Xilinx (XLNX) 10-Q 28 Jul 14 2015 Q1 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	3 Months Ended
	Jun. 28, 2014	Jul. 18, 2014
Document and Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	28-Jun-14	'
Document Fiscal Year Focus	'2015	'
Document Fiscal Period Focus	'Q1	'
Entity Registrant Name	'XILINX INC	'
Entity Central Index Key	'0000743988	'
Entity Well-known Seasoned Issuer	'Yes	'
Entity Voluntary Filers	'No	'
Entity Current Reporting Status	'Yes	'
Current Fiscal Year End Date	'--03-28	'
Entity Filer Category	'Large Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	268,481,840

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Net revenues	$612,633	$578,955
Cost of revenues	189,189	179,700
Gross margin	423,444	399,255
Operating expenses:	'	'
Research and development	122,013	111,541
Selling, general and administrative	92,513	92,387
Amortization of acquisition-related intangibles	2,418	2,418
Total operating expenses	216,944	206,346
Operating income	206,500	192,909
Interest and other expense, net	6,222	9,930
Income before income taxes	200,278	182,979
Provision for income taxes	26,667	25,956
Net income	$173,611	$157,023
Net income per common share:	'	'
Basic (in dollars per share)	$0.65	$0.59
Diluted (in dollars per share)	$0.62	$0.56
Common Stock, Dividends, Per Share, Declared	$0.29	$0.25
Shares used in per share calculations:	'	'
Basic (in shares)	267,648	264,153
Diluted (in shares)	281,579	280,291

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Statement of Comprehensive Income [Abstract]	'	'
Net income	$173,611	$157,023
Other comprehensive income (loss), net of tax:	'	'
Change in net unrealized gains (losses) on available-for-sale securities	7,959	-16,924
Reclassification adjustment for gains on available-for-sale securities	-391	-322
Net change in unrealized gains (losses) on hedging transactions	542	-1,508
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax	-807	706
Cumulative translation adjustment, net	171	-694
Other comprehensive income (loss)	7,474	-18,742
Total comprehensive income	$181,085	$138,281

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Current assets:	'	'
Cash and cash equivalents	$625,032	$973,677	[1]
Short-term investments	1,860,175	1,483,644	[1]
Accounts receivable, net	281,335	267,833	[1]
Inventories	256,791	233,999	[1]
Deferred tax assets	77,325	56,166	[1]
Prepaid expenses and other current assets	68,041	51,828	[1]
Total current assets	3,168,699	3,067,147	[1]
Property, plant and equipment, at cost:	817,844	810,030	[1]
Accumulated depreciation and amortization	-467,108	-454,941	[1]
Net property, plant and equipment	350,736	355,089	[1]
Long-term investments	1,109,645	1,190,775	[1]
Goodwill	159,296	159,296	[1]
Acquisition-related intangibles, net	26,449	28,867	[1]
Other assets	239,394	236,175	[1]
Total Assets	5,054,219	5,037,349	[1]
Current liabilities:	'	'
Accounts payable	99,572	149,695	[1]
Accrued payroll and related liabilities	147,272	157,373	[1]
Income taxes payable	17,578	12,936	[1]
Deferred income on shipments to distributors	69,258	55,099	[1]
Other accrued liabilities	32,404	49,256	[1]
Long-term Debt, Current Maturities	567,764	565,001	[1]
Total current liabilities	933,848	989,360	[1]
Long-term Debt, Excluding Current Maturities	994,110	993,870	[1]
Deferred tax liabilities	283,492	253,433	[1]
Long-term income taxes payable	11,581	11,470	[1]
Other long-term liabilities	1,588	1,535	[1]
Commitments and contingencies	0	0	[1]
Temporary Equity, Carrying Amount, Attributable to Parent	32,236	34,999	[1]
Stockholders' equity:	'	'
Preferred stock, $.01 par value (none issued)	0	0	[1]
Common stock, $.01 par value	2,671	2,686	[1]
Additional paid-in capital	788,016	805,073	[1]
Retained earnings	1,999,751	1,945,471	[1]
Accumulated other comprehensive income (loss)	6,926	-548	[1]
Total stockholders’ equity	2,797,364	2,752,682	[1]
Total Liabilities, Temporary Equity and Stockholders’ Equity	$5,054,219	$5,037,349	[1]
[1]	Derived from audited financial statements

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 28, 2014	Mar. 29, 2014
Statement of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares issued (none issued)	0	0
Common stock, par value	$0.01	$0.01

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014		Jun. 29, 2013
Cash flows from operating activities:	'		'
Net income	$173,611		$157,023
Adjustments to reconcile net income to net cash provided by operating activities:	'		'
Depreciation	13,468		14,033
Amortization	5,205		4,885
Stock-based compensation	22,106		20,954
Net gain on sale of available-for-sale securities	-670		-107
Amortization of debt discounts	3,003		4,025
Provision for deferred income taxes	5,789		22,736
Excess tax benefit from stock-based compensation	-2,660		-2,021
Others	0		53
Changes in assets and liabilities:	'		'
Accounts receivable, net	-13,501		-38,978
Inventories	-22,879		14,373
Prepaid expenses and other current assets	-4,751		-1,050
Other assets	-5,188		-5,020
Accounts payable	-50,123		-3,525
Accrued liabilities	-12,389		11,209
Income taxes payable	4,939		-58,961
Deferred income on shipments to distributors	14,159		4,580
Net cash provided by operating activities	130,119		144,209
Cash flows from investing activities:	'		'
Purchases of available-for-sale securities	-874,367		-1,213,461
Proceeds from sale and maturity of available-for-sale securities	570,043		961,538
Purchases of property, plant and equipment	-9,116		-11,301
Other investing activities	-3,742		36,921
Net cash used in investing activities	-317,182		-226,303
Cash flows from financing activities:	'		'
Payments for Repurchase of Common Stock	101,016		0
Proceeds from issuance of common stock through various stock plans, net	14,195		31,936
Payment of dividends to stockholders	-77,421		-66,007
Excess tax benefit from stock-based compensation	2,660		2,021
Net cash used in financing activities	-161,582		-32,050
Net decrease in cash and cash equivalents	-348,645		-114,144
Cash and cash equivalents at beginning of period	973,677	[1]	623,558
Cash and cash equivalents at end of period	625,032		509,414
Supplemental disclosure of cash flow information:	'		'
Interest paid	7,875		7,875
Income taxes paid, net	$15,856		$62,236
[1]	Derived from audited financial statements

Basis_of_Presentation

Basis of Presentation	3 Months Ended
	Jun. 28, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	'
	Basis of Presentation
	The accompanying interim condensed consolidated financial statements have been prepared in conformity with United States (U.S.) generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X, and should be read in conjunction with the Xilinx, Inc. (Xilinx or the Company) consolidated financial statements filed with the U.S. Securities and Exchange Commission (SEC) on Form 10-K for the fiscal year ended March 29, 2014. The interim financial statements are unaudited, but reflect all adjustments which are, in the opinion of management, of a normal, recurring nature necessary to provide a fair statement of results for the interim periods presented. The results of operations for the interim periods shown in this report are not necessarily indicative of the results that may be expected for the fiscal year ending March 28, 2015 or any future period.
	The Company uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal 2015 and 2014 are 52-week year ending on March 28, 2015 and March 29, 2014, respectively. The quarters ended June 28, 2014 and June 29, 2013 each included 13 weeks.

Recent_Accounting_Changes_and_

Recent Accounting Changes and Accounting Pronouncements	3 Months Ended
	Jun. 28, 2014
Accounting Changes and Error Corrections [Abstract]	'
Accounting Changes and Error Corrections [Text Block]	'
	Recent Accounting Changes and Accounting Pronouncements
	In April 2014, the Financial Accounting Standards Board (FASB) issued the authoritative guidance that outlines a new global revenue recognition standard that replaces virtually all existing US GAAP and IFRS guidance on contracts with customers and the related other assets and deferred costs. The guidance provides a five-step process for recognizing revenue that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard also requires expanded qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The standard is effective for Xilinx beginning in fiscal year 2018, with no option to early adopt under US GAAP. The new standard is required to be applied retrospectively to each prior reporting period presented or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application. The Company is currently evaluating the impact of this new guidance on its consolidated financial statements, including selection of the transition method.

