Xilinx (XLNX) 10-Q 30 Jan 15 2015 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Dec. 27, 2014	Jan. 16, 2015
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	FALSE
Document Period End Date	27-Dec-14
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q3
Entity Registrant Name	XILINX INC
Entity Central Index Key	743988
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	-25
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		261,437,324

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Net revenues	$593,549	$586,816	$1,810,445	$1,764,708
Cost of revenues	179,638	180,792	538,445	543,308
Gross margin	413,911	406,024	1,272,000	1,221,400
Operating expenses:
Research and development	133,455	128,092	393,803	364,635
Selling, general and administrative	88,076	91,794	274,472	280,520
Amortization of acquisition-related intangibles	2,371	2,589	7,167	7,425
Litigation and contingencies	0	-19,190	0	9,410
Total operating expenses	223,902	203,285	675,442	661,990
Operating income	190,009	202,739	596,558	559,410
Interest and other expense, net	4,007	4,807	15,960	25,734
Income before income taxes	186,002	197,932	580,598	533,676
Provision for income taxes	17,536	22,055	67,005	59,315
Net income	$168,466	$175,877	$513,593	$474,361
Net income per common share:
Basic (in dollars per share)	$0.64	$0.66	$1.93	$1.78
Diluted (in dollars per share)	$0.62	$0.61	$1.85	$1.66
Cash dividends per common share	$0.29	$0.25	$0.87	$0.75
Shares used in per share calculations:
Basic (in shares)	262,881	267,780	266,299	266,068
Diluted (in shares)	273,795	288,195	277,709	285,380

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Statement of Comprehensive Income [Abstract]
Net income	$168,466	$175,877	$513,593	$474,361
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on available-for-sale securities	-409	-2,901	3,822	-16,831
Reclassification adjustment for (gains) losses on available-for-sale securities	-1,868	-21	-3,187	-188
Change in net unrealized losses on hedging transactions	-3,896	-96	-6,957	-251
Reclassification adjustment for (gains) losses on hedging transactions	1,786	-259	768	1,836
Cumulative translation adjustment, net	-1,475	290	-1,882	-774
Other comprehensive income (loss)	-5,862	-2,987	-7,436	-16,208
Total comprehensive income	$162,604	$172,890	$506,157	$458,153

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Dec. 27, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Current assets:
Cash and cash equivalents	$1,431,023	$973,677	[1]
Short-term investments	1,489,744	1,483,644	[1]
Accounts receivable, net	187,496	267,833	[1]
Inventories	246,664	233,999	[1]
Deferred tax assets	80,864	56,166	[1]
Prepaid expenses and other current assets	79,349	51,828	[1]
Total current assets	3,515,140	3,067,147	[1]
Property, plant and equipment, at cost	831,505	810,030	[1]
Accumulated depreciation and amortization	-493,591	-454,941	[1]
Net property, plant and equipment	337,914	355,089	[1]
Long-term investments	654,013	1,190,775	[1]
Goodwill	159,296	159,296	[1]
Acquisition-related intangibles, net	21,700	28,867	[1]
Other assets	227,141	236,175	[1]
Total Assets	4,915,204	5,037,349	[1]
Current liabilities:
Accounts payable	58,231	149,695	[1]
Accrued payroll and related liabilities	160,168	157,373	[1]
Income taxes payable	15,370	12,936	[1]
Deferred income on shipments to distributors	51,486	55,099	[1]
Other accrued liabilities	54,470	49,256	[1]
Current portion of long-term debt	573,290	565,001	[1]
Total current liabilities	913,015	989,360	[1]
Long-term debt	994,595	993,870	[1]
Deferred tax liabilities	293,138	253,433	[1]
Long-term income taxes payable	12,688	11,470	[1]
Other long-term liabilities	1,579	1,535	[1]
Commitments and contingencies	0	0	[1]
Temporary equity (Note 10)	26,710	34,999	[1]
Stockholders' equity:
Preferred stock, $.01 par value (none issued)	0	0	[1]
Common stock, $.01 par value	2,611	2,686	[1]
Additional paid-in capital	690,351	805,073	[1]
Retained earnings	1,988,501	1,945,471	[1]
Accumulated other comprehensive loss	-7,984	-548	[1]
Total stockholders’ equity	2,673,479	2,752,682	[1]
Total Liabilities, Temporary Equity and Stockholders’ Equity	$4,915,204	$5,037,349	[1]
[1]	Derived from audited financial statements

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Dec. 27, 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 $)	9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013
Cash flows from operating activities:
Net income	$513,593		$474,361
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	40,857		41,604
Amortization	15,556		14,828
Stock-based compensation	79,900		68,353
Net (gain) loss on sale of available-for-sale securities	-5,508		277
Amortization of debt discounts	9,014		12,144
Provision for deferred income taxes	19,712		70,168
Excess tax benefit from stock-based compensation	-16,669		-20,248
Others	0		-1,512
Changes in assets and liabilities:
Accounts receivable, net	80,337		21,927
Inventories	-12,299		-5,208
Prepaid expenses and other current assets	-11,703		-7,929
Other assets	-322		-15,695
Accounts payable	-91,464		17,357
Accrued liabilities	1,640		28,303
Income taxes payable	5,710		-77,905
Deferred income on shipments to distributors	-3,613		-5,283
Net cash provided by operating activities	624,741		615,542
Cash flows from investing activities:
Purchases of available-for-sale securities	-2,112,128		-3,152,726
Proceeds from sale and maturity of available-for-sale securities	2,646,410		2,758,941
Purchases of property, plant and equipment	-23,682		-30,717
Other investing activities	-7,440		27,092
Net cash provided by (used in) investing activities	503,160		-397,410
Cash flows from financing activities:
Repurchases of common stock	-476,012		-167,121
Proceeds from issuance of common stock through various stock plans, net	19,338		137,363
Payment of dividends to stockholders	-230,550		-200,301
Excess tax benefit from stock-based compensation	16,669		20,248
Net cash used in financing activities	-670,555		-209,811
Net increase in cash and cash equivalents	457,346		8,321
Cash and cash equivalents at beginning of period	973,677	[1]	623,558
Cash and cash equivalents at end of period	1,431,023		631,879
Supplemental disclosure of cash flow information:
Interest paid	28,776		26,526
Income taxes paid, net	$41,252		$67,335
[1]	Derived from audited financial statements

Basis_of_Presentation

Basis of Presentation	9 Months Ended
	Dec. 27, 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 December 27, 2014 and December 28, 2013 each included 13 weeks.

