Plantronics (POLY) 10-Q 30 Jan 18 2018 Q3 Quarterly report Financial data

DOCUMENT AND ENTITY INFORMATION

DOCUMENT AND ENTITY INFORMATION - shares	9 Months Ended
	Dec. 31, 2017	Jan. 26, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	PLANTRONICS INC /CA/
Entity Central Index Key	914,025
Current Fiscal Year End Date	--03-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		33,075,564

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Current assets:
Cash and cash equivalents	$ 280,293	$ 301,970
Short-term investments	218,773	178,179
Accounts receivable, net	143,919	141,177
Inventory, net	64,574	55,456
Other current assets	19,460	22,195
Total current assets	727,019	698,977
Long-term investments	118,870	127,176
Property, plant, and equipment, net	144,802	150,307
Goodwill and purchased intangibles, net	15,498	15,577
Deferred tax assets	14,783	23,242
Other assets	1,681	1,880
Total assets	1,022,653	1,017,159
Current liabilities:
Accounts payable	45,685	42,885
Accrued liabilities	61,906	74,285
Total current liabilities	107,591	117,170
Long term debt, net of issuance costs	492,146	491,059
Long-term income taxes payable	74,476	11,729
Other long-term liabilities	19,419	15,045
Total liabilities	693,632	635,003
Commitments and contingencies (Note 6)
Stockholders' equity:
Common stock	814	804
Additional paid-in capital	858,253	818,777
Accumulated other comprehensive income	1,905	4,694
Retained earnings	294,200	319,931
Total stockholders' equity before treasury stock	1,155,172	1,144,206
Less: Treasury stock, at cost	(826,151)	(762,050)
Total stockholders' equity	329,021	382,156
Total liabilities and stockholders' equity	$ 1,022,653	$ 1,017,159

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net revenues	$ 226,534	$ 232,933	$ 640,760	$ 672,222
Cost of revenues	112,409	122,753	315,720	338,523
Gross profit	114,125	110,180	325,040	333,699
Operating expenses:
Research, development, and engineering	21,257	21,393	62,402	66,116
Selling, general, and administrative	56,196	56,919	170,125	169,581
(Gain) loss, net from litigation settlements	(15)	(103)	(295)	4,287
Restructuring and other related charges (credits)	(84)	113	2,438	(1,350)
Total operating expenses	77,354	78,322	234,670	238,634
Operating income	36,771	31,858	90,370	95,065
Interest expense	(7,341)	(7,322)	(21,904)	(21,867)
Other non-operating income and (expense), net	2,490	427	5,230	4,119
Income before income taxes	31,920	24,963	73,696	77,317
Income tax expense	81,424	2,742	84,419	14,235
Net income (loss)	$ (49,504)	$ 22,221	$ (10,723)	$ 63,082
Earnings (Loss) per common share:
Earnings (Loss) per common share:	$ (1.54)	$ 0.69	$ (0.33)	$ 1.96
Diluted (in dollars per share)	$ (1.54)	$ 0.68	$ (0.33)	$ 1.92
Shares used in computing earnings (loss) per common share:
Basic (in shares)	32,075	32,242	32,384	32,260
Diluted (in shares)	32,075	32,826	32,384	32,895
Cash dividends declared per common share (in dollars per share)	$ 0.15	$ 0.15	$ 0.45	$ 0.45

CONDENSED CONSOLIDATED STATEME4

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (49,504)	$ 22,221	$ (10,723)	$ 63,082
Other comprehensive income (loss):
Foreign currency translation adjustments	0	82	257	(168)
Unrealized gains (losses) on cash flow hedges:
Unrealized cash flow hedge gains (losses) arising during the period	(446)	2,090	(5,093)	2,394
Net (gains) losses reclassified into income for revenue hedges	1,357	(2,178)	2,506	(3,163)
Net (gains) losses reclassified into income for cost of revenue hedges	(61)	756	(193)	2,072
Net unrealized gains (losses) on cash flow hedges	850	668	(2,780)	1,303
Unrealized holding gains (losses) during the period	(658)	(628)	(449)	(586)
Aggregate income tax benefit (expense) of the above items	181	156	182	130
Other comprehensive income (loss)	373	278	(2,790)	679
Comprehensive income (loss)	$ (49,131)	$ 22,499	$ (13,513)	$ 63,761

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (10,723)	$ 63,082
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	15,894	15,624
Amortization of debt issuance costs	1,087	1,087
Stock-based compensation	26,047	25,005
Deferred income taxes	10,490	(753)
Provision for excess and obsolete inventories	2,013	1,292
Restructuring and related charges (credits)	2,438	(1,350)
Cash payments for restructuring charges	(2,911)	(3,793)
Other operating activities	(645)	633
Changes in assets and liabilities:
Accounts receivable, net	(3,153)	(13,448)
Inventory, net	(9,577)	(5,990)
Current and other assets	(3,066)	(2,346)
Accounts payable	2,783	3,626
Accrued liabilities	(15,695)	6,191
Income taxes	66,387	(1,141)
Cash provided by operating activities	81,369	87,719
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sales of investments	54,411	143,631
Proceeds from maturities of investments	146,989	97,253
Purchase of investments	(232,840)	(247,491)
Capital expenditures	(9,403)	(19,603)
Cash used for investing activities	(40,843)	(26,210)
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of common stock	(52,915)	(34,236)
Employees' tax withheld and paid for restricted stock and restricted stock units	(11,186)	(9,444)
Proceeds from issuances under stock-based compensation plans	13,446	6,516
Proceeds from revolving line of credit	8,000	0
Repayments of revolving line of credit	(8,000)	0
Payment of cash dividends	(15,008)	(14,947)
Other financing activity	0	761
Cash used for financing activities	(65,663)	(51,350)
Effect of exchange rate changes on cash and cash equivalents	3,460	(2,964)
Net increase (decrease) in cash and cash equivalents	(21,677)	7,195
Cash and cash equivalents at beginning of period	301,970	235,266
Cash and cash equivalents at end of period	280,293	242,461
SUPPLEMENTAL NON-CASH DISCLOSURES
Accounts payable for purchases of property, plant, and equipment	$ 3,895	$ 1,052

BASIS OF PRESENTATION

BASIS OF PRESENTATION	9 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION In the opinion of management, the accompanying unaudited condensed consolidated financial statements ("financial statements") of Plantronics, Inc. ("Plantronics" or "the Company") have been prepared on a basis materially consistent with the Company's March 31, 2017 audited consolidated financial statements and include all adjustments, consisting of normal recurring adjustments, necessary to fairly state the information set forth herein. Certain information and footnote disclosures normally included in financial statements prepared pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") applicable to interim financial information and in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to such rules and regulations. The financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the fiscal year ended March 31, 2017 , which was filed with the SEC on May 10, 2017 . The results of operations for the interim period ended December 31, 2017 are not necessarily indicative of the results to be expected for the entire fiscal year or any future period. The financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated. The Company’s fiscal year ends on the Saturday closest to the last day of March. The Company’s current and prior fiscal years end on March 31, 2018 and April 1, 2017 , respectively, and both consist of 52 weeks. The Company’s results of operations for the three and nine months ended December 30, 2017 and December 31, 2016 both contain 13 weeks. For purposes of presentation, the Company has indicated its accounting year as ending on March 31 and its interim quarterly periods as ending on the applicable calendar month end. Certain immaterial reclassifications to our previously reported financial information have been made to conform to the current period presentation. In addition, refer to Note 2, Recent Accounting Pronouncements , for details regarding reclassifications made in our condensed consolidated statements of cash flows pursuant to the adoption of new share-based payment accounting guidance in the first quarter of Fiscal Year 2018. Earnings per common share: The Company has a share-based compensation plan under which employees, non-employee directors, and consultants may be granted share-based payment awards, including shares of restricted stock on which non-forfeitable dividends are paid on unvested shares. As such, shares of restricted stock are considered participating securities under the two-class method of calculating earnings per share. Historically, the two-class method of calculating earnings per share did not have a material impact on the Company's earnings per share calculation under the treasury stock method. Beginning in the second quarter of Fiscal Year 2018, the Company applied the two-class method of calculating earnings per share because the ratio of participating securities to the weighted average number of common shares outstanding has increased as compared to the historical average, and this dilution will continue if the Company continues to repurchase its common stock at current levels. During periods of net loss, no effect is given to participating securities since they do not share in the losses of the Company; therefore, the treasury stock method was used to calculate earnings per common share for the three and nine months ended December 31, 2017 . For further details refer to Note 14 , Computation of Earnings Per Common Share . Immaterial Out-of-Period Correction: During the first quarter of Fiscal Year 2018, the Company recognized an out-of-period correction to its Fiscal Year 2017 geographic mix of taxable income, which resulted in an overstatement of Fiscal Year 2017 income tax expense by $2.8 million . The Company's correction, recognized in the quarter ended June 30, 2017, resulted in a $2.8 million benefit to income tax expense. The Company assessed the materiality of this error and concluded it was not material to Fiscal Year 2017 and is not expected to be material to the full Fiscal Year 2018.