Significant_Customers_and_Conc

Significant Customers and Concentrations of Credit Risk (Notes)	3 Months Ended
	Jun. 28, 2014
Significant Customers and Concentrations of Credit Risk [Abstract]	'
Concentration Risk Disclosure [Text Block]	'
	Significant Customers and Concentrations of Credit Risk
	Avnet, Inc. (Avnet), one of the Company’s distributors, distributes the Company’s products worldwide. As of June 28, 2014 and March 29, 2014, Avnet accounted for 63% and 55% of the Company’s total net accounts receivable, respectively. Resale of product through Avnet accounted for 42% and 49% of the Company’s worldwide net revenues in the first quarter of fiscal 2015 and 2014, respectively. The percentage of accounts receivable due from Avnet and the percentage of worldwide net revenues from Avnet are consistent with historical patterns.
	Xilinx is subject to concentrations of credit risk primarily in its trade accounts receivable and investments in debt securities to the extent of the amounts recorded on the consolidated balance sheet. The Company attempts to mitigate the concentration of credit risk in its trade receivables through its credit evaluation process, collection terms, distributor sales to diverse end customers and through geographical dispersion of sales. Xilinx generally does not require collateral for receivables from its end customers or from distributors.
	No end customer accounted for more than 10% of the Company’s worldwide net revenues for the first quarter of fiscal 2015 and 2014.
	The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing more than 82% of its portfolio in AA or higher grade securities as rated by Standard & Poor’s or Moody’s Investors Service. The Company’s methods to arrive at investment decisions are not solely based on the rating agencies’ credit ratings. Xilinx also performs additional credit due diligence and conducts regular portfolio credit reviews, including a review of counterparty credit risk related to the Company’s forward currency exchange contracts. Additionally, Xilinx limits its investments in the debt securities of a single issuer based upon the issuer’s credit rating and attempts to further mitigate credit risk by diversifying risk across geographies and type of issuer.
	As of June 28, 2014, approximately 35% of the portfolio consisted of mortgage-backed securities. All of the mortgage-backed securities in the investment portfolio were issued by U.S. government-sponsored enterprises and agencies and are rated AA+ by Standard & Poor’s and AAA by Moody’s Investors Service.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Jun. 28, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The guidance for fair value measurements established by the FASB defines fair value as the exchange price that would be received from selling an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which Xilinx would transact and also considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance.
	The Company determines the fair value for marketable debt securities using industry standard pricing services, data providers and other third-party sources and by internally performing valuation testing and analysis. The Company primarily uses a consensus price or weighted-average price for its fair value assessment. The Company determines the consensus price using market prices from a variety of industry standard pricing services, data providers, security master files from large financial institutions and other third party sources and uses those multiple prices as inputs into a distribution-curve-based algorithm to determine the daily market value. The pricing services use multiple inputs to determine market prices, including reportable trades, benchmark yield curves, credit spreads and broker/dealer quotes as well as other industry and economic events. For certain securities with short maturities, such as discount commercial paper and certificates of deposit, the security is accreted from purchase price to face value at maturity. If a subsequent transaction on the same security is observed in the marketplace, the price on the subsequent transaction is used as the current daily market price and the security will be accreted to face value based on the revised price. For certain other securities, such as student loan auction rate securities, the Company performs its own valuation analysis using a discounted cash flow pricing model.
	The Company validates the consensus prices by taking random samples from each asset type and corroborating those prices using reported trade activity, benchmark yield curves, binding broker/dealer quotes or other relevant price information. There have not been any changes to the Company’s fair value methodology during the first quarter of fiscal 2015 and the Company did not adjust or override any fair value measurements as of June 28, 2014.
	Fair Value Hierarchy
	The fair value framework requires the categorization of assets and liabilities into three levels based upon the assumptions (inputs) used to price the assets or liabilities. The guidance for fair value measurements requires that assets and liabilities carried at fair value be classified and disclosed in one of the following categories:
	Level 1 — Quoted (unadjusted) prices in active markets for identical assets or liabilities.
	The Company’s Level 1 assets consist of U.S. government and agency securities and money market funds.
	Level 2 — Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability.
	The Company’s Level 2 assets consist of financial institution securities, non-financial institution securities, municipal bonds, U.S. agency securities, foreign government and agency securities, mortgage-backed securities and debt mutual funds. The Company’s Level 2 assets and liabilities also include foreign currency forward contracts and commodity swap contracts.
	Level 3 — Unobservable inputs to the valuation methodology that are supported by little or no market activity and that are significant to the measurement of the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose fair value measurements are determined using pricing models, discounted cash flow methodologies or similar valuation techniques, as well as significant management judgment or estimation.
	The Company’s Level 3 assets and liabilities include student loan auction rate securities.
	Assets and Liabilities Measured at Fair Value on a Recurring Basis
	In instances where the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability. The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of June 28, 2014 and March 29, 2014:
			June 28, 2014
	(In thousands)		Quoted			Significant			Significant			Total Fair
			Prices in			Other			Unobservable			Value
			Active			Observable			Inputs
			Markets for			Inputs			(Level 3)
			Identical			(Level 2)
			Instruments
			(Level 1)
	Assets
	Cash and cash equivalents:
	Money market funds		$	174,031		$	—		$	—		$	174,031
	Financial institution securities		—			124,986			—			124,986
	Non-financial institution securities		—			120,984			—			120,984
	U.S. government and agency securities		25,000			—			—			25,000
	Foreign government and agency securities		—			94,992			—			94,992
	Short-term investments:
	Financial institution securities		—			129,983			—			129,983
	Non-financial institution securities		—			317,015			—			317,015
	Municipal bonds		—			23,495			—			23,495
	U.S. government and agency securities		433,169			99,634			—			532,803
	Foreign government and agency securities		—			315,898			—			315,898
	Mortgage-backed securities		—			442,571			—			442,571
	Debt mutual funds		—			40,703			—			40,703
	Bank loans		—			57,707			—			57,707
	Long-term investments:
	Non-financial institution securities		—			188,007			—			188,007
	Auction rate securities		—			—			20,704			20,704
	Municipal bonds		—			15,346			—			15,346
	U.S. government and agency securities		4,948			31,951			—			36,899
	Mortgage-backed securities		—			789,964			—			789,964
	Debt mutual fund		—			58,725			—			58,725
	Derivative financial instruments, net		—			1,311			—			1,311
	Total assets measured at fair value		$	637,148		$	2,853,272		$	20,704		$	3,511,124
		March 29, 2014
	(In thousands)	Quoted			Significant			Significant			Total Fair
		Prices in			Other			Unobservable			Value
		Active			Observable			Inputs
		Markets for			Inputs			(Level 3)
		Identical			(Level 2)
		Instruments
		(Level 1)
	Assets
	Cash and cash equivalents:
	Money market funds	$	213,988		$	—		$	—		$	213,988
	Financial institution securities	—			131,990			—			131,990
	Non-financial institution securities	—			319,970			—			319,970
	U.S. government and agency securities	69,998			—			—			69,998
	Foreign government and agency securities	—			194,984			—			194,984
	Short-term investments:
Financial institution securities	—			234,916			—			234,916
Non-financial institution securities	—			226,828			—			226,828
Municipal Bonds	—			15,780			—			15,780
U.S. government and agency securities	349,023			89,422			—			438,445
Foreign government and agency securities	—			159,951			—			159,951
Mortgage-backed securities	—			387,508			—			387,508
Debt mutual fund	—			20,216			—			20,216
Long-term investments:
Non-financial institution securities	—			209,274			—			209,274
Auction rate securities	—			—			20,160			20,160
Municipal bonds	—			15,986			—			15,986
U.S. government and agency securities	4,950			36,126			—			41,076
Mortgage-backed securities	—			847,581			—			847,581
Debt mutual fund	—			56,698			—			56,698
Derivative financial instruments, net	—			1,713			—			1,713
Total assets measured at fair value	$	637,959		$	2,948,943		$	20,160		$	3,607,062
Changes in Level 3 Instruments Measured at Fair Value on a Recurring Basis
The following table is a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3):
	Three Months Ended
(In thousands)	June 28, 2014			June 29, 2013
Balance as of beginning of period	$	20,160		$	27,610
Total realized and unrealized gains (losses):
Included in interest and other expense, net	—			(75		)
Included in other comprehensive income	544			846
Sales and settlements, net (1)	—			(300		)
Balance as of end of period	$	20,704		$	28,081
-1	During the first quarter of fiscal 2014, the Company redeemed $300 thousand of student loan auction rate securities, respectively, for cash at par value. There was no redemption during the first quarter of fiscal 2015.
The amount of total losses included in net income attributable to the change in unrealized losses relating to assets and liabilities still held as of the end of the period are summarized as follows:
	Three Months Ended
(In thousands)	June 28, 2014			June 29, 2013
Included in interest and other expense, net	$	—		$	(75	)
As of June 28, 2014, marketable securities measured at fair value using Level 3 inputs were comprised of $20.7 million of student loan auction rate securities. There was no material change to the input assumptions of the pricing model for these student loan auction securities.
The 2037 Convertible Notes, which were fully redeemed on March 12, 2014 (see "Note 10. Debt and Credit Facility"), included embedded features that qualify as an embedded derivative, and was separately accounted for as a discount on the 2037 Convertible Notes. Its fair value was established at the inception of the 2037 Convertible Notes. Prior to the redemption, each quarter, the change in the fair value of the embedded derivative, if any, was recorded in the consolidated statements of income. The Company used a derivative valuation model to derive the value of the embedded derivative. Key inputs into this valuation model were the Company’s current stock price, risk-free interest rates, the stock dividend yield, the stock volatility and the 2037 Convertible Notes’ credit spread over London Interbank Offered Rate. The first three inputs were based on observable market data and were considered Level 2 inputs while the last two inputs required management judgment and were Level 3 inputs.
Financial Instruments Not Recorded at Fair Value on a Recurring Basis
The Company’s 2017 Convertible Notes, 2019 Notes and 2021 Notes are measured at fair value on a quarterly basis for disclosure purposes. The fair values of the 2017 Convertible Notes, 2019 Notes and 2021 Notes as of June 28, 2014 were approximately $1.00 billion, $501.7 million and $505.9 million, respectively, based on the last trading price of the respective debentures for the period (classified as Level 2 in fair value hierarchy due to relatively low trading volume).

Financial_Instruments

Financial Instruments	3 Months Ended
	Jun. 28, 2014
Investments, All Other Investments [Abstract]	'
Financial Instruments	'
	Financial Instruments
	The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented:
		June 28, 2014													March 29, 2014
	(In thousands)	Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value				Amortized Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	Money market funds	$	174,031		$	—		$	—		$	174,031			$	213,988		$	—	$	—		$	213,988
	Financial institution
	securities	254,969			—			—			254,969				366,906			—		—			366,906
	Non-financial institution
	securities	621,880			4,470			(344		)	626,006				753,888			3,428		(1,244		)	756,072
	Auction rate securities	21,500			—			(796		)	20,704				21,500			—		(1,340		)	20,160
	Municipal bonds	38,164			820			(143		)	38,841				31,367			604		(205		)	31,766
	U.S. government and
	agency securities	593,637			1,145			(80		)	594,702				548,568			1,135		(184		)	549,519
	Foreign government and
	agency securities	410,896			—			(6		)	410,890				354,935			—		—			354,935
	Mortgage-backed securities	1,225,050			14,355			(6,870		)	1,232,535				1,234,237			11,380		(10,528		)	1,235,089
	Debt mutual funds	101,350			703			(2,625		)	99,428				81,350			216		(4,652		)	76,914
	Bank loans	57,667			105			(65		)	57,707				—			—		—			—
		$	3,499,144		$	21,598		$	(10,929	)	$	3,509,813			$	3,606,739		$	16,763	$	(18,153	)	$	3,605,349
	The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of June 28, 2014 and March 29, 2014:
		June 28, 2014
		Less Than 12 Months						12 Months or Greater						Total
	(In thousands)	Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses
	Non-financial institution securities	$	32,613		$	(84	)	$	19,902		$	(260	)	$	52,515		$	(344	)
	Auction rate securities	—			—			20,704			(796		)	20,704			(796		)
	Municipal bonds	4,026			(6		)	4,603			(137		)	8,629			(143		)
	U.S. government and
	agency securities	250,910			(31		)	4,369			(49		)	255,279			(80		)
	Foreign government and
	agency securities	124,968			(6		)	—			—			124,968			(6		)
	Mortgage-backed securities	234,724			(2,223		)	274,363			(4,647		)	509,087			(6,870		)
	Debt mutual fund	—			—			58,724			(2,625		)	58,724			(2,625		)
	Bank loans	30,097			(65		)	—			—			30,097			(65		)
		$	677,338		$	(2,415	)	$	382,665		$	(8,514	)	$	1,060,003		$	(10,929	)
		March 29, 2014
		Less Than 12 Months						12 Months or Greater						Total
	(In thousands)	Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses
	Non-financial institution securities	$	112,470		$	(1,167	)	$	4,488		$	(77	)	$	116,958		$	(1,244	)
	Auction rate securities	—			—			20,160			(1,340		)	20,160			(1,340		)
	Municipal bonds	5,917			(166		)	1,743			(39		)	7,660			(205		)
	U.S. government and
	agency securities	118,125			(184		)	—			—			118,125			(184		)
	Mortgage-backed securities	457,903			(7,225		)	132,376			(3,303		)	590,279			(10,528		)
	Debt mutual fund	56,698			(4,652		)	—			—			56,698			$	(4,652	)
		$	751,113		$	(13,394	)	$	158,767		$	(4,759	)	$	909,880		$	(18,153	)
	As of June 28, 2014, the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities due to the general rising of the interest-rate environment, although the percentage of such losses to the total estimated fair value of the mortgage-backed securities was relatively insignificant. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to mortgage-backed securities and debt mutual fund, which were primarily due to the general rising of the interest-rate environment, and failed auction rate securities, which were due to adverse conditions in the global credit markets during the past five years.
	The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of June 28, 2014 and March 29, 2014 were temporary in nature as evidenced by the fluctuations in the gross unrealized losses within the investment categories. These investments are highly rated by the credit rating agencies and there have been no defaults on any of these securities, and we have received interest payments as they become due. Additionally, in the past several years a portion of the Company's investment in the auction rate securities and the mortgage-backed securities were redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more was not significant as of June 28, 2014 and March 29, 2014. The Company neither intends to sell these investments nor concludes that it is more-likely-than-not that it will have to sell them until recovery of their carrying values. The Company also believes that it will be able to collect both principal and interest amounts due to the Company at maturity, given the high credit quality of these investments and any related underlying collateral.
	The amortized cost and estimated fair value of marketable debt securities (financial institution securities, non-financial institution securities, auction rate securities, municipal bonds, U.S. and foreign government and agency securities and mortgage-backed securities), by contractual maturity, are shown below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties.
		June 28, 2014
	(In thousands)	Amortized			Estimated
		Cost			Fair Value
	Due in one year or less	$	1,464		$	1,464
	Due after one year through five years	474			478
	Due after five years through ten years	287			289
	Due after ten years	999			1,005
		$	3,224		$	3,236
	As of June 28, 2014, $762.4 million of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table did not include investments in money market and mutual funds because these funds do not have specific contractual maturities.
	Certain information related to available-for-sale securities is as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Proceeds from sale of available-for-sale securities	$	59,581		$	95,139
	Gross realized gains on sale of available-for-sale securities	$	837		$	1,101
	Gross realized losses on sale of available-for-sale securities	(167		)	(994		)
Net realized gains (losses) on sale of available-for-sale securities	$	670		$	107
Amortization of premiums on available-for-sale securities	$	6,233		$	7,159
The cost of securities matured or sold is based on the specific identification method.

