Plantronics (POLY) 10-Q 29 Oct 13 2014 Q2 Quarterly report Financial data

DOCUMENT_AND_ENTITY_INFORMATIO

DOCUMENT AND ENTITY INFORMATION Document (USD $)	6 Months Ended
	Sep. 30, 2013	Oct. 26, 2013	Sep. 28, 2013
Entity Information [Line Items]
Entity Registrant Name	PLANTRONICS INC /CA/
Entity Central Index Key	914025
Current Fiscal Year End Date	-28
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q2
Amendment Flag
Entity Common Stock, Shares Outstanding		43,774,566
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$2,043,949,950

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$245,980	$228,776
Short-term investments	113,143	116,581
Accounts receivable, net	123,748	128,209
Inventory, net	69,150	67,435
Deferred tax assets	10,065	10,120
Other current assets	15,289	15,369
Total current assets	577,375	566,490
Long-term investments	79,475	80,261
Property, plant, and equipment, net	118,318	99,111
Goodwill and purchased intangibles, net	16,265	16,440
Other assets	2,240	2,303
Total assets	793,673	764,605
Current liabilities:
Accounts payable	29,500	37,067
Accrued liabilities	60,926	66,419
Total current liabilities	90,426	103,486
Deferred tax liabilities	2,833	1,742
Long-term income taxes payable	12,685	12,005
Other long-term liabilities	1,686	925
Total liabilities	107,630	118,158
Commitments and contingencies (Note 7)
Stockholders' equity:
Common stock	769	757
Additional paid-in capital	645,169	612,283
Accumulated other comprehensive income	1,858	5,567
Retained earnings	69,670	28,344
Total stockholders' equity before treasury stock	717,466	646,951
Less: Treasury stock, at cost	-31,423	-504
Total stockholders' equity	686,043	646,447
Total liabilities and stockholders' equity	$793,673	$764,605

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net revenues	$193,980	$179,280	$396,798	$360,645
Cost of revenues	94,366	82,052	191,552	165,721
Gross profit	99,614	97,228	205,246	194,924
Operating expenses:
Research, development, and engineering	20,447	19,581	41,310	39,277
Selling, general, and administrative	48,507	43,130	96,604	89,034
Restructuring and other related charges	-176	0	547	0
Total operating expenses	68,778	62,711	138,461	128,311
Operating income	30,836	34,517	66,785	66,613
Interest and other income (expense), net	359	275	-127	287
Income before income taxes	31,195	34,792	66,658	66,900
Income tax expense	8,057	8,868	16,567	17,413
Net income	$23,138	$25,924	$50,091	$49,487
Earnings per common share:
Basic	$0.54	$0.62	$1.17	$1.19
Diluted	$0.53	$0.61	$1.15	$1.16
Shares used in computing basic earnings per common share	42,810	41,482	42,751	41,571
Shares used in computing diluted earnings per common share	43,597	42,403	43,667	42,521
Cash dividends declared per common share	$0.10	$0.10	$0.20	$0.20

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$23,138	$25,924	$50,091	$49,487
Other comprehensive income, net of tax:
Foreign currency translation adjustments	311	217	-41	-119
Unrealized cash flow hedge gains (losses) arising during the period	-1,949	-632	-3,576	1,534
Net (gains) losses reclassified into income for revenue hedges	128	-1,158	144	-3,019
Net (gains) losses reclassified into income for cost of revenues hedges	26	93	-239	290
Net unrealized gains (losses) on cash flow hedges	-1,795	-1,697	-3,671	-1,195
Unrealized holding gains (losses) during the period	164	46	6	58
Other comprehensive income (loss)	-1,320	-1,434	-3,706	-1,256
Comprehensive income	$21,818	$24,490	$46,385	$48,231

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$50,091	$49,487
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	7,891	7,880
Stock-based compensation	10,953	9,482
Provision for excess and obsolete inventories	3,281	899
Deferred income taxes	5,293	-902
Excess tax benefit from stock-based compensation	-4,086	-679
Other operating activities	1,200	1,265
Changes in assets and liabilities:
Accounts receivable, net	3,082	5,008
Inventory, net	-4,552	-8,230
Current and other assets	-659	-1,218
Accounts payable	-7,567	-3,854
Accrued liabilities	-3,885	-559
Income taxes	-3,436	1,445
Cash provided by operating activities	57,606	60,024
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from sales of short-term investments	50,118	25,057
Proceeds from maturities of short-term investments	54,970	60,890
Purchase of short-term investments	-41,634	-65,411
Proceeds from sales of long-term investments	15,012	2,000
Purchase of long-term investments	-74,720	-33,951
Acquisitions, net of cash acquired	0	-1,723
Capital expenditures	-27,213	-21,526
Cash used for investing activities	-23,467	-34,664
CASH FLOWS FROM FINANCING ACTIVITIES
Repurchase of common stock	-27,313	-19,930
Proceeds from issuances under stock-based compensation plans	18,637	11,888
Employees' tax withheld and paid for restricted stock and restricted stock units	-4,369	-1,729
Proceeds from revolving line of credit	0	18,000
Repayments of revolving line of credit	0	-26,000
Payment of cash dividends	-8,765	-8,490
Excess tax benefit from stock-based compensation	4,086	679
Cash used for financing activities	-17,724	-25,582
Effect of exchange rate changes on cash and cash equivalents	789	-1,184
Net increase (decrease) in cash and cash equivalents	17,204	-1,406
Cash and cash equivalents at beginning of period	228,776	209,335
Cash and cash equivalents at end of period	245,980	207,929
Transfers of long-term investments to short-term investments	$60,424	$48,574

BASIS_OF_PRESENTATION

BASIS OF PRESENTATION	6 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation [Text Block]	BASIS OF PRESENTATION
	The accompanying unaudited condensed consolidated financial statements (“financial statements”) of Plantronics, Inc. (“Plantronics” or "the Company”) have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) applicable to interim financial information.  Certain information and footnote disclosures normally included in financial statements prepared 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.  In the opinion of management, the financial statements have been prepared on a basis consistent with the Company's March 31, 2013 audited consolidated financial statements and include all adjustments, consisting of normal recurring adjustments, necessary to fairly state the information set forth herein.  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, 2013, which was filed with the SEC on May 24, 2013.  The results of operations for the interim period ended September 30, 2013 are not indicative of the results to be expected for the entire fiscal year or any future period.
	The financial statements include the accounts of Plantronics 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 fiscal year ends on March 29, 2014 and consists of 52 weeks. The Company's prior fiscal year ended on March 30, 2013 and also consisted of 52 weeks.  The Company’s results of operations for the three and six months ended September 28, 2013 and September 29, 2012 both contain 13 and 26 weeks, respectively. 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.

RECENT_ACCOUNTING_PRONOUNCEMEN

RECENT ACCOUNTING PRONOUNCEMENTS RECENT ACCOUNTING PRONOUNCEMENTS	6 Months Ended
	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Recent Accounting Pronouncements	RECENT ACCOUNTING PRONOUNCEMENTS
	Recently Issued Pronouncements
	Recent accounting pronouncements issued by the Financial Accounting Standards Board ("FASB") and the SEC did not and are not expected by the Company to have a material impact on the Company's present or future consolidated financial statements.

CASH_CASH_EQUIVALENTS_AND_INVE

CASH, CASH EQUIVALENTS, AND INVESTMENTS	6 Months Ended
	Sep. 30, 2013
CASH, CASH EQUIVALENTS AND INVESTMENTS [Abstract]
Cash, Cash Equivalents, and Investments [Text Block]	CASH, CASH EQUIVALENTS, AND INVESTMENTS
	The following table represents the Company’s cash, cash equivalents, and investments as of September 30, 2013 and March 31, 2013:
	(in thousands)	September 30, 2013									March 31, 2013
		Amortized		Gross		Gross			Fair		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value		Cost		Unrealized		Unrealized			Value
				Gains		Losses							Gains		Losses
	Cash and cash equivalents:
	Cash	$	236,372	$	—	$	—		$	236,372	$	118,881	$	—	$	—		$	118,881
	Cash equivalents	9,607		1		—			9,608		109,895		—		—			109,895
	Total cash and cash equivalents	$	245,979	$	1	$	—		$	245,980	$	228,776	$	—	$	—		$	228,776
	Short-term investments:
	U.S. Treasury Bills and Government Agency Securities	$	56,964	$	33	$	(15	)	$	56,982	$	66,092	$	18	$	(3	)	$	66,107
	Commercial paper	30,835		12		(1		)	30,846		15,670		9		—			15,679
	Corporate bonds	24,294		19		(1		)	24,312		34,766		31		(2		)	34,795
	Certificates of deposit ("CDs")	1,002		1		—			1,003		—		—		—			—
	Total short-term investments	$	113,095	$	65	$	(17	)	$	113,143	$	116,528	$	58	$	(5	)	$	116,581
	Long-term investments:
	U.S. Treasury Bills and Government Agency Securities	$	15,473	$	18	$	(4	)	$	15,487	$	55,317	$	42	$	(1	)	$	55,358
	Corporate bonds	63,926		85		(23		)	63,988		23,878		23		(3		)	23,898
	CDs	—		—		—			—		1,002		3		—			1,005
	Total long-term investments	$	79,399	$	103	$	(27	)	$	79,475	$	80,197	$	68	$	(4	)	$	80,261
	Total cash, cash equivalents and investments	$	438,473	$	169	$	(44	)	$	438,598	$	425,501	$	126	$	(9	)	$	425,618
	As of September 30, 2013 and March 31, 2013, 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.
	The following table summarizes the amortized cost and fair value of the Company’s cash equivalents, short-term investments, and long-term investments, classified by stated maturity as of September 30, 2013 and March 31, 2013:
	(in thousands)	September 30, 2013				March 31, 2013
		Amortized		Fair Value		Amortized			Fair Value
		Cost				Cost
	Due in 1 year or less	$	122,702	$	122,751	$	226,423		$	226,476
	Due in 1 to 3 years	79,399		79,475		80,197			80,261
	Total	$	202,101	$	202,226	$	306,620		$	306,737
	The Company did not incur any material realized or unrealized net gains or losses in the three and six months ended September 30, 2013 and 2012.