Recent_Accounting_Changes_and_

Recent Accounting Changes and Accounting Pronouncements	9 Months Ended
	Dec. 27, 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)	9 Months Ended
	Dec. 27, 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 December 27, 2014 and March 29, 2014, Avnet accounted for 66% and 55% of the Company’s total net accounts receivable, respectively. For the third quarter and first nine months of fiscal 2015, resale of product through Avnet accounted for 40% and 42% of the Company’s worldwide net revenues, respectively. For the third quarter and the first nine months of fiscal 2014, resale of product through Avnet accounted for 45% and 47% of the Company’s worldwide net revenues, respectively. The percentage of worldwide net revenues from Avnet was consistent with historical patterns. While the percentage of accounts receivable due from Avnet increased as of December 27, 2014 compared to as of March 29, 2014 was due to timing, it was 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 third quarter as well as the first nine months of fiscal 2015 and 2014.
	The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 91% 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 December 27, 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	9 Months Ended
	Dec. 27, 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 nine months of fiscal 2015 and the Company did not adjust or override any fair value measurements as of December 27, 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. government and agency securities, foreign government and agency securities, mortgage-backed securities, asset-backed securities, bank loans 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 December 27, 2014 and March 29, 2014:
			December 27, 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 equivalents:
	Money market funds		$	302,542		$	—		$	—		$	302,542
	Financial institution securities		—			143,999			—			143,999
	Non-financial institution securities		—			120,988			—			120,988
	U.S. government and agency securities		219,997			197,200			—			417,197
	Foreign government and agency securities		—			320,977			—			320,977
	Short-term investments:
	Financial institution securities		—			75,000			—			75,000
	Non-financial institution securities		—			86,593			—			86,593
	Municipal bonds		—			33,606			—			33,606
	U.S. government and agency securities		217,742			53,692			—			271,434
	Foreign government and agency securities		—			28,995			—			28,995
	Asset-backed securities		—			202,914			—			202,914
	Mortgage-backed securities		—			654,898			—			654,898
	Debt mutual funds		—			39,500			—			39,500
	Bank loans		—			96,804			—			96,804
	Long-term investments:
	Auction rate securities		—			—			10,325			10,325
	Asset-backed securities		—			11,463						11,463
	Municipal bonds		—			10,132			—			10,132
	U.S. government and agency securities		—			6,758			—			6,758
	Mortgage-backed securities		—			559,160			—			559,160
	Debt mutual fund		—			56,175			—			56,175
	Total assets measured at fair value		$	740,281		$	2,698,854		$	10,325		$	3,449,460
	Liabilities
	Derivative financial instruments, net		$	—		$	6,453		$	—		$	6,453
	Total liabilities measured at fair value		$	—		$	6,453		$	—		$	6,453
	Net assets measured at fair value		$	740,281		$	2,692,401		$	10,325		$	3,443,007
		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 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						Nine Months Ended
(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
Balance as of beginning of period	$	20,608		$	22,229		$	20,160		$	27,610
Total realized and unrealized gains (losses):
Included in interest and other expense, net	—			(221		)	—			462
Included in other comprehensive income	717			870			1,165			1,456
Sales and settlements, net (1)	(11,000		)	(3,650		)	(11,000		)	(10,300		)
Balance as of end of period	$	10,325		$	19,228		$	10,325		$	19,228
-1	During the first nine months of fiscal 2015 and 2014, the Company redeemed $11.0 million and $10.3 million, respectively, of student loan auction rate securities for cash at par value.
The amount of total gains (losses) included in net income attributable to the change in unrealized gains (losses) relating to assets and liabilities still held as of the end of the period are summarized as follows:
	Three Months Ended						Nine Months Ended
(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
Included in interest and other expense, net	$	—		$	(221	)	$	—		$	462
As of December 27, 2014, marketable securities measured at fair value using Level 3 inputs were comprised of $10.3 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 3.125% Junior Convertible Debentures due March 15, 2037 (2037 Convertible Notes), which were fully redeemed on March 12, 2014, 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 2.625% Senior Convertible Debentures due June 15, 2017 (2017 Convertible Notes), 2.125% Notes due 2019 (2019 Notes) and 3.000% Notes due 2021 (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 December 27, 2014 were approximately $912.0 million, $494.9 million and $505.0 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	9 Months Ended
	Dec. 27, 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:
		December 27, 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	$	302,542		$	—		$	—		$	302,542			$	213,988		$	—	$	—		$	213,988
	Financial institution
	securities	218,999			—			—			218,999				366,906			—		—			366,906
	Non-financial institution
	securities	207,535			50			(4		)	207,581				753,888			3,428		(1,244		)	756,072
	Auction rate securities	10,500			—			(175		)	10,325				21,500			—		(1,340		)	20,160
	Municipal bonds	43,328			603			(193		)	43,738				31,367			604		(205		)	31,766
	U.S. government and
	agency securities	695,442			81			(134		)	695,389				548,568			1,135		(184		)	549,519
	Foreign government and
	agency securities	349,972			—			—			349,972				354,935			—		—			354,935
	Mortgage-backed securities	1,208,162			12,214			(6,318		)	1,214,058				1,234,237			11,380		(10,528		)	1,235,089
	Asset-backed securities	213,833			1,019			(475		)	214,377				—			—		—			—
	Debt mutual funds	101,350			—			(5,675		)	95,675				81,350			216		(4,652		)	76,914
	Bank loans	98,203			80			(1,479		)	96,804				—			—		—			—
		$	3,449,866		$	14,047		$	(14,453	)	$	3,449,460			$	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 December 27, 2014 and March 29, 2014:
		December 27, 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	$	4,385		$	(4	)	$	—		$	—		$	4,385		$	(4	)
	Auction rate securities	—			—			10,325			(175		)	10,325			(175		)
	Municipal bonds	8,814			(113		)	2,968			(80		)	11,782			(193		)
	U.S. government and
	agency securities	137,031			(134		)	—			—			137,031			(134		)
	Mortgage-backed securities	362,105			(2,808		)	181,355			(3,510		)	543,460			(6,318		)
	Asset-backed securities	157,697			(475		)	—			—			157,697			(475		)
	Debt mutual fund	39,500			(500		)	56,175			(5,175		)	95,675			(5,675		)
	Bank loans	84,886			(1,479		)	—			—			84,886			(1,479		)
		$	794,418		$	(5,513	)	$	250,823		$	(8,940	)	$	1,045,241		$	(14,453	)
		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 December 27, 2014, the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities and bank loans due to the general rising of the interest-rate environment. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to debt mutual fund and mortgage-backed securities, which were primarily due to the general rising of the interest-rate environment and foreign currency movement.
	The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of December 27, 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 December 27, 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, mortgage-backed securities, asset-backed securities and bank loans), 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.
		December 27, 2014
	(In thousands)	Amortized			Estimated
		Cost			Fair Value
	Due in one year or less	$	1,410,505		$	1,410,527
	Due after one year through five years	292,035			291,562
	Due after five years through ten years	383,473			383,800
	Due after ten years	959,961			965,354
		$	3,045,974		$	3,051,243
	As of December 27, 2014, $1.1 billion 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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Proceeds from sale of available-for-sale securities	$	478,562		$	97,519		$	774,406		$	296,679
	Gross realized gains on sale of available-for-sale securities	$	4,759		$	401		7,838			1,768
	Gross realized losses on sale of available-for-sale securities	(1,663		)	(530		)	(2,330		)	(2,045		)
	Net realized gains (losses) on sale of available-for-sale securities	$	3,096		$	(129	)	$	5,508		$	(277	)
Amortization of premiums on available-for-sale securities	$	5,913		$	6,458		$	18,559		$	20,521
The cost of securities matured or sold is based on the specific identification method.

Derivative_Financial_Instrumen

Derivative Financial Instruments	9 Months Ended
	Dec. 27, 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 December 27, 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)	December 27, 2014			March 29, 2014
	Singapore Dollar	$	53,462		$	60,551
	Euro	41,202			46,062
	Indian Rupee	21,152			18,631
	British Pound	13,287			12,056
	Japanese Yen	7,805			9,273
		$	136,908		$	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 November 2016. The net unrealized losses, 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 December 27, 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 December 27, 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 December 27, 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
	December 27, 2014	Prepaid expenses and other current assets	$	176		Other accrued liabilities	$	6,629
	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 the third quarter and the first nine months of fiscal 2015 and 2014:
		Three Months Ended							Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013				December 27, 2014			December 28, 2013
	Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	$	(2,110	)	$	(355	)		$	(6,189	)	$	1,585
	Amount of (gains) losses reclassified from accumulated other comprehensive income into income (effective portion) *	$	1,786		$	(259	)		$	768		$	1,836
	Amount of gains (losses) recorded (ineffective portion) *	$	(3	)	$	5			$	(16	)	$	11
	*	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

StockBased_Compensation_Plans

Stock-Based Compensation Plans	9 Months Ended
	Dec. 27, 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							Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013				December 27, 2014			December 28, 2013
	Stock-based compensation included in:
	Cost of revenues	$	2,339		$	1,966			$	6,408		$	5,628
	Research and development	14,909			11,912				40,245			33,474
	Selling, general and administrative	11,806			10,461				33,247			29,251
		$	29,054		$	24,339			$	79,900		$	68,353
	During the first nine months 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 $12.3 million and $17.0 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 Company also considers the actual contractual term in determining the expected life of options granted. The Company's stock-based compensation expense relating to options during the first nine months of fiscal 2015 and 2014 was 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 third quarter of fiscal 2015 was $40.76 ($42.37 for the third quarter of fiscal 2014), and for the first nine months of fiscal 2015 was $43.76 ($38.13 for the first nine months of fiscal 2014), which were calculated based on estimates at the date of grant using the following weighted-average assumptions:
		Three Months Ended					Nine Months Ended
		December 27, 2014		December 28, 2013			December 27, 2014			December 28, 2013
	Risk-free interest rate	1.3	%	0.7	%		0.7	%		0.7	%
	Dividend yield	2.7	%	2.2	%		2.4	%		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	(1,417	)	$	26.03
	Forfeited/cancelled/expired	(16	)	$	32.85
	December 27, 2014	3,847		$	24.89
	Options exercisable at:
	December 27, 2014	3,750		$	24.64
	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 December 27, 2014, 15.6 million shares remained available for grant under the 2007 Equity Plan.
	The total pre-tax intrinsic value of options exercised during the three and nine months ended December 27, 2014 was $11.7 million and $27.7 million, respectively. The total pre-tax intrinsic value of options exercised during the three and nine months ended December 28, 2013 was $5.5 million and $70.7 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	2,754		$	43.76
	Vested	(2,264	)	$	33.62
	Cancelled	(292	)	$	36.45
	December 27, 2014	7,099		$	38.86
	For the majority of restricted stock units granted, the number of shares of common stock issued on the date the RSU awards vest is net of the minimum statutory withholding requirements that we pay in cash to the appropriate taxing authorities on behalf of our employees. In the condensed consolidated statement of cash flows, these amounts have been included as a reduction in the cash proceeds from issuance of common stock under our various stock plans. During the first nine months of fiscal 2015 and 2014, we withheld $33.2 million and $16.8 million worth of RSU awards, respectively, to satisfy the employees’ tax obligations.
	Employee Stock Purchase Plan
	Under the ESPP, shares are only issued during the second and fourth quarters of each fiscal year. Employees purchased 446 thousand shares for $14.9 million during the second quarter of fiscal 2015 and 529 thousand shares for $14.6 million in the second quarter of fiscal 2014. The per-share weighted-average fair value of stock purchase rights granted under the ESPP during the second quarter of fiscal 2015 and 2014 was $14.12 and $11.24, respectively. The fair values of stock purchase plan rights granted in the second quarter of fiscal 2015 and 2014 were estimated at the date of grant using the following assumptions:
		2015		2014
	Expected life of options (years)	1.25		1.25
	Expected stock price volatility	0.25		0.23
	Risk-free interest rate	0.2	%	0.2	%
	Dividend yield	2.8	%	2.1	%
	The next scheduled purchase under the ESPP is in the fourth quarter of fiscal 2015. On August 13, 2014, the stockholders approved an amendment to increase the authorized number of shares reserved for issuance under the ESPP by 2.0 million shares. As of December 27, 2014, 11.3 million shares were available for future issuance.