Derivative_Financial_Instrumen

Derivative Financial Instruments	3 Months Ended
	Jun. 28, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Financial Instruments	'
	Derivative Financial Instruments
	The Company’s primary objective for holding derivative financial instruments is to manage foreign currency exchange rate risk and interest rate risk. As a result of the use of derivative financial instruments, the Company is exposed to the risk that counterparties to derivative contracts may fail to meet their contractual obligations. The Company manages counterparty credit risk in derivative contracts by reviewing counterparty creditworthiness on a regular basis, establishing collateral requirement and limiting exposure to any single counterparty. The right of set-off that exists with certain transactions enables the Company to net amounts due to and from the counterparty, reducing the maximum loss from credit risk in the event of counterparty default.
	As of June 28, 2014 and March 29, 2014, the Company had the following outstanding forward currency exchange contracts (in notional amount), which were derivative financial instruments:
	(In thousands and U.S. dollars)	June 28, 2014			March 29, 2014
	Singapore Dollar	$	60,052		$	60,551
	Euro	48,558			46,062
	Indian Rupee	20,919			18,631
	British Pound	12,874			12,056
	Japanese Yen	9,489			9,273
		$	151,892		$	146,573
	As part of the Company’s strategy to reduce volatility of operating expenses due to foreign exchange rate fluctuations, the Company employs a hedging program with a forward outlook of up to two years for major foreign-currency-denominated operating expenses. The outstanding forward currency exchange contracts expire at various dates through May 2016. The net unrealized gains, which approximate the fair market value of the outstanding forward currency exchange contracts, are expected to be realized into net income within the next two years.
	As of June 28, 2014, all of the forward foreign currency exchange contracts were designated and qualified as cash flow hedges and the effective portion of the gain or loss on the forward contracts was reported as a component of other comprehensive income (loss) and reclassified into net income in the same period during which the hedged transaction affects earnings. The estimated amount of such gains or losses as of June 28, 2014 that is expected to be reclassified into earnings was not material. The ineffective portion of the gains or losses on the forward contracts was included in the net income for all periods presented.
	The Company may enter into forward foreign currency exchange contracts to hedge firm commitments such as acquisitions and capital expenditures. Gains and losses on foreign currency forward contracts that are designated as hedges of anticipated transactions, for which a firm commitment has been attained and the hedged relationship has been effective, are deferred and included in income or expenses in the same period that the underlying transaction is settled. Gains and losses on any instruments not meeting the above criteria are recognized in income or expenses in the consolidated statements of income as they are incurred.
	The Company had the following derivative instruments as of June 28, 2014 and March 29, 2014, located on the condensed consolidated balance sheet, utilized for risk management purposes detailed above:
		Foreign Exchange Contracts
		Asset Derivatives				Liability Derivatives
	(In thousands)	Balance Sheet Location	Fair Value			Balance Sheet Location	Fair Value
	June 28, 2014	Prepaid expenses and other current assets	$	1,986		Other accrued liabilities	$	675
	29-Mar-14	Prepaid expenses and other current assets	$	2,648		Other accrued liabilities	$	935
	The Company does not offset or net the fair value amounts of derivative financial instruments in its condensed consolidated balance sheets. The potential effect of rights of set-off associated with the derivative financial instruments was not material to the Company's condensed consolidated balance sheet for all periods presented.
	The following table summarizes the effect of derivative instruments on the condensed consolidated statements of income for first quarter of fiscal 2015 and 2014:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Amount of losses recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	$	(265	)	$	(802	)
	Amount of (gains) losses reclassified from accumulated other comprehensive income into income (effective portion) *	$	807		$	(706	)
	Amount of gains (losses) recorded (ineffective portion) *	$	30		$	(18	)
	*	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	3 Months Ended
	Jun. 28, 2014
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Stock-Based Compensation Plans	'
	Stock-Based Compensation Plans
	The Company’s equity incentive plans are broad-based, long-term retention programs that cover employees, consultants and non-employee directors of the Company. These plans are intended to attract and retain talented employees, consultants and non-employee directors and to provide such persons with a proprietary interest in the Company.
	Stock-Based Compensation
	The following table summarizes stock-based compensation expense related to stock awards granted under the Company’s equity incentive plans and rights to acquire stock granted under the Company’s Employee Stock Purchase Plan (ESPP):
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Stock-based compensation included in:
	Cost of revenues	$	1,992		$	1,804
	Research and development	10,505			10,219
	Selling, general and administrative	9,609			8,931
		$	22,106		$	20,954
	During the first quarter of fiscal 2015 and 2014, the tax benefits realized for the tax deduction from option exercises and other awards credited to additional paid-in capital were $2.0 million and $1.5 million, respectively.
	The fair values of stock options and stock purchase plan rights under the Company’s equity incentive plans and ESPP were estimated as of the grant date using the Black-Scholes option pricing model. The Company’s expected stock price volatility assumption for stock options is estimated using implied volatility of the Company’s traded options. The expected life of options granted is based on the historical exercise activity as well as the expected disposition of all options outstanding. The expected life of options granted also considers the actual contractual term. The Company's stock-based compensation expense relating to options granted during the first quarter of fiscal 2015 and 2014 were not material.
	The estimated fair values of restricted stock unit (RSU) awards were calculated based on the market price of Xilinx common stock on the date of grant, reduced by the present value of dividends expected to be paid on Xilinx common stock prior to vesting. The per share weighted-average fair value of RSUs granted during the first quarter of fiscal 2015 was $40.69 ($34.23 for the first quarter of fiscal 2014), which were calculated based on estimates at the date of grant using the following weighted-average assumptions:
		Three Months Ended
		June 28, 2014		June 29, 2013
	Risk-free interest rate	0.9	%	0.5	%
	Dividend yield	2.5	%	2.5	%
	Employee Stock Option Plans
	A summary of the Company’s option plans activity and related information is as follows:
		Options Outstanding
	(Shares in thousands)	Number of Shares		Weighted-Average Exercise Price Per Share
	30-Mar-13	12,753		$	28.01
	Granted	8		$	41.08
	Exercised	(7,421	)	$	29.95
	Forfeited/cancelled/expired	(60	)	$	35.61
	29-Mar-14	5,280		$	25.22
	Granted	—		$	—
	Exercised	(538	)	$	27.57
	Forfeited/cancelled/expired	(7	)	$	38.24
	June 28, 2014	4,735		$	24.93
	Options exercisable at:
	June 28, 2014	4,528		$	24.61
	March 29, 2014	4,935		$	24.87
	The types of awards allowed under the 2007 Equity Incentive Plan (2007 Equity Plan) include incentive stock options, non-qualified stock options, RSUs, restricted stock and stock appreciation rights. To date, the Company has issued a mix of non-qualified stock options and RSUs under the 2007 Equity Plan. As of June 28, 2014, 14.7 million shares remained available for grant under the 2007 Equity Plan.
	The total pre-tax intrinsic value of options exercised during the three months ended June 28, 2014 and June 29, 2013 was $11.1 million and $12.8 million, respectively. This intrinsic value represents the difference between the exercise price and the fair market value of the Company’s common stock on the date of exercise.
	RSU Awards
	A summary of the Company’s RSU activity and related information is as follows:
		RSUs Outstanding
	(Shares in thousands)	Number of Shares		Weighted-Average Grant-Date Fair Value Per Share
	30-Mar-13	5,996		$	30.83
	Granted	3,297		$	38.9
	Vested	(2,066	)	$	29.25
	Cancelled	(326	)	$	32.28
	29-Mar-14	6,901		$	35.08
	Granted	403		$	40.69
	Vested	(78	)	$	31.56
	Cancelled	(69	)	$	34.09
	June 28, 2014	7,157		$	35.45
	Employee Stock Purchase Plan
	Under the Company’s ESPP, no shares were issued during the first quarter of fiscal 2015 or 2014. The next scheduled purchase under the ESPP is in the second quarter of fiscal 2015. As of June 28, 2014, 9.7 million shares were available for future issuance.

Net_Income_Per_Common_Share

Net Income Per Common Share	3 Months Ended
	Jun. 28, 2014
Earnings Per Share [Abstract]	'
Net Income Per Common Share	'
	Net Income Per Common Share
	The computation of basic net income per common share for all periods presented is derived from the information on the condensed consolidated statements of income, and there are no reconciling items in the numerator used to compute diluted net income per common share. The following table summarizes the computation of basic and diluted net income per common share:
	(In thousands, except per share amounts)	June 28, 2014		June 29, 2013
	Net income available to common stockholders	$	173,611	$	157,023
	Weighted average common shares outstanding-basic	267,648		264,153
	Dilutive effect of employee equity incentive plans	4,568		5,015
	Dilutive effect of 2017 Convertible Notes and warrants	9,363		4,878
	Dilutive effect of 2037 Convertible Notes	—		6,245
	Weighted average common shares outstanding-diluted	281,579		280,291
	Basic earnings per common share	$	0.65	$	0.59
	Diluted earnings per common share	$	0.62	$	0.56
	The total shares used in the denominator of the diluted net income per common share calculation includes potentially dilutive common equivalent shares outstanding that are not included in basic net income per common share by applying the treasury stock method to the impact of the equity incentive plans and to the incremental shares issuable assuming conversion of the Company's convertible debt and warrants (see "Note 10. Debt and Credit Facility" for more discussion of the Company's debt and warrants).
	Outstanding stock options and RSUs under the Company's stock award plans and warrants to purchase approximately 206 thousand and 22.7 million shares, for the first quarter of fiscal 2015 and 2014, respectively, were excluded from diluted net income per common share by applying the treasury stock method, as their inclusion would have been antidilutive. These options, RSUs and warrants could be dilutive in the future if the Company’s average share price increases and is greater than the combined exercise prices and the unamortized fair values of these options, RSUs and warrants.
	To hedge against potential dilution upon conversion of the 2017 Convertible Notes, the Company also purchased call options on its common stock from the hedge counterparties. The call options give the Company the right to purchase up to 20.2 million shares of its common stock at $29.64 per share. These call options are not considered for purposes of calculating the total shares outstanding under the basic and diluted net income per share, as their effect would be anti-dilutive. Upon exercise, the call options would serve to neutralize the dilutive effect of the 2017 Convertible Notes and potentially reduce the weighted number of diluted shares used in per share calculations.

Inventories

Inventories	3 Months Ended
	Jun. 28, 2014
Inventory Disclosure [Abstract]	'
Inventory Disclosure [Text Block]	'
	Inventories
	Inventories are stated at the lower of actual cost (determined using the first-in, first-out method), or market (estimated net realizable value) and are comprised of the following:
	(In thousands)	June 28, 2014		March 29, 2014
	Raw materials	$	17,039	$	15,306
	Work-in-process	206,897		192,067
	Finished goods	32,855		26,626
		$	256,791	$	233,999