FAIR_VALUE_MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Text Block]	FAIR VALUE MEASUREMENTS
	The following tables present the Company’s financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of September 30, 2013 and March 31, 2013.
	Fair Values as of September 30, 2013:
	(in thousands)	Level 1		Level 2		Total
	Cash and cash equivalents:
	Cash	$	236,372	$	—	$	236,372
	Mutual funds	609		—		609
	Commercial paper	—		8,999		8,999
	Short-term investments:
	Government Agency Securities	—		56,982		56,982
	Commercial paper	—		30,846		30,846
	Corporate bonds	—		24,312		24,312
	CDs	—		1,003		1,003
	Long-term investments:
	Government Agency Securities	—		15,487		15,487
	Corporate bonds	—		63,988		63,988
	Other current assets:
	Derivative assets	—		70		70
	Total assets measured at fair value	$	236,981	$	201,687	$	438,668
	Accrued liabilities:
	Derivative liabilities	$	8	$	2,435	$	2,443
	Fair Values as of March 31, 2013:
	(in thousands)	Level 1		Level 2		Total
	Cash and cash equivalents:
	Cash	$	118,881	$	—	$	118,881
	U.S. Treasury Bills	104,995		—		104,995
	Commercial paper	—		4,900		4,900
	Short-term investments:
	U.S. Treasury Bills and Government Agency Securities	7,243		58,864		66,107
	Commercial paper	—		15,679		15,679
	Corporate bonds	—		34,795		34,795
	Long-term investments:
	U.S. Treasury Bills and Government Agency Securities	22,904		32,454		55,358
	Corporate bonds	—		23,898		23,898
	CDs	—		1,005		1,005
	Other current assets:
	Derivative assets	—		1,665		1,665
	Total assets measured at fair value	$	254,023	$	173,260	$	427,283
	Accrued liabilities:
	Derivative liabilities	$	3	$	291	$	294
	There were no transfers between fair value measurement levels during the three and six months ended September 30, 2013 and 2012.
	Refer to Note 12, Foreign Currency Derivatives, which discloses the nature of the Company's derivative assets and liabilities as of September 30, 2013 and March 31, 2013.
	All financial assets and liabilities are recognized or disclosed at fair value in the financial statements. 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. Level 1 financial liabilities consist of derivative contracts that have closed but have not settled. 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, CDs, and derivative foreign currency call and put option contracts. 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 call and put option contracts is determined using pricing models that use observable market inputs.

DETAILS_OF_CERTAIN_BALANCE_SHE

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS	6 Months Ended
	Sep. 30, 2013
Balance Sheet Related Disclosures [Abstract]
DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS	DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS
	Accounts receivable, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Accounts receivable	$	147,581		$	151,250
	Provisions for returns	(7,756		)	(8,957		)
	Provisions for promotions, rebates, and other	(15,771		)	(13,675		)
	Provisions for doubtful accounts and sales allowances	(306		)	(409		)
	Accounts receivable, net	$	123,748		$	128,209
	Inventory, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Raw materials	$	33,659		$	28,743
	Work in process	432			82
	Finished goods	35,059			38,610
	Inventory, net	$	69,150		$	67,435
	Property, plant, and equipment, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Land	$	13,961		$	13,961
	Buildings and improvements (useful life: 7-30 years)	89,434			72,263
	Machinery and equipment (useful life: 2-10 years)	94,737			88,538
	Software (useful life: 5-6 years)	31,268			30,538
	Construction in progress	17,892			16,101
		247,292			221,401
	Accumulated depreciation and amortization	(128,974		)	(122,290		)
	Property, plant, and equipment, net	$	118,318		$	99,111
	Depreciation and amortization was $3.7 million and $7.7 million for the three and six months ended September 30, 2013, respectively, and $4.0 million and $7.7 million for the same periods in the prior year, respectively.
	Included in Software are unamortized capitalized software costs of $5.6 million and $6.1 million at September 30, 2013 and March 31, 2013, respectively. Amortization related to capitalized software costs was immaterial for the three months ended September 30, 2013 and 2012, and was $1.2 million and $1.5 million for the six months ended September 30, 2013 and 2012, respectively.
	Accrued Liabilities:
		September 30,			March 31,
	(in thousands)	2013			2013
	Employee compensation and benefits	$	23,164		$	29,796
	Warranty obligation	12,881			13,410
	Accrued advertising, sales, and marketing	4,245			3,735
	Deferred revenue	3,994			3,072
	Liabilities related to derivatives contracts	2,443			294
	Income taxes payable	—			3,376
	Restructuring and other related charges (1)	47			1,165
	Accrued other	14,152			11,571
	Accrued liabilities	$	60,926		$	66,419
	(1) Refer to Note 16, Restructuring and Other Related Charges, for more information on the Company's restructuring activity.
	The Company's warranty obligation is included as a component of accrued liabilities in the condensed consolidated balance sheets. Changes in the warranty obligation during the six months ended September 30, 2013 were as follows:
		Six Months Ended			Six Months Ended
	(in thousands)	September 30, 2013			September 30, 2012
	Warranty obligation at March 31, 2013	$	13,410		$	13,346
	Warranty provision relating to products shipped	4,154			7,440
	Deductions for warranty claims processed	(4,683		)	(8,064		)
	Warranty obligation at September 30, 2013	$	12,881		$	12,722

GOODWILL_AND_PURCHASED_INTANGI

GOODWILL AND PURCHASED INTANGIBLE ASSETS	6 Months Ended
	Sep. 30, 2013
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Purchased Intangible Assets [Text Block]	GOODWILL
	Goodwill as of September 30, 2013 and March 31, 2013 was $15.5 million, net of accumulated impairment of $54.6 million.

COMMITMENTS_AND_CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	COMMITMENTS AND CONTINGENCIES
	Minimum Future Rental Payments
	The Company leases certain equipment and facilities under operating leases expiring in various years through fiscal year 2022.  Minimum future rental payments under non-cancelable operating leases having remaining terms in excess of one year as of September 30, 2013 are as follows:
	Fiscal Year Ending March 31,	(in thousands)
	2014 (remaining 6 months)	$	1,997
	2015	1,920
	2016	1,341
	2017	730
	2018	652
	Thereafter	1,576
	Total minimum future rental payments	$	8,216
	Total rent expense for operating leases for the three and six months ended September 30, 2013 was $2.6 million and $4.1 million, respectively, which included $1.2 million and $1.5 million, respectively, related to early exit lease charges. Total rent expense for operating leases for the three and six months ended September 30, 2012 was $1.4 million and $2.8 million, respectively.
	Unconditional Purchase Obligations
	The Company utilizes several outsourcing partners to manufacture sub-assemblies for the Company’s products. These outsourcing partners acquire components and build product based on demand information supplied by the Company, which typically covers periods up to 270 days. The Company also obtains individual components for its products from a wide variety of individual suppliers. Consistent with industry practice, the Company acquires components through a combination of purchase orders, supplier contracts, and open orders based on projected demand information. As of September 30, 2013, the Company had outstanding off-balance sheet third-party manufacturing, component purchase, and other general and administrative commitments of $244.5 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 or 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, Plantronics also provides protection to customers against claims related to undiscovered liabilities, additional product liability, or environmental obligations.  In addition, the Company has entered into indemnification agreements with its directors and certain of its officers 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. The Company maintains director and officer insurance, which may cover certain liabilities arising from its obligation to indemnify its directors and officers in certain circumstances. It is not possible to determine the aggregate maximum potential loss under these indemnification agreements due to the limited history of prior indemnification claims and the unique facts and circumstances involved in each particular agreement. Such indemnification agreements 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. sued Plantronics, Inc. in the U.S. District Court for the District of Delaware, alleging violations of the Sherman Act, the Clayton Act, and Delaware common law. In its complaint, GN specifically alleges four causes of action: monopolization, attempted monopolization, concerted action in restraint of trade, and tortious interference with business relations. GN claims that Plantronics dominates the market for headsets sold into contact centers in the United States and that a critical channel for sales of headsets to contact centers is through a limited network of specialized independent distributors (“SIDs”). GN asserts that Plantronics attracts SIDs through Plantronics only distributor agreements and the use of these agreements is allegedly illegal. The Company denies each of the allegations in the complaint and is vigorously defending itself. Given the preliminary nature of the case, the Company is unable to estimate an amount or range of any reasonably possible losses resulting from these allegations.
	In addition, 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. 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.

CREDIT_AGREEMENT

CREDIT AGREEMENT	6 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	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 May 3, 2013 to extend its term to May 9, 2016 (as amended, "the Credit Agreement"). The Credit Agreement provides for a $100.0 million unsecured revolving line of credit ("line of credit") and, if requested by the Company, the Bank may increase its commitment thereunder by up to $100.0 million, for a total facility size of up to $200.0 million. As of September 30, 2013 and March 31, 2013, the Company had no outstanding borrowings under the line of credit.
	Loans under the Credit Agreement bear interest at the election of the Company (i) at the Bank's announced prime rate less 1.50% per annum, (ii) at a daily one month LIBOR rate plus 1.10% per annum or (iii) at an adjusted LIBOR rate, for a term of one, three or six months, plus 1.10% per annum. Interest on the loans is payable quarterly in arrears. In addition, the Company pays a fee equal to 0.20% per annum on the average daily unused amount of the line of credit, which is payable quarterly in arrears.
	Principal, together with accrued and unpaid interest, is due on the amended maturity date, May 9, 2016. The Company may prepay the loans and terminate the commitments in whole at any time, without premium or penalty, subject to reimbursement of certain costs in the case of LIBOR loans.
	The Company's obligations under the Credit Agreement are guaranteed by the Company's domestic subsidiaries, subject to certain exceptions.
	The line of credit requires the Company to comply with a maximum ratio of funded debt to earnings before interest, taxes, depreciation and amortization ("EBITDA") and a minimum EBITDA coverage ratio, in each case, at each fiscal quarter end 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 Credit Agreement at the end of each fiscal quarter of at least $200.0 million.
	The line of credit contains affirmative covenants, including covenants regarding the payment of taxes and other liabilities, maintenance of insurance, reporting requirements and compliance with applicable laws and regulations. The line of credit also contains negative covenants, among other things, limiting, subject to certain monetary thresholds, the ability of the Company to incur debt, make capital expenditures, grant liens, make acquisitions, and make investments. The events of default under the line of credit include payment defaults, cross defaults with certain other indebtedness, breaches of covenants, judgment defaults, and bankruptcy and insolvency events involving the Company or any of its subsidiaries. The Company was in compliance with all covenants at September 30, 2013.