Net_Income_Per_Common_Share

Net Income Per Common Share	9 Months Ended
	Dec. 27, 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:
		Three Months Ended				Nine Months Ended
	(In thousands, except per share amounts)	December 27, 2014		December 28, 2013		December 27, 2014		December 28, 2013
	Net income available to common stockholders	$	168,466	$	175,877	$	513,593	$	474,361
	Weighted average common shares outstanding-basic	262,881		267,780		266,299		266,068
	Dilutive effect of employee equity incentive plans	3,138		4,686		3,463		4,600
	Dilutive effect of 2017 Convertible Notes and warrants	7,776		7,695		7,947		7,091
	Dilutive effect of 2037 Convertible Notes	—		8,034		—		7,621
	Weighted average common shares outstanding-diluted	273,795		288,195		277,709		285,380
	Basic earnings per common share	$	0.64	$	0.66	$	1.93	$	1.78
	Diluted earnings per common share	$	0.62	$	0.61	$	1.85	$	1.66
	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 to purchase approximately 139 thousand and 3.2 million shares, for the third quarter and the first nine months of fiscal 2015, respectively, were excluded from diluted net income per common share by applying the treasury stock method, as their inclusion would have been anti-dilutive. These options and RSUs 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 and RSUs.
	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 counter-parties. 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	9 Months Ended
	Dec. 27, 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)	December 27, 2014		March 29, 2014
	Raw materials	$	14,094	$	15,306
	Work-in-process	198,270		192,067
	Finished goods	34,300		26,626
		$	246,664	$	233,999

Debt_and_Credit_Facility

Debt and Credit Facility	9 Months Ended
	Dec. 27, 2014
Debt Disclosure [Abstract]
Debt and Credit Facility [Text Block]	Debt and Credit Facility
	2017 Convertible Notes
	As of December 27, 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 December 27, 2014 and as a result, the 2017 Convertible Notes were convertible at the option of the holders. As of December 27, 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 is 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 is 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)	December 27, 2014			29-Mar-14
	Liability component:
	Principal amount of the 2017 Convertible Notes	$	600,000		$	600,000
	Unamortized discount of liability component	(37,565		)	(49,223		)
	Hedge accounting adjustment – sale of interest rate swap	10,855			14,224
	Net carrying value of the 2017 Convertible Notes	$	573,290		$	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 December 27, 2014, the remaining term of the 2017 Convertible Notes is 2.5 years. As of December 27, 2014, the if-converted the value of the 2017 Convertible Notes was $903.3 million.
	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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014		December 28, 2013
	Contractual coupon interest	$	3,938		$	3,938		$	11,813	$	11,813
	Amortization of debt issuance costs	362			362			1,086		1,086
	Amortization of debt discount, net	2,763			2,763			8,289		8,289
	Total interest expense related to the 2017 Convertible Notes	$	7,063		$	7,063		$	21,188	$	21,188
	To hedge against potential dilution upon conversion of the 2017 Convertible Notes, the Company purchased call options on its common stock from the hedge counter parties. 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 counter parties, which give the hedge counter parties 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 December 27, 2014 and March 29, 2014:
	(In thousands)	December 27, 2014			29-Mar-14
	Principal amount of the 2019 Notes	$	500,000		$	500,000
	Unamortized discount of the 2019 Notes	(2,199		)	(2,574		)
	Principal amount of the 2021 Notes	500,000			500,000
	Unamortized discount of the 2021 Notes	(3,206		)	(3,556		)
	Total carrying value	$	994,595		$	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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014		December 28, 2013
	Contractual coupon interest	$	6,406		$	—		$	19,219	$	—
	Amortization of debt issuance costs	146			—			436		—
	Amortization of debt discount, net	244			—			725		—
	Total interest expense related to the 2019 and 2021 Notes	$	6,796		$	—		$	20,380	$	—
	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 December 27, 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	9 Months Ended
	Dec. 27, 2014
Common Stock Repurchase Program [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. In August 2012, the Board authorized the repurchase of up to $750.0 million of the Company’s common stock and debentures (2012 Repurchase Program). In November 2014, the Board authorized the repurchase of an additional $800.0 million of the Company's common stock (2014 Repurchase Program). The shares authorized for purchase under the 2014 Repurchase Program are in addition to the shares authorized for purchase under the 2012 Repurchase Program. The 2012 and 2014 Repurchase Programs have no stated expiration date.
	Through December 27, 2014, the Company has used $727.6 million of the $750.0 million authorized under the 2012 Repurchase Program, and none of the $800.0 million authorized under the 2014 Repurchase Program, leaving $822.4 million available for future repurchases under the 2014 and 2012 Repurchase Program. The Company’s current policy is to retire all repurchased shares, and consequently, no treasury shares were held as of December 27, 2014 and March 29, 2014.
	During the first nine months of fiscal 2015, the Company repurchased 11.0 million shares of common stock in the open market for a total of $475.0 million under the 2012 Repurchase Program. During the first nine months of fiscal 2014, the Company repurchased 3.7 million shares of common stock in the open market for a total of $167.1 million.

Interest_and_Other_Expense_Net

Interest and Other Expense, Net	9 Months Ended
	Dec. 27, 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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Interest income	$	11,375		$	9,545		$	28,268		$	20,511
	Interest expense	(13,859		)	(14,050		)	(41,567		)	(40,955		)
	Other expense, net	(1,523		)	(302		)	(2,661		)	(5,290		)
		$	(4,007	)	$	(4,807	)	$	(15,960	)	$	(25,734	)

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income	9 Months Ended
	Dec. 27, 2014
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Loss
	Comprehensive 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 loss are as follows:
	(In thousands)	December 27, 2014			29-Mar-14
	Accumulated unrealized losses on available-for-sale securities, net of tax	$	(254	)	$	(889	)
	Accumulated unrealized gains (losses) on hedging transactions, net of tax	(5,391		)	798
	Accumulated cumulative translation adjustment, net of tax	(2,339		)	(457		)
	Accumulated other comprehensive loss	$	(7,984	)	$	(548	)
	The related tax effects of other comprehensive loss were not material for all periods presented.

Income_Taxes

Income Taxes	9 Months Ended
	Dec. 27, 2014
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes
	The Company recorded tax provisions of $17.5 million and $67.0 million for the third quarter and the first nine months of fiscal 2015, respectively, representing effective tax rates of 9% and 12%, respectively. The Company recorded tax provisions of $22.1 million and $59.3 million for the third quarter and the first nine months of fiscal 2014, respectively, representing effective tax rates of 11% for both periods.
	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 December 27, 2014, determined in accordance with FASB authoritative guidance for measuring uncertain tax positions, increased by $797 thousand in the third quarter of fiscal 2015 to $27.2 million. The total amount of unrecognized tax benefits that, if realized in a future period, would favorably affect the effective tax rate was $11.7 million as of December 27, 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 2011. The Company is no longer subject to U.S. state audits for years through fiscal 2009. The Company is no longer subject to tax audits in Ireland for years through fiscal 2009.

Commitments

Commitments	9 Months Ended
	Dec. 27, 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 three months)	$	1,589
	2016	5,162
	2017	2,476
	2018	2,241
	2019	1,806
	Thereafter	3,576
	Total	$	16,850
	Aggregate future rental income to be received, which includes rents from both owned and leased property, totaled $2.9 million as of December 27, 2014. Rent expense, net of rental income, under all operating leases was $792 thousand and $2.4 million for the three and nine months ended December 27, 2014, respectively. Rent expense, net of rental income, under all operating leases was $735 thousand and $2.2 million for the three and nine months ended December 28, 2013, respectively. Rental income was not material for the third quarter and the first nine months of fiscal 2015 and 2014.
	Other commitments as of December 27, 2014 totaled $97.6 million and consisted of purchases of inventory and other non-cancelable purchase obligations related to subcontractors that manufacture silicon wafers and provide assembly and 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 December 27, 2014, the Company also had $40.1 million of non-cancelable license obligations to providers of electronic design automation software and hardware/software maintenance expiring at various dates through June 2017.