RECENT ACCOUNTING PRONOUNCEMENT

RECENT ACCOUNTING PRONOUNCEMENTS	9 Months Ended
	Dec. 31, 2017
Accounting Changes and Error Corrections [Abstract]
RECENT ACCOUNTING PRONOUNCEMENTS	RECENT ACCOUNTING PRONOUNCEMENTS Recently Issued Pronouncements In May 2014, the Financial Accounting Standards Board ("FASB") issued guidance regarding revenue from contracts with customers. While the standard supersedes existing revenue recognition guidance, it closely aligns with current U.S. GAAP. Under the new standard, revenue will be recognized at the time control of a good or service is transferred to a customer for the amount of consideration received or to be received for that specific good or service. Entities may use a full retrospective approach or report the cumulative effect as of the date of adoption. In March 2016, the FASB issued additional guidance concerning "Principal versus Agent" considerations (reporting revenue gross versus net); in April 2016, the FASB issued additional guidance on identifying performance obligations and licensing; and in May 2016, the FASB issued additional guidance on collectability, non-cash consideration, presentation of sales tax, and transition. These updates are intended to improve the operability and understandability of the implementation guidance and have the same effective date and transition requirements as the greater "contracts with customers" standard. The Company will adopt the standard, as amended, in the first quarter of its fiscal year ending March 31, 2019, utilizing the modified retrospective method of adoption. The Company has completed its initial review of the impact of this guidance, and does not anticipate a material impact on its revenue recognition policies. The Company will continue to assess all potential impacts of the standard, and currently believes the most significantly impacted areas are the following: • Software Revenue: The Company currently defers revenue for the value of software where vendor specific objective evidence ("VSOE") of fair value has not been established for undelivered items. Under Topic 606, revenue for such licenses will be recognized at the transfer of control, rather than ratably, as the VSOE requirement no longer applies and the value of the remaining services are not material in the context of the contract. At December 31, 2017, deferred revenue under Topic 605 for these licenses was $2.1 million . The Company expects the remaining balance of such deferred revenue will be eliminated as a cumulative effect adjustment of implementing Topic 606 in the first quarter of its fiscal year ending March 31, 2019. • Marketing Development Funds: The Company frequently provides marketing development funds to its channel partners. Under topic 605, our marketing development funds are recognized as a reduction of revenue at the later of when the related revenue is recognized or when the program is offered to the channel partner. Applying the criteria of Topic 606, these marketing development programs qualify as variable consideration, and are assigned as a reduction of the transaction price of the contract. This results in a timing difference such that all or some of the funds related to a program may be recognized in different periods than under Topic 605, depending on the circumstances. Based on analysis of prior periods, we anticipate that this timing difference impacts revenue by immaterial amounts in a given period. The full impact of the adjustment is still being analyzed by the Company. • Revenue Reserves: The Company establishes reserves for Discounts and Rebates and Sales Returns at the end of each fiscal period. These reserves are estimated based on current relevant and historical data, but there can be some variability associated with unforeseen changes in customer claim and return patterns. Under Topic 606, in cases where there is uncertainty around the variable consideration amount, a constraint, or an adjustment to ensure that a significant revenue reversal will not occur, on that consideration must be considered. Based on analysis of prior periods, we anticipate that impact of introducing this constraint will not materially impact revenue. The full impact of the adjustment is still being analyzed by the Company. In addition, the standard also requires new, expanded disclosures regarding revenue recognition. The Company will continue to monitor additional changes, modifications, clarifications or interpretations being undertaken by the FASB, which may impact its current conclusions. In January 2016, the FASB issued guidance regarding the recognition and measurement of financial assets and liabilities. Changes to the current U.S. GAAP model primarily affect the accounting for equity investments, financial liabilities under the fair value option, and the presentation and disclosure requirements for financial instruments. In addition, the FASB clarified guidance related to the valuation allowance assessment when recognizing deferred tax assets resulting from unrealized losses on available-for-sale debt securities. The Company is required to adopt the standard in the first quarter of its fiscal year ending March 31, 2019, but may elect to adopt earlier as permitted under the standard. The Company is currently evaluating what impact, if any, the adoption of this standard will have on its consolidated financial statements and related disclosures. In February 2016, the FASB issued guidance regarding both operating and financing leases, requiring lessees to recognize on their balance sheets "right-of-use assets" and corresponding lease liabilities, measured on a discounted basis over the lease term. Virtually all leases will be subject to this treatment except leases that meet the definition of a "short-term lease". For expense recognition, the dual model requiring leases to be classified as either operating or finance leases has been retained from the prior standard. Operating leases will result in straight-line expense while finance leases will result in a front-loaded expense pattern. Classification will use criteria very similar to those applied in current lease accounting, but without explicit bright lines. Extensive additional quantitative and qualitative disclosures, including significant judgments made by management, will be required to provide greater insight into the extent of expense recognized and expected to be recognized. The new lease guidance will essentially eliminate off-balance sheet financing. The guidance is effective for the Company's fiscal year ending March 31, 2020. The new standard must be adopted using a modified retrospective transition that provides for certain practical expedients and requires the new guidance to be applied at the beginning of the earliest comparative period presented. The Company expects adoption of this guidance will materially increase the assets and liabilities recorded on its condensed consolidated balance sheets, but is still evaluating the impact on its consolidated financial statements and related disclosures. In June 2016, the FASB issued guidance regarding the measurement of credit losses on financial instruments, which changes the impairment model for most financial assets. The new model uses a forward-looking expected loss method, which will generally result in earlier recognition of allowances for losses. The guidance is effective for the Company's fiscal year ending March 31, 2021 with early adoption permitted beginning in the first quarter of Fiscal Year 2020. The Company is currently evaluating the impact the adoption of this standard will have on its consolidated financial statements and related disclosures. In January 2017, the FASB issued guidance that revises the definition of a business, providing a more robust framework for determining when a set of assets and activities is deemed a business. The guidance is effective for the Company's fiscal year ending March 31, 2019, including interim periods within that year, and is not expected to have a material impact on the Company's consolidated financial statements or related disclosures. In January 2017, the FASB issued guidance that simplifies the process required to test goodwill for impairment. The guidance is effective for the Company's fiscal year ending March 31, 2021, and is not expected to have a material impact on the Company's consolidated financial statements or related disclosures. In March 2017, the FASB issued guidance related to the amortization of premiums on purchased callable debt securities. This guidance shortens the amortization period for certain callable debt securities purchased at a premium by requiring that the premium be amortized to the earliest call date instead of the maturity date. This guidance is effective for the Company's fiscal year ending March 31, 2020, including interim periods within that year. The Company expects the impact to be immaterial. In May 2017, the FASB issued guidance that clarifies the scope of modification accounting with respect to changes to the terms or conditions of a share-based payment award. This guidance is effective for the Company's fiscal year ending March 31, 2019, including interim periods within that year. The Company is currently evaluating the impact the adoption of this standard will have on its consolidated financial statements and related disclosures, but expects the impact to be immaterial. In August 2017, the FASB issued guidance that eliminates the requirement to separately measure and report hedge ineffectiveness and that generally requires, for qualifying hedges, the entire change in the fair value of a hedging instrument to be presented in the same income statement line as the hedged item. The guidance also modifies the accounting for components excluded from the assessment of hedge effectiveness, eases documentation and assessment requirements, and modifies certain disclosure requirements. The new standard must be adopted using a modified retrospective transition with a cumulative effect adjustment recorded to opening retained earnings as of the initial adoption date. This guidance is effective for the Company's fiscal year ending March 31, 2020, including interim periods within that year. The Company is currently evaluating the impact the adoption of this standard will have on its consolidated financial statements and related disclosures, but expects the impact to be immaterial. Recently Adopted Pronouncement Beginning Fiscal Year 2018, the Company adopted the FASB's new guidance, Improvements to Employee Share-Based Payment Accounting , which changes among other things, how the tax effects of share-based awards are recognized. This new guidance requires excess tax benefits and tax deficiencies to be recognized in the provision for income taxes as discrete items in the period when the awards vest or are settled, whereas previously such income tax effects were recorded as part of additional paid-in capital. The provision for income taxes for the three months ended December 31, 2017 included excess tax benefits that did not materially reduce the Company's effective tax rate. The provision for income taxes for the nine months ended December 31, 2017 included excess tax benefits of $1.9 million , which reduced the Company's effective tax rate by 2.6 percentage points. The recognized excess tax benefits resulted from share-based compensation awards that vested or settled in the first nine months of 2017. This guidance also eliminates the requirement to reclassify cash flows related to excess tax benefits from operating activities to financing activities on the consolidated statements of cash flows. The Company adopted this provision retrospectively by reclassifying $1.0 million of excess tax benefits from financing activities to operating activities in the condensed consolidated statement of cash flows for the nine months ended December 31, 2016. The Company also excluded the related tax benefits when applying the treasury stock method for computing diluted shares outstanding on a prospective basis as required by this guidance. In addition, the Company elected to continue its current practice of estimating expected forfeitures. The Company made no changes to its presentation of withholding taxes on the settlement of share-based payment awards, which were already presented as financing activities. The amount of excess tax benefits and deficiencies recognized in the provision for income taxes will fluctuate from period-to-period based on the price of the Company’s stock, the volume of share-based instruments settled or vested, and the value assigned to share-based instruments under U.S. GAAP. Refer to additional discussion in Note 13, Income Taxes .

CASH, CASH EQUIVALENTS, AND INV

CASH, CASH EQUIVALENTS, AND INVESTMENTS	9 Months Ended
	Dec. 31, 2017
CASH, CASH EQUIVALENTS AND INVESTMENTS [Abstract]
CASH, CASH EQUIVALENTS, AND INVESTMENTS	CASH, CASH EQUIVALENTS, AND INVESTMENTS The following tables summarize the Company’s cash and available-for-sale securities’ amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category recorded as cash and cash equivalents, short-term, or long-term investments as of December 31, 2017 and March 31, 2017 (in thousands): December 31, 2017 Amortized Gross Gross Fair Cash & Cash Equivalents Short-term investments (due in 1 year or less) Long-term investments (due in 1 to 3 years) Cash $ 272,063 $ — $ — $ 272,063 $ 272,063 $ — $ — Level 1: Mutual Funds 14,298 399 (70 ) 14,627 — 14,627 — US Treasury Notes 71,684 — (210 ) 71,474 4,998 42,348 24,128 Money Market Funds 239 — — 239 239 — — Subtotal 86,221 399 (280 ) 86,340 5,237 56,975 24,128 Level 2: Government Agency Securities 56,667 — (276 ) 56,391 — 31,300 25,091 Commercial Paper 32,944 — — 32,944 2,993 29,951 — Corporate Bonds 142,148 45 (375 ) 141,818 — 77,175 64,643 Certificates of Deposits ("CDs") 28,383 — (3 ) 28,380 — 23,372 5,008 Subtotal 260,142 45 (654 ) 259,533 2,993 161,798 94,742 Total cash, cash equivalents $ 618,426 $ 444 $ (934 ) $ 617,936 $ 280,293 $ 218,773 $ 118,870 March 31, 2017 Amortized Gross Gross Fair Cash & Cash Equivalents Short-term investments (due in 1 year or less) Long-term investments (due in 1 to 3 years) Cash $ 295,877 $ — $ — $ 295,877 $ 295,877 $ — $ — Level 1: Mutual Funds 12,079 352 (32 ) 12,399 — 12,399 — US Treasury Notes 35,960 — (68 ) 35,892 — 17,560 18,332 Money Market Funds — — — — — — — Subtotal 48,039 352 (100 ) 48,291 — 29,959 18,332 Level 2: Government Agency Securities 54,415 20 (164 ) 54,271 — 15,309 38,962 Commercial Paper 47,152 — — 47,152 6,093 41,059 — Corporate Bonds 141,508 64 (224 ) 141,348 — 73,676 67,672 Certificates of Deposits ("CDs") 20,383 3 — 20,386 — 18,176 2,210 Subtotal 263,458 87 (388 ) 263,157 6,093 148,220 108,844 Total cash, cash equivalents $ 607,374 $ 439 $ (488 ) $ 607,325 $ 301,970 $ 178,179 $ 127,176 As of December 31, 2017 and March 31, 2017 , with the exception of assets related to the Company's deferred compensation plan, all of the Company's investments are classified as available-for-sale securities. The carrying value of available-for-sale securities included in cash equivalents approximates fair value because of the short maturity of those instruments. For more information regarding the Company's deferred compensation plan, refer to Note 4 , Deferred Compensation . The Company did not incur any material realized or unrealized gains or losses in the three and nine months ended December 31, 2016 and 2017 . There were no transfers between fair value measurement levels during the three and nine months ended December 31, 2016 and 2017 . All financial assets and liabilities are recognized or disclosed at fair value in the financial statements or the accompanying notes thereto. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level 1 The Company's Level 1 financial assets consist of Mutual Funds and US Treasury Notes. The fair value of Level 1 financial instruments is measured based on the quoted market price of identical securities. Level 2 The Company's Level 2 financial assets and liabilities consist of Government Agency Securities, Commercial Paper, Corporate Bonds, and Certificates of Deposits ("CDs") , derivative foreign currency contracts, and long-term debt. The fair value of Level 2 investment securities is determined based on other observable inputs, including multiple non-binding quotes from independent pricing services. Non-binding quotes are based on proprietary valuation models that are prepared by the independent pricing services and use algorithms based on inputs such as observable market data, quoted market prices for similar securities, issuer spreads, and internal assumptions of the broker. The Company corroborates the reasonableness of non-binding quotes received from the independent pricing services using a variety of techniques depending on the underlying instrument, including: (i) comparing them to actual experience gained from the purchases and maturities of investment securities, (ii) comparing them to internally developed cash flow models based on observable inputs, and (iii) monitoring changes in ratings of similar securities and the related impact on fair value. The fair value of Level 2 derivative foreign currency contracts is determined using pricing models that use observable market inputs. For more information regarding the Company's derivative assets and liabilities, refer to Note 12 , Foreign Currency Derivatives . The fair value of Level 2 long-term debt is determined based on inputs that were observable in the market, including the trading price of the notes when available. For more information regarding the Company's 5.50% Senior Notes, refer to Note 7 , Debt. Level 3 The Company's unsecured revolving credit facility falls under the Level 3 hierarchy. The fair value of the Company’s line of credit approximates its carrying value because the interest rate is variable and approximates rates currently available to the Company.

DEFERRED COMPENSATION

DEFERRED COMPENSATION	9 Months Ended
	Dec. 31, 2017
Compensation Related Costs [Abstract]
DEFERRED COMPENSATION	DEFERRED COMPENSATION As of December 31, 2017 , the Company held bank deposits of $0.8 million and investments in mutual funds totaling $14.6 million , all of which related to debt and equity securities that are held in rabbi trusts under non-qualified deferred compensation plans. The total related deferred compensation liability was $15.9 million at December 31, 2017 . As of March 31, 2017 , the Company held bank deposits of $0.8 million and investments in mutual funds totaling $12.4 million . The total related deferred compensation liability at March 31, 2017 was $13.7 million . The bank deposits are recorded on the condensed consolidated balance sheets under "cash and cash equivalents". The securities are classified as trading securities and are recorded on the condensed consolidated balance sheets under "short-term investments". The liability is recorded on the condensed consolidated balance sheets under "other long-term liabilities" and "accrued liabilities".