STOCKBASED_COMPENSATION

STOCK-BASED COMPENSATION	6 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	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							Six Months Ended
			September 30,							September 30,
	(in thousands)		2013				2012			2013			2012
	Cost of revenues		$	638			$	526		$	1,173		$	1,122
	Research, development and engineering		1,652				1,256			3,020			2,380
	Selling, general and administrative		3,675				3,080			6,760			5,980
	Stock-based compensation included in operating expenses		5,327				4,336			9,780			8,360
	Total stock-based compensation		5,965				4,862			10,953			9,482
	Income tax benefit		(1,838		)		(1,532		)	(3,275		)	(2,914		)
	Total stock-based compensation, net of tax		$	4,127			$	3,330		$	7,678		$	6,568
	Stock Options
	The following is a summary of the Company’s stock option activity during the six months ended September 30, 2013:
		Options Outstanding
		Number of			Weighted				Weighted	Aggregate
		Shares			Average				Average	Intrinsic
					Exercise				Remaining	Value
					Price				Contractual Life
		(in thousands)							(in years)	(in thousands)
	Outstanding at March 31, 2013	2,415			$	27.96
	Options granted	176			$	45.98
	Options exercised	(667	)		$	24.09
	Options forfeited or expired	(10	)		$	32.74
	Outstanding at September 30, 2013	1,914			$	30.94			4.2	$	29,739
	Vested and expected to vest at September 30, 2013	1,872			$	30.76			4.2	$	29,419
	Exercisable at September 30, 2013	1,275			$	27.85			3.4	$	23,735
	The total intrinsic value of options exercised during the six months ended September 30, 2013 and 2012 was $14.5 million and $4.5 million, respectively.  Intrinsic value is defined as the amount by which the fair value of the underlying stock exceeds the exercise price at the time of option exercise. The total cash received as a result of stock option exercises during the six months ended September 30, 2013 was $16.1 million, net of taxes.
	As of September 30, 2013, total unrecognized compensation cost related to unvested stock options was $5.8 million, which is expected to be recognized over a weighted average period of 1.9 years.
	Restricted Stock
	Restricted stock consists of awards of restricted stock and restricted stock units ("RSUs"). The following is a summary of the Company’s restricted stock activity during the six months ended September 30, 2013:
		Number of			Weighted Average Grant Date Fair Value
		Shares
		(in thousands)
	Non-vested at March 31, 2013	1,025			$	33.34
	Restricted stock granted	541			$	46.1
	Restricted stock vested	(274	)		$	32.61
	Restricted stock forfeited	(31	)		$	36.86
	Non-vested at September 30, 2013	1,261			$	38.88
	The weighted average grant-date fair value of awards of restricted stock is based on the quoted market price of the Company's common stock on the date of grant. The weighted average grant-date fair value of restricted stock granted during the six months ended September 30, 2013 and 2012 was $46.10 and $32.05, respectively. The total fair value of restricted stock that vested during the six months ended September 30, 2013 and 2012 was $8.9 million and $4.9 million, respectively.
	As of September 30, 2013, total unrecognized compensation cost related to unvested restricted stock was $34.4 million, which is expected to be recognized over a weighted average period of 2.3 years.
	Valuation Assumptions
	The Company estimates the fair value of stock options and Employee Stock Purchase Plan (“ESPP”) shares using a Black-Scholes option valuation model.  At the date of grant, the Company estimated the fair value of each stock option grant and purchase right granted under the ESPP using the following weighted average assumptions:
			Three Months Ended							Six Months Ended
			September 30,							September 30,
	Employee Stock Options		2013				2012			2013			2012
	Expected volatility		30.7		%		43.5		%	33.5		%	42.2		%
	Risk-free interest rate		1.2		%		0.5		%	0.7		%	0.6		%
	Expected dividends		0.8		%		1.3		%	0.9		%	1.3		%
	Expected life (in years)		4.2				4.3			4.2			4.3
	Weighted-average grant date fair value		$	11.64			$	10.84		$	11.83		$	10.43
	ESPP
	Expected volatility		24.9		%		38.4		%	24.9		%	38.4		%
	Risk-free interest rate		0.1		%		0.1		%	0.1		%	0.1		%
	Expected dividends		0.9		%		1.1		%	0.9		%	1.1		%
	Expected life (in years)		0.5				0.5			0.5			0.5
	Weighted-average grant date fair value		$	9.58			$	8.95		$	9.58		$	8.95

COMMON_STOCK_REPURCHASES

COMMON STOCK REPURCHASES	6 Months Ended
	Sep. 30, 2013
Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	COMMON STOCK REPURCHASES
	From time to time, the Company's Board of Directors ("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 six months ended September 30, 2013 and 2012 are discussed below. As of September 30, 2013, there remained 274,874 shares authorized for repurchase under the program approved by the Board on August 6, 2012 and there were no remaining shares authorized under previously approved programs.
	Open Market Repurchases
	Under Board authorized programs, in the six months ended September 30, 2013 and 2012, the Company repurchased 607,033 shares and 633,613 shares, respectively, of its common stock in the open market for a total cost of $27.3 million and $19.9 million, respectively, and at an average price per share of $44.99 and $31.45, respectively.
	In addition, the Company withheld shares valued at $4.4 million in the six months ended September 30, 2013, compared to $1.7 million in the six months ended September 30, 2012, 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 effect of 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 and did not represent an expense to the Company.

ACCUMULATED_OTHER_COMPREHENSIV

ACCUMULATED OTHER COMPREHENSIVE INCOME	6 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income [Text Block]	ACCUMULATED OTHER COMPREHENSIVE INCOME
	The components of accumulated other comprehensive income ("AOCI"), net of immaterial tax effects, are as follows:
	(in thousands)	September 30, 2013			31-Mar-13
	Accumulated unrealized gain (loss) on cash flow hedges	$	(2,325	)	$	1,349
	Accumulated foreign currency translation adjustments	4,091			4,131
	Accumulated unrealized gain on investments	92			87
	Accumulated other comprehensive income	$	1,858		$	5,567

FOREIGN_CURRENCY_DERIVATIVES

FOREIGN CURRENCY DERIVATIVES	6 Months Ended
	Sep. 30, 2013
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 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 due to credit risk that it would incur 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 contracts as of September 30, 2013.  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 Plantronics and the counterparty as a result of multiple, separate derivative transactions. As of September 30, 2013, the Company has International Swaps and Derivatives Association (ISDA) agreements with three applicable banks and financial institutions which contain netting provisions. Plantronics has elected to present the fair value of derivative assets and liabilities within the Company's consolidated balance sheet on a gross basis even when derivative transactions are subject to master netting arrangements and may otherwise qualify for net presentation. However, the following tables provide information as if the Company had elected to offset the asset and liability balances of derivative instruments, netted in accordance with various criteria in the event of default or termination as stipulated by the terms of netting arrangements with each of the counterparties. 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 the applicable dates presented below, no cash collateral had been received or pledged related to these derivative instruments.
	Offsetting of Financial Assets/Liabilities under Master Netting Agreements with Derivative Counterparties
	As of September 30, 2013:
		Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Liabilities			Cash Collateral Received			Net Amount of Derivative Assets
	Derivatives subject to master netting agreements	$	70		$	(70	)	$	—		$	—
	Derivatives not subject to master netting agreements	—									—
	Total	$	70								$	—
		Gross Amount of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Assets			Cash Collateral Received			Net Amount of Derivative Liabilities
	Derivatives subject to master netting agreements	$	(1,577	)	$	70		$	—		$	(1,507	)
	Derivatives not subject to master netting agreements	(866		)							(866		)
	Total	$	(2,443	)							$	(2,373	)
	As of March 31, 2013:
		Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Liabilities			Cash Collateral Received			Net Amount of Derivative Assets
	Derivatives subject to master netting agreements	$	1,005		$	(215	)	$	—		$	790
	Derivatives not subject to master netting agreements	660									660
	Total	$	1,665								$	1,450
		Gross Amount of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Assets			Cash Collateral Received			Net Amount of Derivative Liabilities
	Derivatives subject to master netting agreements	$	(215	)	$	215		$	—		$	—
	Derivatives not subject to master netting agreements	(79		)							(79		)
	Total	$	(294	)							$	(79	)
	Refer to Note 4, Fair Value Measurements, for disclosure of the Company's fair value hierarchy for its derivative instruments.
	Non-Designated Hedges
	As of September 30, 2013, the Company had foreign currency forward contracts denominated in Euros ("EUR"), British Pound Sterling ("GBP"), and Australian Dollars ("AUD").  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 September 30, 2013:
		Local Currency				USD Equivalent				Position		Maturity
		(in thousands)				(in thousands)
	EUR	€	16,000			$	21,632			Sell EUR		1 month
	GBP	£	2,600			$	4,191			Sell GBP		1 month
	AUD	A$	4,600			$	4,276			Sell AUD		1 month
	Foreign currency transactions, net of the effect of forward contract hedging activity, resulted in immaterial net gains and immaterial net losses, respectively in the three and six months ended September 30, 2013 and immaterial net gains and immaterial net losses, respectively, in the three and six months ended September 30, 2012, which are included in interest and other income (expense), net in the condensed consolidated statements of operations.
	Cash Flow Hedges
	On a monthly basis, the Company enters into option contracts with a one-year term.  The Company does not purchase options for trading purposes.  As of September 30, 2013, the Company had foreign currency option contracts of approximately €50.8 million and £21.0 million.  As of March 31, 2013, the Company had foreign currency option contracts of approximately €50.2 million and £19.9 million.
	In the three and six months ended September 30, 2013, an immaterial loss on cash flow hedges was recognized in net revenues in the condensed consolidated statement of operations, compared to realized gains of $1.2 million and $3.1 million for the three and six months periods in the prior year, respectively.  A loss of $2.0 million, net of tax, in accumulated other comprehensive income ("AOCI") as of September 30, 2013 is expected to be reclassified to net revenues during the next 12 months due to the recognition of the hedged forecasted sales.
	The Company hedges expenditures denominated in Mexican Peso (“MX$”), which are designated as cash flow hedges and are accounted for under the hedge accounting provisions of the Derivatives and Hedging Topic of the FASB ASC.  The Company hedges a portion of the forecasted MX$ denominated expenditures with a cross-currency swap.  The effective portion of the hedge gain or loss is initially reported as a component of AOCI and subsequently reclassified into cost of revenues when the hedged exposure affects operations.  Any ineffective portion of related gains or losses is recorded in the condensed consolidated statements of operations immediately.  As of September 30, 2013 and March 31, 2013, the Company had foreign currency swap contracts of approximately MX$361.1 million and MX$325.4 million, respectively.
	In the three and six months ended September 30, 2013 and 2012, there were no material realized gains or losses on MX$ cash flow hedges recognized in cost of revenues in the condensed consolidated statement of operations and there were no material gains or losses in AOCI as of September 30, 2013 to be recognized during the next 12 months due to the recognition of the hedged forecasted expenditures.
	The following table summarizes the notional value of the Company’s outstanding MX$ cross-currency swaps and approximate USD Equivalent at September 30, 2013:
		Local Currency				USD Equivalent				Position		Maturity
		(in thousands)				(in thousands)
	MX$	$	361,100			$	27,500			Buy MX$		Monthly over	15 months
	The amounts in the tables below include fair value adjustments related to the Company’s own credit risk and counterparty credit risk.
	Fair Value of Derivative Contracts
	The fair value of derivative contracts was as follows:
			Derivative Assets								Derivative Liabilities
			Reported in Other Current Assets								Reported in Accrued Liabilities
			September 30,				March 31,				September 30,			March 31,
	(in thousands)		2013				2013				2013			2013
	Foreign exchange contracts designated as cash flow hedges		$	70			$	1,665			$	2,443		$	294
	Effect of Designated Derivative Contracts on AOCI
	The following table represents the balance of designated derivative contracts as of September 30, 2013 and March 31, 2013, and the pre-tax impact of designated derivative contracts on AOCI for the six months ended September 30, 2013:
	(in thousands)		Gain (loss) included in AOCI as of March 31, 2013				Amount of gain (loss)				Amount of gain (loss)			Gain (loss) included in AOCI as of September 30, 2013
							recognized in AOCI				reclassified from AOCI
							(effective portion)				to income (loss)
											(effective portion)
	Foreign exchange contracts designated as cash flow hedges		$	1,371			$	(3,646	)		$	98		$	(2,373	)
	Effect of Designated Derivative Contracts on the Condensed Consolidated Statements of Operations
	The effect of designated derivative contracts on results of operations recognized in gross profit in the condensed consolidated statements of operations was as follows:
			Three Months Ended								Six Months Ended
			September 30,								September 30,
	(in thousands)		2013				2012				2013			2012
Gain (loss) on foreign exchange contracts designated as cash flow hedges		$	(156	)		$	1,074			$	98		$	2,768
Effect of Non-Designated Derivative Contracts on the Condensed Consolidated Statements of Operations
The effect of non-designated derivative contracts on results of operations recognized in interest and other income (expense), net in the condensed consolidated statements of operations was as follows:
		Three Months Ended								Six Months Ended
		September 30,								September 30,
(in thousands)		2013				2012				2013			2012
Gain (loss) on foreign exchange contracts		$	(1,266	)		$	(648	)		$	(1,193	)	$	819