Product_Warranty_and_Indemnifi

Product Warranty and Indemnification	9 Months Ended
	Dec. 27, 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 third 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	9 Months Ended
	Dec. 27, 2014
Loss Contingency [Abstract]
Contingencies	Contingencies
	Patent Litigation
	On July 17, 2014, a patent infringement lawsuit was filed by PLL Technologies, Inc. (PTI) against the Company 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 and costs.  The Company is unable to estimate its range of possible loss, if any, in this matter at this time.
	On November 7, 2014, the Company filed a complaint for declaratory judgment against Papst Licensing GmbH & Co., KG (Papst)in the U.S. District Court for the Northern District of California (Xilinx, Inc. v. Papst Licensing GmbH & Co., KG, Case No. 3:14-CV-04963) (the California Action). On the same date, a patent infringement lawsuit was filed by Papst against the Company in the U.S. District Court for the District of Delaware (Papst Licensing GmbH & Co., KG v. Xilinx, Inc., Case No. 1:14-CV-01376) (the Delaware Action).  Both the California Action and the Delaware Action pertain to the same two patents. In the California Action, the Company seeks judgments of non-infringement of the patents by the Company and judgments that the patents are invalid and unenforceable, as well as costs. In the Delaware Action, Papst seeks unspecified damages, interest and costs.   The Company is unable to estimate its range of possible loss, if any, in this matter at this time.
	On January 31, 2014, Evan Levine and Keith McClellan filed an action on behalf of the United States in the United States District Court for the Eastern District of Kentucky (United States of America, ex. rel. Evan Levine and Keith McClellan v. Avnet Inc., et. al., Case No. 14-cv-00017).   The matter alleges violations of the False Claims Act, 31 U.S.C. Section 3729 et seq. and was filed under seal pursuant to 31 U.S.C. Section 3730(b)(2).  The lawsuit seeks to recover, on behalf of the United States, $11 thousand for each unspecified, allegedly false and fraudulent claim, plus treble damages.  The government investigated the allegations in the complaint and on September 12, 2014, filed a Notice of Election to Decline Intervention.  On September 22, 2014, the Court unsealed the complaint and ordered it to be served on the defendants.  On November 21, 2014, the government moved to dismiss the complaint with prejudice.  That same day, Mr. McClellan filed a notice of dismissal, leaving Mr. Levine as the only remaining relator.   The Company was served with the complaint on December 11, 2014.  Plaintiffs and the Company have agreed to a stipulation extending the Company's time to respond to the complaint up to and including February 2, 2015.  Based on currently available information, the Company does not believe the resolution of this matter will have a material adverse effect on its business, financial position or future results of operations.
	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	9 Months Ended
	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquisition-Related Intangibles	Goodwill and Acquisition-Related Intangibles
	As of December 27, 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)	December 27, 2014			29-Mar-14			Amortization Life
	Goodwill	$	159,296		$	159,296
	Core technology, gross	91,860			91,860			5.7 years
	Less accumulated amortization	(70,301		)	(63,267		)
	Core technology, net	21,559			28,593
	Other intangibles, gross	46,716			46,716			2.7 years
	Less accumulated amortization	(46,575		)	(46,442		)
	Other intangibles, net	141			274
	Total acquisition-related intangibles, gross	138,576			138,576
	Less accumulated amortization	(116,876		)	(109,709		)
	Total acquisition-related intangibles, net	$	21,700		$	28,867
	Amortization expense for acquisition-related intangibles for the three and nine months ended December 27, 2014 was $2.4 million and $7.2 million, respectively. Based on the carrying value of acquisition-related intangibles recorded as of December 27, 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 three months)	$	2,371
	2016	8,935
	2017	7,131
	2018	2,660
	2019	603
	Total	$	21,700

Subsequent_Events_Notes

Subsequent Events (Notes)	9 Months Ended
	Dec. 27, 2014
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events
	On January 20, 2015, the Company’s Board of Directors declared a cash dividend of $0.29 per common share for the fourth quarter of fiscal 2015. The dividend is payable on February 25, 2015 to stockholders of record on February 4, 2015.

Derivative_Financial_Instrumen1

Derivative Financial Instruments Derivative Financial Instruments (Policies)	9 Months Ended
	Dec. 27, 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.

StockBased_Compensation_Plans_

Stock-Based Compensation Plans (Policies)	9 Months Ended
	Dec. 27, 2014
Accounting Policies [Abstract]
Share based compensation, Restricted Stock and Restricted Stock Units Policy [Policy Text Block]	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.
Share-based Compensation, Option and Incentive Plans Policy [Policy Text Block]	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 Company also considers the actual contractual term in determining the expected life of options granted.

Inventories_Inventories_Polici

Inventories Inventories (Policies)	9 Months Ended
	Dec. 27, 2014
Inventory Disclosure [Abstract]
Inventory, Policy [Policy Text Block]	Inventories are stated at the lower of actual cost (determined using the first-in, first-out method), or market (estimated net realizable value)

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Dec. 27, 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 December 27, 2014 and March 29, 2014:
			December 27, 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 equivalents:
	Money market funds		$	302,542		$	—		$	—		$	302,542
	Financial institution securities		—			143,999			—			143,999
	Non-financial institution securities		—			120,988			—			120,988
	U.S. government and agency securities		219,997			197,200			—			417,197
	Foreign government and agency securities		—			320,977			—			320,977
	Short-term investments:
	Financial institution securities		—			75,000			—			75,000
	Non-financial institution securities		—			86,593			—			86,593
	Municipal bonds		—			33,606			—			33,606
	U.S. government and agency securities		217,742			53,692			—			271,434
	Foreign government and agency securities		—			28,995			—			28,995
	Asset-backed securities		—			202,914			—			202,914
	Mortgage-backed securities		—			654,898			—			654,898
	Debt mutual funds		—			39,500			—			39,500
	Bank loans		—			96,804			—			96,804
	Long-term investments:
	Auction rate securities		—			—			10,325			10,325
	Asset-backed securities		—			11,463						11,463
	Municipal bonds		—			10,132			—			10,132
	U.S. government and agency securities		—			6,758			—			6,758
	Mortgage-backed securities		—			559,160			—			559,160
	Debt mutual fund		—			56,175			—			56,175
	Total assets measured at fair value		$	740,281		$	2,698,854		$	10,325		$	3,449,460
	Liabilities
	Derivative financial instruments, net		$	—		$	6,453		$	—		$	6,453
	Total liabilities measured at fair value		$	—		$	6,453		$	—		$	6,453
	Net assets measured at fair value		$	740,281		$	2,692,401		$	10,325		$	3,443,007
		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 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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Balance as of beginning of period	$	20,608		$	22,229		$	20,160		$	27,610
	Total realized and unrealized gains (losses):
	Included in interest and other expense, net	—			(221		)	—			462
	Included in other comprehensive income	717			870			1,165			1,456
	Sales and settlements, net (1)	(11,000		)	(3,650		)	(11,000		)	(10,300		)
	Balance as of end of period	$	10,325		$	19,228		$	10,325		$	19,228
	-1	During the first nine months of fiscal 2015 and 2014, the Company redeemed $11.0 million and $10.3 million, respectively, of student loan auction rate securities 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 gains (losses) included in net income attributable to the change in unrealized gains (losses) relating to assets and liabilities still held as of the end of the period are summarized as follows:
		Three Months Ended						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Included in interest and other expense, net	$	—		$	(221	)	$	—		$	462