Debt_and_Credit_Facility

Debt and Credit Facility	3 Months Ended
	Jun. 28, 2014
Debt Disclosure [Abstract]	'
Debt and Credit Facility [Text Block]	'
	Debt and Credit Facility
	2017 Convertible Notes
	As of June 28, 2014, the Company had $600.0 million principal amount of 2017 Convertible Notes outstanding. The 2017 Convertible Notes are senior in right of payment to the Company’s existing and future unsecured indebtedness that is expressly subordinated in right of payment to the 2017 Convertible Notes, and are ranked equally with all of our other existing and future unsecured senior indebtedness, including the 2019 and 2021 Notes discussed below. The Company may not redeem the 2017 Convertible Notes prior to maturity.
	The 2017 Convertible Notes are convertible, subject to certain conditions, into shares of Xilinx common stock at a conversion rate of 33.7391 shares of common stock per $1 thousand principal amount of the 2017 Convertible Notes, representing an effective conversion price of approximately $29.64 per share of common stock. The conversion rate is subject to adjustment for certain events as outlined in the indenture governing the 2017 Convertible Notes, but will not be adjusted for accrued interest. One of the conditions allowing holders of the 2017 Convertible Notes to convert during any fiscal quarter is if the last reported sale price of the Company's common stock for at least 20 trading days during a period of 30 consecutive trading days ending on the last trading day of the preceding fiscal quarter is greater than or equal to 130% of the conversion price on each applicable trading day. This condition was met as of June 28, 2014 and as a result, the 2017 Convertible Notes were convertible at the option of the holders. As of June 28, 2014, the 2017 Convertible Notes were classified as a current liability on the Company's condensed consolidated balance sheet. Additionally, a portion of the equity component attributable to the conversion feature of the 2017 Convertible Notes was classified in temporary stockholders' equity. The amount classified as temporary equity was equal to the difference between the principal amount and carrying value of the 2017 Convertible Notes.
	Upon conversion, the Company would pay the holders of the 2017 Convertible Notes cash up to the aggregate principal amount of the 2017 Convertible Notes. If the conversion value exceeds the principal amount, the Company would deliver shares of its common stock in respect to the remainder of its conversion obligation in excess of the aggregate principal amount (conversion spread). Accordingly, there would be no adjustment to the numerator in the net income per common share computation for the cash settled portion of the 2017 Convertible Notes, as that portion of the debt liability will always be settled in cash. The conversion spread will be included in the denominator for the computation of diluted net income per common share, using the treasury stock method.
	The carrying values of the liability and equity components of the 2017 Convertible Notes are reflected in the Company’s condensed consolidated balance sheets as follows:
	(In thousands)	June 28, 2014			29-Mar-14
	Liability component:
	Principal amount of the 2017 Convertible Notes	$	600,000		$	600,000
	Unamortized discount of liability component	(45,337		)	(49,223		)
	Hedge accounting adjustment – sale of interest rate swap	13,101			14,224
	Net carrying value of the 2017 Convertible Notes	$	567,764		$	565,001
	Equity component (including temporary equity) – net carrying value	$	66,415		$	66,415
	The remaining unamortized debt discount, net of the hedge accounting adjustment from the previous sale of the interest rate swap, is being amortized as additional non-cash interest expense over the expected remaining term of the 2017 Convertible Notes. As of June 28, 2014, the remaining term of the 2017 Convertible Notes is 2.9 years.
	Interest expense related to the 2017 Convertible Notes was included in interest and other expense, net on the condensed consolidated statements of income as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Contractual coupon interest	$	3,938		$	3,938
	Amortization of debt issuance costs	362			362
	Amortization of debt discount, net	2,763			2,763
	Total interest expense related to the 2017 Convertible Notes	$	7,063		$	7,063
	To hedge against potential dilution upon conversion of the 2017 Convertible Notes, the Company purchased call options on its common stock from the hedge counterparties. The call options give the Company the right to purchase up to 20.2 million shares of its common stock at $29.64 per share. The call options will terminate upon the earlier of the maturity of the 2017 Convertible Notes or the last day any of the 2017 Convertible Notes remain outstanding. To reduce the hedging cost, under separate transactions the Company sold warrants to the hedge counterparties, which give the hedge counterparties the right to purchase up to 20.2 million shares of the Company’s common stock at $41.99 per share. These warrants expire on a gradual basis over a specified period starting on September 13, 2017.
	2019 and 2021 Notes
	On March 12, 2014, the Company issued $500.0 million principal amount of 2019 Notes and $500.0 million principal amount of 2021 Notes with maturity dates of March 15, 2019 and March 15, 2021 respectively. The 2019 and 2021 Notes were offered to the public at a discounted price of 99.477% and 99.281% of par, respectively. Interest on the 2019 and 2021 Notes is payable semiannually on March 15 and September 15.
	The Company received net proceeds of $990.1 million from issuance of the 2019 and 2021 Notes, after the debt discounts and deduction of debt issuance costs. The debt discounts and issuance costs are amortized to interest expense over the terms of the 2019 and 2021 Notes.
	The following table summarizes the carrying value of the 2019 and 2021 Notes as of June 28, 2014 and March 29, 2014:
	(In thousands)	June 28, 2014			29-Mar-14
	Principal amount of the 2019 Notes	$	500,000		$	500,000
	Unamortized discount of the 2019 Notes	(2,449		)	(2,574		)
	Principal amount of the 2021 Notes	500,000			500,000
	Unamortized discount of the 2021 Notes	(3,441		)	(3,556		)
	Total carrying value	$	994,110		$	993,870
	Interest expense related to the 2019 and 2021 Notes was included in interest and other expense, net on the condensed consolidated statements of income as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Contractual coupon interest	$	6,406		$	—
	Amortization of debt issuance costs	156			—
	Amortization of debt discount, net	240			—
	Total interest expense related to the 2019 and 2021 Notes	$	6,802		$	—
	Revolving Credit Facility
	On December 7, 2011, the Company entered into a $250.0 million senior unsecured revolving credit facility with a syndicate of banks (expiring in December 2016). Borrowings under the credit facility will bear interest at a benchmark rate plus an applicable margin based upon the Company’s credit rating. In connection with the credit facility, the Company is required to maintain certain financial and nonfinancial covenants. As of June 28, 2014, the Company had made no borrowings under this credit facility and was not in violation of any of the covenants.

Common_Stock_Repurchase_Progra

Common Stock Repurchase Program	3 Months Ended
	Jun. 28, 2014
Stockholders' Equity Note [Abstract]	'
Common Stock and Debentures Repurchase Program [Text Block]	'
	Common Stock Repurchase Program
	The Board of Directors has approved stock repurchase programs enabling the Company to repurchase its common stock in the open market or through negotiated transactions with independent financial institutions. The last approval was the 2012 Repurchase program, which was authorized by the Board in August 2012 to repurchase $750.0 million of the Company’s common stock. The 2012 Repurchase Program has no stated expiration date.
	Through June 28, 2014, the Company has used $352.7 million of the $750.0 million authorized under the 2012 Repurchase Program, leaving $397.3 million available for future repurchases. The Company’s current policy is to retire all repurchased shares, and consequently, no treasury shares were held as of June 28, 2014 and March 29, 2014.
	During the first quarter of 2015, the Company repurchased 2.1 million shares of common stock in the open market for a total of $100.0 million. There was no repurchase of common stock during the first quarter of fiscal 2014.

Interest_and_Other_Expense_Net

Interest and Other Expense, Net	3 Months Ended
	Jun. 28, 2014
Other Income and Expenses [Abstract]	'
Interest and Other Expense, Net	'
	Interest and Other Expense, Net
	The components of interest and other expense, net are as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Interest income	$	8,501		$	5,603
	Interest expense	(13,865		)	(13,859		)
	Other expense, net	(858		)	(1,674		)
		$	(6,222	)	$	(9,930	)

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	3 Months Ended
	Jun. 28, 2014
Equity [Abstract]	'
Accumulated Other Comprehensive Income (Loss)	'
	Accumulated Other Comprehensive Income (Loss)
	Comprehensive income (loss) is defined as the change in equity of a company during a period from transactions and other events and circumstances from non-owner sources. The components of accumulated other comprehensive income (loss) are as follows:
	(In thousands)	June 28, 2014			29-Mar-14
	Accumulated unrealized gains (losses) on available-for-sale securities, net of tax	$	6,679		$	(889	)
	Accumulated unrealized gains on hedging transactions, net of tax	533			798
	Accumulated cumulative translation adjustment, net of tax	(286		)	(457		)
	Accumulated other comprehensive income (loss)	$	6,926		$	(548	)
	The related tax effects of other comprehensive income (loss) were not material for all periods presented.

Income_Taxes

Income Taxes	3 Months Ended
	Jun. 28, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	The Company recorded a tax provision of $26.7 million for the first quarter of fiscal 2015 as compared to $26.0 million in the same prior year period, representing effective tax rates of 13% and 14%, respectively.
	The difference between the U.S. federal statutory tax rate of 35% and the Company’s effective tax rate in all periods is primarily due to income earned in lower tax rate jurisdictions, for which no U.S. income tax has been provided, as the Company intends to permanently reinvest these earnings outside of the U.S.
	The Company’s total gross unrecognized tax benefits as of June 28, 2014, determined in accordance with FASB authoritative guidance for measuring uncertain tax positions, was $26.4 million. The total amount of unrecognized tax benefits that, if realized in a future period, would favorably affect the effective tax rate was $11.0 million as of June 28, 2014. It is reasonably possible that changes to our unrecognized tax benefits could be significant in the next twelve months due to tax audit settlements and lapses of statutes of limitation. As a result of uncertainties regarding tax audit settlements and their possible outcomes, an estimate of the range of increase or decrease that could occur in the next twelve months cannot be made.
	The Company’s policy is to include interest and penalties related to income tax liabilities within the provision for income taxes on the condensed consolidated statements of income. The balance of accrued interest and penalties recorded in the condensed consolidated balance sheets and the amounts of interest and penalties included in the Company's provision for income taxes were not material for all periods presented.
	The Company is no longer subject to U.S. federal audits by taxing authorities for years through fiscal 2010. The Company is no longer subject to U.S. state audits for years through fiscal 2004, except for fiscal years 1996 through 2001 which are still open for audit purposes. The Company is no longer subject to tax audits in Ireland for years through fiscal 2009.

Commitments

Commitments	3 Months Ended
	Jun. 28, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Commitments	'
	Commitments
	Xilinx leases some of its facilities and office buildings under non-cancelable operating leases that expire at various dates through October 2021. Additionally, Xilinx entered into a land lease in conjunction with the Company’s building in Singapore, which will expire in November 2035 and the lease cost was settled in an up-front payment in June 2006. Some of the operating leases for facilities and office buildings require payment of operating costs, including property taxes, repairs, maintenance and insurance. Most of the Company’s leases contain renewal options for varying terms. Approximate future minimum lease payments under non-cancelable operating leases are as follows:
	Fiscal	(In thousands)
	2015 (remaining nine months)	$	4,514
	2016	4,019
	2017	2,335
	2018	2,102
	2019	1,701
	Thereafter	3,625
	Total	$	18,296
	Aggregate future rental income to be received, which includes rents from both owned and leased property, totaled $3.8 million as of June 28, 2014. Rent expense, net of rental income, under all operating leases was $911 thousand and $766 thousand for the three months ended June 28, 2014 and June 29, 2013, respectively. Rental income was not material for the first quarter of fiscal 2015 or 2014.
	Other commitments as of June 28, 2014 totaled $115.7 million and consisted of purchases of inventory and other non-cancelable purchase obligations related to subcontractors that manufacture silicon wafers and provide assembly and some test services. The Company expects to receive and pay for these materials and services in the next three to six months, as the products meet delivery and quality specifications. As of June 28, 2014, the Company also had $21.8 million of non-cancelable license obligations to providers of electronic design automation software and hardware/software maintenance expiring at various dates through December 2016.

Product_Warranty_and_Indemnifi

Product Warranty and Indemnification (Notes)	3 Months Ended
	Jun. 28, 2014
Product Warranties Disclosures [Abstract]	'
Product Warranty Disclosure [Text Block]	'
	Product Warranty and Indemnification
	The Company generally sells products with a limited warranty for product quality. The Company provides an accrual for known product issues if a loss is probable and can be reasonably estimated. As of the end of the first quarter of fiscal 2015 and the end of fiscal 2014, the accrual balance of the product warranty liability was immaterial.
	The Company offers, subject to certain terms and conditions, to indemnify customers and distributors for costs and damages awarded against these parties in the event the Company’s hardware products are found to infringe third-party intellectual property rights, including patents, copyrights or trademarks, and to compensate certain customers for limited specified costs they actually incur in the event our hardware products experience epidemic failure.  To a lesser extent, the Company may from time-to-time offer limited indemnification with respect to its software products.  The terms and conditions of these indemnity obligations are limited by contract, which obligations are typically perpetual from the effective date of the agreement. The Company has historically received only a limited number of requests for indemnification under these provisions and has not made any significant payments pursuant to these provisions. The Company cannot estimate the maximum amount of potential future payments, if any, that the Company may be required to make as a result of these obligations due to the limited history of indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim and indemnification provision. However, there can be no assurances that the Company will not incur any financial liabilities in the future as a result of these obligations.