INCOME_TAXES

INCOME TAXES	6 Months Ended
	Sep. 30, 2013
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 rate for the three and six months ended September 30, 2013 was 25.8% and 24.9%, respectively, compared to 25.5% and 26.0%, respectively, for the same periods in the prior year. The effective tax rates differ from the statutory rate due to the impact of foreign operations taxed at different statutory rates, tax credits, state taxes, and other factors.
	Included in long-term income taxes payable in the condensed consolidated balance sheets as of September 30, 2013 and March 31, 2013 were unrecognized tax benefits of $11.8 million and $11.1 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 is $1.9 million as of September 30, 2013 as compared to $2.0 million as of March 31, 2013.  No penalties have been accrued.
	The Company is under examination by the Internal Revenue Service for its 2010 tax year and the California Franchise Tax Board for its 2007 and 2008 tax years.  Foreign income tax matters for material tax jurisdictions have been concluded for tax years prior to fiscal 2007, except for the United Kingdom, which has 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.

COMPUTATION_OF_EARNINGS_PER_CO

COMPUTATION OF EARNINGS PER COMMON SHARE	6 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]
COMPUTATION OF EARNINGS PER COMMON SHARE	COMPUTATION OF EARNINGS PER COMMON SHARE
	The Company has a share-based compensation plan under which employees may be granted share-based 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 as described in the Earnings per Share Topic of the FASB ASC. The two-class method of calculating earnings per share did not have a material impact on the Company's earnings per share calculation for the three and six month periods ending September 30, 2013 or 2012.
	The following table sets forth the computation of basic and diluted earnings per common share for the three and six months ended September 30, 2013 and 2012:
		Three Months Ended				Six Months Ended
		September 30,				September 30,
	(in thousands, except per share data)	2013		2012		2013		2012
	Numerator:
	Net income	$	23,138	$	25,924	$	50,091	$	49,487
	Denominator:
	Weighted average common shares-basic	42,810		41,482		42,751		41,571
	Dilutive effect of employee equity incentive plans	787		921		916		950
	Weighted average common shares-diluted	43,597		42,403		43,667		42,521
	Basic earnings per common share	$	0.54	$	0.62	$	1.17	$	1.19
	Diluted earnings per common share	$	0.53	$	0.61	$	1.15	$	1.16
	Potentially dilutive securities excluded from diluted earnings per common share because their effect is anti-dilutive	183		1,061		162		1,081

REVENUE_AND_MAJOR_CUSTOMERS_No

REVENUE AND MAJOR CUSTOMERS (Notes)	6 Months Ended
	Sep. 30, 2013
REVENUE AND MAJOR CUSTOMERS [Abstract]
Revenue and Major Customers [Text Block]	REVENUE AND MAJOR CUSTOMERS
	The Company designs, manufactures, markets, and sells headsets for business and consumer applications, and other specialty products for the hearing impaired.  With respect to headsets, it makes products for use in offices and contact centers, with mobile and cordless phones, and with computers and gaming consoles.  Major product categories include “Office and Contact Center”, which includes corded and cordless communication headsets, audio processors, and telephone systems; “Mobile”, which includes Bluetooth and corded products for mobile phone applications; “Gaming and Computer Audio”, which includes personal computer ("PC") and gaming headsets; and “Clarity”, which includes specialty products marketed for hearing impaired individuals.
	The following table presents net revenues by product group for the three and six months ended September 30, 2013 and 2012:
		Three Months Ended				Six Months Ended
		September 30,				September 30,
	(in thousands)	2013		2012		2013		2012
	Net revenues from unaffiliated customers:
	Office and Contact Center	$	139,945	$	133,119	$	291,128	$	267,152
	Mobile	42,685		33,305		84,309		69,462
	Gaming and Computer Audio	8,156		7,797		14,607		14,586
	Clarity	3,194		5,059		6,754		9,445
	Total net revenues	$	193,980	$	179,280	$	396,798	$	360,645
	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 six months ended September 30, 2013 and 2012. The following table presents net revenues by geography:
		Three Months Ended				Six Months Ended
		September 30,				30-Sep-13
	(in thousands)	2013		2012		2013		2012
	Net revenues from unaffiliated customers:
	U.S.	$	115,795	$	107,513	$	237,113	$	211,591
	Europe and Africa	43,094		38,951		87,479		80,527
	Asia Pacific	23,280		19,839		47,160		43,418
	Americas, excluding U.S.	11,811		12,977		25,046		25,109
	Total international net revenues	78,185		71,767		159,685		149,054
	Total net revenues	$	193,980	$	179,280	$	396,798	$	360,645
	One customer, Ingram Micro, accounted for 10.1% and 10.3%, respectively of net revenues for the three and six months ended September 30, 2013. This customer also accounted for 10% of net revenues for the three months ended September 30, 2012. No customer accounted for 10% or more of net revenues for the six months ended September 30, 2012.
	Ingram Micro also accounted for 11.7% and 10.3% of net accounts receivable in the condensed consolidated balance sheets at September 30, 2013 and March 31, 2013, respectively.

SUBSEQUENT_EVENTS

SUBSEQUENT EVENTS	3 Months Ended
	Sep. 30, 2013
Subsequent Events [Abstract]
Subsequent Events [Text Block]	SUBSEQUENT EVENTS
	On October 29, 2013, the Company's Board of Directors declared a cash dividend of $0.10 per share of the Company's common stock, payable on December 10, 2013 to stockholders of record at the close of business on November 20, 2013.

CASH_CASH_EQUIVALENTS_AND_INVE1

CASH, CASH EQUIVALENTS, AND INVESTMENTS (Tables)	6 Months Ended
	Sep. 30, 2013
CASH, CASH EQUIVALENTS AND INVESTMENTS [Abstract]
Cash, Cash Equivalents, and Investments [Table Text Block]	The following table represents the Company’s cash, cash equivalents, and investments as of September 30, 2013 and March 31, 2013:
	(in thousands)	September 30, 2013									March 31, 2013
		Amortized		Gross		Gross			Fair		Amortized		Gross		Gross			Fair
		Cost		Unrealized		Unrealized			Value		Cost		Unrealized		Unrealized			Value
				Gains		Losses							Gains		Losses
	Cash and cash equivalents:
	Cash	$	236,372	$	—	$	—		$	236,372	$	118,881	$	—	$	—		$	118,881
	Cash equivalents	9,607		1		—			9,608		109,895		—		—			109,895
	Total cash and cash equivalents	$	245,979	$	1	$	—		$	245,980	$	228,776	$	—	$	—		$	228,776
	Short-term investments:
	U.S. Treasury Bills and Government Agency Securities	$	56,964	$	33	$	(15	)	$	56,982	$	66,092	$	18	$	(3	)	$	66,107
	Commercial paper	30,835		12		(1		)	30,846		15,670		9		—			15,679
	Corporate bonds	24,294		19		(1		)	24,312		34,766		31		(2		)	34,795
	Certificates of deposit ("CDs")	1,002		1		—			1,003		—		—		—			—
	Total short-term investments	$	113,095	$	65	$	(17	)	$	113,143	$	116,528	$	58	$	(5	)	$	116,581
	Long-term investments:
	U.S. Treasury Bills and Government Agency Securities	$	15,473	$	18	$	(4	)	$	15,487	$	55,317	$	42	$	(1	)	$	55,358
	Corporate bonds	63,926		85		(23		)	63,988		23,878		23		(3		)	23,898
	CDs	—		—		—			—		1,002		3		—			1,005
	Total long-term investments	$	79,399	$	103	$	(27	)	$	79,475	$	80,197	$	68	$	(4	)	$	80,261
	Total cash, cash equivalents and investments	$	438,473	$	169	$	(44	)	$	438,598	$	425,501	$	126	$	(9	)	$	425,618
Amortized Cost and Fair Value of Cash Equivalents, Short-Term Investments, and Long-Term Investments by Stated Maturity [Table Text Block]	The following table summarizes the amortized cost and fair value of the Company’s cash equivalents, short-term investments, and long-term investments, classified by stated maturity as of September 30, 2013 and March 31, 2013:
	(in thousands)	September 30, 2013				March 31, 2013
		Amortized		Fair Value		Amortized			Fair Value
		Cost				Cost
	Due in 1 year or less	$	122,702	$	122,751	$	226,423		$	226,476
	Due in 1 to 3 years	79,399		79,475		80,197			80,261
	Total	$	202,101	$	202,226	$	306,620		$	306,737