Financial_Instruments_Tables

Financial Instruments (Tables)	9 Months Ended
	Dec. 27, 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:
		December 27, 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	$	302,542		$	—		$	—		$	302,542			$	213,988		$	—	$	—		$	213,988
	Financial institution
	securities	218,999			—			—			218,999				366,906			—		—			366,906
	Non-financial institution
	securities	207,535			50			(4		)	207,581				753,888			3,428		(1,244		)	756,072
	Auction rate securities	10,500			—			(175		)	10,325				21,500			—		(1,340		)	20,160
	Municipal bonds	43,328			603			(193		)	43,738				31,367			604		(205		)	31,766
	U.S. government and
	agency securities	695,442			81			(134		)	695,389				548,568			1,135		(184		)	549,519
	Foreign government and
	agency securities	349,972			—			—			349,972				354,935			—		—			354,935
	Mortgage-backed securities	1,208,162			12,214			(6,318		)	1,214,058				1,234,237			11,380		(10,528		)	1,235,089
	Asset-backed securities	213,833			1,019			(475		)	214,377				—			—		—			—
	Debt mutual funds	101,350			—			(5,675		)	95,675				81,350			216		(4,652		)	76,914
	Bank loans	98,203			80			(1,479		)	96,804				—			—		—			—
		$	3,449,866		$	14,047		$	(14,453	)	$	3,449,460			$	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 December 27, 2014 and March 29, 2014:
		December 27, 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	$	4,385		$	(4	)	$	—		$	—		$	4,385		$	(4	)
	Auction rate securities	—			—			10,325			(175		)	10,325			(175		)
	Municipal bonds	8,814			(113		)	2,968			(80		)	11,782			(193		)
	U.S. government and
	agency securities	137,031			(134		)	—			—			137,031			(134		)
	Mortgage-backed securities	362,105			(2,808		)	181,355			(3,510		)	543,460			(6,318		)
	Asset-backed securities	157,697			(475		)	—			—			157,697			(475		)
	Debt mutual fund	39,500			(500		)	56,175			(5,175		)	95,675			(5,675		)
	Bank loans	84,886			(1,479		)	—			—			84,886			(1,479		)
		$	794,418		$	(5,513	)	$	250,823		$	(8,940	)	$	1,045,241		$	(14,453	)
		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
		December 27, 2014
	(In thousands)	Amortized			Estimated
		Cost			Fair Value
	Due in one year or less	$	1,410,505		$	1,410,527
	Due after one year through five years	292,035			291,562
	Due after five years through ten years	383,473			383,800
	Due after ten years	959,961			965,354
		$	3,045,974		$	3,051,243
Information on sale of available-for-sale securities	Certain information related to available-for-sale securities is as follows:
		Three Months Ended						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Proceeds from sale of available-for-sale securities	$	478,562		$	97,519		$	774,406		$	296,679
	Gross realized gains on sale of available-for-sale securities	$	4,759		$	401		7,838			1,768
	Gross realized losses on sale of available-for-sale securities	(1,663		)	(530		)	(2,330		)	(2,045		)
	Net realized gains (losses) on sale of available-for-sale securities	$	3,096		$	(129	)	$	5,508		$	(277	)
	Amortization of premiums on available-for-sale securities	$	5,913		$	6,458		$	18,559		$	20,521

Derivative_Financial_Instrumen2

Derivative Financial Instruments (Tables)	9 Months Ended
	Dec. 27, 2014
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Forward currency exchange contracts outstanding	As of December 27, 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)	December 27, 2014			March 29, 2014
	Singapore Dollar	$	53,462		$	60,551
	Euro	41,202			46,062
	Indian Rupee	21,152			18,631
	British Pound	13,287			12,056
	Japanese Yen	7,805			9,273
		$	136,908		$	146,573
Derivative Instruments Located on Condensed Consolidated Balance Sheet	The Company had the following derivative instruments as of December 27, 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
	December 27, 2014	Prepaid expenses and other current assets	$	176		Other accrued liabilities	$	6,629
	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 the third quarter and the first nine months of fiscal 2015 and 2014:
		Three Months Ended							Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013				December 27, 2014			December 28, 2013
	Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	$	(2,110	)	$	(355	)		$	(6,189	)	$	1,585
	Amount of (gains) losses reclassified from accumulated other comprehensive income into income (effective portion) *	$	1,786		$	(259	)		$	768		$	1,836
	Amount of gains (losses) recorded (ineffective portion) *	$	(3	)	$	5			$	(16	)	$	11
	*	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

StockBased_Compensation_Plans_1

Stock-Based Compensation Plans (Tables)	9 Months Ended
	Dec. 27, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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							Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013				December 27, 2014			December 28, 2013
	Stock-based compensation included in:
	Cost of revenues	$	2,339		$	1,966			$	6,408		$	5,628
	Research and development	14,909			11,912				40,245			33,474
	Selling, general and administrative	11,806			10,461				33,247			29,251
		$	29,054		$	24,339			$	79,900		$	68,353
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 third quarter of fiscal 2015 was $40.76 ($42.37 for the third quarter of fiscal 2014), and for the first nine months of fiscal 2015 was $43.76 ($38.13 for the first nine months of fiscal 2014), which were calculated based on estimates at the date of grant using the following weighted-average assumptions:
		Three Months Ended					Nine Months Ended
		December 27, 2014		December 28, 2013			December 27, 2014			December 28, 2013
	Risk-free interest rate	1.3	%	0.7	%		0.7	%		0.7	%
	Dividend yield	2.7	%	2.2	%		2.4	%		2.5	%
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	The fair values of stock purchase plan rights granted in the second quarter of fiscal 2015 and 2014 were estimated at the date of grant using the following assumptions:
		2015		2014
	Expected life of options (years)	1.25		1.25
	Expected stock price volatility	0.25		0.23
	Risk-free interest rate	0.2	%	0.2	%
	Dividend yield	2.8	%	2.1	%
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	(1,417	)	$	26.03
	Forfeited/cancelled/expired	(16	)	$	32.85
	December 27, 2014	3,847		$	24.89
	Options exercisable at:
	December 27, 2014	3,750		$	24.64
	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	2,754		$	43.76
	Vested	(2,264	)	$	33.62
	Cancelled	(292	)	$	36.45
	December 27, 2014	7,099		$	38.86

Net_Income_Per_Common_Share_Ne

Net Income Per Common Share Net Income Per Common Share (Tables)	9 Months Ended
	Dec. 27, 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:
		Three Months Ended				Nine Months Ended
	(In thousands, except per share amounts)	December 27, 2014		December 28, 2013		December 27, 2014		December 28, 2013
	Net income available to common stockholders	$	168,466	$	175,877	$	513,593	$	474,361
	Weighted average common shares outstanding-basic	262,881		267,780		266,299		266,068
	Dilutive effect of employee equity incentive plans	3,138		4,686		3,463		4,600
	Dilutive effect of 2017 Convertible Notes and warrants	7,776		7,695		7,947		7,091
	Dilutive effect of 2037 Convertible Notes	—		8,034		—		7,621
	Weighted average common shares outstanding-diluted	273,795		288,195		277,709		285,380
	Basic earnings per common share	$	0.64	$	0.66	$	1.93	$	1.78
	Diluted earnings per common share	$	0.62	$	0.61	$	1.85	$	1.66

Inventories_Inventories_Tables

Inventories Inventories (Tables)	9 Months Ended
	Dec. 27, 2014
Inventory Disclosure [Abstract]
Schedule of Inventory, Current [Table Text Block]	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)	December 27, 2014		March 29, 2014
	Raw materials	$	14,094	$	15,306
	Work-in-process	198,270		192,067
	Finished goods	34,300		26,626
		$	246,664	$	233,999

Debt_and_Credit_Facility_Table

Debt and Credit Facility (Tables)	9 Months Ended
	Dec. 27, 2014
2017 Convertible Notes [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)	December 27, 2014			29-Mar-14
	Liability component:
	Principal amount of the 2017 Convertible Notes	$	600,000		$	600,000
	Unamortized discount of liability component	(37,565		)	(49,223		)
	Hedge accounting adjustment – sale of interest rate swap	10,855			14,224
	Net carrying value of the 2017 Convertible Notes	$	573,290		$	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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014		December 28, 2013
	Contractual coupon interest	$	3,938		$	3,938		$	11,813	$	11,813
	Amortization of debt issuance costs	362			362			1,086		1,086
	Amortization of debt discount, net	2,763			2,763			8,289		8,289
	Total interest expense related to the 2017 Convertible Notes	$	7,063		$	7,063		$	21,188	$	21,188
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 December 27, 2014 and March 29, 2014:
	(In thousands)	December 27, 2014			29-Mar-14
	Principal amount of the 2019 Notes	$	500,000		$	500,000
	Unamortized discount of the 2019 Notes	(2,199		)	(2,574		)
	Principal amount of the 2021 Notes	500,000			500,000
	Unamortized discount of the 2021 Notes	(3,206		)	(3,556		)
	Total carrying value	$	994,595		$	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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014		December 28, 2013
	Contractual coupon interest	$	6,406		$	—		$	19,219	$	—
	Amortization of debt issuance costs	146			—			436		—
	Amortization of debt discount, net	244			—			725		—
	Total interest expense related to the 2019 and 2021 Notes	$	6,796		$	—		$	20,380	$	—

Recovered_Sheet1

Interest And Other Expense, Net (Tables)	9 Months Ended
	Dec. 27, 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						Nine Months Ended
	(In thousands)	December 27, 2014			December 28, 2013			December 27, 2014			December 28, 2013
	Interest income	$	11,375		$	9,545		$	28,268		$	20,511
	Interest expense	(13,859		)	(14,050		)	(41,567		)	(40,955		)
	Other expense, net	(1,523		)	(302		)	(2,661		)	(5,290		)
		$	(4,007	)	$	(4,807	)	$	(15,960	)	$	(25,734	)

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	9 Months Ended
	Dec. 27, 2014
Equity [Abstract]
Components of accumulated other comprehensive income (loss)	The components of accumulated other comprehensive loss are as follows:
	(In thousands)	December 27, 2014			29-Mar-14
	Accumulated unrealized losses on available-for-sale securities, net of tax	$	(254	)	$	(889	)
	Accumulated unrealized gains (losses) on hedging transactions, net of tax	(5,391		)	798
	Accumulated cumulative translation adjustment, net of tax	(2,339		)	(457		)
	Accumulated other comprehensive loss	$	(7,984	)	$	(548	)