Contingencies

Contingencies	3 Months Ended
	Jun. 28, 2014
Loss Contingency [Abstract]	'
Contingencies	'
	Contingencies
	Patent Litigation
	On February 14, 2011, the Company filed a complaint for declaratory judgment of patent non-infringement and invalidity against Intellectual Ventures in the U.S. District Court for the Northern District of California. On September 30, 2011, the Company amended its complaint in this case to eliminate certain defendants and patents from the action (Xilinx, Inc. v. Intellectual Ventures I LLC and Intellectual Ventures II LLC, Case No CV11-0671) (California Case I). The lawsuit pertained to one patent and sought judgment of non-infringement by Xilinx and judgment that the patent is invalid and unenforceable, as well as costs and attorneys’ fees.
	On February 15, 2011, Intellectual Ventures added the Company as a defendant in its complaint for patent infringement previously filed against Altera Corporation (Altera), Microsemi Corporation (Microsemi) and Lattice Semiconductor Corporation (Lattice) in the U.S. District Court for the District of Delaware (Intellectual Ventures I LLC and Intellectual Ventures II LLC v. Altera Corporation, Microsemi Corporation, Lattice Semiconductor Corporation and Xilinx, Inc., Case No. 10-CV-1065) (Delaware Case). The lawsuit pertained to five patents, four of which the Company was alleged to be infringing. Intellectual Ventures sought unspecified damages, interest and attorneys’ fees. Altera, Microsemi and Lattice were previously dismissed from the case with prejudice.
	On October 17, 2011, Xilinx filed a complaint for patent non-infringement and invalidity and violation of California Business and Professions Code Section 17200 in the U.S. District Court for the Northern District of California against Intellectual Ventures and related entities as well as additional defendants (Xilinx, Inc. v. Intellectual Ventures, LLC. Intellectual Ventures Management, LLC, Detelle Relay KG, LLC, Roldan Block NY LLC, Latrosse Technologies LLC, TR Technologies Foundation LLC, Taichi Holdings, LLC, Noregin Assets N.V., LLC and Intellectual Venture Funding LLC Case No CV-04407) (California Case II). By order dated January 25, 2012, the Court granted with leave to amend defendants' motion to dismiss our claim for violation of California Business and Professions Code section 17200. The Company amended its complaint to remove the claim for violation of California Business and Professions Code section 17200. The remainder of the lawsuit pertained to two patents and sought judgments of non-infringement by Xilinx and judgments that the patents are invalid and unenforceable, as well as costs and attorneys’ fees.
	On May 1, 2014, the Company entered into a confidential settlement agreement with Intellectual Ventures. Under the terms of the settlement, Intellectual Ventures agreed to dismiss with prejudice all outstanding patent litigation against Xilinx. On May 2, 2014, the U.S. District Court for the Northern District of California dismissed California Case I and California Case II and the U.S. District Court for the District of Delaware dismissed the Delaware Case.
	On November 5, 2012, a patent infringement lawsuit was filed by Conversant Intellectual Property Management Inc. (Conversant), formerly known as Mosaid Technologies, against the Company in the U.S. District Court for the Eastern District of Texas (Mosaid Technologies Inc. v. Xilinx, Inc., Case No. 6:12-CV-00847). The lawsuit pertained to five patents and Conversant sought unspecified damages, costs, fees, royalties and injunctive relief.
	On May 30, 2014, the Company entered into a confidential settlement agreement with Conversant. Under the settlement, Conversant agreed to dismiss with prejudice all outstanding patent litigation against Xilinx. On June 19, 2014, the U.S. District Court for the Eastern District of Texas dismissed the suit.
	On July 17, 2014, a patent infringement lawsuit was filed by PLL Technologies, Inc. (PTI) against the Company and three additional named defendants in the U.S. District Court for the District of Delaware (PLL Technologies, Inc. v. Xilinx, Inc., Case No. 1:14-CV-00945).  The lawsuit pertains to one patent and PTI seeks unspecified damages, interest, costs, and fees.  The Company is unable to estimate its range of possible loss, if any, in this matter at this time.
	Other Matters
	Except as stated above, there are no pending legal proceedings of a material nature to which the Company is a party or of which any of its property is the subject.
	From time to time, the Company is involved in various disputes and litigation matters that arise in the ordinary course of its business. These include disputes and lawsuits related to intellectual property, mergers and acquisitions, licensing, contract law, tax, regulatory, distribution arrangements, employee relations and other matters. Periodically, the Company reviews the status of each matter and assesses its potential financial exposure. If the potential loss from any claim or legal proceeding is considered probable and a range of possible losses can be estimated, the Company accrues a liability for the estimated loss. Legal proceedings are subject to uncertainties, and the outcomes are difficult to predict. Because of such uncertainties, accruals are based only on the best information available at the time. As additional information becomes available, the Company continues to reassess the potential liability related to pending claims and litigation and may revise estimates.

Goodwill_and_AcquisitionRelate

Goodwill and Acquisition-Related Intangibles	3 Months Ended
	Jun. 28, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Goodwill and Acquisition-Related Intangibles	'
	Goodwill and Acquisition-Related Intangibles
	As of June 28, 2014 and March 29, 2014, the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows:
								Weighted-Average
	(In thousands)	June 28, 2014			29-Mar-14			Amortization Life
	Goodwill	$	159,296		$	159,296
	Core technology, gross	91,860			91,860			5.7 years
	Less accumulated amortization	(65,612		)	(63,267		)
	Core technology, net	26,248			28,593
	Other intangibles, gross	46,716			46,716			2.7 years
	Less accumulated amortization	(46,515		)	(46,442		)
	Other intangibles, net	201			274
	Total acquisition-related intangibles, gross	138,576			138,576
	Less accumulated amortization	(112,127		)	(109,709		)
	Total acquisition-related intangibles, net	$	26,449		$	28,867
	Amortization expense for acquisition-related intangibles for the three months ended June 28, 2014 and June 29, 2013 was $2.4 million and $2.4 million , respectively. Based on the carrying value of acquisition-related intangibles recorded as of June 28, 2014, and assuming no subsequent impairment of the underlying assets, the annual amortization expense for acquisition-related intangibles is expected to be as follows:
	Fiscal	(In thousands)
	2015 (remaining nine months)	$	7,120
	2016	8,935
	2017	7,131
	2018	2,660
	2019	603
	Total	$	26,449

Subsequent_Events_Notes

Subsequent Events (Notes)	3 Months Ended
	Jun. 28, 2014
Subsequent Events [Abstract]	'
Subsequent Events [Text Block]	'
	Subsequent Events
	On July 21, 2014, the Company’s Board of Directors declared a cash dividend of $0.29 per common share for the second quarter of fiscal 2015. The dividend is payable on August 27, 2014 to stockholders of record on August 6, 2014.

Derivative_Financial_Instrumen1

Derivative Financial Instruments Derivative Financial Instruments (Policies)	3 Months Ended
	Jun. 28, 2014
Accounting Policies [Abstract]	'
Derivatives, Policy [Policy Text Block]	'
	Gains and losses on foreign currency forward contracts that are designated as hedges of anticipated transactions, for which a firm commitment has been attained and the hedged relationship has been effective, are deferred and included in income or expenses in the same period that the underlying transaction is settled. Gains and losses on any instruments not meeting the above criteria are recognized in income or expenses in the consolidated statements of income as they are incurred.

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Jun. 28, 2014
Fair Value Disclosures [Abstract]	'
Assets and liabilities measured at fair value on a recurring basis	'
	The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of June 28, 2014 and March 29, 2014:
			June 28, 2014
	(In thousands)		Quoted			Significant			Significant			Total Fair
			Prices in			Other			Unobservable			Value
			Active			Observable			Inputs
			Markets for			Inputs			(Level 3)
			Identical			(Level 2)
			Instruments
			(Level 1)
	Assets
	Cash and cash equivalents:
	Money market funds		$	174,031		$	—		$	—		$	174,031
	Financial institution securities		—			124,986			—			124,986
	Non-financial institution securities		—			120,984			—			120,984
	U.S. government and agency securities		25,000			—			—			25,000
	Foreign government and agency securities		—			94,992			—			94,992
	Short-term investments:
	Financial institution securities		—			129,983			—			129,983
	Non-financial institution securities		—			317,015			—			317,015
	Municipal bonds		—			23,495			—			23,495
	U.S. government and agency securities		433,169			99,634			—			532,803
	Foreign government and agency securities		—			315,898			—			315,898
	Mortgage-backed securities		—			442,571			—			442,571
	Debt mutual funds		—			40,703			—			40,703
	Bank loans		—			57,707			—			57,707
	Long-term investments:
	Non-financial institution securities		—			188,007			—			188,007
	Auction rate securities		—			—			20,704			20,704
	Municipal bonds		—			15,346			—			15,346
	U.S. government and agency securities		4,948			31,951			—			36,899
	Mortgage-backed securities		—			789,964			—			789,964
	Debt mutual fund		—			58,725			—			58,725
	Derivative financial instruments, net		—			1,311			—			1,311
	Total assets measured at fair value		$	637,148		$	2,853,272		$	20,704		$	3,511,124
		March 29, 2014
	(In thousands)	Quoted			Significant			Significant			Total Fair
		Prices in			Other			Unobservable			Value
		Active			Observable			Inputs
		Markets for			Inputs			(Level 3)
		Identical			(Level 2)
		Instruments
		(Level 1)
	Assets
	Cash and cash equivalents:
	Money market funds	$	213,988		$	—		$	—		$	213,988
	Financial institution securities	—			131,990			—			131,990
	Non-financial institution securities	—			319,970			—			319,970
	U.S. government and agency securities	69,998			—			—			69,998
	Foreign government and agency securities	—			194,984			—			194,984
	Short-term investments:
	Financial institution securities	—			234,916			—			234,916
	Non-financial institution securities	—			226,828			—			226,828
	Municipal Bonds	—			15,780			—			15,780
	U.S. government and agency securities	349,023			89,422			—			438,445
	Foreign government and agency securities	—			159,951			—			159,951
	Mortgage-backed securities	—			387,508			—			387,508
	Debt mutual fund	—			20,216			—			20,216
	Long-term investments:
	Non-financial institution securities	—			209,274			—			209,274
	Auction rate securities	—			—			20,160			20,160
	Municipal bonds	—			15,986			—			15,986
	U.S. government and agency securities	4,950			36,126			—			41,076
	Mortgage-backed securities	—			847,581			—			847,581
Debt mutual fund	—			56,698			—			56,698
Derivative financial instruments, net	—			1,713			—			1,713
Total assets measured at fair value	$	637,959		$	2,948,943		$	20,160		$	3,607,062
Changes in Level 3 instruments measured at fair value on a recurring basis	'
	The following table is a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3):
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Balance as of beginning of period	$	20,160		$	27,610
	Total realized and unrealized gains (losses):
	Included in interest and other expense, net	—			(75		)
	Included in other comprehensive income	544			846
	Sales and settlements, net (1)	—			(300		)
	Balance as of end of period	$	20,704		$	28,081
	-1	During the first quarter of fiscal 2014, the Company redeemed $300 thousand of student loan auction rate securities, respectively, for cash at par value.
Gains or (losses) included in net income attributable to change in unrealized gains or losses relating to assets and liabilities	'
	The amount of total losses included in net income attributable to the change in unrealized losses relating to assets and liabilities still held as of the end of the period are summarized as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Included in interest and other expense, net	$	—		$	(75	)

Financial_Instruments_Tables

Financial Instruments (Tables)	3 Months Ended
	Jun. 28, 2014
Investments, All Other Investments [Abstract]	'
Available-for-sale securities	'
	The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented:
		June 28, 2014													March 29, 2014
	(In thousands)	Amortized Cost			Gross Unrealized Gains			Gross Unrealized Losses			Estimated Fair Value				Amortized Cost			Gross Unrealized Gains		Gross Unrealized Losses			Estimated Fair Value
	Money market funds	$	174,031		$	—		$	—		$	174,031			$	213,988		$	—	$	—		$	213,988
	Financial institution
	securities	254,969			—			—			254,969				366,906			—		—			366,906
	Non-financial institution
	securities	621,880			4,470			(344		)	626,006				753,888			3,428		(1,244		)	756,072
	Auction rate securities	21,500			—			(796		)	20,704				21,500			—		(1,340		)	20,160
	Municipal bonds	38,164			820			(143		)	38,841				31,367			604		(205		)	31,766
	U.S. government and
	agency securities	593,637			1,145			(80		)	594,702				548,568			1,135		(184		)	549,519
	Foreign government and
	agency securities	410,896			—			(6		)	410,890				354,935			—		—			354,935
	Mortgage-backed securities	1,225,050			14,355			(6,870		)	1,232,535				1,234,237			11,380		(10,528		)	1,235,089
	Debt mutual funds	101,350			703			(2,625		)	99,428				81,350			216		(4,652		)	76,914
	Bank loans	57,667			105			(65		)	57,707				—			—		—			—
		$	3,499,144		$	21,598		$	(10,929	)	$	3,509,813			$	3,606,739		$	16,763	$	(18,153	)	$	3,605,349
Fair values and gross unrealized losses of the investments	'
	The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of June 28, 2014 and March 29, 2014:
		June 28, 2014
		Less Than 12 Months						12 Months or Greater						Total
	(In thousands)	Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses
	Non-financial institution securities	$	32,613		$	(84	)	$	19,902		$	(260	)	$	52,515		$	(344	)
	Auction rate securities	—			—			20,704			(796		)	20,704			(796		)
	Municipal bonds	4,026			(6		)	4,603			(137		)	8,629			(143		)
	U.S. government and
	agency securities	250,910			(31		)	4,369			(49		)	255,279			(80		)
	Foreign government and
	agency securities	124,968			(6		)	—			—			124,968			(6		)
	Mortgage-backed securities	234,724			(2,223		)	274,363			(4,647		)	509,087			(6,870		)
	Debt mutual fund	—			—			58,724			(2,625		)	58,724			(2,625		)
	Bank loans	30,097			(65		)	—			—			30,097			(65		)
		$	677,338		$	(2,415	)	$	382,665		$	(8,514	)	$	1,060,003		$	(10,929	)
		March 29, 2014
		Less Than 12 Months						12 Months or Greater						Total
	(In thousands)	Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses			Fair Value			Gross Unrealized Losses
	Non-financial institution securities	$	112,470		$	(1,167	)	$	4,488		$	(77	)	$	116,958		$	(1,244	)
	Auction rate securities	—			—			20,160			(1,340		)	20,160			(1,340		)
	Municipal bonds	5,917			(166		)	1,743			(39		)	7,660			(205		)
	U.S. government and
	agency securities	118,125			(184		)	—			—			118,125			(184		)
	Mortgage-backed securities	457,903			(7,225		)	132,376			(3,303		)	590,279			(10,528		)
	Debt mutual fund	56,698			(4,652		)	—			—			56,698			$	(4,652	)
		$	751,113		$	(13,394	)	$	158,767		$	(4,759	)	$	909,880		$	(18,153	)
Amortized cost and estimated fair value of marketable debt securities	'
		June 28, 2014
	(In thousands)	Amortized			Estimated
		Cost			Fair Value
	Due in one year or less	$	1,464		$	1,464
	Due after one year through five years	474			478
	Due after five years through ten years	287			289
	Due after ten years	999			1,005
		$	3,224		$	3,236
Information on sale of available-for-sale securities	'
	Certain information related to available-for-sale securities is as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Proceeds from sale of available-for-sale securities	$	59,581		$	95,139
	Gross realized gains on sale of available-for-sale securities	$	837		$	1,101
	Gross realized losses on sale of available-for-sale securities	(167		)	(994		)
	Net realized gains (losses) on sale of available-for-sale securities	$	670		$	107
	Amortization of premiums on available-for-sale securities	$	6,233		$	7,159