FAIR_VALUE_MEASUREMENTS_Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]
Fair Value Hierarchy of Financial Assets and Liabilities [Table Text Block]	The following tables present the Company’s financial assets and liabilities, measured at fair value, by level within the fair value hierarchy as of September 30, 2013 and March 31, 2013.
	Fair Values as of September 30, 2013:
	(in thousands)	Level 1		Level 2		Total
	Cash and cash equivalents:
	Cash	$	236,372	$	—	$	236,372
	Mutual funds	609		—		609
	Commercial paper	—		8,999		8,999
	Short-term investments:
	Government Agency Securities	—		56,982		56,982
	Commercial paper	—		30,846		30,846
	Corporate bonds	—		24,312		24,312
	CDs	—		1,003		1,003
	Long-term investments:
	Government Agency Securities	—		15,487		15,487
	Corporate bonds	—		63,988		63,988
	Other current assets:
	Derivative assets	—		70		70
	Total assets measured at fair value	$	236,981	$	201,687	$	438,668
	Accrued liabilities:
	Derivative liabilities	$	8	$	2,435	$	2,443
	Fair Values as of March 31, 2013:
	(in thousands)	Level 1		Level 2		Total
	Cash and cash equivalents:
	Cash	$	118,881	$	—	$	118,881
	U.S. Treasury Bills	104,995		—		104,995
	Commercial paper	—		4,900		4,900
	Short-term investments:
	U.S. Treasury Bills and Government Agency Securities	7,243		58,864		66,107
	Commercial paper	—		15,679		15,679
	Corporate bonds	—		34,795		34,795
	Long-term investments:
	U.S. Treasury Bills and Government Agency Securities	22,904		32,454		55,358
	Corporate bonds	—		23,898		23,898
	CDs	—		1,005		1,005
	Other current assets:
	Derivative assets	—		1,665		1,665
	Total assets measured at fair value	$	254,023	$	173,260	$	427,283
	Accrued liabilities:
	Derivative liabilities	$	3	$	291	$	294

DETAILS_OF_CERTAIN_BALANCE_SHE1

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS (Tables)	6 Months Ended
	Sep. 30, 2013
Balance Sheet Related Disclosures [Abstract]
Accounts receivable, net [Table Text Block]	Accounts receivable, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Accounts receivable	$	147,581		$	151,250
	Provisions for returns	(7,756		)	(8,957		)
	Provisions for promotions, rebates, and other	(15,771		)	(13,675		)
	Provisions for doubtful accounts and sales allowances	(306		)	(409		)
	Accounts receivable, net	$	123,748		$	128,209
Inventory, net [Table Text Block]	Inventory, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Raw materials	$	33,659		$	28,743
	Work in process	432			82
	Finished goods	35,059			38,610
	Inventory, net	$	69,150		$	67,435
Property, plant, and equipment [Table Text Block]	Property, plant, and equipment, net:
		September 30,			March 31,
	(in thousands)	2013			2013
	Land	$	13,961		$	13,961
	Buildings and improvements (useful life: 7-30 years)	89,434			72,263
	Machinery and equipment (useful life: 2-10 years)	94,737			88,538
	Software (useful life: 5-6 years)	31,268			30,538
	Construction in progress	17,892			16,101
		247,292			221,401
	Accumulated depreciation and amortization	(128,974		)	(122,290		)
	Property, plant, and equipment, net	$	118,318		$	99,111
Accrued liabilities [Table Text Block]	Accrued Liabilities:
		September 30,			March 31,
	(in thousands)	2013			2013
	Employee compensation and benefits	$	23,164		$	29,796
	Warranty obligation	12,881			13,410
	Accrued advertising, sales, and marketing	4,245			3,735
	Deferred revenue	3,994			3,072
	Liabilities related to derivatives contracts	2,443			294
	Income taxes payable	—			3,376
	Restructuring and other related charges (1)	47			1,165
	Accrued other	14,152			11,571
	Accrued liabilities	$	60,926		$	66,419
Changes in the warranty obligation [Table Text Block]	Changes in the warranty obligation during the six months ended September 30, 2013 were as follows:
		Six Months Ended			Six Months Ended
	(in thousands)	September 30, 2013			September 30, 2012
	Warranty obligation at March 31, 2013	$	13,410		$	13,346
	Warranty provision relating to products shipped	4,154			7,440
	Deductions for warranty claims processed	(4,683		)	(8,064		)
	Warranty obligation at September 30, 2013	$	12,881		$	12,722

COMMITMENTS_AND_CONTINGENCIES_

COMMITMENTS AND CONTINGENCIES (Tables)	6 Months Ended
	Sep. 30, 2013
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	Minimum future rental payments under non-cancelable operating leases having remaining terms in excess of one year as of September 30, 2013 are as follows:
	Fiscal Year Ending March 31,	(in thousands)
	2014 (remaining 6 months)	$	1,997
	2015	1,920
	2016	1,341
	2017	730
	2018	652
	Thereafter	1,576
	Total minimum future rental payments	$	8,216

STOCKBASED_COMPENSATION_Tables

STOCK-BASED COMPENSATION (Tables)	6 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Expense Included in Statements of Operations [Table Text Block]	The following table summarizes the amount of stock-based compensation included in the condensed consolidated statements of operations:
			Three Months Ended							Six Months Ended
			September 30,							September 30,
	(in thousands)		2013				2012			2013			2012
	Cost of revenues		$	638			$	526		$	1,173		$	1,122
	Research, development and engineering		1,652				1,256			3,020			2,380
	Selling, general and administrative		3,675				3,080			6,760			5,980
	Stock-based compensation included in operating expenses		5,327				4,336			9,780			8,360
	Total stock-based compensation		5,965				4,862			10,953			9,482
	Income tax benefit		(1,838		)		(1,532		)	(3,275		)	(2,914		)
	Total stock-based compensation, net of tax		$	4,127			$	3,330		$	7,678		$	6,568
Summary of Stock Option Activity [Table Text Block]	The following is a summary of the Company’s stock option activity during the six months ended September 30, 2013:
		Options Outstanding
		Number of			Weighted				Weighted	Aggregate
		Shares			Average				Average	Intrinsic
					Exercise				Remaining	Value
					Price				Contractual Life
		(in thousands)							(in years)	(in thousands)
	Outstanding at March 31, 2013	2,415			$	27.96
	Options granted	176			$	45.98
	Options exercised	(667	)		$	24.09
	Options forfeited or expired	(10	)		$	32.74
	Outstanding at September 30, 2013	1,914			$	30.94			4.2	$	29,739
	Vested and expected to vest at September 30, 2013	1,872			$	30.76			4.2	$	29,419
	Exercisable at September 30, 2013	1,275			$	27.85			3.4	$	23,735
Summary of Restricted Stock Activity [Table Text Block]	Restricted stock consists of awards of restricted stock and restricted stock units ("RSUs"). The following is a summary of the Company’s restricted stock activity during the six months ended September 30, 2013:
		Number of			Weighted Average Grant Date Fair Value
		Shares
		(in thousands)
	Non-vested at March 31, 2013	1,025			$	33.34
	Restricted stock granted	541			$	46.1
	Restricted stock vested	(274	)		$	32.61
	Restricted stock forfeited	(31	)		$	36.86
	Non-vested at September 30, 2013	1,261			$	38.88
Valuation Assumptions [Table Text Block]	At the date of grant, the Company estimated the fair value of each stock option grant and purchase right granted under the ESPP using the following weighted average assumptions:
			Three Months Ended							Six Months Ended
			September 30,							September 30,
	Employee Stock Options		2013				2012			2013			2012
	Expected volatility		30.7		%		43.5		%	33.5		%	42.2		%
	Risk-free interest rate		1.2		%		0.5		%	0.7		%	0.6		%
	Expected dividends		0.8		%		1.3		%	0.9		%	1.3		%
	Expected life (in years)		4.2				4.3			4.2			4.3
	Weighted-average grant date fair value		$	11.64			$	10.84		$	11.83		$	10.43
	ESPP
	Expected volatility		24.9		%		38.4		%	24.9		%	38.4		%
	Risk-free interest rate		0.1		%		0.1		%	0.1		%	0.1		%
	Expected dividends		0.9		%		1.1		%	0.9		%	1.1		%
	Expected life (in years)		0.5				0.5			0.5			0.5
	Weighted-average grant date fair value		$	9.58			$	8.95		$	9.58		$	8.95

ACCUMULATED_OTHER_COMPREHENSIV1

ACCUMULATED OTHER COMPREHENSIVE INCOME (Tables)	6 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Schedule of Accumulated Other Comprehensive Income [Table Text Block]	The components of accumulated other comprehensive income ("AOCI"), net of immaterial tax effects, are as follows:
	(in thousands)	September 30, 2013			31-Mar-13
	Accumulated unrealized gain (loss) on cash flow hedges	$	(2,325	)	$	1,349
	Accumulated foreign currency translation adjustments	4,091			4,131
	Accumulated unrealized gain on investments	92			87
	Accumulated other comprehensive income	$	1,858		$	5,567