Commitments_Tables

Commitments (Tables)	9 Months Ended
	Dec. 27, 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 three months)	$	1,589
	2016	5,162
	2017	2,476
	2018	2,241
	2019	1,806
	Thereafter	3,576
	Total	$	16,850

Goodwill_and_AcquisitionRelate1

Goodwill and Acquisition-Related Intangibles (Tables)	9 Months Ended
	Dec. 27, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Gross and net amounts of goodwill and of acquisition-related intangibles	As of December 27, 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)	December 27, 2014			29-Mar-14			Amortization Life
	Goodwill	$	159,296		$	159,296
	Core technology, gross	91,860			91,860			5.7 years
	Less accumulated amortization	(70,301		)	(63,267		)
	Core technology, net	21,559			28,593
	Other intangibles, gross	46,716			46,716			2.7 years
	Less accumulated amortization	(46,575		)	(46,442		)
	Other intangibles, net	141			274
	Total acquisition-related intangibles, gross	138,576			138,576
	Less accumulated amortization	(116,876		)	(109,709		)
	Total acquisition-related intangibles, net	$	21,700		$	28,867
Schedule of expected annual amortization expense for acquisition-related intangibles	Based on the carrying value of acquisition-related intangibles recorded as of December 27, 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 three months)	$	2,371
	2016	8,935
	2017	7,131
	2018	2,660
	2019	603
	Total	$	21,700

Significant_Customers_and_Conc1

Significant Customers and Concentrations of Credit Risk (Details)	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Mar. 29, 2014
	Customer	Customer	Customer	Customer
Significant Customers and Concentrations of Credit Risk [Abstract]
Percentage of Accounts Receivable Accounted From Company Distributor One	66.00%		66.00%		55.00%
Percentage of net revenues through resale of product from Company Distributor One	40.00%	45.00%	42.00%	47.00%
Number of End Customers Accounted For 10% or More of Net Revenues	0	0	0	0
Percentage of higher grade securities investment in debt securities			91.00%
Percentage of Mortgage Backed Securities In Investment Portfolio	35.00%		35.00%

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 27, 2014		Dec. 28, 2013		Sep. 27, 2014	Mar. 29, 2014	Sep. 28, 2013	Mar. 30, 2013
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$10,325		$19,228		$10,325		$19,228		$20,608	$20,160	$22,229	$27,610
Derivative Asset										1,713
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	0		-221		0		462
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	717		870		1,165		1,456
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, (Sales), Issuances, (Settlements)	-11,000	[1]	-3,650	[1]	-11,000	[1]	-10,300	[1]
Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Derivative Asset										1,713
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	3,449,460				3,449,460					3,607,062
Derivative Liability	6,453				6,453
Financial and Nonfinancial Liabilities, Fair Value Disclosure	6,453				6,453
Fair Value Assets Measured On Recurring Basis Net	3,443,007				3,443,007
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	740,281				740,281					637,959
Derivative Liability	0				0					0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0				0
Fair Value Assets Measured On Recurring Basis Net	740,281				740,281
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	2,698,854				2,698,854					2,948,943
Derivative Liability	6,453				6,453
Financial and Nonfinancial Liabilities, Fair Value Disclosure	6,453				6,453
Fair Value Assets Measured On Recurring Basis Net	2,692,401				2,692,401
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	10,325				10,325					20,160
Derivative Liability	0				0					0
Financial and Nonfinancial Liabilities, Fair Value Disclosure	0				0
Fair Value Assets Measured On Recurring Basis Net	10,325				10,325
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	302,542				302,542					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	143,999				143,999					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	120,988				120,988					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	417,197				417,197					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	320,977				320,977					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	302,542				302,542					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					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					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	219,997				219,997					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					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					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	143,999				143,999					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	120,988				120,988					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	197,200				197,200					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	320,977				320,977					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					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					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					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					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					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	75,000				75,000					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	86,593				86,593					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	33,606				33,606					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	271,434				271,434					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	28,995				28,995					159,951
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	202,914				202,914
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	654,898				654,898					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	39,500				39,500					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	96,804				96,804
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					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					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					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	217,742				217,742					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					0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-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] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	0				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					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				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	75,000				75,000					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	86,593				86,593					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	33,606				33,606					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	53,692				53,692					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	28,995				28,995					159,951
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	202,914				202,914
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	654,898				654,898					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	39,500				39,500					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	96,804				96,804
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					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					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					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					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					0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-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] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	0				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					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				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										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	10,325				10,325					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	10,132				10,132					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	6,758				6,758					41,076
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	11,463				11,463
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	559,160				559,160					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	56,175				56,175					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
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					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					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	0				0					4,950
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-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] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	0				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					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										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					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	10,132				10,132					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	6,758				6,758					36,126
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value	11,463				11,463
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	559,160				559,160					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	56,175				56,175					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
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	10,325				10,325					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					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					0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Total assets measured at fair value
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					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					$0
[1]	During the first nine months of fiscal 2015 and 2014, the Company redeemed $11.0 million and $10.3 million, respectively, of student loan auction rate securities for cash at par value.

Fair_Value_Measurements_Detail1

Fair Value Measurements (Details 1) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 27, 2014		Dec. 28, 2013
Changes in Level 3 instruments measured at fair value on a recurring basis
Balance as of beginning of period	$20,608		$22,229		$20,160		$27,610
Gains (losses) included in interest and other expense, net	0		-221		0		462
Gains (losses) included in other comprehensive income (loss)	717		870		1,165		1,456
Sales and settlements, net	-11,000	[1]	-3,650	[1]	-11,000	[1]	-10,300	[1]
Balance as of end of period	$10,325		$19,228		$10,325		$19,228
[1]	During the first nine months of fiscal 2015 and 2014, the Company redeemed $11.0 million and $10.3 million, respectively, of student loan auction rate securities for cash at par value.

Fair_Value_Measurements_Detail2

Fair Value Measurements (Details 2)	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Fair Value Disclosures [Abstract]
Fair Value, Assets and Liabilities Measured on Recurring Basis, Gain (Loss) Included in Earnings, Description	0	-221	0	462

Fair_Value_Measurements_Detail3

Fair Value Measurements (Details Textual) (USD $)	Dec. 27, 2014	Mar. 29, 2014
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Noncurrent	$654,013,000	$1,190,775,000	[1]
Available-for-sale Securities	3,449,460,000	3,605,349,000
2019 Notes Payable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debentures	494,900,000
2021 Notes Payable [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debentures	505,000,000
Auction Rate Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Noncurrent	10,325,000	20,160,000
2017 Convertible Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debentures	$912,000,000
[1]	Derived from audited financial statements

Financial_Instruments_Details

Financial Instruments (Details) (USD $)	Dec. 27, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Available-for-sale securities
Amortized Cost	$3,449,866	$3,606,739
Available-for-sale Securities, Gross Unrealized Gains (Instant)	14,047	16,763
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-14,453	-18,153
Available-for-sale Securities, Noncurrent	654,013	1,190,775	[1]
Estimated Fair Value	3,449,460	3,605,349
Money Market Funds [Member]
Available-for-sale securities
Amortized Cost	302,542	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	302,542	213,988
financial institution securities [Member]
Available-for-sale securities
Amortized Cost	218,999	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	218,999	366,906
Non-financial institution securities [Member]
Available-for-sale securities
Amortized Cost	207,535	753,888
Available-for-sale Securities, Gross Unrealized Gains (Instant)	50	3,428
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-4	-1,244
Estimated Fair Value	207,581	756,072
Auction Rate Securities [Member]
Available-for-sale securities
Amortized Cost	10,500	21,500
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-175	-1,340
Available-for-sale Securities, Noncurrent	10,325	20,160
Municipal Bonds [Member]
Available-for-sale securities
Amortized Cost	43,328	31,367
Available-for-sale Securities, Gross Unrealized Gains (Instant)	603	604
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-193	-205
Estimated Fair Value	43,738	31,766
U.S. Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	695,442	548,568
Available-for-sale Securities, Gross Unrealized Gains (Instant)	81	1,135
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-134	-184
Estimated Fair Value	695,389	549,519
Foreign Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	349,972	354,935
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	0	0
Estimated Fair Value	349,972	354,935
Mortgage-Backed Securities [Member]
Available-for-sale securities
Amortized Cost	1,208,162	1,234,237
Available-for-sale Securities, Gross Unrealized Gains (Instant)	12,214	11,380
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-6,318	-10,528
Estimated Fair Value	1,214,058	1,235,089
Asset-backed Securities [Member]
Available-for-sale securities
Amortized Cost	213,833	0
Available-for-sale Securities, Gross Unrealized Gains (Instant)	1,019	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-475	0
Estimated Fair Value	214,377	0
Debt Mutual Fund [Member]
Available-for-sale securities
Amortized Cost	101,350	81,350
Available-for-sale Securities, Gross Unrealized Gains (Instant)	0	216
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-5,675	-4,652
Estimated Fair Value	95,675	76,914
Bank Loans [Member]
Available-for-sale securities
Amortized Cost	98,203	0
Available-for-sale Securities, Gross Unrealized Gains (Instant)	80	0
Available-for-sale Securities, Gross Unrealized Losses (Instant)	-1,479	0
Estimated Fair Value	$96,804	$0
[1]	Derived from audited financial statements