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Tables)	3 Months Ended
	Jun. 28, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Forward currency exchange contracts outstanding	'
	As of June 28, 2014 and March 29, 2014, the Company had the following outstanding forward currency exchange contracts (in notional amount), which were derivative financial instruments:
	(In thousands and U.S. dollars)	June 28, 2014			March 29, 2014
	Singapore Dollar	$	60,052		$	60,551
	Euro	48,558			46,062
	Indian Rupee	20,919			18,631
	British Pound	12,874			12,056
	Japanese Yen	9,489			9,273
		$	151,892		$	146,573
Derivative Instruments Located on Condensed Consolidated Balance Sheet	'
	The Company had the following derivative instruments as of June 28, 2014 and March 29, 2014, located on the condensed consolidated balance sheet, utilized for risk management purposes detailed above:
		Foreign Exchange Contracts
		Asset Derivatives				Liability Derivatives
	(In thousands)	Balance Sheet Location	Fair Value			Balance Sheet Location	Fair Value
	June 28, 2014	Prepaid expenses and other current assets	$	1,986		Other accrued liabilities	$	675
	29-Mar-14	Prepaid expenses and other current assets	$	2,648		Other accrued liabilities	$	935
Effect Of Derivative Instruments On Condensed Consolidated Statements Of Income	'
	The following table summarizes the effect of derivative instruments on the condensed consolidated statements of income for first quarter of fiscal 2015 and 2014:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Amount of losses recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	$	(265	)	$	(802	)
	Amount of (gains) losses reclassified from accumulated other comprehensive income into income (effective portion) *	$	807		$	(706	)
	Amount of gains (losses) recorded (ineffective portion) *	$	30		$	(18	)
	*	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Tables)	3 Months Ended
	Jun. 28, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	'
	The per share weighted-average fair value of RSUs granted during the first quarter of fiscal 2015 was $40.69 ($34.23 for the first quarter of fiscal 2014), which were calculated based on estimates at the date of grant using the following weighted-average assumptions:
		Three Months Ended
		June 28, 2014		June 29, 2013
	Risk-free interest rate	0.9	%	0.5	%
	Dividend yield	2.5	%	2.5	%
Stock-Based compensation expense	'
	The following table summarizes stock-based compensation expense related to stock awards granted under the Company’s equity incentive plans and rights to acquire stock granted under the Company’s Employee Stock Purchase Plan (ESPP):
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Stock-based compensation included in:
	Cost of revenues	$	1,992		$	1,804
	Research and development	10,505			10,219
	Selling, general and administrative	9,609			8,931
		$	22,106		$	20,954
Employee Stock Option [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary of option plans activity	'
	A summary of the Company’s option plans activity and related information is as follows:
		Options Outstanding
	(Shares in thousands)	Number of Shares		Weighted-Average Exercise Price Per Share
	30-Mar-13	12,753		$	28.01
	Granted	8		$	41.08
	Exercised	(7,421	)	$	29.95
	Forfeited/cancelled/expired	(60	)	$	35.61
	29-Mar-14	5,280		$	25.22
	Granted	—		$	—
	Exercised	(538	)	$	27.57
	Forfeited/cancelled/expired	(7	)	$	38.24
	June 28, 2014	4,735		$	24.93
	Options exercisable at:
	June 28, 2014	4,528		$	24.61
	March 29, 2014	4,935		$	24.87
Restricted Stock Units (RSUs) [Member]	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'
Summary of restricted stock unit activity and related information	'
	A summary of the Company’s RSU activity and related information is as follows:
		RSUs Outstanding
	(Shares in thousands)	Number of Shares		Weighted-Average Grant-Date Fair Value Per Share
	30-Mar-13	5,996		$	30.83
	Granted	3,297		$	38.9
	Vested	(2,066	)	$	29.25
	Cancelled	(326	)	$	32.28
	29-Mar-14	6,901		$	35.08
	Granted	403		$	40.69
	Vested	(78	)	$	31.56
	Cancelled	(69	)	$	34.09
	June 28, 2014	7,157		$	35.45

Net_Income_Per_Common_Share_Ne

Net Income Per Common Share Net Income Per Common Share (Tables)	3 Months Ended
	Jun. 28, 2014
Earnings Per Share [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	'
	The following table summarizes the computation of basic and diluted net income per common share:
	(In thousands, except per share amounts)	June 28, 2014		June 29, 2013
	Net income available to common stockholders	$	173,611	$	157,023
	Weighted average common shares outstanding-basic	267,648		264,153
	Dilutive effect of employee equity incentive plans	4,568		5,015
	Dilutive effect of 2017 Convertible Notes and warrants	9,363		4,878
	Dilutive effect of 2037 Convertible Notes	—		6,245
	Weighted average common shares outstanding-diluted	281,579		280,291
	Basic earnings per common share	$	0.65	$	0.59
	Diluted earnings per common share	$	0.62	$	0.56

Inventories_Inventories_Tables

Inventories Inventories (Tables)	3 Months Ended
	Jun. 28, 2014
Inventory Disclosure [Abstract]	'
Schedule of Inventory, Current [Table Text Block]	'
	(In thousands)	June 28, 2014		March 29, 2014
	Raw materials	$	17,039	$	15,306
	Work-in-process	206,897		192,067
	Finished goods	32,855		26,626
		$	256,791	$	233,999

Debt_and_Credit_Facility_Table

Debt and Credit Facility (Tables)	3 Months Ended
	Jun. 28, 2014
Two And Six Two Five Percent Senior Convertible Debentures [Member] | Two And Six Two Five Percent Senior Convertible Debentures [Member]	'
Schedule of Debt Instruments [Line Items]	'
Carrying values of liability and equity components of debentures	'
	The carrying values of the liability and equity components of the 2017 Convertible Notes are reflected in the Company’s condensed consolidated balance sheets as follows:
	(In thousands)	June 28, 2014			29-Mar-14
	Liability component:
	Principal amount of the 2017 Convertible Notes	$	600,000		$	600,000
	Unamortized discount of liability component	(45,337		)	(49,223		)
	Hedge accounting adjustment – sale of interest rate swap	13,101			14,224
	Net carrying value of the 2017 Convertible Notes	$	567,764		$	565,001
	Equity component (including temporary equity) – net carrying value	$	66,415		$	66,415
Interest Expense Related to Debentures [Table Text Block]	'
	Interest expense related to the 2017 Convertible Notes was included in interest and other expense, net on the condensed consolidated statements of income as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Contractual coupon interest	$	3,938		$	3,938
	Amortization of debt issuance costs	362			362
	Amortization of debt discount, net	2,763			2,763
	Total interest expense related to the 2017 Convertible Notes	$	7,063		$	7,063
2019 and 2021 Notes Payable [Member]	'
Schedule of Debt Instruments [Line Items]	'
Schedule of Long-term Debt Instruments [Table Text Block]	'
	The following table summarizes the carrying value of the 2019 and 2021 Notes as of June 28, 2014 and March 29, 2014:
	(In thousands)	June 28, 2014			29-Mar-14
	Principal amount of the 2019 Notes	$	500,000		$	500,000
	Unamortized discount of the 2019 Notes	(2,449		)	(2,574		)
	Principal amount of the 2021 Notes	500,000			500,000
	Unamortized discount of the 2021 Notes	(3,441		)	(3,556		)
	Total carrying value	$	994,110		$	993,870
Interest Expense Related to Debentures [Table Text Block]	'
	Interest expense related to the 2019 and 2021 Notes was included in interest and other expense, net on the condensed consolidated statements of income as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Contractual coupon interest	$	6,406		$	—
	Amortization of debt issuance costs	156			—
	Amortization of debt discount, net	240			—
	Total interest expense related to the 2019 and 2021 Notes	$	6,802		$	—

Recovered_Sheet1

Interest And Other Expense, Net (Tables)	3 Months Ended
	Jun. 28, 2014
Other Income and Expenses [Abstract]	'
Components of interest and other expense, net	'
	The components of interest and other expense, net are as follows:
		Three Months Ended
	(In thousands)	June 28, 2014			June 29, 2013
	Interest income	$	8,501		$	5,603
	Interest expense	(13,865		)	(13,859		)
	Other expense, net	(858		)	(1,674		)
		$	(6,222	)	$	(9,930	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Jun. 28, 2014
Equity [Abstract]	'
Components of accumulated other comprehensive income (loss)	'
	The components of accumulated other comprehensive income (loss) are as follows:
	(In thousands)	June 28, 2014			29-Mar-14
	Accumulated unrealized gains (losses) on available-for-sale securities, net of tax	$	6,679		$	(889	)
	Accumulated unrealized gains on hedging transactions, net of tax	533			798
	Accumulated cumulative translation adjustment, net of tax	(286		)	(457		)
	Accumulated other comprehensive income (loss)	$	6,926		$	(548	)

Commitments_Tables

Commitments (Tables)	3 Months Ended
	Jun. 28, 2014
Commitments and Contingencies Disclosure [Abstract]	'
Future minimum lease payments under non-cancelable operating leases	'
	Approximate future minimum lease payments under non-cancelable operating leases are as follows:
	Fiscal	(In thousands)
	2015 (remaining nine months)	$	4,514
	2016	4,019
	2017	2,335
	2018	2,102
	2019	1,701
	Thereafter	3,625
	Total	$	18,296

Goodwill_and_AcquisitionRelate1

Goodwill and Acquisition-Related Intangibles (Tables)	3 Months Ended
	Jun. 28, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'
Gross and net amounts of goodwill and of acquisition-related intangibles	'
	As of June 28, 2014 and March 29, 2014, the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows:
								Weighted-Average
	(In thousands)	June 28, 2014			29-Mar-14			Amortization Life
	Goodwill	$	159,296		$	159,296
	Core technology, gross	91,860			91,860			5.7 years
	Less accumulated amortization	(65,612		)	(63,267		)
	Core technology, net	26,248			28,593
	Other intangibles, gross	46,716			46,716			2.7 years
	Less accumulated amortization	(46,515		)	(46,442		)
	Other intangibles, net	201			274
	Total acquisition-related intangibles, gross	138,576			138,576
	Less accumulated amortization	(112,127		)	(109,709		)
	Total acquisition-related intangibles, net	$	26,449		$	28,867
Schedule of expected annual amortization expense for acquisition-related intangibles	'
	Based on the carrying value of acquisition-related intangibles recorded as of June 28, 2014, and assuming no subsequent impairment of the underlying assets, the annual amortization expense for acquisition-related intangibles is expected to be as follows:
	Fiscal	(In thousands)
	2015 (remaining nine months)	$	7,120
	2016	8,935
	2017	7,131
	2018	2,660
	2019	603
	Total	$	26,449

Significant_Customers_and_Conc1

Significant Customers and Concentrations of Credit Risk (Details)	3 Months Ended		12 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Mar. 29, 2014
	Customer	Customer	Customer
Significant Customers and Concentrations of Credit Risk [Abstract]	'	'	'
Percentage of Accounts Receivable Accounted From Company Distributor One	63.00%	'	55.00%
Percentage of net revenues through resale of product from Company Distributor One	42.00%	49.00%	'
Number of End Customers Accounted For 10% or More of Net Revenues	0	0	0
Percentage of higher grade securities investment in debt securities	82.00%	'	'
Percentage of Mortgage Backed Securities In Investment Portfolio	35.00%	'	'