FOREIGN_CURRENCY_DERIVATIVES_T

FOREIGN CURRENCY DERIVATIVES (Tables)	6 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Offsetting Assets [Table Text Block]
		Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Liabilities			Cash Collateral Received			Net Amount of Derivative Assets
	Derivatives subject to master netting agreements	$	1,005		$	(215	)	$	—		$	790
	Derivatives not subject to master netting agreements	660									660
	Total	$	1,665								$	1,450
		Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Liabilities			Cash Collateral Received			Net Amount of Derivative Assets
	Derivatives subject to master netting agreements	$	70		$	(70	)	$	—		$	—
	Derivatives not subject to master netting agreements	—									—
	Total	$	70								$	—
Offsetting Liabilities [Table Text Block]
		Gross Amount of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Assets			Cash Collateral Received			Net Amount of Derivative Liabilities
	Derivatives subject to master netting agreements	$	(1,577	)	$	70		$	—		$	(1,507	)
	Derivatives not subject to master netting agreements	(866		)							(866		)
	Total	$	(2,443	)							$	(2,373	)
		Gross Amount of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets			Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements
	(in thousands)				Gross Amount of Eligible Offsetting Recognized Derivative Assets			Cash Collateral Received			Net Amount of Derivative Liabilities
	Derivatives subject to master netting agreements	$	(215	)	$	215		$	—		$	—
	Derivatives not subject to master netting agreements	(79		)							(79		)
	Total	$	(294	)							$	(79	)
Notional Value of Outstanding Foreign Exchange Currency Contracts [Table Text Block]	The following table summarizes the notional value of the Company’s outstanding foreign exchange currency contracts and approximate U.S. Dollar ("USD") equivalent at September 30, 2013:
		Local Currency				USD Equivalent				Position		Maturity
		(in thousands)				(in thousands)
	EUR	€	16,000			$	21,632			Sell EUR		1 month
	GBP	£	2,600			$	4,191			Sell GBP		1 month
	AUD	A$	4,600			$	4,276			Sell AUD		1 month
Effect of Designated Derivative Contracts Recognized in Gross Profit [Table Text Block]	The effect of designated derivative contracts on results of operations recognized in gross profit in the condensed consolidated statements of operations was as follows:
			Three Months Ended								Six Months Ended
			September 30,								September 30,
	(in thousands)		2013				2012				2013			2012
	Gain (loss) on foreign exchange contracts designated as cash flow hedges		$	(156	)		$	1,074			$	98		$	2,768
Notional Value of Outstanding Cross-Currency Swaps [Table Text Block]	The following table summarizes the notional value of the Company’s outstanding MX$ cross-currency swaps and approximate USD Equivalent at September 30, 2013:
		Local Currency				USD Equivalent				Position		Maturity
		(in thousands)				(in thousands)
	MX$	$	361,100			$	27,500			Buy MX$		Monthly over	15 months
Fair Value of Derivative Contracts Under the Derivatives and Hedging Topic of the FASB ASC [Table Text Block]	The fair value of derivative contracts was as follows:
			Derivative Assets								Derivative Liabilities
			Reported in Other Current Assets								Reported in Accrued Liabilities
			September 30,				March 31,				September 30,			March 31,
	(in thousands)		2013				2013				2013			2013
	Foreign exchange contracts designated as cash flow hedges		$	70			$	1,665			$	2,443		$	294
Balance of Designated Derivative Contracts and the Pre-Tax Impact on Accumulated Other Comprehensive Income [Table Text Block]	The following table represents the balance of designated derivative contracts as of September 30, 2013 and March 31, 2013, and the pre-tax impact of designated derivative contracts on AOCI for the six months ended September 30, 2013:
	(in thousands)		Gain (loss) included in AOCI as of March 31, 2013				Amount of gain (loss)				Amount of gain (loss)			Gain (loss) included in AOCI as of September 30, 2013
							recognized in AOCI				reclassified from AOCI
							(effective portion)				to income (loss)
											(effective portion)
	Foreign exchange contracts designated as cash flow hedges		$	1,371			$	(3,646	)		$	98		$	(2,373	)
Effect of Non-Designated Derivative Contracts Recognized in Interest and Other Income, Net [Table Text Block]	The effect of non-designated derivative contracts on results of operations recognized in interest and other income (expense), net in the condensed consolidated statements of operations was as follows:
			Three Months Ended								Six Months Ended
			September 30,								September 30,
	(in thousands)		2013				2012				2013			2012
	Gain (loss) on foreign exchange contracts		$	(1,266	)		$	(648	)		$	(1,193	)	$	819

COMPUTATION_OF_EARNINGS_PER_CO1

COMPUTATION OF EARNINGS PER COMMON SHARE (Tables)	6 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings per Common Share [Table Text Block]	The following table sets forth the computation of basic and diluted earnings per common share for the three and six months ended September 30, 2013 and 2012:
		Three Months Ended				Six Months Ended
		September 30,				September 30,
	(in thousands, except per share data)	2013		2012		2013		2012
	Numerator:
	Net income	$	23,138	$	25,924	$	50,091	$	49,487
	Denominator:
	Weighted average common shares-basic	42,810		41,482		42,751		41,571
	Dilutive effect of employee equity incentive plans	787		921		916		950
	Weighted average common shares-diluted	43,597		42,403		43,667		42,521
	Basic earnings per common share	$	0.54	$	0.62	$	1.17	$	1.19
	Diluted earnings per common share	$	0.53	$	0.61	$	1.15	$	1.16
	Potentially dilutive securities excluded from diluted earnings per common share because their effect is anti-dilutive	183		1,061		162		1,081

REVENUE_AND_MAJOR_CUSTOMERS_Ta

REVENUE AND MAJOR CUSTOMERS (Tables)	6 Months Ended
	Sep. 30, 2013
REVENUE AND MAJOR CUSTOMERS [Abstract]
Net Revenues by Product Group [Table Text Block]	The following table presents net revenues by product group for the three and six months ended September 30, 2013 and 2012:
		Three Months Ended				Six Months Ended
		September 30,				September 30,
	(in thousands)	2013		2012		2013		2012
	Net revenues from unaffiliated customers:
	Office and Contact Center	$	139,945	$	133,119	$	291,128	$	267,152
	Mobile	42,685		33,305		84,309		69,462
	Gaming and Computer Audio	8,156		7,797		14,607		14,586
	Clarity	3,194		5,059		6,754		9,445
	Total net revenues	$	193,980	$	179,280	$	396,798	$	360,645
Net Revenues by Geography [Table Text Block]	The following table presents net revenues by geography:
		Three Months Ended				Six Months Ended
		September 30,				30-Sep-13
	(in thousands)	2013		2012		2013		2012
	Net revenues from unaffiliated customers:
	U.S.	$	115,795	$	107,513	$	237,113	$	211,591
	Europe and Africa	43,094		38,951		87,479		80,527
	Asia Pacific	23,280		19,839		47,160		43,418
	Americas, excluding U.S.	11,811		12,977		25,046		25,109
	Total international net revenues	78,185		71,767		159,685		149,054
	Total net revenues	$	193,980	$	179,280	$	396,798	$	360,645

BASIS_OF_PRESENTATION_Details

BASIS OF PRESENTATION (Details)	3 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2014	Mar. 31, 2013
Number of Weeks [Abstract]
Number of Weeks In Fiscal Year			P52W	P52W
Quarter To Date Number of Weeks In Fiscal Quarter	P13W	P13W

CASH_CASH_EQUIVALENTS_AND_INVE2

CASH, CASH EQUIVALENTS, AND INVESTMENTS (Details) (USD $)	3 Months Ended	12 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and Cash Equivalents, Fair Value	$245,980	$228,776	$207,929	$209,335
Cash, Cash Equivalents Before Unrealized Gains And Losses, and Amortized Cost Basis of Available-For-Sale Securities	438,473	425,501
Cash Equivalents and Available-For-Sale Securities, Gross Unrealized Gains	169	126
Cash Equivalents and Available-For-Sale Securities, Gross Unrealized Losses	-44	-9
Cash and Fair Value of Cash Equivalents and Available-For-Sale Securities	438,598	425,618
Available for Sale Securities, Debt Maturities [Abstract]
Due in 1 year or less (amortized cost)	122,702	226,423
Due in 1 to 3 years (amortized cost)	79,399	80,197
Due in 1 year or less (fair value)	122,751	226,476
Due in 1 to 3 years (fair value)	79,475	80,261
Total amortized cost	202,101	306,620
Total fair value	202,226	306,737
U.S. Treasury Bills and Government Agency Securities [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	15,473	55,317
Available-for-sale securities, gross unrealized gains	18	42
Available-for-sale securities, gross unrealized losses	-4	-1
Available-for-sale securities, fair value	15,487	55,358
Corporate Bonds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	63,926	23,878
Available-for-sale securities, gross unrealized gains	85	23
Available-for-sale securities, gross unrealized losses	-23	-3
Available-for-sale securities, fair value	63,988	23,898
Certificates of Deposit [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	0	1,002
Available-for-sale securities, gross unrealized gains	0	3
Available-for-sale securities, gross unrealized losses	0	0
Available-for-sale securities, fair value	0	1,005
U.S. Treasury Bills and Government Agency Securities [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	56,964	66,092
Available-for-sale securities, gross unrealized gains	33	18
Available-for-sale securities, gross unrealized losses	-15	-3
Available-for-sale securities, fair value	56,982	66,107
Commercial Paper [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	30,835	15,670
Available-for-sale securities, gross unrealized gains	12	9
Available-for-sale securities, gross unrealized losses	-1	0
Available-for-sale securities, fair value	30,846	15,679
Corporate Bonds [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	24,294	34,766
Available-for-sale securities, gross unrealized gains	19	31
Available-for-sale securities, gross unrealized losses	-1	-2
Available-for-sale securities, fair value	24,312	34,795
Certificates of Deposit [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	1,002
Available-for-sale securities, gross unrealized gains	1
Available-for-sale securities, gross unrealized losses	0
Available-for-sale securities, fair value	1,003
Cash [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash	236,372	118,881
Cash Equivalents [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash Equivalents Before Unrealized Gains And Losses	9,607	109,895
Cash Equivalents, Gross Unrealized Gains	1	0
Cash Equivalents, Gross Unrealized Losses	0	0
Cash equivalents, fair value	9,608	109,895
Cash and cash equivalents [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Cash and Cash Equivalents Before Unrealized Gains And Losses	245,979	228,776
Cash Equivalents, Gross Unrealized Gains	1	0
Cash Equivalents, Gross Unrealized Losses	0	0
Cash and Cash Equivalents, Fair Value	245,980	228,776
Short-term Investments [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	113,095	116,528
Available-for-sale securities, gross unrealized gains	65	58
Available-for-sale securities, gross unrealized losses	-17	-5
Available-for-sale securities, fair value	113,143	116,581
Long-term investments [Member]
Schedule of Cash, Cash Equivalents and Investments [Line Items]
Available-for-sale securities, amortized cost basis	79,399	80,197
Available-for-sale securities, gross unrealized gains	103	68
Available-for-sale securities, gross unrealized losses	-27	-4
Available-for-sale securities, fair value	$79,475	$80,261

FAIR_VALUE_MEASUREMENTS_Detail

FAIR VALUE MEASUREMENTS (Details) (USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Total assets measured at fair value	$236,981	$254,023
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Total assets measured at fair value	201,687	173,260
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Total assets measured at fair value	438,668	427,283
U.S. Treasury Bills and Government Agency Securities [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	15,487	55,358
Corporate Bonds [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	63,988	23,898
Certificates of Deposit [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	1,005
U.S. Treasury Bills and Government Agency Securities [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	56,982	66,107
Commercial Paper [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	30,846	15,679
Corporate Bonds [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	24,312	34,795
Certificates of Deposit [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	1,003
Cash and Cash Equivalents [Member] | Cash [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	236,372	118,881
Cash and Cash Equivalents [Member] | Cash [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Cash and Cash Equivalents [Member] | Cash [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	236,372	118,881
Cash and Cash Equivalents [Member] | Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	609
Cash and Cash Equivalents [Member] | Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0
Cash and Cash Equivalents [Member] | Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	609
Cash and Cash Equivalents [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure		104,995
Cash and Cash Equivalents [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure		0
Cash and Cash Equivalents [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure		104,995
Cash and Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Cash and Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	8,999	4,900
Cash and Cash Equivalents [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	8,999	4,900
Short-term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	7,243
Short-term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	56,982	58,864
Short-term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	56,982	66,107
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	0
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	30,846	15,679
Short-term Investments [Member] | Commercial Paper [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	30,846	15,679
Short-term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	0
Short-term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	24,312	34,795
Short-term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	24,312	34,795
Short-term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0
Short-term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	1,003
Short-term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	1,003
Long Term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	22,904
Long Term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	15,487	32,454
Long Term Investments [Member] | U.S. Treasury Bills and Government Agency Securities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	15,487	55,358
Long Term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	0	0
Long Term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	63,988	23,898
Long Term Investments [Member] | Corporate Bonds [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure	63,988	23,898
Long Term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure		1,005
Long Term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure		0
Long Term Investments [Member] | Certificates of Deposit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Available-for-sale Securities, Fair Value Disclosure		1,005
Other Current Assets [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Derivative assets	0	0
Other Current Assets [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Derivative assets	70	1,665
Other Current Assets [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Assets, Balance Sheet Groupings [Abstract]
Derivative assets	70	1,665
Accrued Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Derivative liabilities	8	3
Accrued Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Derivative liabilities	2,435	291
Accrued Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Derivative liabilities	$2,443	$294