DETAILS OF CERTAIN BALANCE SHEE

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS	9 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS	DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS Accounts receivable, net: March 31, December 31, (in thousands) 2017 2017 Accounts receivable $ 184,759 $ 196,175 Provisions for returns (10,541 ) (11,438 ) Provisions for promotions, rebates, and other (32,438 ) (39,886 ) Provisions for doubtful accounts and sales allowances (603 ) (932 ) Accounts receivable, net $ 141,177 $ 143,919 Inventory, net: March 31, December 31, (in thousands) 2017 2017 Raw materials $ 20,260 $ 23,485 Work in process 215 243 Finished goods 34,981 40,846 Inventory, net $ 55,456 $ 64,574 Accrued Liabilities: March 31, December 31, (in thousands) 2017 2017 Employee compensation and benefits $ 36,415 $ 23,719 Accrued interest on 5.50% Senior Notes 10,407 3,419 Warranty obligation 6,863 7,418 VAT/Sales tax payable 5,433 6,182 Derivative liabilities 1,323 4,425 Accrued other 13,844 16,743 Accrued liabilities $ 74,285 $ 61,906 The Company's warranty obligation is included as a component of accrued liabilities on the condensed consolidated balance sheets. Changes in the warranty obligation during the nine months ended December 31, 2016 and 2017 were as follows: Nine Months Ended (in thousands) 2016 2017 Warranty obligation at beginning of period $ 8,537 $ 8,697 Warranty provision related to products shipped 7,248 7,367 Deductions for warranty claims processed (7,246 ) (7,711 ) Adjustments related to preexisting warranties 408 1,086 Warranty obligation at end of period (1) $ 8,947 $ 9,439 (1) Includes both short-term and long-term portion of warranty obligation; the prior table shows only the short-term portion included in accrued liabilities on our condensed consolidated balance sheet. The long-term portion is included in other long-term liabilities.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	9 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Unconditional Purchase Obligations The Company purchases materials and services from a variety of suppliers and manufacturers. During the normal course of business and to manage manufacturing operations and general and administrative activities, the Company may enter into firm, non-cancelable, and unconditional purchase obligations for which amounts are not recorded on the consolidated balance sheets. As of December 31, 2017 , the Company had outstanding off-balance sheet third-party manufacturing, component purchase, and other general and administrative commitments of $192.3 million . Other Guarantees and Obligations In the ordinary course of business, the Company may provide indemnifications of varying scope and terms to customers, vendors, lessors, business partners, purchasers of assets or subsidiaries and other parties with respect to certain matters, including, but not limited to, losses arising out of the Company's breach of agreements or representations and warranties made by the Company, services to be provided by the Company, intellectual property infringement claims made by third parties or, with respect to the sale of assets of a subsidiary, matters related to the Company's conduct of business and tax matters prior to the sale. From time to time, the Company indemnifies customers against combinations of loss, expense, or liability arising from various triggering events relating to the sale and use of its products and services. In addition, the Company also provides indemnification to customers against claims related to undiscovered liabilities, additional product liability, or environmental obligations. The Company has also entered into indemnification agreements with its directors, officers and certain other personnel that will require the Company, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers of the Company or certain of its affiliated entities. The Company maintains director and officer liability insurance, which may cover certain liabilities arising from its obligation to indemnify its directors, officers and certain other personnel in certain circumstances. It is not possible to determine the aggregate maximum potential loss under these agreements due to the limited history of prior claims and the unique facts and circumstances involved in each particular claim. Such indemnification obligations might not be subject to maximum loss clauses. Historically, the Company has not incurred material costs as a result of obligations under these agreements and it has not accrued any liabilities related to such indemnification obligations in the condensed consolidated financial statements. Claims and Litigation On October 12, 2012, GN Netcom, Inc. ("GN") sued the Company in the United States ("U.S.") District Court for the District of Delaware (“Court”), alleging violations of the Sherman Act, the Clayton Act, and Delaware common law. In its complaint, GN specifically alleged four causes of action: monopolization, attempted monopolization, concerted action in restraint of trade, and tortious interference with business relations. GN claimed that the Company dominates the market for headsets sold into contact centers in the U.S. and that a critical channel for sales of headsets to contact centers is through a limited network of specialized independent distributors (“SIDs”). GN asserted that the Company attracts SIDs through exclusive distributor agreements and alleged that the use of these agreements is illegal. GN sought injunctive relief, total damages in an unspecified amount, plus attorneys’ fees and costs, as well as unspecified legal and equitable relief. The case was tried to a jury in October, 2017, resulting in a verdict in favor of the Company. GN filed a motion for new trial in November, 2017, and that motion was denied by the Court in January, 2018. The Company filed a motion for attorneys’ fees in November, 2017 and that motion was denied by the Court in January, 2018. The Company filed a motion for certain recoverable costs, and the parties stipulated to an immaterial amount, which GN will pay the Company. If the jury verdict were to be overturned on appeal, the Company would have to repay that amount to GN. GN has not indicated whether it plans to file an appeal of the jury’s verdict. In a letter dated May 1, 2017, the Company received a Notice of Proposed Debarment from the General Services Administration ("GSA") informing the Company that the GSA has proposed that the Company be debarred from participation in Federal procurement and non-procurement programs based on the above spoliation order issued in the GN litigation matter. The Company submitted a response to the GSA demonstrating that it is a responsible contractor and that a suspension or debarment is neither necessary to protect the government nor warranted. The GSA found “no cause” for debarment of Plantronics and terminated the proceeding against the Company in August 2017. In addition to the specific matter discussed above, the Company is involved in various legal proceedings arising in the normal course of conducting business. For such legal proceedings, where applicable, the Company has accrued an amount that reflects the aggregate liability deemed probable and estimable, but this amount is not material to the Company's financial condition, results of operations, or cash flows. With respect to proceedings for which no accrual has been made, the Company is not able to estimate an amount or range of any reasonably possible additional losses because of the preliminary nature of many of these proceedings, the difficulty in ascertaining the applicable facts relating to many of these proceedings, the variable treatment of claims made in many of these proceedings, and the difficulty of predicting the settlement value of many of these proceedings. However, based upon the Company's historical experience, the resolution of these proceedings is not expected to have a material effect on the Company's financial condition, results of operations or cash flows. The Company may incur substantial legal fees, which are expensed as incurred, in defending against these legal proceedings.

DEBT

DEBT	9 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
DEBT	DEBT 5.50% Senior Notes In May 2015, the Company issued $500.0 million aggregate principal amount of 5.50% senior notes (the “5.50% Senior Notes”). The 5.50% Senior Notes mature on May 31, 2023, and bear interest at a rate of 5.50% per annum, payable semi-annually on May 15 and November 15, commencing on November 15, 2015. The Company received net proceeds of $488.4 million from the issuance of the 5.50% Senior Notes, net of issuance costs of $11.6 million which are being amortized to interest expense over the term of the 5.50% Senior Notes using the effective interest method. A portion of the proceeds was used to repay all then-outstanding amounts under our revolving line of credit agreement with Wells Fargo Bank and the remaining proceeds were used primarily for share repurchases. The fair value of the 5.50% Senior Notes was determined based on inputs that were observable in the market, including the trading price of the 5.50% Senior Notes when available (Level 2). The estimated fair value and carrying value of the 5.50% Senior Notes were as follows: March 31, 2017 December 31, 2017 (in thousands) Fair Value Carrying Value Fair Value Carrying Value 5.50% Senior Notes $ 505,150 $ 491,059 $ 520,425 $ 492,146 The Company may redeem all or a part of the 5.50% Senior Notes, upon not less than 30 or more than a 60 day notice; however, the applicable redemption price will be determined as follows: Redemption Period Requiring Payment of: Redemption Up To 35% Using Cash Proceeds From An Equity Offering (3) : Make-Whole (1) Premium (2) Date Specified Price 5.50% Senior Notes Prior to May 15, 2018 On or after May 15, 2018 Prior to May 15, 2018 105.500% (1) If the Company redeems the notes prior to the applicable date, the redemption price is principal plus a make-whole premium equal to the present value of the remaining scheduled interest payments as described in the applicable indenture, together with accrued and unpaid interest. (2) If the Company redeems the notes on or after the applicable date, the price is principal plus a premium which declines over time as specified in the applicable indenture, together with accrued and unpaid interest. (3) If the Company redeems the notes prior to the applicable date with net cash proceeds of one or more equity offerings, the price is equal to the amount specified above, together with accrued and unpaid interest, subject to a maximum redemption of 35% of the aggregate principal amount of the respective note being redeemed. In addition, upon the occurrence of certain change of control triggering events, the Company may be required to repurchase the 5.50% Senior Notes, at a price equal to 101% of their principal amount, plus accrued and unpaid interest to the date of repurchase. The 5.50% Senior Notes contain restrictive covenants that, among other things, limit the Company's ability to create certain liens and enter into sale and leaseback transactions; create, assume, incur, or guarantee additional indebtedness of its subsidiaries without such subsidiary guaranteeing the 5.50% Senior Notes on an unsecured unsubordinated basis; and consolidate or merge with, or convey, transfer or lease all or substantially all of the assets of the Company and its subsidiaries to another person. As of December 31, 2017 , the Company was in compliance with all covenants. Revolving Credit Agreement On May 9, 2011 , the Company entered into a credit agreement with Wells Fargo Bank, National Association ("the Bank"), which was most recently amended on April 28, 2017 (as amended, the "Amended Credit Agreement") to extend the term of the Credit Agreement by one year to May 9, 2020 , and to amend certain of the covenants, which are defined below. The Amended Credit Agreement provides for a $100.0 million unsecured revolving credit facility. Revolving loans under the Credit Agreement will bear interest, at the Company’s election, at (i) the Bank’s announced prime rate less 1.20% per annum or (ii) a daily one-month LIBOR rate plus 1.40% per annum. Interest is payable quarterly in arrears on the first day of each of April, July, October and January. Principal, together with all accrued and unpaid interest, on the revolving loans is due and payable on May 9, 2020 . The Company is also obligated to pay a commitment fee of 0.37% per annum on the average daily unused amount of the revolving line of credit, which fee shall be payable quarterly in arrears on the first day of each of April, July, October and January. The Company may prepay the loans and terminate the commitments under the Credit Agreement at any time, without premium or penalty, subject to the reimbursement of certain costs. During the three months ended December 31, 2017 the Company borrowed and repaid $8 million from our line of credit, and as of March 31, 2017 and December 31, 2017 , the Company had no outstanding borrowings on the line of credit. The Amended Credit Agreement contains customary affirmative and negative covenants, including, among other things, covenants limiting the ability of the Company to incur debt, make capital expenditures, grant liens, merge or consolidate, and make investments. The Amended Credit Agreement also requires the Company to comply with certain financial covenants, including (i) a maximum ratio of funded debt to EBITDA of 3.25 :1 (previously 3 :1) and (ii) a minimum EBITDA coverage ratio, in each case, tested as of each fiscal quarter and determined on a rolling four-quarter basis. In addition, the Company and its subsidiaries are required to maintain unrestricted cash, cash equivalents and marketable securities plus availability under the Amended Credit Agreement at the end of each fiscal quarter of at least $300.0 million . The Amended Credit Agreement contains customary events of default that include, among other things, payment defaults, covenant defaults, cross-defaults with certain other indebtedness, bankruptcy and insolvency defaults, and judgment defaults. The occurrence of an event of default could result in the acceleration of the obligations under the Amended Credit Agreement. As of March 31, 2017 and December 31, 2017 , the Company was in compliance with all covenants.