Financial_Instruments_Details_

Financial Instruments (Details 1) (USD $)	Dec. 27, 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	$794,418	$751,113
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-5,513	-13,394
Available-for-Sale Securities, 12 Months or Greater, Fair Value	250,823	158,767
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-8,940	-4,759
Available-for-Sale Securities, Fair Value, Total	1,045,241	909,880
Available-for-Sale Securities, Gross Unrealized Losses, Total	-14,453	-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	4,385	112,470
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-4	-1,167
Available-for-Sale Securities, 12 Months or Greater, Fair Value	0	4,488
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	0	-77
Available-for-Sale Securities, Fair Value, Total	4,385	116,958
Available-for-Sale Securities, Gross Unrealized Losses, Total	-4	-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	10,325	20,160
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-175	-1,340
Available-for-Sale Securities, Fair Value, Total	10,325	20,160
Available-for-Sale Securities, Gross Unrealized Losses, Total	-175	-1,340
Municipal Bonds [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	8,814	5,917
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-113	-166
Available-for-Sale Securities, 12 Months or Greater, Fair Value	2,968	1,743
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-80	-39
Available-for-Sale Securities, Fair Value, Total	11,782	7,660
Available-for-Sale Securities, Gross Unrealized Losses, Total	-193	-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	137,031	118,125
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-134	-184
Available-for-Sale Securities, 12 Months or Greater, Fair Value	0	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	0	0
Available-for-Sale Securities, Fair Value, Total	137,031	118,125
Available-for-Sale Securities, Gross Unrealized Losses, Total	-134	-184
Mortgage-Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	362,105	457,903
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-2,808	-7,225
Available-for-Sale Securities, 12 Months or Greater, Fair Value	181,355	132,376
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-3,510	-3,303
Available-for-Sale Securities, Fair Value, Total	543,460	590,279
Available-for-Sale Securities, Gross Unrealized Losses, Total	-6,318	-10,528
Asset-backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	157,697
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-475
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	157,697
Available-for-Sale Securities, Gross Unrealized Losses, Total	-475
Debt Mutual Fund [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	39,500	56,698
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-500	-4,652
Available-for-Sale Securities, 12 Months or Greater, Fair Value	56,175	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	-5,175	0
Available-for-Sale Securities, Fair Value, Total	95,675	56,698
Available-for-Sale Securities, Gross Unrealized Losses, Total	-5,675	-4,652
Bank Loans [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	84,886
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	-1,479
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	84,886
Available-for-Sale Securities, Gross Unrealized Losses, Total	($1,479)

Financial_Instruments_Details_1

Financial Instruments (Details 2) (USD $)	Dec. 27, 2014
Investments, All Other Investments [Abstract]
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$1,082,400,000
Amortized cost and estimated fair value of marketable debt securities
Amortized Cost Due in one year or less	1,410,505,000
Amortized Cost Due after one year through five years	292,035,000
Amortized Cost Due after five years through ten years	383,473,000
Amortized Cost Due after ten years	959,961,000
Amortized Cost Total	3,045,974,000
Estimated Fair Value Due in one year or less	1,410,527,000
Estimated Fair Value Due after one year through five years	291,562,000
Estimated Fair Value Due after five years through ten years	383,800,000
Estimated Fair Value Due after ten years	965,354,000
Estimated Fair Value Total	$3,051,243,000

Financial_Instruments_Details_2

Financial Instruments (Details 3) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Investments, All Other Investments [Abstract]
Proceeds from Sale of Available-for-sale Securities	$478,562	$97,519	$774,406	$296,679
Information on sale of available-for-sale securities
Gross realized gains on sale of available-for-sale securities	4,759	401	7,838	1,768
Gross realized losses on sale of available-for-sale securities	-1,663	-530	-2,330	-2,045
Net realized gains (losses) on sale of available-for-sale securities	3,096	-129	5,508	-277
Amortization of premiums on available-for-sale securities	$5,913	$6,458	$18,559	$20,521

Derivative_Financial_Instrumen3

Derivative Financial Instruments (Details) (USD $)	Dec. 27, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Derivative [Line Items]
Derivative Asset, Notional Amount	$136,908	$146,573
Singapore Dollar [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	53,462	60,551
Euro [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	41,202	46,062
Indian Rupee [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	21,152	18,631
British Pound [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	13,287	12,056
Japanese Yen [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	$7,805	$9,273

Derivative_Financial_Instrumen4

Derivative Financial Instruments (Details 1) (USD $)	Dec. 27, 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	$176	$2,648
Other accrued liabilities
Derivative Instruments located on Condensed Consolidated Balance sheet
Liability Derivatives, Fair Value	$6,629	$935

Derivative_Financial_Instrumen5

Derivative Financial Instruments (Details 2) (Cash Flow Hedging [Member], USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014		Dec. 28, 2013		Dec. 27, 2014		Dec. 28, 2013
Foreign Exchange Contracts [Member]
Effect of derivative instruments located on condensed consolidated Statements of Income
Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging)	($2,110)		($355)		($6,189)		$1,585
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)	1,786	[1]	-259	[1]	768	[1]	1,836	[1]
Amount of gains (losses) recorded (ineffective portion)	($3)	[1]	$5	[1]	($16)	[1]	$11	[1]
[1]	Recorded in Interest and Other Expense location within the condensed consolidated statements of income.

Derivative_Financial_Instrumen6

Derivative Financial Instruments (Details Textual)	9 Months Ended
	Dec. 27, 2014
Derivative [Line Items]
Hedging Program number of years	2 years
Maturity of Foreign Currency Derivatives	14-Nov-16

StockBased_Compensation_Plans_2

Stock-Based Compensation Plans (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$29,054	$24,339	$79,900	$68,353
Cost of Revenues [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	2,339	1,966	6,408	5,628
Research and Development [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	14,909	11,912	40,245	33,474
Selling, General and Administrative Expenses [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$11,806	$10,461	$33,247	$29,251

StockBased_Compensation_Plans_3

Stock-Based Compensation Plans (Details 1) (Restricted Stock Units (RSUs) [Member])	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Restricted Stock Units (RSUs) [Member]
Weighted average assumptions in estimation of fair value of stock options
Risk-free interest rate	1.30%	0.70%	0.70%	0.70%
Dividend yield	2.70%	2.20%	2.40%	2.50%

StockBased_Compensation_Plans_4

Stock-Based Compensation Plans (Details 2) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 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	-1,417	-7,421
Number of Shares, Forfeited/Cancelled/Expired	-16	-60
Number of Shares, Ending Balance	3,847	5,280
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Number	3,750	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	$26.03	$29.95
Weighted-Average Exercise Price Per Share, Forfeited/Cancelled/Expired	$32.85	$35.61
Weighted-Average Exercise Price Per Share, Ending Balance Balance	$24.89	$25.22
Weighted-Average Exercise Price Per Share, Options Exercisable	$24.64	$24.87

StockBased_Compensation_Plans_5

Stock-Based Compensation Plans (Details 3) (USD $)	9 Months Ended	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 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	2,754	3,297
Number of Shares, Vested	-2,264	-2,066
Number of Shares, Forfeited/Cancelled	-292	-326
Number of Shares, Ending Balance	7,099	6,901
Weighted-Average Grant-Date Fair Value, Beginning Balance	$35.08	$30.83
Weighted-Average Grant-Date Fair Value, Granted	$43.76	$38.90
Weighted-Average Grant-Date Fair Value, Vested	$33.62	$29.25
Weighted-Average Grant-Date Fair Value, Forfeited/Cancelled	$36.45	$32.28
Weighted-Average Grant-Date Fair Value, Ending Balance	$38.86	$35.08

StockBased_Compensation_Plans_6

Stock-Based Compensation Plans (Details Textual) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended	3 Months Ended
In Millions, except Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Mar. 29, 2014	Sep. 27, 2014	Sep. 28, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Payments Related to Tax Withholding for Share-based Compensation			$33.20	$16.80
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Adjustment to Additional Paid in Capital, Income Tax Effect from Share-based Compensation, Net			12.3	17
Weighted-Average Grant-Date Fair Value, Granted			$43.76		$38.90
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	11.7	5.5	27.7	70.7
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted	$40.76	$42.37		$38.13
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	1.30%	0.70%	0.70%	0.70%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.70%	2.20%	2.40%	2.50%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Employee Stock Purchase Plans						446,000	529,000
Stock Issued During Period, Value, Employee Stock Purchase Plan						$14.90	$14.60
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term						1 year 3 months	1 year 3 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate						24.88%	23.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate						0.20%	0.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate						2.80%	2.10%
Equity Plan Two Thousand Seven [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Available for Grant	15,600,000		15,600,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted						$14.12	$11.24
Employee Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Shares Reserved	2,000,000		2,000,000
Shares Available for Grant	11,300,000		11,300,000