DETAILS_OF_CERTAIN_BALANCE_SHE2

DETAILS OF CERTAIN BALANCE SHEET ACCOUNTS (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Accounts receivable, net [Line Items]
Accounts receivable	$147,581,000		$147,581,000		$151,250,000
Accounts receivable, net	123,748,000		123,748,000		128,209,000
Inventory, net [Abstract]
Raw materials	33,659,000		33,659,000		28,743,000
Work in process	432,000		432,000		82,000
Finished goods	35,059,000		35,059,000		38,610,000
Inventory, net	69,150,000		69,150,000		67,435,000
Property, plant, and equipment, net [Abstract]
Land	13,961,000		13,961,000		13,961,000
Buildings and improvements	89,434,000		89,434,000		72,263,000
Machinery and equipment	94,737,000		94,737,000		88,538,000
Software	31,268,000		31,268,000		30,538,000
Construction in progress	17,892,000		17,892,000		16,101,000
Property, plant, and equipment, gross	247,292,000		247,292,000		221,401,000
Accumulated depreciation and amortization	-128,974,000		-128,974,000		-122,290,000
Property, plant, and equipment, net	118,318,000		118,318,000		99,111,000
Depreciation and amortization	3,700,000	4,000,000	7,700,000	7,700,000
Document Period End Date			30-Sep-13
Capitalized Computer Software, Amortization			1,200,000	1,500,000
Unamortized capitalized computer software costs	5,600,000		5,600,000		6,100,000
Accrued Liabilities [Abstract]
Employee compensation and benefits	23,164,000		23,164,000		29,796,000
Warranty obligation	12,881,000		12,881,000		13,410,000
Accrued advertising, sales, and marketing	4,245,000		4,245,000		3,735,000
Deferred revenue	3,994,000		3,994,000		3,072,000
Liabilities related to derivative contracts	2,443,000		2,443,000		294,000
Income taxes payable	0		0		3,376,000
Restructuring and other related charges	47,000		47,000		1,165,000
Accrued other	14,152,000		14,152,000		11,571,000
Accrued liabilities	60,926,000		60,926,000		66,419,000
Changes in the Warranty Obligation [Roll Forward]
Warranty obligation at March 31, 2013			13,410,000	13,346,000
Warranty provision relating to products shipped			4,154,000	7,440,000
Deductions for warranty claims processed			-4,683,000	-8,064,000
Warranty obligation at September 30, 2013	12,881,000	12,722,000	12,881,000	12,722,000
Buildings and improvements [Member] | Minimum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			7 years
Buildings and improvements [Member] | Maximum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			30 years
Machinery and equipment [Member] | Minimum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			2 years
Machinery and equipment [Member] | Maximum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			10 years
Software [Member] | Minimum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			5 years
Software [Member] | Maximum [Member]
Property, plant, and equipment, net [Abstract]
Property, plant, and equipment, estimated useful lives			6 years
Provisions for returns [Member]
Accounts receivable, net [Line Items]
Accounts Receivable Reserves	-7,756,000		-7,756,000		-8,957,000
Provisions for promotions, rebates, and other [Member]
Accounts receivable, net [Line Items]
Accounts Receivable Reserves	-15,771,000		-15,771,000		-13,675,000
Provisions for doubtful accounts and sales allowances [Member]
Accounts receivable, net [Line Items]
Accounts Receivable Reserves	($306,000)		($306,000)		($409,000)

GOODWILL_AND_PURCHASED_INTANGI1

GOODWILL AND PURCHASED INTANGIBLE ASSETS (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$15.50
Accumulated impairment loss	$54.60

COMMITMENTS_AND_CONTINGENCIES_1

COMMITMENTS AND CONTINGENCIES (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Loss Contingencies [Line Items]
Unrecorded Unconditional Purchase Obligation	$244,500,000		$244,500,000
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2014 (remaining 6 months)	1,997,000		1,997,000
2015	1,920,000		1,920,000
2016	1,341,000		1,341,000
2017	730,000		730,000
2018	652,000		652,000
Thereafter	1,576,000		1,576,000
Total minimum future rental payments	8,216,000		8,216,000
Total rent expense for operating leases	2,600,000	1,400,000	4,100,000	2,800,000
Early exit lease termination charge	$1,200,000		$1,500,000

CREDIT_AGREEMENT_Details

CREDIT AGREEMENT (Details) (USD $)	1 Months Ended	3 Months Ended	6 Months Ended
In Millions, unless otherwise specified	31-May-11	Sep. 30, 2013	Sep. 30, 2013	3-May-13	Mar. 31, 2013
Line of Credit Facility [Line Items]
Line of Credit Facility, Initiation Date	9-May-11
Line of Credit Facility, Latest Amendment Date				3-May-13
Line of Credit Facility, Maximum Borrowing Capacity		$100	$100
Potential Increase to Borrowing Capacity		100	100
Total Facility Size, Including Potential Increase to Borrowing Capacity		200	200
Outstanding Borrowings Under The Line Of Credit		0	0		0
One Month Term			1 month
Three Month Term			3 months
Six Month Term			6 months
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage		0.20%
Line of Credit Facility, Expiration Date		9-May-16
Minimum Required Liquid Funds		$200
Line Of Credit Facility Interest Rate Spread Below The Banks Announced Prime Rate [Member]
Line of Credit Facility [Line Items]
Loans Under The Credit Agreement, Basis Spread on Variable Rate		1.50%
Line Of Credit Facility Interest Rate Spread Above A Daily One Month LIBOR Rate [Member]
Line of Credit Facility [Line Items]
Loans Under The Credit Agreement, Basis Spread on Variable Rate		1.10%
Line Of Credit Facility Interest Rate Spread Above Adjusted LIBOR Rate For A Term Of One Three Or Six Months [Member]
Line of Credit Facility [Line Items]
Loans Under The Credit Agreement, Basis Spread on Variable Rate		1.10%

STOCKBASED_COMPENSATION_Detail

STOCK-BASED COMPENSATION (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	$4,127	$3,330	$7,678	$6,568
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	638	526	1,173	1,122
Research, development, and engineering [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	1,652	1,256	3,020	2,380
Selling, general, and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	3,675	3,080	6,760	5,980
Stock-based compensation expense included in operating expenses [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	5,327	4,336	9,780	8,360
Total stock-based compensation [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	5,965	4,862	10,953	9,482
Income tax benefit [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock-based compensation	($1,838)	($1,532)	($3,275)	($2,914)

STOCKBASED_COMPENSATION_Stock_

STOCK-BASED COMPENSATION Stock Option Activity (Details) (Stock Options [Member], USD $)	3 Months Ended	6 Months Ended
Share data in Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding at March 31, 2013		2,415
Options granted		176
Options exercised		-667
Options forfeited or expired		-10
Options outstanding at September 30, 2013	1,914	1,914
Weighted average exercise price of options outstanding, March 31, 2013		$27.96
Weighted average exercise price of options granted		$45.98
Weighted average exercise price of options exercised		$24.09
Weighted average exercise price of options forfeited or expired		$32.74
Weighted average exercise price of options outstanding, September 30, 2013	$30.94	$30.94
Weighted average remaining contractual life of options outstanding at September 30, 2013	4 years 73 days
Aggregate intrinsic value of options outstanding at September 30, 2013	$29,739,000	$29,739,000
Vested and expected to vest at September 30, 2013	1,872	1,872
Weighted average exercise price of options vested and expected to vest at September 30, 2013	$30.76	$30.76
Weighted average remaining contractual life of options vested and expected to vest at September 30, 2013	4 years 73 days
Aggregate intrinsic value of options vested and expected to vest at September 30, 2013	29,419,000	29,419,000
Exercisable at September 30, 2013	1,275	1,275
Weighted average exercise price of options exercisable at September 30, 2013	$27.85	$27.85
Weighted average remaining contractual life of options exercisable at September 30, 2013	3 years 146 days
Aggregate intrinsic value of options exercisable at September 30, 2013	23,735,000	23,735,000
Total intrinsic value of options exercised		14,500,000	4,500,000
Total cash received as a result of stock option exercises, net of taxes		16,100,000
Total unrecognized compensation cost related to unvested stock options	$5,800,000	$5,800,000
Weighted average period of recognition for unrecognized compensation cost related to unvested stock options	1 year 329 days

STOCKBASED_COMPENSATION_Restri

STOCK-BASED COMPENSATION Restricted Stock Activity (Details) (Restricted Stock [Member], USD $)	3 Months Ended	6 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Non-vested Restricted Stock at March 31, 2013		1,025
Restricted stock granted		541
Restricted stock vested		-274
Restricted stock forfeited		-31
Non-vested Restricted Stock at September 30, 2013	1,261	1,261
Weighted Average Grant Date Fair Value of Non-Vested Restricted Stock, March 31, 2013		$33.34
Weighted average grant date fair value of restricted stock granted		$46.10	$32.05
Weighted average grant date fair value of restricted stock vested		$32.61
Weighted average grant date fair value of restricted stock forfeited		$36.86
Weighted Average Grant Date Fair Value of Non-Vested Restricted Stock, September 30, 2013	$38.88	$38.88
Restricted Stock Awards Vested in Period, Total Fair Value		$8.90	$4.90
Non-vested restricted stock awards, total unrecognized compensation cost	$34.40	$34.40
Weighted average number of years over which compensation cost related to non-vested restricted stock awards will be recognized	2 years 110 days