RESTRUCTURING AND OTHER RELATED

RESTRUCTURING AND OTHER RELATED CHARGES (CREDITS)	9 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
RESTRUCTURING AND OTHER RELATED CHARGES (CREDITS)	RESTRUCTURING AND OTHER RELATED CHARGES (CREDITS) During the first nine months of Fiscal Year 2018 and as part of its ongoing effort to reduce costs, improve profitability, and focus on its key strategic initiatives, the Company executed an asset sale agreement to dispose of substantially all assets of its Clarity division, primarily inventories and tooling fixed assets, for an immaterial sales price. The buyer in this arrangement was a former employee of the Company, who acted as Clarity's President but who was not an executive officer or director of the Company. As part of the buyer's separation from Plantronics, the Company accelerated vesting on his outstanding restricted stock, resulting in an immaterial stock-compensation modification charge. In connection with the sale, the Company is leasing the facility it owns in Chattanooga, Tennessee, to the buyer for a period of twelve months. The Company also entered into a transition services agreement with the buyer to provide customer support services on a cost-recovery basis, which are not expected to be material, for a period of one year. The Company also recorded immaterial impairment charges on assets previously used in Clarity operations that have no further value to the Company. In addition to the sale of the Clarity division and the related restructuring actions, the Company reduced headcount in certain divisions and terminated a lease in the Netherlands before the end of its contractual term, resulting in a charge equal to the present value of the remaining future minimum lease payments. In connection with this exit, the Company wrote off certain fixed assets that will no longer be used. Finally, the Company reorganized its Brazilian operations and as a result, wrote off an unrecoverable indirect tax asset. As of December 31, 2017 , the remaining obligation related to severance amounts due is immaterial and will be settled within 12 months. During the quarter ended December 31, 2017 , we recorded an immaterial adjustment to restructuring and other related charges (credits) resulting from a change in estimate from amounts previously recorded. The associated charges for the nine months ended December 31, 2017 are recorded in restructuring and other related charges (credits), cost of revenues, and selling, general, and administrative expense in the condensed consolidated statements of operations, as follows: Nine months ended December 31, 2017 (in millions) Total Charges Restructuring and Other Related Charges (Credits) Cost of Revenues Selling, General, and Administrative Severance benefits from reduction-in-force $ 1.3 $ 1.3 $ — $ — Lease exit charge and asset impairments in Netherlands 0.7 0.7 — — Write-off of unrecoverable indirect tax asset in Brazil 0.7 — 0.7 — Asset impairments related to previous Clarity operations 0.4 0.4 — — Loss on Clarity asset sale 0.9 — 0.9 — Accelerated vesting of restricted stock 0.2 — — 0.2 Totals $ 4.2 $ 2.4 $ 1.6 $ 0.2

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	9 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION The Company recognizes the grant-date fair value of stock-based compensation as compensation expense using the straight-line attribution approach over the service period for which the stock-based compensation is expected to vest. The following table summarizes the amount of stock-based compensation included in the condensed consolidated statements of operations: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Cost of revenues $ 794 $ 917 $ 2,414 $ 2,709 Research, development, and engineering 1,771 2,049 6,663 6,158 Selling, general, and administrative 6,124 5,063 15,928 17,180 Stock-based compensation included in operating expenses 7,895 7,112 22,591 23,338 Total stock-based compensation 8,689 8,029 25,005 26,047 Income tax expense (benefit) (2,986 ) 2,039 (8,635 ) (5,650 ) Total stock-based compensation, net of tax $ 5,703 $ 10,068 $ 16,370 $ 20,397

COMMON STOCK REPURCHASES

COMMON STOCK REPURCHASES	9 Months Ended
	Dec. 31, 2017
Equity [Abstract]
COMMON STOCK REPURCHASES	COMMON STOCK REPURCHASES From time to time, the Company's Board of Directors (the "Board") has authorized programs under which the Company may repurchase shares of its common stock, depending on market conditions, in the open market or through privately negotiated transactions. Repurchased shares are held as treasury stock until they are retired or re-issued. Repurchases by the Company pursuant to Board-authorized programs during the nine months ended December 31, 2016 and 2017 are discussed below. As of December 31, 2017 , there remained 730,932 shares authorized for repurchase under the repurchase program approved by the Board on July 27, 2017 . There were no remaining shares authorized under previously approved programs. In the nine months ended December 31, 2016 and 2017 , the Company repurchased 764,176 shares and 1,138,903 shares, respectively, of its common stock in the open market for a total cost of $34.2 million and $52.9 million , respectively, and at an average price per share of $44.80 and $46.46 , respectively. In addition, the Company withheld shares valued at $9.4 million and $11.2 million in the nine months ended December 31, 2016 and 2017 , respectively, in satisfaction of employee tax withholding obligations upon the vesting of restricted stock granted under the Company's stock plans. The amounts withheld were equivalent to the employees' minimum statutory tax withholding requirements and are reflected as a financing activity within the Company's condensed consolidated statements of cash flows. These share withholdings have the same effect as share repurchases by the Company as they reduce the number of shares that would have otherwise been issued in connection with the vesting of shares subject to the restricted stock grants.

ACCUMULATED OTHER COMPREHENSIVE

ACCUMULATED OTHER COMPREHENSIVE INCOME	9 Months Ended
	Dec. 31, 2017
Equity [Abstract]
ACCUMULATED OTHER COMPREHENSIVE INCOME	ACCUMULATED OTHER COMPREHENSIVE INCOME The components of accumulated other comprehensive income ("AOCI"), net of immaterial tax effects, are as follows: (in thousands) March 31, 2017 December 31, 2017 Accumulated unrealized gain (loss) on cash flow hedges (1) $ 529 $ (2,200 ) Accumulated foreign currency translation adjustments 4,428 4,685 Accumulated unrealized gain (loss) on investments (263 ) (580 ) Accumulated other comprehensive income $ 4,694 $ 1,905 (1) Refer to Note 12 , Foreign Currency Derivatives, which discloses the nature of the Company's derivative assets and liabilities as of March 31, 2017 and December 31, 2017 .

FOREIGN CURRENCY DERIVATIVES

FOREIGN CURRENCY DERIVATIVES	9 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
FOREIGN CURRENCY DERIVATIVES	FOREIGN CURRENCY DERIVATIVES The Company's foreign currency derivatives consist primarily of foreign currency forward exchange contracts, option contracts, and cross-currency swaps. The Company does not purchase derivative financial instruments for speculative trading purposes. The derivatives expose the Company to credit risk to the extent the counterparties may be unable to meet the terms of the derivative instrument. The Company's maximum exposure to loss that it would incur due to credit risk if parties to derivative contracts failed completely to perform according to the terms of the contracts was equal to the carrying value of the Company's derivative assets as of December 31, 2017 . The Company seeks to mitigate such risk by limiting its counterparties to large financial institutions. In addition, the Company monitors the potential risk of loss with any one counterparty resulting from this type of credit risk on an ongoing basis. The Company enters into master netting arrangements with counterparties when possible to mitigate credit risk in derivative transactions. A master netting arrangement may allow each counterparty to net settle amounts owed between the Company and the counterparty as a result of multiple, separate derivative transactions. As of December 31, 2017 , the Company had International Swaps and Derivatives Association (ISDA) agreements with four applicable banks and financial institutions which contained netting provisions. Plantronics has elected to present the fair value of derivative assets and liabilities on the Company's condensed consolidated balance sheet on a gross basis even when derivative transactions are subject to master netting arrangements and may otherwise qualify for net presentation. For each counterparty, if netted, the Company would offset the asset and liability balances of all derivatives at the end of the reporting period. Derivatives not subject to master netting agreements are not eligible for net presentation. As of March 31, 2017 and December 31, 2017 , no cash collateral had been received or pledged related to these derivative instruments. The gross fair value of the Company's outstanding derivative contracts at the end of each period was as follows: (in thousands) March 31, 2017 December 31, 2017 Derivative Assets (1) Non-designated hedges $ 86 $ 19 Cash flow hedges 2,034 332 Total Derivative Assets $ 2,120 $ 351 Derivative Liabilities (2) Non-designated hedges $ 286 $ 1,155 Cash flow hedges 1,109 3,345 Total Derivative Liabilities $ 1,395 $ 4,500 (1) Short-term derivative assets are recorded in "other current assets" and long-term derivative assets are recorded in "deferred tax and other assets". As of December 31, 2017 the portion of derivative assets classified as long-term was immaterial. (2) Short-term derivative liabilities are recorded in "accrued liabilities" and long-term derivative liabilities are recorded in "other long-term liabilities". As of December 31, 2017 the portion of derivative liabilities classified as long-term was immaterial. Non-Designated Hedges As of December 31, 2017 , the Company had foreign currency forward contracts denominated in Euros ("EUR"), British Pound Sterling ("GBP"), Australian Dollars ("AUD"), and Canadian Dollars ("CAD"). The Company does not elect to obtain hedge accounting for these forward contracts. These forward contracts hedge against a portion of the Company’s foreign currency-denominated cash balances, receivables, and payables. The following table summarizes the notional value of the Company’s outstanding foreign exchange currency contracts and approximate U.S. Dollar ("USD") equivalent at December 31, 2017 : (in thousands) Local Currency USD Equivalent Position Maturity EUR € 38,700 $ 46,560 Sell EUR 1 month GBP £ 5,100 $ 6,899 Sell GBP 1 month AUD A$ 14,200 $ 11,092 Sell AUD 1 month CAD C$ 2,900 $ 2,315 Sell CAD 1 month Effect of Non-Designated Derivative Contracts on the Condensed Consolidated Statements of Operations The effect of non-designated derivative contracts recognized in other non-operating income and (expense), net in the condensed consolidated statements of operations was as follows: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Gain (loss) on foreign exchange contracts $ 3,801 $ 848 $ 5,551 $ 6,083 Cash Flow Hedges Costless Collars The Company hedges a portion of the forecasted EUR and GBP denominated revenues with costless collars. On a monthly basis, the Company enters into option contracts with a six to eleven month term. Collar contracts are scheduled to mature at the beginning of each fiscal quarter, at which time the instruments convert to forward contracts. The Company also enters into cash flow forwards with a three month term. Once the hedged revenues are recognized, the forward contracts become non-designated hedges to protect the resulting foreign monetary asset position for the Company. The notional value of the Company's outstanding EUR and GBP option and forward contracts at the end of each period was as follows: March 31, 2017 December 31, 2017 (in millions) EUR GBP EUR GBP Option contracts €73.5 £23.9 €75.8 £22.9 Forward contracts €11.2 £3.3 €13.0 £4.1 The Company will reclassify all amounts accumulated in other comprehensive income into earnings within the next twelve months. Cross-currency Swaps The Company hedges a portion of the forecasted Mexican Peso (“MXN”) denominated expenditures with a cross-currency swap. As of March 31, 2017 and December 31, 2017 , the Company had foreign currency swap contracts of approximately MXN 287.2 million and MXN 76.3 million , respectively. The following table summarizes the notional value of the Company’s outstanding MXN cross-currency swaps and approximate USD Equivalent at December 31, 2017 : (in thousands) Local Currency USD Equivalent Position Maturity MXN $ 76,340 $ 3,935 Buy MXN Monthly over 6 months Effect of Designated Derivative Contracts on AOCI and Condensed Consolidated Statements of Operations The following table presents the pre-tax effects of derivative instruments designated as cash flow hedges on accumulated other comprehensive income and the condensed consolidated statements of operations for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Gain (loss) included in AOCI as of beginning of period $ (471 ) $ (3,089 ) $ (1,106 ) $ 541 Amount of gain (loss) recognized in other comprehensive income (“OCI”) (effective portion) 2,090 (446 ) 2,394 (5,093 ) Amount of gain (loss) reclassified from OCI into net revenues (effective portion) 2,178 1,357 3,163 2,506 Amount of gain (loss) reclassified from OCI into cost of revenues (effective portion) (756 ) (61 ) (2,072 ) (193 ) Total amount of gain (loss) reclassified from AOCI to income (loss) (effective portion) 1,422 1,296 1,091 2,313 Gain (loss) included in AOCI as of end of period $ 197 $ (2,239 ) $ 197 $ (2,239 ) During the three and nine months ended December 31, 2016 and 2017 the Company recognized an immaterial gain and immaterial loss on the ineffective portion of its cash flow hedges, respectively, which is reported in other non-operating income and (expense), net in the condensed consolidated statements of operations.

