,344	40,776
Dilutive common equivalent shares:
Weighted average stock options (in shares)	0	0
Weighted average restricted stock units (in shares)	0	595
Denominator for diluted net income per share - weighted average shares outstanding (in shares)	93,344	41,371
Net income (loss) per share:
Basic net income (loss) per share (in USD per share)	$ (0.10)	$ 0.19
Diluted net income (loss) per share (in USD per share)	$ (0.10)	$ 0.19

NET INCOME (LOSS) PER SHARE -69

NET INCOME (LOSS) PER SHARE - Summary of Antidilutive Securities Excluded from Computation of Diluted EPS (Details) - shares shares in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Restricted stock units (in shares)	2,282	19

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details)	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Income Tax Disclosure [Abstract]
Effective tax rate	34.10%	37.40%

SEGMENT AND GEOGRAPHIC INFORM71

SEGMENT AND GEOGRAPHIC INFORMATION - Narrative (Details)	3 Months Ended
	Jun. 30, 2016Segment
Segment Reporting [Abstract]
Number of operating segments	5
Number of reportable segments	1

SEGMENT AND GEOGRAPHIC INFORM72

SEGMENT AND GEOGRAPHIC INFORMATION - Summary of Total Revenue by Geography (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Total revenue	$ 268,952	$ 100,743
Reportable Geographical Components | United States
Segment Reporting Information [Line Items]
Total revenue	172,772	78,273
Reportable Geographical Components | Europe
Segment Reporting Information [Line Items]
Total revenue	41,855	12,607
Reportable Geographical Components | Asia
Segment Reporting Information [Line Items]
Total revenue	26,843	3,532
Reportable Geographical Components | Rest of the world
Segment Reporting Information [Line Items]
Total revenue	$ 27,482	$ 6,331

RELATED PARTY TRANSACTIONS - Na

RELATED PARTY TRANSACTIONS - Narrative (Details) - Member of board of directors - USD ($)	3 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
EMC, Corp.
Related Party Transaction [Line Items]
Revenue from related parties	$ 57,000	$ 79,000
Mitre Corp.
Related Party Transaction [Line Items]
Revenue from related parties	11,000	$ 0
State Street
Related Party Transaction [Line Items]
Revenue from related parties	$ 60,000