STOCKBASED_COMPENSATION_Valuat

STOCK-BASED COMPENSATION Valuation Assumptions (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility	30.70%	43.50%	33.50%	42.20%
Risk-free interest rate	1.20%	0.50%	0.70%	0.60%
Expected dividends	0.80%	1.30%	0.90%	1.30%
Expected life (in years)	4 years 73 days	4 years 110 days	4 years 73 days	4 years 110 days
Weighted-average grant date fair value	$11.64	$10.84	$11.83	$10.43
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected volatility			24.90%	38.40%
Risk-free interest rate			0.10%	0.10%
Expected dividends			0.90%	1.10%
Expected life (in years)			183 days	183 days
Weighted-average grant date fair value			$9.58	$8.95

COMMON_STOCK_REPURCHASES_Detai

COMMON STOCK REPURCHASES (Details) (USD $)	6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	274,874
Treasury Stock, Shares, Acquired	607,033	633,613
Treasury Stock, Value, Acquired, Cost Method	$27,300,000	$19,900,000
Treasury Stock Acquired, Average Cost Per Share	$44.99	$31.45
Employees' Taxes Withheld And Paid For Restricted Stock And Restricted Stock Units	$4,369,000	$1,729,000

ACCUMULATED_OTHER_COMPREHENSIV2

ACCUMULATED OTHER COMPREHENSIVE INCOME (Details) (USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated unrealized gain (loss) on cash flow hedges	($2,325)	$1,349
Accumulated foreign currency translation adjustments	4,091	4,131
Accumulated unrealized gain (loss) on investments	92	87
Accumulated other comprehensive income	$1,858	$5,567

FOREIGN_CURRENCY_DERIVATIVES_D

FOREIGN CURRENCY DERIVATIVES (Details)

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

3 Months Ended

6 Months Ended

Sep. 30, 2012

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Mar. 31, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Sep. 30, 2013

Mar. 31, 2013

USD ($)

USD ($)

USD ($)

Foreign exchange option, EURO [Member]

Foreign exchange option, EURO [Member]

Foreign exchange option, GBP [Member]

Foreign exchange option, GBP [Member]

Foreign Exchange Forward, EURO [Member]

Foreign Exchange Forward, EURO [Member]

Foreign Exchange Forward, EURO [Member]

Foreign Exchange Forward, EURO [Member]

Foreign Exchange Forward, GBP [Member]

Foreign Exchange Forward, GBP [Member]

Foreign Exchange Forward, GBP [Member]

Foreign Exchange Forward, GBP [Member]

Foreign Exchange Forward, AUD [Member]

Foreign Exchange Forward, AUD [Member]

Foreign Exchange Forward, AUD [Member]

Foreign Exchange Forward, AUD [Member]

Foreign currency swap contract [Member]

Foreign currency swap contract [Member]

Foreign currency swap contract [Member]

Foreign currency swap contract [Member]

Foreign currency swap contract [Member]

EUR (€)

EUR (€)

GBP (£)

GBP (£)

USD ($)

EUR (€)

USD ($)

EUR (€)

USD ($)

GBP (£)

USD ($)

GBP (£)

USD ($)

AUD

USD ($)

AUD

USD ($)

MXN

USD ($)

MXN

MXN

Derivative [Line Items]

One Month Maturity

1 month

1 month

1 month

1 month

1 month

1 month

Monthly Maturity Over 18 Months

15 months

15 months

Foreign Currency Cash Flow Hedge Gain (Loss) Reclassified to Earnings, Net, GBP and Euro

$1,200,000

$3,100,000

Foreign Currency Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months

-2,000,000

Notional Amount of Foreign Currency Derivative Instruments

€ 50,800,000

€ 50,200,000

£ 21,000,000

£ 19,900,000

$21,632,000

€ 16,000,000

$21,632,000

€ 16,000,000

$4,191,000

£ 2,600,000

$4,191,000

£ 2,600,000

$4,276,000

4,600,000

$4,276,000

4,600,000

$27,500,000

361,100,000

$27,500,000

361,100,000

325,400,000

Derivative, Currency Sold

Sell EUR

Sell EUR

Sell GBP

Sell GBP

Sell AUD

Sell AUD

Derivative, Currency Bought

Buy MX$

Buy MX$

Derivative, Remaining Maturity

1 month

1 month

1 month

1 month

1 month

1 month

15 months

15 months

FOREIGN_CURRENCY_DERIVATIVES_F

FOREIGN CURRENCY DERIVATIVES FOREIGN CURRENCY DERIVATIVES (Details 1) (Credit Risk Contract [Member], USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Credit Risk Contract [Member]
Offsetting Assets [Line Items]
Derivatives subject to master netting agreements, Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets	$70	$1,005
Derivatives subject to master netting agreements, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements	-70	-215
Derivatives subject to master netting agreements, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheets that are Subject to Master Netting Agreements, Cash Collateral Received	0	0
Derivatives subject to master netting agreements, Net Amount of Derivative Assets	0	790
Derivatives not subject to master netting agreements	0	660
Gross Amount of Derivative Assets Presented in the Condensed Consolidated Balance Sheets, Total	70	1,665
Net Amount of Derivative Assets, Total	$0	$1,450

FOREIGN_CURRENCY_DERIVATIVES_F1

FOREIGN CURRENCY DERIVATIVES FOREIGN CURRENCY DERIVATIVES (Details 2) (USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Offsetting Liabilities [Line Items]
Liabilities related to derivative contracts	($2,443)	($294)
Credit Risk Contract [Member]
Offsetting Liabilities [Line Items]
Liabilities related to derivative contracts	-1,577	-215
Derivatives subject to master netting agreements, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements, Gross Amount of Eligible Offsetting Recognized Derivative Assets	70	215
Derivatives subject to master netting agreements, Gross Amounts Not Offset in the Condensed Consolidated Balance Sheet that are Subject to Master Netting Agreements, Cash Collateral Received	0	0
Derivatives subject to master netting agreements, Net Amount of Derivative Liabilities	-1,507	0
Derivatives not subject to master netting agreements, Net Amount of Derivative Liabilities	-866	-79
Gross Amount of Derivative Liabilities Presented in the Condensed Consolidated Balance Sheets	-2,443	-294
Net Amount of Derivative Liabilities, Total	($2,373)	($79)

FOREIGN_CURRENCY_DERIVATIVES_D1

FOREIGN CURRENCY DERIVATIVES (Details 3) (USD $)	Sep. 30, 2013	Mar. 31, 2013
In Thousands, unless otherwise specified
Derivatives, Fair Value [Line Items]
Foreign exchange contracts designated as cash flow hedges, Derivative Liabilities	$2,443	$294
Foreign Exchange Contracts Designated as Cash Flow Hedges [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange contracts designated as cash flow hedges, Derivative Assets	70	1,665
Foreign Exchange Contracts Designated as Cash Flow Hedges [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Foreign exchange contracts designated as cash flow hedges, Derivative Liabilities	$2,443	$294

FOREIGN_CURRENCY_DERIVATIVES_D2

FOREIGN CURRENCY DERIVATIVES (Details 4) (USD $)	6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes In Net Gain (Loss) From Cash Flow Hedges, Pre Tax Effect	($2,373)	$1,371
Amount of gain (loss) recognized in AOCI (effective portion)	-3,646
Amount of gain (loss) reclassified from AOCI to income (loss) (effective portion)	$98

FOREIGN_CURRENCY_DERIVATIVES_D3

FOREIGN CURRENCY DERIVATIVES (Details 5) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) on foreign exchange contracts	($156)	$1,074	$98	$2,768
Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Gain (loss) on foreign exchange contracts	($1,266)	($648)	($1,193)	$819

INCOME_TAXES_Details

INCOME TAXES (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Income Tax Disclosure [Abstract]
Effective tax rate	25.80%	25.50%	24.90%	26.00%
Unrecognized tax benefits	$11,800,000		$11,800,000		$11,100,000
Accrued interest related to unrecognized tax benefits	1,900,000		1,900,000		2,000,000
Accrued penalties	$0		$0		$0

COMPUTATION_OF_EARNINGS_PER_CO2

COMPUTATION OF EARNINGS PER COMMON SHARE (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share [Abstract]
Net income	$23,138	$25,924	$50,091	$49,487
Earnings Per Share, Basic and Diluted [Abstract]
Weighted average common shares-basic	42,810	41,482	42,751	41,571
Dilutive effect of employee equity incentive plans	787	921	916	950
Weighted average common shares-diluted	43,597	42,403	43,667	42,521
Basic earnings per common share	$0.54	$0.62	$1.17	$1.19
Diluted earnings per common share	$0.53	$0.61	$1.15	$1.16
Potentially dilutive securities excluded from diluted earnings per common share because their effect is anti-dilutive	183	1,061	162	1,081

REVENUE_AND_MAJOR_CUSTOMERS_De

REVENUE AND MAJOR CUSTOMERS (Details) (USD $)	3 Months Ended		6 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
	Customer	Customer	Customer	Customer	Customer
Revenue from External Customer [Line Items]
Total net revenues	$193,980	$179,280	$396,798	$360,645
Number of Major Customers, Ten Percent Or Greater, Net Revenues	1	1	1	0
Number of Major Customers, Ten Percent Or Greater, Net Accounts Receivable	1		1		1
Concentration, net revenues	10.10%	10.00%	10.30%
Concentration, accounts receivable	11.70%		11.70%		10.30%
US
Revenue from External Customer [Line Items]
Net revenues	115,795	107,513	237,113	211,591
Europe and Africa [Member]
Revenue from External Customer [Line Items]
Net revenues	43,094	38,951	87,479	80,527
Asia Pacific [Member]
Revenue from External Customer [Line Items]
Net revenues	23,280	19,839	47,160	43,418
Americas, excluding U.S. [Member]
Revenue from External Customer [Line Items]
Net revenues	11,811	12,977	25,046	25,109
Total international net revenues
Revenue from External Customer [Line Items]
Net revenues	78,185	71,767	159,685	149,054
Office and Contact Center [Member]
Revenue from External Customer [Line Items]
Net revenues	139,945	133,119	291,128	267,152
Mobile [Member]
Revenue from External Customer [Line Items]
Net revenues	42,685	33,305	84,309	69,462
Gaming and Computer Audio [Member]
Revenue from External Customer [Line Items]
Net revenues	8,156	7,797	14,607	14,586
Clarity [Member]
Revenue from External Customer [Line Items]
Net revenues	$3,194	$5,059	$6,754	$9,445

SUBSEQUENT_EVENTS_Details

SUBSEQUENT EVENTS (Details) (USD $)	0 Months Ended		1 Months Ended
	Dec. 11, 2013	Nov. 21, 2013	Nov. 30, 2013	Aug. 06, 2013
Subsequent Events [Abstract]
Dividends Payable, Date Declared, Day, Month and Year			29-Oct-13
Cash dividend payable per share				$0.10
Dividends Payable, Date to be Paid, Day, Month and Year	10-Dec-13
Dividends Payable, Date of Record, Day, Month and Year		20-Nov-13