INCOME TAXES

INCOME TAXES	9 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The Company and its subsidiaries are subject to taxation in the U.S. and in various foreign and state jurisdictions. The effective tax rates for the three months ended December 31, 2016 and 2017 were 11.0% and 255.1% , respectively. The effective tax rates for the nine months ended December 31, 2016 and 2017 were 18.4% and 114.6% , respectively. On December 22, 2017, the Tax Cuts and Jobs Act (H.R. 1) (the “Act”) was signed into law in the United States. The Act includes several changes to existing tax law, including, among other things, a permanent reduction in the corporate income tax rate from 35% to 21% and the move from a worldwide to a territorial tax system. The move to a territorial tax system was accompanied by federal taxation of a one-time deemed repatriation of accumulated unremitted earnings (hereafter, the "toll charge"), which the Company will elect to pay over an eight-year period as permitted under the Act. The Company recorded a $69.3 million toll charge as part of income tax expense in the quarter ended December 31, 2017, representing a provisional estimate based on a 15.5% tax applied to foreign unremitted cash and cash equivalents and an 8% tax applied to permanently reinvested foreign assets. The provisional toll charge increased our effective tax rate by 217.2% and 94.1% for the three and nine months ended December 30, 2017, respectively. As part of the Act, the Company also completed its remeasurement of deferred tax assets as of December 31, 2017 to the new future federal tax rate of 21% , thereby reducing the Company’s deferred tax assets by $2.1 million . The rate change resulted in an overall increase to the Company’s effective tax rate by 6.6% and 2.9% for the three and nine months ended December 31, 2017, respectively. In addition, prior to its third quarter of Fiscal Year 2018, the Company did not recognize a deferred tax liability related to unremitted foreign earnings because its plans did not require the Company to repatriate earnings from foreign operations to fund U.S. operations. The Company expects to fund payment of the toll charge by repatriating a portion of its foreign earnings and as such, has recorded a deferred tax liability of $5.0 million related to state income taxes and foreign withholding taxes that will become due as the Company repatriates foreign earnings. This increased the Company’s effective tax rate by 15.6% and 6.8% for the three and nine months ended December 31, 2017, respectively. Finally, the Company files its federal tax return on a fiscal year-end and is therefore required to pro-rate the new and old tax rates during Fiscal Year 2018. The blended, annualized tax rate applied to Fiscal Year 2018 income is 31.56% . This reduction in the federal tax rate reduced the Company’s global tax rate by 2.3% and 1.0% for the three and nine months ended December 31, 2017, respectively. The provisional estimate for the toll charge will be finalized when the Company completes its substantive review of unremitted foreign earnings through examination of statutory filings and tax returns of the Company's foreign subsidiaries and fiscal branches that span a 30 -year period. The Company must also analyze the impact of foreign exchange rates and inflation on the historical information to support foreign tax credits available to offset the toll charge. In addition, the Company's estimate of the toll charge obligation may change due to legislative technical corrections, the IRS' promulgation of regulations to interpret the Act, and changes in accounting standards for income taxes or related interpretations in response to the Act. This review and finalization of the toll charge provisional estimate will be completed within a twelve month measurement period from the date of enactment. The Company recorded a correction to the geographic mix of income during the three months ended June 30, 2017 related to Fiscal Year 2017, which reduced income in a high tax jurisdiction and increased income in a low tax jurisdiction. This correction resulted in a reduction to the Company’s effective tax rate by 3.5 percentage points for the nine months ended December 31, 2017 as compared to the prior year period and had no impact on the three months ended December 31, 2017 . For additional details regarding this correction refer to Note 1, Basis of Presentation . The Company adopted new stock-based compensation accounting guidance effective the beginning of Fiscal Year 2018. Excess tax benefits associated with employee equity plans were previously recorded in additional paid-in capital and the adoption of this guidance had an immaterial impact on the Company's effective tax rate for the three months ended December 31, 2017, but resulted in a reduction to the Company's effective tax rate by 2.6 percentage points for the nine months ended December 31, 2017 . The amount of excess tax benefits or deficiencies will fluctuate from period-to-period based on the price of the Company’s stock, the volume of share-based instruments settled or vested, and the value assigned to employee equity awards under U.S. GAAP. Included in long-term income taxes payable in the condensed consolidated balance sheets as of March 31, 2017 and December 31, 2017 were unrecognized tax benefits of $12.9 million and $12.3 million , respectively, which would favorably impact the effective tax rate in future periods if recognized. The Company’s continuing practice is to recognize interest and/or penalties related to income tax matters in income tax expense in the condensed consolidated statements of operations. The accrued interest related to unrecognized tax benefits was $1.7 million and $1.4 million as of March 31, 2017 and December 31, 2017 , respectively. No penalties have been accrued. The Company and its subsidiaries are subject to taxation in the U.S. federal and various foreign and state jurisdictions. The Company’s Fiscal Year 2016 federal income tax return is currently under examination by the Internal Revenue Service. Foreign income tax matters for material tax jurisdictions have been concluded for tax years prior to Fiscal Year 2012. The Company believes that an adequate provision has been made for any adjustments that may result from tax examinations; however, the outcome of such examinations cannot be predicted with certainty. If any issues addressed in the tax examinations are resolved in a manner inconsistent with the Company's expectations, the Company could be required to adjust its provision for income tax in the period such resolution occurs. The timing of any resolution and/or closure of tax examinations is not certain.

COMPUTATION OF EARNINGS (LOSS)

COMPUTATION OF EARNINGS (LOSS) PER COMMON SHARE	9 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
COMPUTATION OF EARNINGS (LOSS) PER COMMON SHARE	COMPUTATION OF EARNINGS (LOSS) PER COMMON SHARE Basic earnings (loss) per share is calculated by dividing net income associated with common shareholders by the weighted-average number of common shares outstanding during the period. Diluted earnings (loss) per share assumes the issuance of additional shares of common stock by the Company upon exercise of all outstanding stock options and vesting of restricted stock, if the effect is dilutive, in accordance with the treasury stock method or two-class method (whichever is more dilutive). Refer to Note 1, Basis of Presentation , for additional information regarding the Company's computation of earnings (loss) per common share. The following table sets forth the computation of basic and diluted earnings (loss) per common share for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands, except per share data) 2016 2017 2016 2017 Basic earnings (loss) per common share: Numerator: Net income (loss) $ 22,221 $ (49,504 ) $ 63,082 $ (10,723 ) Denominator: Weighted average common shares, basic 32,242 32,075 32,260 32,384 Dilutive effect of employee equity incentive plans 584 — 635 — Weighted average common shares-diluted 32,826 32,075 32,895 32,384 Basic earnings (loss) per common share $ 0.69 $ (1.54 ) $ 1.96 $ (0.33 ) Diluted earnings (loss) per common share $ 0.68 $ (1.54 ) $ 1.92 $ (0.33 ) Potentially dilutive securities excluded from diluted earnings (loss) per common share because their effect is anti-dilutive 473 968 573 1,107

REVENUE AND MAJOR CUSTOMERS

REVENUE AND MAJOR CUSTOMERS	9 Months Ended
	Dec. 31, 2017
REVENUE AND MAJOR CUSTOMERS [Abstract]
REVENUE AND MAJOR CUSTOMERS	REVENUE AND MAJOR CUSTOMERS The Company designs, manufactures, markets, and sells headsets for business and consumer applications. With respect to headsets, the Company makes products for use in offices and contact centers and, with mobile devices, cordless phones, computers, and gaming consoles. The following table presents net revenues by product group for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Net revenues from unaffiliated customers: Enterprise $ 157,345 $ 167,640 $ 467,784 $ 485,152 Consumer 75,588 58,894 204,438 155,608 Total net revenues $ 232,933 $ 226,534 $ 672,222 $ 640,760 For reporting purposes, revenue is attributed to each geographic region based on the location of the customer. Other than the U.S., no country accounted for 10% or more of the Company's net revenues for the three and nine months ended December 31, 2016 and 2017 . The following table presents net revenues by geography: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Net revenues from unaffiliated customers: U.S. $ 123,719 $ 106,455 $ 371,019 $ 326,360 Europe and Africa 63,233 73,620 168,722 184,761 Asia Pacific 27,164 27,553 81,979 75,664 Americas, excluding U.S. 18,817 18,906 50,502 53,975 Total international net revenues 109,214 120,079 301,203 314,400 Total net revenues $ 232,933 $ 226,534 $ 672,222 $ 640,760 One customer, Ingram Micro Group, accounted for 10.5% and 10.6% of net revenues for the three and nine months ended December 31, 2016 . One customer, Ingram Micro Group, accounted for 10.7% and 11.6% of net revenues for the three and nine months ended December 31, 2017 , respectively. One customer, Ingram Micro Group, accounted for 17.6% of total net accounts receivable at March 31, 2017 . Two customers, Ingram Micro Group and D&H Distributors, accounted for 13.5% and 13.8% , respectively, of total net accounts receivable at December 31, 2017 .

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	9 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS On January 30, 2018 , the Company announced that its Audit Committee had declared and approved the payment of a dividend of $0.15 per share on March 9, 2018 to holders of record on February 20, 2018 .

BASIS OF PRESENTATION (Policies

BASIS OF PRESENTATION (Policies)	9 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation	In the opinion of management, the accompanying unaudited condensed consolidated financial statements ("financial statements") of Plantronics, Inc. ("Plantronics" or "the Company") have been prepared on a basis materially consistent with the Company's March 31, 2017 audited consolidated financial statements and include all adjustments, consisting of normal recurring adjustments, necessary to fairly state the information set forth herein. Certain information and footnote disclosures normally included in financial statements prepared pursuant to the rules and regulations of the Securities and Exchange Commission ("SEC") applicable to interim financial information and in accordance with accounting principles generally accepted in the United States of America ("U.S. GAAP") have been condensed or omitted pursuant to such rules and regulations. The financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in the Company's Annual Report on Form 10-K for the fiscal year ended March 31, 2017 , which was filed with the SEC on May 10, 2017 . The results of operations for the interim period ended December 31, 2017 are not necessarily indicative of the results to be expected for the entire fiscal year or any future period. The financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated.
Fiscal period	The Company’s fiscal year ends on the Saturday closest to the last day of March. The Company’s current and prior fiscal years end on March 31, 2018 and April 1, 2017 , respectively, and both consist of 52 weeks. The Company’s results of operations for the three and nine months ended December 30, 2017 and December 31, 2016 both contain 13 weeks. For purposes of presentation, the Company has indicated its accounting year as ending on March 31 and its interim quarterly periods as ending on the applicable calendar month end.
Earnings per common share	Earnings per common share: The Company has a share-based compensation plan under which employees, non-employee directors, and consultants may be granted share-based payment awards, including shares of restricted stock on which non-forfeitable dividends are paid on unvested shares. As such, shares of restricted stock are considered participating securities under the two-class method of calculating earnings per share. Historically, the two-class method of calculating earnings per share did not have a material impact on the Company's earnings per share calculation under the treasury stock method. Beginning in the second quarter of Fiscal Year 2018, the Company applied the two-class method of calculating earnings per share because the ratio of participating securities to the weighted average number of common shares outstanding has increased as compared to the historical average, and this dilution will continue if the Company continues to repurchase its common stock at current levels.