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Derivative Asset	$1,311	$1,713
Fair Value, Inputs, Level 1 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Derivative Asset	0	'
Fair Value, Inputs, Level 2 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Derivative Asset	1,311	1,713
Fair Value, Inputs, Level 3 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Derivative Asset	0	'
Fair Value, Measurements, Recurring [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	3,511,124	3,607,062
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	637,148	637,959
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	2,853,272	2,948,943
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	20,704	20,160
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Money Market Funds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	174,031	213,988
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	124,986	131,990
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	120,984	319,970
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	25,000	69,998
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	94,992	194,984
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	174,031	213,988
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	25,000	69,998
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	124,986	131,990
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	120,984	319,970
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	94,992	194,984
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	129,983	234,916
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	317,015	226,828
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	23,495	15,780
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	532,803	438,445
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	315,898	159,951
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	442,571	387,508
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	40,703	20,216
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Bank Loans [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	57,707	'
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	433,169	349,023
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Bank Loans [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	'
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	129,983	234,916
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	317,015	226,828
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	23,495	15,780
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	99,634	89,422
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	315,898	159,951
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	442,571	387,508
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	40,703	20,216
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Loans [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	57,707	'
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Bank Loans [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	'
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	188,007	209,274
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Student loan auction rate securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	20,704	20,160
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	15,346	15,986
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	36,899	41,076
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	789,964	847,581
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	58,725	56,698
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Student loan auction rate securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	4,948	4,950
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	188,007	209,274
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Student loan auction rate securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	15,346	15,986
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	31,951	36,126
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	789,964	847,581
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	58,725	56,698
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Student loan auction rate securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	20,704	20,160
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]	'	'
Assets and Liabilities Measured at Fair Value on a Recurring Basis	'	'
Total assets measured at fair value	$0	$0

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 1) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014		Jun. 29, 2013
Changes in Level 3 instruments measured at fair value on a recurring basis	'		'
Balance as of beginning of period	$20,160		$27,610
Gains (losses) included in interest and other expense, net	0		-75
Gains (losses) included in other comprehensive income (loss)	544		846
Sales and settlements, net	0	[1]	-300	[1]
Balance as of end of period	$20,704		$28,081
[1]	During the first quarter of fiscal 2014, the Company redeemed $300 thousand of student loan auction rate securities, respectively, for cash at par value. There was no redemption during the first quarter of fiscal 2015.

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 2)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Fair Value Disclosures [Abstract]	'	'
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings, Description	'0	'-75

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details Textual) (USD $)	Jun. 28, 2014	Mar. 29, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities, Noncurrent	$1,109,645,000	$1,190,775,000	[1]
Available-for-sale Securities	3,509,813,000	3,605,349,000
Two And One Two Five Percent 2019 Senior Debentures [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of debentures	501,700,000	'
Three Point Zero Percent 2021 Senior Debentures [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of debentures	505,900,000	'
Auction Rate Securities [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Available-for-sale Securities, Noncurrent	20,704,000	20,160,000
Two And Six Two Five Percent Senior Convertible Debentures [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fair value of debentures	$1,000,000,000	'
[1]	Derived from audited financial statements

Financial_Instruments_Details

Financial Instruments (Details) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Available-for-sale securities	'	'
Amortized Cost	$3,499,144	$3,606,739
Available-for-sale Securities, Gross Unrealized Gains (Instant)	21,598	16,763
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-10,929	-18,153
Available-for-sale Securities, Noncurrent	1,109,645	1,190,775	[1]
Estimated Fair Value	3,509,813	3,605,349
Money Market Funds [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	174,031	213,988
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	0	0
Estimated Fair Value	174,031	213,988
financial institution securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	254,969	366,906
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	0	0
Estimated Fair Value	254,969	366,906
Non-financial institution securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	621,880	753,888
Available-for-sale Securities, Gross Unrealized Gains (Instant)	4,470	3,428
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-344	-1,244
Estimated Fair Value	626,006	756,072
Auction Rate Securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	21,500	21,500
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-796	-1,340
Available-for-sale Securities, Noncurrent	20,704	20,160
Municipal Bonds [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	38,164	31,367
Available-for-sale Securities, Gross Unrealized Gains (Instant)	820	604
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-143	-205
Estimated Fair Value	38,841	31,766
U.S. Government and Agency Securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	593,637	548,568
Available-for-sale Securities, Gross Unrealized Gains (Instant)	1,145	1,135
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-80	-184
Estimated Fair Value	594,702	549,519
Foreign Government and Agency Securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	410,896	354,935
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-6	0
Estimated Fair Value	410,890	354,935
Mortgage-Backed Securities [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	1,225,050	1,234,237
Available-for-sale Securities, Gross Unrealized Gains (Instant)	14,355	11,380
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-6,870	-10,528
Estimated Fair Value	1,232,535	1,235,089
Debt Mutual Fund [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	101,350	81,350
Available-for-sale Securities, Gross Unrealized Gains (Instant)	703	216
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-2,625	-4,652
Estimated Fair Value	99,428	76,914
Bank Loans [Member]	'	'
Available-for-sale securities	'	'
Amortized Cost	57,667	0
Available-for-sale Securities, Gross Unrealized Gains (Instant)	105	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-65	0
Estimated Fair Value	$57,707	$0
[1]	Derived from audited financial statements

Financial_Instruments_Details_

Financial Instruments (Details 1) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	$677,338	$751,113
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-2,415	-13,394
Available-for-Sale Securities, 12 Months or Greater, Fair Value	382,665	158,767
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-8,514	-4,759
Available-for-Sale Securities, Fair Value, Total	1,060,003	909,880
Available-for-Sale Securities, Gross Unrealized Losses, Total	-10,929	-18,153
Non-financial institution securities [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	32,613	112,470
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-84	-1,167
Available-for-Sale Securities, 12 Months or Greater, Fair Value	19,902	4,488
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-260	-77
Available-for-Sale Securities, Fair Value, Total	52,515	116,958
Available-for-Sale Securities, Gross Unrealized Losses, Total	-344	-1,244
Auction Rate Securities [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	0	0
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	0	0
Available-for-Sale Securities, 12 Months or Greater, Fair Value	20,704	20,160
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-796	-1,340
Available-for-Sale Securities, Fair Value, Total	20,704	20,160
Available-for-Sale Securities, Gross Unrealized Losses, Total	-796	-1,340
Municipal Bonds [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	4,026	5,917
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-6	-166
Available-for-Sale Securities, 12 Months or Greater, Fair Value	4,603	1,743
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-137	-39
Available-for-Sale Securities, Fair Value, Total	8,629	7,660
Available-for-Sale Securities, Gross Unrealized Losses, Total	-143	-205
U.S. Government and Agency Securities [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	250,910	118,125
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-31	-184
Available-for-Sale Securities, 12 Months or Greater, Fair Value	4,369	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-49	0
Available-for-Sale Securities, Fair Value, Total	255,279	118,125
Available-for-Sale Securities, Gross Unrealized Losses, Total	-80	-184
Foreign Government Debt Securities [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	124,968	'
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-6	'
Available-for-Sale Securities, 12 Months or Greater, Fair Value	0	'
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	0	'
Available-for-Sale Securities, Fair Value, Total	124,968	'
Available-for-Sale Securities, Gross Unrealized Losses, Total	-6	'
Mortgage-Backed Securities [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	234,724	457,903
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-2,223	-7,225
Available-for-Sale Securities, 12 Months or Greater, Fair Value	274,363	132,376
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-4,647	-3,303
Available-for-Sale Securities, Fair Value, Total	509,087	590,279
Available-for-Sale Securities, Gross Unrealized Losses, Total	-6,870	-10,528
Debt Mutual Fund [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	0	56,698
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	0	-4,652
Available-for-Sale Securities, 12 Months or Greater, Fair Value	58,724	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-2,625	0
Available-for-Sale Securities, Fair Value, Total	58,724	56,698
Available-for-Sale Securities, Gross Unrealized Losses, Total	-2,625	-4,652
Bank Loans [Member]	'	'
Fair values and gross unrealized losses of the investments	'	'
Available-for-Sale Securities, Less Than 12 Months, Fair Value	30,097	'
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-65	'
Available-for-Sale Securities, 12 Months or Greater, Fair Value	0	'
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	0	'
Available-for-Sale Securities, Fair Value, Total	30,097	'
Available-for-Sale Securities, Gross Unrealized Losses, Total	($65)	'

Financial_Instruments_Details_1

Financial Instruments (Details 2) (USD $)	Jun. 28, 2014
Investments, All Other Investments [Abstract]	'
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$762,400,000
Amortized cost and estimated fair value of marketable debt securities	'
Amortized Cost Due in one year or less	1,464,000
Amortized Cost Due after one year through five years	474,000
Amortized Cost Due after five years through ten years	287,000
Amortized Cost Due after ten years	999,000
Amortized Cost Total	3,224,000
Estimated Fair Value Due in one year or less	1,464,000
Estimated Fair Value Due after one year through five years	478,000
Estimated Fair Value Due after five years through ten years	289,000
Estimated Fair Value Due after ten years	1,005,000
Estimated Fair Value Total	$3,236,000

Financial_Instruments_Details_2

Financial Instruments (Details 3) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Investments, All Other Investments [Abstract]	'	'
Proceeds from Sale of Available-for-sale Securities	$59,581	$95,139
Information on sale of available-for-sale securities	'	'
Gross realized gains on sale of available-for-sale securities	837	1,101
Gross realized losses on sale of available-for-sale securities	-167	-994
Net realized gains (losses) on sale of available-for-sale securities	670	107
Amortization of premiums on available-for-sale securities	$6,233	$7,159

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	$151,892	$146,573
Singapore Dollar [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	60,052	60,551
Euro [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	48,558	46,062
Indian Rupee [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	20,919	18,631
British Pound [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	12,874	12,056
Japanese Yen [Member]	'	'
Derivative [Line Items]	'	'
Derivative Asset, Notional Amount	$9,489	$9,273

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 1) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Prepaid expenses and other current assets	'	'
Derivative Instruments located on Condensed Consolidated Balance sheet	'	'
Asset Derivatives, Fair Value	$1,986	$2,648
Other accrued liabilities	'	'
Derivative Instruments located on Condensed Consolidated Balance sheet	'	'
Liability Derivatives, Fair Value	$675	$935

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Details 2) (Cash Flow Hedging [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014		Jun. 29, 2013
Foreign Exchange Contracts [Member]	'		'
Effect of derivative instruments located on condensed consolidated Statements of Income	'		'
Amount of losses recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	($265)		($802)
Interest And Other Expense, Net [Member]	'		'
Effect of derivative instruments located on condensed consolidated Statements of Income	'		'
Amount of gains (losses) reclassified from accumulated other comprehensive income into income (effective portion)	-807	[1]	706	[1]
Amount of gains (losses) recorded (ineffective portion)	$30	[1]	($18)	[1]
[1]	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

Derivative_Financial_Instrumen6

Derivative Financial Instruments (Details Textual)	3 Months Ended
	Jun. 28, 2014
Derivative [Line Items]	'
Hedging Program number of years	'2 years
Maturity of Foreign Currency Derivatives	31-May-16

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Details) (Employee Stock Purchase Plan [Member], USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Stock Based compensation expense	'	'
Stock-based compensation effect on income before taxes	$22,106	$20,954
Cost of Revenues [Member]	'	'
Stock Based compensation expense	'	'
Stock-based compensation effect on income before taxes	1,992	1,804
Research and Development [Member]	'	'
Stock Based compensation expense	'	'
Stock-based compensation effect on income before taxes	10,505	10,219
Selling, General and Administrative Expenses [Member]	'	'
Stock Based compensation expense	'	'
Stock-based compensation effect on income before taxes	$9,609	$8,931

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 1) (Restricted Stock Units (RSUs) [Member])	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Restricted Stock Units (RSUs) [Member]	'	'
Weighted average assumptions in estimation of fair value of stock options	'	'
Risk-free interest rate	0.90%	0.50%
Dividend yield	2.50%	2.50%

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 2) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 28, 2014	Mar. 29, 2014
Summary of options activity	'	'
Number of Shares, Beginning Balance	5,280	12,753
Number of Shares, Granted	0	8
Number of Shares, Exercised	538	7,421
Number of Shares, Forfeited/Cancelled/Expired	7	60
Number of Shares, Ending Balance	4,735	5,280
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	4,528	4,935
Weighted-Average Exercise Price Per Share, Beginning Balance	$25.22	$28.01
Weighted-Average Exercise Price Per Share, Granted	$0	$41.08
Weighted-Average Exercise Price Per Share, Exercised	$27.57	$29.95
Weighted-Average Exercise Price Per Share, Forfeited/Cancelled/Expired	$38.24	$35.61
Weighted-Average Exercise Price Per Share, Ending Balance Balance	$24.93	$25.22
Weighted-Average Exercise Price Per Share, Options Exercisable	$24.61	$24.87