CASH, CASH EQUIVALENTS, AND I23

CASH, CASH EQUIVALENTS, AND INVESTMENTS (Tables)	9 Months Ended
	Dec. 31, 2017
CASH, CASH EQUIVALENTS AND INVESTMENTS [Abstract]
Cash, Cash Equivalents, and Investments	The following tables summarize the Company’s cash and available-for-sale securities’ amortized cost, gross unrealized gains, gross unrealized losses, and fair value by significant investment category recorded as cash and cash equivalents, short-term, or long-term investments as of December 31, 2017 and March 31, 2017 (in thousands): December 31, 2017 Amortized Gross Gross Fair Cash & Cash Equivalents Short-term investments (due in 1 year or less) Long-term investments (due in 1 to 3 years) Cash $ 272,063 $ — $ — $ 272,063 $ 272,063 $ — $ — Level 1: Mutual Funds 14,298 399 (70 ) 14,627 — 14,627 — US Treasury Notes 71,684 — (210 ) 71,474 4,998 42,348 24,128 Money Market Funds 239 — — 239 239 — — Subtotal 86,221 399 (280 ) 86,340 5,237 56,975 24,128 Level 2: Government Agency Securities 56,667 — (276 ) 56,391 — 31,300 25,091 Commercial Paper 32,944 — — 32,944 2,993 29,951 — Corporate Bonds 142,148 45 (375 ) 141,818 — 77,175 64,643 Certificates of Deposits ("CDs") 28,383 — (3 ) 28,380 — 23,372 5,008 Subtotal 260,142 45 (654 ) 259,533 2,993 161,798 94,742 Total cash, cash equivalents $ 618,426 $ 444 $ (934 ) $ 617,936 $ 280,293 $ 218,773 $ 118,870 March 31, 2017 Amortized Gross Gross Fair Cash & Cash Equivalents Short-term investments (due in 1 year or less) Long-term investments (due in 1 to 3 years) Cash $ 295,877 $ — $ — $ 295,877 $ 295,877 $ — $ — Level 1: Mutual Funds 12,079 352 (32 ) 12,399 — 12,399 — US Treasury Notes 35,960 — (68 ) 35,892 — 17,560 18,332 Money Market Funds — — — — — — — Subtotal 48,039 352 (100 ) 48,291 — 29,959 18,332 Level 2: Government Agency Securities 54,415 20 (164 ) 54,271 — 15,309 38,962 Commercial Paper 47,152 — — 47,152 6,093 41,059 — Corporate Bonds 141,508 64 (224 ) 141,348 — 73,676 67,672 Certificates of Deposits ("CDs") 20,383 3 — 20,386 — 18,176 2,210 Subtotal 263,458 87 (388 ) 263,157 6,093 148,220 108,844 Total cash, cash equivalents $ 607,374 $ 439 $ (488 ) $ 607,325 $ 301,970 $ 178,179 $ 127,176

DETAILS OF CERTAIN BALANCE SH24

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS (Tables)	9 Months Ended
	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Accounts receivable, net	Accounts receivable, net: March 31, December 31, (in thousands) 2017 2017 Accounts receivable $ 184,759 $ 196,175 Provisions for returns (10,541 ) (11,438 ) Provisions for promotions, rebates, and other (32,438 ) (39,886 ) Provisions for doubtful accounts and sales allowances (603 ) (932 ) Accounts receivable, net $ 141,177 $ 143,919
Inventory, net	Inventory, net: March 31, December 31, (in thousands) 2017 2017 Raw materials $ 20,260 $ 23,485 Work in process 215 243 Finished goods 34,981 40,846 Inventory, net $ 55,456 $ 64,574
Accrued liabilities	Accrued Liabilities: March 31, December 31, (in thousands) 2017 2017 Employee compensation and benefits $ 36,415 $ 23,719 Accrued interest on 5.50% Senior Notes 10,407 3,419 Warranty obligation 6,863 7,418 VAT/Sales tax payable 5,433 6,182 Derivative liabilities 1,323 4,425 Accrued other 13,844 16,743 Accrued liabilities $ 74,285 $ 61,906
Changes in the warranty obligation	Changes in the warranty obligation during the nine months ended December 31, 2016 and 2017 were as follows: Nine Months Ended (in thousands) 2016 2017 Warranty obligation at beginning of period $ 8,537 $ 8,697 Warranty provision related to products shipped 7,248 7,367 Deductions for warranty claims processed (7,246 ) (7,711 ) Adjustments related to preexisting warranties 408 1,086 Warranty obligation at end of period (1) $ 8,947 $ 9,439 (1) Includes both short-term and long-term portion of warranty obligation; the prior table shows only the short-term portion included in accrued liabilities on our condensed consolidated balance sheet. The long-term portion is included in other long-term liabilities.

DEBT (Tables)

DEBT (Tables)	9 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Debt at Fair Value	The fair value of the 5.50% Senior Notes was determined based on inputs that were observable in the market, including the trading price of the 5.50% Senior Notes when available (Level 2). The estimated fair value and carrying value of the 5.50% Senior Notes were as follows: March 31, 2017 December 31, 2017 (in thousands) Fair Value Carrying Value Fair Value Carrying Value 5.50% Senior Notes $ 505,150 $ 491,059 $ 520,425 $ 492,146
Summary of Debt Redemption	The Company may redeem all or a part of the 5.50% Senior Notes, upon not less than 30 or more than a 60 day notice; however, the applicable redemption price will be determined as follows: Redemption Period Requiring Payment of: Redemption Up To 35% Using Cash Proceeds From An Equity Offering (3) : Make-Whole (1) Premium (2) Date Specified Price 5.50% Senior Notes Prior to May 15, 2018 On or after May 15, 2018 Prior to May 15, 2018 105.500% (1) If the Company redeems the notes prior to the applicable date, the redemption price is principal plus a make-whole premium equal to the present value of the remaining scheduled interest payments as described in the applicable indenture, together with accrued and unpaid interest. (2) If the Company redeems the notes on or after the applicable date, the price is principal plus a premium which declines over time as specified in the applicable indenture, together with accrued and unpaid interest. (3) If the Company redeems the notes prior to the applicable date with net cash proceeds of one or more equity offerings, the price is equal to the amount specified above, together with accrued and unpaid interest, subject to a maximum redemption of 35% of the aggregate principal amount of the respective note being redeemed.

RESTRUCTURING AND OTHER RELAT26

RESTRUCTURING AND OTHER RELATED CHARGES (CREDITS) (Tables)	9 Months Ended
	Dec. 31, 2017
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	The associated charges for the nine months ended December 31, 2017 are recorded in restructuring and other related charges (credits), cost of revenues, and selling, general, and administrative expense in the condensed consolidated statements of operations, as follows: Nine months ended December 31, 2017 (in millions) Total Charges Restructuring and Other Related Charges (Credits) Cost of Revenues Selling, General, and Administrative Severance benefits from reduction-in-force $ 1.3 $ 1.3 $ — $ — Lease exit charge and asset impairments in Netherlands 0.7 0.7 — — Write-off of unrecoverable indirect tax asset in Brazil 0.7 — 0.7 — Asset impairments related to previous Clarity operations 0.4 0.4 — — Loss on Clarity asset sale 0.9 — 0.9 — Accelerated vesting of restricted stock 0.2 — — 0.2 Totals $ 4.2 $ 2.4 $ 1.6 $ 0.2

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	9 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense Included in Statements of Operations	The following table summarizes the amount of stock-based compensation included in the condensed consolidated statements of operations: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Cost of revenues $ 794 $ 917 $ 2,414 $ 2,709 Research, development, and engineering 1,771 2,049 6,663 6,158 Selling, general, and administrative 6,124 5,063 15,928 17,180 Stock-based compensation included in operating expenses 7,895 7,112 22,591 23,338 Total stock-based compensation 8,689 8,029 25,005 26,047 Income tax expense (benefit) (2,986 ) 2,039 (8,635 ) (5,650 ) Total stock-based compensation, net of tax $ 5,703 $ 10,068 $ 16,370 $ 20,397

ACCUMULATED OTHER COMPREHENSI28

ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	9 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Income	The components of accumulated other comprehensive income ("AOCI"), net of immaterial tax effects, are as follows: (in thousands) March 31, 2017 December 31, 2017 Accumulated unrealized gain (loss) on cash flow hedges (1) $ 529 $ (2,200 ) Accumulated foreign currency translation adjustments 4,428 4,685 Accumulated unrealized gain (loss) on investments (263 ) (580 ) Accumulated other comprehensive income $ 4,694 $ 1,905 (1) Refer to Note 12 , Foreign Currency Derivatives, which discloses the nature of the Company's derivative assets and liabilities as of March 31, 2017 and December 31, 2017 .

FOREIGN CURRENCY DERIVATIVES (T

FOREIGN CURRENCY DERIVATIVES (Tables)	9 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of Outstanding Derivative Contracts	The gross fair value of the Company's outstanding derivative contracts at the end of each period was as follows: (in thousands) March 31, 2017 December 31, 2017 Derivative Assets (1) Non-designated hedges $ 86 $ 19 Cash flow hedges 2,034 332 Total Derivative Assets $ 2,120 $ 351 Derivative Liabilities (2) Non-designated hedges $ 286 $ 1,155 Cash flow hedges 1,109 3,345 Total Derivative Liabilities $ 1,395 $ 4,500 (1) Short-term derivative assets are recorded in "other current assets" and long-term derivative assets are recorded in "deferred tax and other assets". As of December 31, 2017 the portion of derivative assets classified as long-term was immaterial. (2) Short-term derivative liabilities are recorded in "accrued liabilities" and long-term derivative liabilities are recorded in "other long-term liabilities". As of December 31, 2017 the portion of derivative liabilities classified as long-term was immaterial.
Notional Value of Outstanding Foreign Exchange Currency Contracts	The notional value of the Company's outstanding EUR and GBP option and forward contracts at the end of each period was as follows: March 31, 2017 December 31, 2017 (in millions) EUR GBP EUR GBP Option contracts €73.5 £23.9 €75.8 £22.9 Forward contracts €11.2 £3.3 €13.0 £4.1 The following table summarizes the notional value of the Company’s outstanding foreign exchange currency contracts and approximate U.S. Dollar ("USD") equivalent at December 31, 2017 : (in thousands) Local Currency USD Equivalent Position Maturity EUR € 38,700 $ 46,560 Sell EUR 1 month GBP £ 5,100 $ 6,899 Sell GBP 1 month AUD A$ 14,200 $ 11,092 Sell AUD 1 month CAD C$ 2,900 $ 2,315 Sell CAD 1 month
Effect of Non-Designated Derivative Contracts Recognized in Interest and Other Income, Net	The effect of non-designated derivative contracts recognized in other non-operating income and (expense), net in the condensed consolidated statements of operations was as follows: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Gain (loss) on foreign exchange contracts $ 3,801 $ 848 $ 5,551 $ 6,083
Notional Value of Outstanding Cross-Currency Swaps	The following table summarizes the notional value of the Company’s outstanding MXN cross-currency swaps and approximate USD Equivalent at December 31, 2017 : (in thousands) Local Currency USD Equivalent Position Maturity MXN $ 76,340 $ 3,935 Buy MXN Monthly over 6 months
Reclassification out of Accumulated Other Comprehensive Income	The following table presents the pre-tax effects of derivative instruments designated as cash flow hedges on accumulated other comprehensive income and the condensed consolidated statements of operations for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Gain (loss) included in AOCI as of beginning of period $ (471 ) $ (3,089 ) $ (1,106 ) $ 541 Amount of gain (loss) recognized in other comprehensive income (“OCI”) (effective portion) 2,090 (446 ) 2,394 (5,093 ) Amount of gain (loss) reclassified from OCI into net revenues (effective portion) 2,178 1,357 3,163 2,506 Amount of gain (loss) reclassified from OCI into cost of revenues (effective portion) (756 ) (61 ) (2,072 ) (193 ) Total amount of gain (loss) reclassified from AOCI to income (loss) (effective portion) 1,422 1,296 1,091 2,313 Gain (loss) included in AOCI as of end of period $ 197 $ (2,239 ) $ 197 $ (2,239 )

COMPUTATION OF EARNINGS (LOSS30

COMPUTATION OF EARNINGS (LOSS) PER COMMON SHARE (Tables)	9 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Common Share	The following table sets forth the computation of basic and diluted earnings (loss) per common share for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands, except per share data) 2016 2017 2016 2017 Basic earnings (loss) per common share: Numerator: Net income (loss) $ 22,221 $ (49,504 ) $ 63,082 $ (10,723 ) Denominator: Weighted average common shares, basic 32,242 32,075 32,260 32,384 Dilutive effect of employee equity incentive plans 584 — 635 — Weighted average common shares-diluted 32,826 32,075 32,895 32,384 Basic earnings (loss) per common share $ 0.69 $ (1.54 ) $ 1.96 $ (0.33 ) Diluted earnings (loss) per common share $ 0.68 $ (1.54 ) $ 1.92 $ (0.33 ) Potentially dilutive securities excluded from diluted earnings (loss) per common share because their effect is anti-dilutive 473 968 573 1,107