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 3) (USD $)	3 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 28, 2014	Mar. 29, 2014
Summary Of Restricted Stock Unit Activity and Related Information	'	'
Number of Shares, Beginning Balance	6,901	5,996
Number of Shares, Granted	403	3,297
Number of Shares, Vested	78	2,066
Number of Shares, Forfeited/Cancelled	69	326
Number of Shares, Ending Balance	7,157	6,901
Weighted-Average Grant-Date Fair Value, Beginning Balance	$35.08	$30.83
Weighted-Average Grant-Date Fair Value, Vested	$31.56	$29.25
Weighted-Average Grant-Date Fair Value, Forfeited/Cancelled	$34.09	$32.28
Weighted-Average Grant-Date Fair Value, Ending Balance	$35.45	$35.08

StockBased_Compensation_Plans_5

Stock-Based Compensation Plans (Details Textual) (USD $)	3 Months Ended		12 Months Ended
In Millions, except Share data, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013	Mar. 29, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Stock Issued During Period, Shares, Employee Stock Purchase Plans	'	0	'
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$2	$1.50	'
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$11.10	$12.80	'
Restricted Stock Units (RSUs) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Weighted-Average Grant-Date Fair Value, Granted	$40.69	$34.23	$38.90
Employee Stock Purchase Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Shares Available for Grant	9,700,000	'	'
Equity Plan Two Thousand Seven [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Shares Available for Grant	14,700,000	'	'

Net_Income_Per_Common_Share_De

Net Income Per Common Share (Details) (USD $)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Schedule of Debt Instruments [Line Items]	'	'
Antidilutive shares excluded from computation of dilutive net income per common share	206,000	22,700,000
Two And Six Two Five Percent Senior Convertible Debentures [Member]	'	'
Schedule of Debt Instruments [Line Items]	'	'
Maximum number of common shares to be purchased under call option	20,200,000	'
Price Per Share To Be Purchase By Company Under Call Option	29.64	'

Net_Income_Per_Common_Share_Ne1

Net Income Per Common Share Net Income Per Common Share (Details 2) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Earnings Per Share [Abstract]	'	'
Net income	$173,611	$157,023
Weighted Average Number of Shares Outstanding, Basic	267,648	264,153
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	4,568	5,015
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities and Warrants	9,363	4,878
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0	6,245
Weighted Average Number of Shares Outstanding, Diluted	281,579	280,291
Earnings Per Share, Basic	$0.65	$0.59
Earnings Per Share, Diluted	$0.62	$0.56

Inventories_Inventories_Detail

Inventories Inventories (Details) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]	'	'
Inventory, Raw Materials, Gross	$17,039	$15,306
Inventory, Work in Process, Gross	206,897	192,067
Inventory, Finished Goods, Gross	32,855	26,626
Inventory, Net	$256,791	$233,999	[1]
[1]	Derived from audited financial statements

Debt_and_Credit_Facility_Detai

Debt and Credit Facility (Details) (USD $)	3 Months Ended				3 Months Ended					3 Months Ended
	Jun. 28, 2014	Mar. 29, 2014		Mar. 29, 2014	Jun. 29, 2013	Jun. 28, 2014	Mar. 29, 2014	Jun. 28, 2014	Mar. 29, 2014	Jun. 28, 2014	Mar. 29, 2014
				Two And Six Two Five Percent Senior Convertible Debentures [Member]	Two And One Two Five Percent 2019 Senior Debentures [Member]	Three Point Zero Percent 2021 Senior Debentures [Member]	Three Point Zero Percent 2021 Senior Debentures [Member]	Two And One Two Five Percent 2019 Senior Debentures [Member]	Two And One Two Five Percent 2019 Senior Debentures [Member]	Two And Six Two Five Percent Senior Convertible Debentures [Member]	Two And Six Two Five Percent Senior Convertible Debentures [Member]
Debt Instrument [Line Items]	'	'		'	'	'	'	'	'	'	'
Price Per Share To Be Purchase By Company Under Call Option	'	'		'	'	'	'	'	'	$29.64	'
Debt Instrument, Face Amount	'	'		'	'	$500,000,000	$500,000,000	$500,000,000	$500,000,000	$600,000,000	$600,000,000
Debt Instrument, Unamortized Discount	'	'		'	'	-3,441,000	-3,556,000	-2,449,000	-2,574,000	-45,337,000	-49,223,000
Debt Instrument Carrying Amount Of Liability Component	'	'		565,001,000	'	'	'	'	'	567,764,000	'
2019 Debt instrument, Maturity Date	15-Mar-19	'		'	'	'	'	'	'	'	'
2021 Debt instrument, Maturity Date	15-Mar-21	'		'	'	'	'	'	'	'	'
Equity component - net carrying value	'	'		'	'	'	'	'	'	66,415,000	66,415,000
Discount Percent of Par	'	'		'	'	99.28%	'	99.48%	'	'	'
Proceeds from Issuance of Long-term Debt	'	'		'	990,100,000	'	'	'	'	'	'
Long-term Debt, Excluding Current Maturities	$994,110,000	$993,870,000	[1]	'	'	'	'	'	'	'	'
[1]	Derived from audited financial statements

Debt_and_Credit_Facility_Detai1

Debt and Credit Facility (Details 1) (USD $)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Mar. 29, 2014
			2019 and 2021 Notes Payable [Member]	2019 and 2021 Notes Payable [Member]	Two And One Two Five Percent 2019 Senior Debentures [Member]	Two And One Two Five Percent 2019 Senior Debentures [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'
Debt Instrument, Face Amount	'	'	'	'	$500,000,000	$500,000,000
Interest Expense, Debt, Excluding Amortization	'	'	6,406,000	0	'	'
Debt Instrument, Unamortized Discount	'	'	'	'	2,449,000	2,574,000
Amortization of Financing Costs	'	'	156,000	0	'	'
Amortization of Debt Discount (Premium)	3,003,000	4,025,000	240,000	0	'	'
Interest Expense, Debt	'	'	6,802,000	0	'	'
Proceeds from Issuance of Long-term Debt	'	'	'	990,100,000	'	'
Line of Credit Facility, Expiration Date	31-Dec-16	'	'	'	'	'
Line of Credit Facility, Maximum Borrowing Capacity	250,000,000	'	'	'	'	'
Line of Credit Facility, Average Outstanding Amount	$0	'	'	'	'	'

Debt_and_Credit_Facility_Detai2

Debt and Credit Facility (Details 2) (USD $)	3 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013	Mar. 29, 2014
Short-term Debt [Line Items]	'	'	'
Amortization of Debt Discount (Premium)	$3,003,000	$4,025,000	'
Two And Six Two Five Percent Senior Convertible Debentures [Member]	'	'	'
Short-term Debt [Line Items]	'	'	'
Maximum number of common shares to be purchased under call option	20.2	'	'
Debt Instrument, Convertible, Remaining Discount Amortization Period	'2 years 11 months 12 days	'	'
Debt Instrument, Face Amount	600,000,000	'	600,000,000
Debt Instrument, Convertible, Conversion Ratio	33.7391	'	'
Debt Instrument, Unamortized Discount	45,337,000	'	49,223,000
Hedge Accounting Adjustment - Sale Of Interest Rate Swap	13,101,000	'	14,224,000
Debt Instrument Carrying Amount Of Liability Component	567,764,000	'	'
Debt Instrument, Convertible, Carrying Amount of Equity Component	66,415,000	'	66,415,000
Interest Expense, Debt, Excluding Amortization	3,938,000	3,938,000	'
Amortization of Financing Costs	362,000	362,000	'
Amortization of Debt Discount (Premium)	2,763,000	2,763,000	'
Interest Expense, Debt	7,063,000	7,063,000	'
Base conversion, block amount of senior convertible debenture	$1,000	'	'
Warrants, number of shares the holders have the right to purchase	20.2	'	'
Class of Warrant or Right, Exercise Price of Warrants or Rights	41.9889	'	'
Convertible debt, conversion price	$29.64	'	'

Common_Stock_Repurchase_Progra1

Common Stock Repurchase Program (Details) (USD $)	1 Months Ended	3 Months Ended
	Aug. 31, 2012	Jun. 28, 2014	Jun. 29, 2013
Accelerated Share Repurchases [Line Items]	'	'	'
Treasury shares	'	0	'
Stock Repurchased During Period, Shares	'	-2,100,000	'
Payments for Repurchase of Common Stock	'	$101,016,000	0
Repurchase Program 2012 [Member]	'	'	'
Accelerated Share Repurchases [Line Items]	'	'	'
Amount authorized for common stock repurchase	750,000,000	'	'
Stock Repurchased and Retired During Period, Value	'	352,700,000	'
Total amount available for future repurchases	'	$397,300,000	'
Stock Repurchased and Retired During Period, Shares	'	'	0

Interest_and_Other_Expense_Net1

Interest and Other Expense, Net (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013
Components of interest and other expense	'	'
Interest income	$8,501	$5,603
Interest expense	-13,865	-13,859
Other income (expense), net	-858	-1,674
Interest and other expense, net	($6,222)	($9,930)

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	Jun. 28, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Components of accumulated other comprehensive income (loss)	'	'
Accumulated unrealized gains (losses) on available-for-sale securities, net of tax	$6,679	($889)
Accumulated unrealized gain (losses) on hedging transactions, net of tax	533	798
Accumulated cumulative translation adjustment, net of tax	-286	-457
Accumulated other comprehensive income (loss)	$6,926	($548)	[1]
[1]	Derived from audited financial statements

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Income Tax Disclosure [Abstract]	'	'
Income Tax Expense (Benefit)	$26,667,000	$25,956,000
Effective Income Tax Rate Reconciliation, Percent	13.00%	14.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	'
Unrecognized Tax Benefits	26,400,000	'
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$11,000,000	'

Commitments_Details

Commitments (Details) (USD $)	Jun. 28, 2014
In Thousands, unless otherwise specified
Future Minimum Lease Payments Under Non-Cancelable Operating Leases	'
2015 (remaining nine months)	$4,514
2016	4,019
2017	2,335
2018	2,102
2019	1,701
Thereafter	3,625
Total	$18,296

Commitments_Details_Textual

Commitments (Details Textual) (USD $)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Loss Contingencies [Line Items]	'	'
Lease Expiration Date	31-Oct-21	'
Aggregate future rental income to be received	$3,800,000	'
Rent expense, net of rental income	911,000	766,000
Other commitments	115,700,000	'
Non-cancelable license obligations	$21,800,000	'
Software and Maintenance License Obligations Expiration Date	31-Dec-16	'
Minimum [Member]	'	'
Loss Contingencies [Line Items]	'	'
Purchase Commitments, Period for Payment	'3 months	'
Maximum [Member]	'	'
Loss Contingencies [Line Items]	'	'
Purchase Commitments, Period for Payment	'6 months	'

Goodwill_and_AcquisitionRelate2

Goodwill and Acquisition-Related Intangibles (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Mar. 29, 2014
Gross and net amounts of goodwill and of acquisition-related intangibles	'	'
Goodwill	$159,296	$159,296	[1]
Total acquisition-related intangibles, gross	138,576	138,576
Less accumulated amortization	-112,127	-109,709
Total	26,449	28,867
Core Technology [Member]	'	'
Gross and net amounts of goodwill and of acquisition-related intangibles	'	'
Total acquisition-related intangibles, gross	91,860	91,860
Less accumulated amortization	-65,612	-63,267
Total	26,248	28,593
Weighted-Average Amortization Life	'5 years 8 months 18 days	'
Other Intangibles [Member]	'	'
Gross and net amounts of goodwill and of acquisition-related intangibles	'	'
Total acquisition-related intangibles, gross	46,716	46,716
Less accumulated amortization	-46,515	-46,442
Total	$201	$274
Weighted-Average Amortization Life	'2 years 8 months 12 days	'
[1]	Derived from audited financial statements

Goodwill_and_AcquisitionRelate3

Goodwill and Acquisition-Related Intangibles (Details 1) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 29, 2013	Mar. 29, 2014
Goodwill and Intangible Assets Disclosure [Abstract]	'	'	'
Amortization of acquisition-related intangibles	$2,418	$2,418	'
Schedule of expected annual amortization expense for acquisition-related intangibles	'	'	'
2015	7,120	'	'
2016	8,935	'	'
2017	7,131	'	'
2018	2,660	'	'
2019	603	'	'
Total	$26,449	'	$28,867

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended
	Jun. 28, 2014	Jun. 29, 2013
Subsequent Events [Abstract]	'	'
Common Stock, Dividends, Per Share, Declared	$0.29	$0.25