REVENUE AND MAJOR CUSTOMERS (Ta

REVENUE AND MAJOR CUSTOMERS (Tables)	9 Months Ended
	Dec. 31, 2017
REVENUE AND MAJOR CUSTOMERS [Abstract]
Net Revenues by Product Group	The following table presents net revenues by product group for the three and nine months ended December 31, 2016 and 2017 : Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Net revenues from unaffiliated customers: Enterprise $ 157,345 $ 167,640 $ 467,784 $ 485,152 Consumer 75,588 58,894 204,438 155,608 Total net revenues $ 232,933 $ 226,534 $ 672,222 $ 640,760
Net Revenues by Geography	The following table presents net revenues by geography: Three Months Ended December 31, Nine Months Ended (in thousands) 2016 2017 2016 2017 Net revenues from unaffiliated customers: U.S. $ 123,719 $ 106,455 $ 371,019 $ 326,360 Europe and Africa 63,233 73,620 168,722 184,761 Asia Pacific 27,164 27,553 81,979 75,664 Americas, excluding U.S. 18,817 18,906 50,502 53,975 Total international net revenues 109,214 120,079 301,203 314,400 Total net revenues $ 232,933 $ 226,534 $ 672,222 $ 640,760

BASIS OF PRESENTATION (Details)

BASIS OF PRESENTATION (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)	$ 81,424		$ 2,742	$ 84,419	$ 14,235
Out-of-Period Error Resulting in Overstatement of Income Tax Expense [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)		$ (2,800)
Out-of-Period Error Resulting in Overstatement of Income Tax Expense [Member] | Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Income tax expense (benefit)						$ 2,800

RECENT ACCOUNTING PRONOUNCEME33

RECENT ACCOUNTING PRONOUNCEMENTS (Details) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Deferred revenue	$ 2,100
Excess tax benefits	$ 1,900
Reduction in effective tax rate due to adoption of accounting standard	2.60%
Amount reclassified out of financing activities	$ 65,663	$ 51,350
Amount reclassified into operating activities	$ 81,369	87,719
Accounting Standards Update 2016-09 [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Amount reclassified out of financing activities		1,000
Amount reclassified into operating activities		$ 1,000

CASH, CASH EQUIVALENTS, AND I34

CASH, CASH EQUIVALENTS, AND INVESTMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	$ 280,293	$ 301,970	$ 242,461	$ 235,266
Short-term investments (due in 1 year or less)	218,773	178,179
Long-term investments (due in 1 to 3 years)	118,870	127,176
Total cash, cash equivalents and investments measured at fair value, amortized cost	618,426	607,374
Total cash, cash equivalents and investments measured at fair value, gross unrealized gains	444	439
Total cash, cash equivalents and investments measured at fair value, gross unrealized losses	(934)	(488)
Total cash, cash equivalents and investments measured at fair value, fair value	617,936	607,325
Cash [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	272,063	295,877
Level 1 [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	5,237	0
Available-for-sale Securities, amortized cost basis	86,221	48,039
Available-for-sale Securities, gross unrealized gains	399	352
Available-for-sale Securities, gross unrealized losses	(280)	(100)
Available-for-sale Securities, fair value	86,340	48,291
Short-term investments (due in 1 year or less)	56,975	29,959
Long-term investments (due in 1 to 3 years)	24,128	18,332
Level 1 [Member] | Mutual Funds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	14,298	12,079
Available-for-sale Securities, gross unrealized gains	399	352
Available-for-sale Securities, gross unrealized losses	(70)	(32)
Available-for-sale Securities, fair value	14,627	12,399
Short-term investments (due in 1 year or less)	14,627	12,399
Long-term investments (due in 1 to 3 years)	0	0
Level 1 [Member] | US Treasury Notes [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	4,998	0
Available-for-sale Securities, amortized cost basis	71,684	35,960
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	(210)	(68)
Available-for-sale Securities, fair value	71,474	35,892
Short-term investments (due in 1 year or less)	42,348	17,560
Long-term investments (due in 1 to 3 years)	24,128	18,332
Level 1 [Member] | Money Market Funds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	239	0
Available-for-sale Securities, amortized cost basis	239	0
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	0	0
Available-for-sale Securities, fair value	239	0
Level 2 [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	2,993	6,093
Available-for-sale Securities, amortized cost basis	260,142	263,458
Available-for-sale Securities, gross unrealized gains	45	87
Available-for-sale Securities, gross unrealized losses	(654)	(388)
Available-for-sale Securities, fair value	259,533	263,157
Short-term investments (due in 1 year or less)	161,798	148,220
Long-term investments (due in 1 to 3 years)	94,742	108,844
Level 2 [Member] | Government Agency Securities [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	56,667	54,415
Available-for-sale Securities, gross unrealized gains	0	20
Available-for-sale Securities, gross unrealized losses	(276)	(164)
Available-for-sale Securities, fair value	56,391	54,271
Short-term investments (due in 1 year or less)	31,300	15,309
Long-term investments (due in 1 to 3 years)	25,091	38,962
Level 2 [Member] | Commercial Paper [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	2,993	6,093
Available-for-sale Securities, amortized cost basis	32,944	47,152
Available-for-sale Securities, gross unrealized gains	0	0
Available-for-sale Securities, gross unrealized losses	0	0
Available-for-sale Securities, fair value	32,944	47,152
Short-term investments (due in 1 year or less)	29,951	41,059
Long-term investments (due in 1 to 3 years)	0	0
Level 2 [Member] | Corporate Bonds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	142,148	141,508
Available-for-sale Securities, gross unrealized gains	45	64
Available-for-sale Securities, gross unrealized losses	(375)	(224)
Available-for-sale Securities, fair value	141,818	141,348
Short-term investments (due in 1 year or less)	77,175	73,676
Long-term investments (due in 1 to 3 years)	64,643	67,672
Level 2 [Member] | Certificates of Deposit [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and cash equivalents	0	0
Available-for-sale Securities, amortized cost basis	28,383	20,383
Available-for-sale Securities, gross unrealized gains	0	3
Available-for-sale Securities, gross unrealized losses	(3)	0
Available-for-sale Securities, fair value	28,380	20,386
Short-term investments (due in 1 year or less)	23,372	18,176
Long-term investments (due in 1 to 3 years)	$ 5,008	$ 2,210

DEFERRED COMPENSATION (Details)

DEFERRED COMPENSATION (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Bank deposits held	$ 280,293	$ 301,970	$ 242,461	$ 235,266
Short-term investments [Member] | Mutual funds [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Investments	14,600	12,400
Other long-term liabilities [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation liability, noncurrent	15,900	13,700
Bank Time Deposits [Member] | Cash and cash equivalents [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Bank deposits held	$ 800	$ 800

DETAILS OF CERTAIN BALANCE SH36

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS - Accounts Receivable, net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Accounts receivable, net [Line Items]
Accounts receivable	$ 196,175	$ 184,759
Accounts receivable, net	143,919	141,177
Provision for returns [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	(11,438)	(10,541)
Provision for promotions, rebates and other [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	(39,886)	(32,438)
Provisions for doubtful accounts and sales allowances [Member]
Accounts receivable, net [Line Items]
Accounts receivable, reserves	$ (932)	$ (603)

DETAILS OF CERTAIN BALANCE SH37

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS - Inventory, net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Inventory, Net [Abstract]
Raw materials	$ 23,485	$ 20,260
Work in process	243	215
Finished goods	40,846	34,981
Inventory, net	$ 64,574	$ 55,456

DETAILS OF CERTAIN BALANCE SH38

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017	May 31, 2015
Accrued Liabilities [Abstract]
Employee compensation and benefits	$ 23,719	$ 36,415
Accrued interest on 5.50% Senior Notes	3,419	10,407
Warranty obligation	7,418	6,863
VAT/Sales tax payable	6,182	5,433
Derivative liabilities	4,425	1,323
Accrued other	16,743	13,844
Accrued liabilities	$ 61,906	$ 74,285
5.50% Senior Notes [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Stated interest rate of debt instrument	5.50%		5.50%

DETAILS OF CERTAIN BALANCE SH39

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS - Warranty Obligation (Details) - USD ($) $ in Thousands	9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Changes in the Warranty Obligation [Roll Forward]
Warranty obligation at beginning of period	$ 8,697	$ 8,537
Warranty provision related to products shipped	7,367	7,248
Deductions for warranty claims processed	(7,711)	(7,246)
Adjustments related to preexisting warranties	1,086	408
Warranty obligation at end of period	$ 9,439	$ 8,947

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) $ in Millions	Dec. 31, 2017USD ($)
Commitments and Contingencies Disclosure [Abstract]
Unconditional purchase obligations	$ 192.3

DEBT (Details)

DEBT (Details)	Apr. 27, 2017	May 02, 2016	May 09, 2011	May 31, 2015USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Apr. 28, 2017USD ($)	Mar. 31, 2017USD ($)
Debt Disclosure [Line Items]
Initiation date of credit agreement			May 9, 2011
Amendment date of Credit Agreement		Apr. 28, 2017
Credit facility expiration date							May 9, 2020
Commitment fee percentage							0.37%
Proceeds from line of credit					$ 8,000,000
Repayment of line of credit					8,000,000
Outstanding borrowings under line of credit					$ 0	$ 0	$ 0		$ 0
Maximum ratio of funded debt to EBITDA	3					3.25
Minimum required liquid funds							$ 300,000,000
Line Of Credit Facility Interest Rate Spread Below The Banks Announced Prime Rate [Member]
Debt Disclosure [Line Items]
Spread for interest rate							1.20%
Line Of Credit Facility Interest Rate Spread Above A Daily One Month LIBOR Rate [Member]
Debt Disclosure [Line Items]
Spread for interest rate							1.40%
Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Principal amount of debt issued				$ 500,000,000
Stated interest rate of debt instrument				5.50%	5.50%	5.50%	5.50%
Proceeds from issuance of senior notes, net of issuance costs				$ 488,400,000
Debt issuance costs				$ 11,600,000
Debt redemption percentage price, Specified Price				105.50%
Repurchase price, percentage of principal amount				101.00%
Minimum [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Debt redemption notice period				30 days
Maximum [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Debt redemption notice period				60 days
Percentage of debt redeemed				35.00%
Level 2 [Member] | Fair Value [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Long-term debt, 5.50% Senior Notes					$ 520,425,000	$ 520,425,000	$ 520,425,000		505,150,000
Level 2 [Member] | Carrying Value [Member] | Senior Notes [Member] | 5.50% Senior Notes [Member]
Debt Disclosure [Line Items]
Long-term debt, 5.50% Senior Notes					$ 492,146,000	$ 492,146,000	$ 492,146,000		$ 491,059,000
Revolving Credit Facility [Member]
Debt Disclosure [Line Items]
Maximum borrowing capacity of unsecured revolving credit facility								$ 100,000,000

RESTRUCTURING AND OTHER RELAT42

RESTRUCTURING AND OTHER RELATED CHARGES (CREDITS) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)	$ (84)	$ 113	$ 2,438	$ (1,350)
Totals			4,200
Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			2,400
Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			1,600
Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			200
Severance Benefits from Reduction-In-Force [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			1,300
Severance Benefits from Reduction-In-Force [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			1,300
Severance Benefits from Reduction-In-Force [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Severance Benefits from Reduction-In-Force [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Lease Exit Charge and Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			700
Lease Exit Charge and Asset Impairment [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			700
Lease Exit Charge and Asset Impairment [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Lease Exit Charge and Asset Impairment [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Write-off of Unrecoverable Indirect Tax Asset in Brazil [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			700
Write-off of Unrecoverable Indirect Tax Asset in Brazil [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Write-off of Unrecoverable Indirect Tax Asset in Brazil [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			700
Write-off of Unrecoverable Indirect Tax Asset in Brazil [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Asset Impairments Related to Previous Clarity Operations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			400
Asset Impairments Related to Previous Clarity Operations [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			400
Asset Impairments Related to Previous Clarity Operations [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Asset Impairments Related to Previous Clarity Operations [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Loss on Clarity Asset Sale [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			900
Loss on Clarity Asset Sale [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Loss on Clarity Asset Sale [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			900
Loss on Clarity Asset Sale [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Accelerated Vesting of Restricted Stock [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			200
Accelerated Vesting of Restricted Stock [Member] | Restructuring and Other Related Charges (Credits) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Accelerated Vesting of Restricted Stock [Member] | Cost of Revenues [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			0
Accelerated Vesting of Restricted Stock [Member] | Selling, General and Administrative Expenses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other related charges (credits)			$ 200
Clarity [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member]
Restructuring Cost and Reserve [Line Items]
Term of lease			12 months
Term of transition services agreement			1 year

STOCK-BASED COMPENSATION (Detai

STOCK-BASED COMPENSATION (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 8,029	$ 8,689	$ 26,047	$ 25,005
Income tax expense (benefit)	2,039	(2,986)	(5,650)	(8,635)
Total stock-based compensation, net of tax	10,068	5,703	20,397	16,370
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	917	794	2,709	2,414
Research, development, and engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	2,049	1,771	6,158	6,663
Selling, general, and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	5,063	6,124	17,180	15,928
Stock-based compensation expense included in operating expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 7,112	$ 7,895	$ 23,338	$ 22,591

COMMON STOCK REPURCHASES (Detai

COMMON STOCK REPURCHASES (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Remaining shares authorized for repurchase under program	730,932
Shares repurchased	1,138,903	764,176
Total cost of shares repurchased	$ 52,915	$ 34,236
Average cost per share of shares repurchased (in dollars per share)	$ 46.46	$ 44.80
Value of shares withheld in satisfaction of employee tax withholding obligations	$ 11,186	$ 9,444

ACCUMULATED OTHER COMPREHENSI45

ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Mar. 31, 2017
Equity [Abstract]
Accumulated unrealized gain (loss) on cash flow hedges	[1]	$ (2,200)	$ 529
Accumulated foreign currency translation adjustments		4,685	4,428
Accumulated unrealized gain (loss) on investments		(580)	(263)
Accumulated other comprehensive income		$ 1,905	$ 4,694
[1]	Refer to Note 12, Foreign Currency Derivatives, which discloses the nature of the Company's derivative assets and liabilities as of March 31, 2017 and December 31, 2017.

FOREIGN CURRENCY DERIVATIVES (D

FOREIGN CURRENCY DERIVATIVES (Details) MXN in Thousands, $ in Thousands	9 Months Ended
	Dec. 31, 2017USD ($)financial_institution	Dec. 31, 2017MXNfinancial_institution	Mar. 31, 2017MXN
Derivative [Line Items]
Number of financial institutions company has International Swap and Derivatives Association agreements	4	4
Foreign currency swap contract [Member]
Derivative [Line Items]
Notional amount of contracts	$ 3,935	MXN 76,340	MXN 287,200
Cash flow hedges [Member] | Options [Member] | Minimum [Member]
Derivative [Line Items]
Term of derivative contract	6 months
Cash flow hedges [Member] | Options [Member] | Maximum [Member]
Derivative [Line Items]
Term of derivative contract	11 months
Cash flow hedges [Member] | Forwards [Member]
Derivative [Line Items]
Term of derivative contract	3 months

FOREIGN CURRENCY DERIVATIVES 47

FOREIGN CURRENCY DERIVATIVES (Details 1) - USD ($) $ in Thousands	Dec. 31, 2017	Mar. 31, 2017
Derivative [Line Items]
Total Derivative Liabilities	$ 4,425	$ 1,323
Other Current Assets [Member]
Derivative [Line Items]
Total Derivative Assets	351	2,120
Other Current Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivative Assets	19	86
Other Liabilities [Member]
Derivative [Line Items]
Total Derivative Liabilities	4,500	1,395
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivative Liabilities	1,155	286
Cash flow hedges [Member] | Other Current Assets [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivative Assets	332	2,034
Cash flow hedges [Member] | Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Total Derivative Liabilities	$ 3,345	$ 1,109

FOREIGN CURRENCY DERIVATIVES 48

FOREIGN CURRENCY DERIVATIVES (Details 2) - 9 months ended Dec. 31, 2017 € in Thousands, £ in Thousands, CAD in Thousands, AUD in Thousands, $ in Thousands	EUR (€)	CAD	GBP (£)	AUD	USD ($)
Foreign Exchange Forward, EURO [Member]
Derivative [Line Items]
Notional amount of contracts	€ 38,700				$ 46,560
Position	Sell EUR
Maturity	1 month
Foreign Exchange Forward, GBP [Member]
Derivative [Line Items]
Notional amount of contracts			£ 5,100		6,899
Position	Sell GBP
Maturity	1 month
Foreign Exchange Forward, AUD [Member]
Derivative [Line Items]
Notional amount of contracts				AUD 14,200	11,092
Position	Sell AUD
Maturity	1 month
Foreign Exchange Forward, CAD [Member]
Derivative [Line Items]
Notional amount of contracts		CAD 2,900			$ 2,315
Position	Sell CAD
Maturity	1 month

FOREIGN CURRENCY DERIVATIVES 49

FOREIGN CURRENCY DERIVATIVES (Details 3) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) on foreign exchange contracts	$ 848	$ 3,801	$ 6,083	$ 5,551

FOREIGN CURRENCY DERIVATIVES 50

FOREIGN CURRENCY DERIVATIVES (Details 4)	Dec. 31, 2017EUR (€)	Dec. 31, 2017GBP (£)	Mar. 31, 2017EUR (€)	Mar. 31, 2017GBP (£)
Option contracts [Member]
Derivative [Line Items]
Notional amount of contracts	€ 75,800,000	£ 22,900,000	€ 73,500,000	£ 23,900,000
Forward contracts [Member]
Derivative [Line Items]
Notional amount of contracts	€ 13,000,000	£ 4,100,000	€ 11,200,000	£ 3,300,000

FOREIGN CURRENCY DERIVATIVES 51

FOREIGN CURRENCY DERIVATIVES (Details 5) - Foreign currency swap contract [Member] MXN in Thousands, $ in Thousands	9 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2017MXN	Mar. 31, 2017MXN
Derivative [Line Items]
Notional amount of contracts	$ 3,935	MXN 76,340	MXN 287,200
Position	Buy MXN
Maturity	6 months

FOREIGN CURRENCY DERIVATIVES 52

FOREIGN CURRENCY DERIVATIVES (Details 6) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Gain (Loss) Included in Accumulated Other Comprehensive Income [Roll Forward]
Gain (loss) included in AOCI as of beginning of period	$ (3,089)	$ (471)	$ 541	$ (1,106)
Amount of gain (loss) recognized in other comprehensive income (“OCI”) (effective portion)	(446)	2,090	(5,093)	2,394
Amount of gain (loss) reclassified from OCI into net revenues (effective portion)	226,534	232,933	640,760	672,222
Amount of gain (loss) reclassified from OCI into cost of revenues (effective portion)	(112,409)	(122,753)	(315,720)	(338,523)
Total amount of gain (loss) reclassified from AOCI to income (loss) (effective portion)	(1,296)	(1,422)	(2,313)	(1,091)
Gain (loss) included in AOCI as of end of period	(2,239)	197	(2,239)	197
Reclassification out of Accumulated Other Comprehensive Income [Member]
Gain (Loss) Included in Accumulated Other Comprehensive Income [Roll Forward]
Amount of gain (loss) reclassified from OCI into net revenues (effective portion)	1,357	2,178	2,506	3,163
Amount of gain (loss) reclassified from OCI into cost of revenues (effective portion)	$ (61)	$ (756)	$ (193)	$ (2,072)

INCOME TAXES (Details)

INCOME TAXES (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2018	Mar. 31, 2017
Income Tax Contingency [Line Items]
Effective tax rate	255.10%	11.00%	114.60%	18.40%
Toll charge	$ 69,300,000
Increase in effective tax rate due to toll charge	217.20%		94.10%
Decrease in deferred tax assets			$ 2,100,000
Change in enacted tax rate	6.60%		2.90%
Undistributed foreign earnings	$ 5,000,000		$ 5,000,000
Increase in tax rate due to undistributed foreign earnings	15.60%		6.80%
Decrease in global tax rate	2.30%		1.00%
Period under review			30 years
Reduction in effective tax rate due to correction to the geographic mix of income			3.50%
Reduction in effective tax rate due to adoption of accounting standard			2.60%
Unrecognized tax benefits	$ 12,300,000		$ 12,300,000			$ 12,900,000
Accrued interest related to unrecognized tax benefits	1,400,000		1,400,000			1,700,000
Accrued penalties	$ 0		$ 0			$ 0
Scenario, Forecast [Member]
Income Tax Contingency [Line Items]
Federal statutory income tax rate					31.56%

COMPUTATION OF EARNINGS (LOSS54

COMPUTATION OF EARNINGS (LOSS) PER COMMON SHARE (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net income (loss)	$ (49,504)	$ 22,221	$ (10,723)	$ 63,082
Denominator:
Weighted average common shares-basic (in shares)	32,075	32,242	32,384	32,260
Dilutive effect of employee equity incentive plans (in shares)	0	584	0	635
Weighted average common shares-diluted (in shares)	32,075	32,826	32,384	32,895
Basic earnings (loss) per common share (in dollars per share)	$ (1.54)	$ 0.69	$ (0.33)	$ 1.96
Diluted earnings (loss) per common share (in dollars per share)	$ (1.54)	$ 0.68	$ (0.33)	$ 1.92
Potentially dilutive securities excluded from diluted earnings per common share because their effect is anti-dilutive	968	473	1,107	573

REVENUE AND MAJOR CUSTOMERS (De

REVENUE AND MAJOR CUSTOMERS (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2017USD ($)Customer	Dec. 31, 2016USD ($)Customer	Dec. 31, 2017USD ($)Customer	Dec. 31, 2016USD ($)Customer	Mar. 31, 2017Customer
Revenue from External Customer [Line Items]
Net revenues	$ 226,534	$ 232,933	$ 640,760	$ 672,222
US [Member]
Revenue from External Customer [Line Items]
Net revenues	106,455	123,719	326,360	371,019
Europe and Africa [Member]
Revenue from External Customer [Line Items]
Net revenues	73,620	63,233	184,761	168,722
Asia Pacific [Member]
Revenue from External Customer [Line Items]
Net revenues	27,553	27,164	75,664	81,979
Americas, excluding U.S. [Member]
Revenue from External Customer [Line Items]
Net revenues	18,906	18,817	53,975	50,502
Total international net revenues [Member]
Revenue from External Customer [Line Items]
Net revenues	120,079	109,214	314,400	301,203
Enterprise [Member]
Revenue from External Customer [Line Items]
Net revenues	167,640	157,345	485,152	467,784
Consumer [Member]
Revenue from External Customer [Line Items]
Net revenues	$ 58,894	$ 75,588	$ 155,608	$ 204,438
Net Revenues [Member] | Customer Concentration Risk [Member] | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Number of major customers, ten percent or greater, net revenues | Customer	1	1	1	1
Concentration risk percentage	10.70%	10.50%	11.60%	10.60%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Ingram Micro [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage			13.50%		17.60%
Number of major customers, ten percent or greater, net accounts receivable | Customer	2		2		1
Accounts Receivable [Member] | Customer Concentration Risk [Member] | D&H Distributors [Member]
Revenue from External Customer [Line Items]
Concentration risk percentage			13.80%

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent Event [Member]	Feb. 20, 2018$ / shares
Subsequent Event [Line Items]
Dividends declared date	Jan. 30, 2018
Cash dividend payable per share (in dollars per share)	$ 0.15
Dividend payable date	Mar. 9, 2018
Date of stockholders on record for dividends declared	Feb. 20, 2018