Net_Income_Per_Common_Share_De

Net Income Per Common Share (Details) (USD $)	3 Months Ended	9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 27, 2014
Schedule of Debt Instruments [Line Items]
Antidilutive shares excluded from computation of dilutive net income per common share	0.1	3.2
2017 Convertible Notes [Member]
Schedule of Debt Instruments [Line Items]
Maximum number of common shares to be purchased under call option	20.2	20.2
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		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Earnings Per Share [Abstract]
Net income	$168,466	$175,877	$513,593	$474,361
Weighted Average Number of Shares Outstanding, Basic	262,881	267,780	266,299	266,068
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	3,138	4,686	3,463	4,600
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities and Warrants	7,776	7,695	7,947	7,091
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0	8,034	0	7,621
Weighted Average Number of Shares Outstanding, Diluted	273,795	288,195	277,709	285,380
Earnings Per Share, Basic	$0.64	$0.66	$1.93	$1.78
Earnings Per Share, Diluted	$0.62	$0.61	$1.85	$1.66

Inventories_Inventories_Detail

Inventories Inventories (Details) (USD $)	Dec. 27, 2014	Mar. 29, 2014
In Thousands, unless otherwise specified
Inventory Disclosure [Abstract]
Inventory, Raw Materials, Gross	$14,094	$15,306
Inventory, Work in Process, Gross	198,270	192,067
Inventory, Finished Goods, Gross	34,300	26,626
Inventory, Net	$246,664	$233,999	[1]
[1]	Derived from audited financial statements

Debt_and_Credit_Facility_Detai

Debt and Credit Facility (Details) (USD $)	12 Months Ended		9 Months Ended	3 Months Ended
	Mar. 29, 2014		Dec. 27, 2014	Dec. 27, 2014
Debt Instrument [Line Items]
Long-term Debt, Excluding Current Maturities	$993,870,000	[1]	$994,595,000	$994,595,000
2019 and 2021 Notes Payable [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt	990,100,000
2021 Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	500,000,000		500,000,000	500,000,000
Debt Instrument, Unamortized Discount	-3,556,000		-3,206,000	-3,206,000
Debt instrument, Maturity Date			15-Mar-21
Discount Percent of Par			99.28%	99.28%
2019 Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	500,000,000		500,000,000	500,000,000
Debt Instrument, Unamortized Discount	-2,574,000		-2,199,000	-2,199,000
Debt instrument, Maturity Date			15-Mar-19
Discount Percent of Par			99.48%	99.48%
2017 Convertible Notes [Member]
Debt Instrument [Line Items]
Price Per Share To Be Purchase By Company Under Call Option				$29.64
Debt Instrument, Face Amount	600,000,000		600,000,000	600,000,000
Debt Instrument, Unamortized Discount	-49,223,000		-37,565,000	-37,565,000
Debt Instrument Carrying Amount Of Liability Component	565,001,000		573,290,000	573,290,000
Equity component - net carrying value	$66,415,000		$66,415,000	$66,415,000
[1]	Derived from audited financial statements

Debt_and_Credit_Facility_Detai1

Debt and Credit Facility (Details 1) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Mar. 29, 2014
Debt Instrument [Line Items]
Amortization of Debt Discount (Premium)			$9,014,000	$12,144,000
Line of Credit Facility, Expiration Date			31-Dec-16
Line of Credit Facility, Maximum Borrowing Capacity	250,000,000		250,000,000
Line of Credit Facility, Average Outstanding Amount			0
2019 and 2021 Notes Payable [Member]
Debt Instrument [Line Items]
Interest Expense, Debt, Excluding Amortization	6,406,000	0	19,219,000	0
Amortization of Financing Costs	146,000	0	436,000	0
Amortization of Debt Discount (Premium)	244,000	0	725,000	0
Interest Expense, Debt	6,796,000	0	20,380,000	0
Proceeds from Issuance of Long-term Debt					990,100,000
2019 Notes Payable [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	500,000,000		500,000,000		500,000,000
Debt Instrument, Unamortized Discount	$2,199,000		$2,199,000		$2,574,000

Debt_and_Credit_Facility_Detai2

Debt and Credit Facility (Details 2) (USD $)	3 Months Ended		9 Months Ended
Share data in Millions, except Per Share data, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Mar. 29, 2014
Short-term Debt [Line Items]
Amortization of Debt Discount (Premium)			$9,014,000	$12,144,000
2017 Convertible Notes [Member]
Short-term Debt [Line Items]
Maximum number of common shares to be purchased under call option	20.2		20.2
Debt Instrument, Convertible, Remaining Discount Amortization Period			2 years 5 months 19 days
Debt Instrument, Face Amount	600,000,000		600,000,000		600,000,000
Debt Instrument, Convertible, Conversion Ratio	33.7391
Debt Instrument, Unamortized Discount	37,565,000		37,565,000		49,223,000
Hedge Accounting Adjustment - Sale Of Interest Rate Swap	10,855,000		10,855,000		14,224,000
Debt Instrument Carrying Amount Of Liability Component	573,290,000		573,290,000		565,001,000
Debt Instrument, Convertible, Carrying Amount of Equity Component	66,415,000		66,415,000		66,415,000
Interest Expense, Debt, Excluding Amortization	3,938,000	3,938,000	11,813,000	11,813,000
Amortization of Financing Costs	362,000	362,000	1,086,000	1,086,000
Amortization of Debt Discount (Premium)	2,763,000	2,763,000	8,289,000	8,289,000
Interest Expense, Debt	7,063,000	7,063,000	21,188,000	21,188,000
Base conversion, block amount of senior convertible debenture	1,000
Warrants, number of shares the holders have the right to purchase	20.2		20.2
Class of Warrant or Right, Exercise Price of Warrants or Rights	41.9889		41.9889
Convertible debt, conversion price	$29.64		$29.64
Debt Instrument, Convertible, If-converted Value in Excess of Principal	$903,300,000		$903,300,000

Common_Stock_Repurchase_Progra1

Common Stock Repurchase Program (Details) (USD $)	9 Months Ended		1 Months Ended		28 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Nov. 30, 2014	Aug. 31, 2012	Dec. 27, 2014	Mar. 29, 2014
Accelerated Share Repurchases [Line Items]
Treasury shares	0				0	0
Stock Repurchased During Period, Shares	-11,000,000
Payments for Repurchase of Common Stock	$476,012,000	$167,121,000
Repurchase Program Two Thousand Fourteen [Member]
Accelerated Share Repurchases [Line Items]
Amount authorized for common stock repurchase			800,000,000
Stock Repurchased and Retired During Period, Value	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	475,000,000	167,100,000			727,600,000
Total amount available for future repurchases	$822,400,000
Stock Repurchased and Retired During Period, Shares		3,700,000

Interest_and_Other_Expense_Net1

Interest and Other Expense, Net (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Components of interest and other expense
Interest income	$11,375	$9,545	$28,268	$20,511
Interest expense	-13,859	-14,050	-41,567	-40,955
Other income (expense), net	-1,523	-302	-2,661	-5,290
Interest and other expense, net	($4,007)	($4,807)	($15,960)	($25,734)

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income (Details) (USD $)	Dec. 27, 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	($254)	($889)
Accumulated unrealized gain (losses) on hedging transactions, net of tax	-5,391	798
Accumulated cumulative translation adjustment, net of tax	-2,339	-457
Accumulated other comprehensive income (loss)	($7,984)	($548)	[1]
[1]	Derived from audited financial statements

Income_Taxes_Details_Textual

Income Taxes (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$17,536,000	$22,055,000	$67,005,000	$59,315,000
Effective Income Tax Rate Reconciliation, Percent	9.00%	11.00%	12.00%	11.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
Unrecognized Tax Benefits, Period Increase (Decrease)	800,000
Unrecognized Tax Benefits	27,200,000		27,200,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$11,700,000		$11,700,000

Commitments_Details

Commitments (Details) (USD $)	Dec. 27, 2014
In Thousands, unless otherwise specified
Future Minimum Lease Payments Under Non-Cancelable Operating Leases [Abstract]
2015 (remaining 3 months)	$1,589
2016	5,162
2017	2,476
2018	2,241
2019	1,806
Thereafter	3,576
Total	$16,850

Commitments_Details_Textual

Commitments (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Commitments [Line Items]
Lease Expiration Date			31-Oct-21
Aggregate future rental income to be received	$2,900,000		$2,900,000
Rent expense, net of rental income	792,000	735,000	2,400,000	2,200,000
Other commitments	97,600,000		97,600,000
Non-cancelable license obligations	$40,100,000		$40,100,000
Software and Maintenance License Obligations Expiration Date			30-Jun-17
Minimum [Member]
Commitments [Line Items]
Purchase Commitments, Period for Payment			3 months
Maximum [Member]
Commitments [Line Items]
Purchase Commitments, Period for Payment			6 months

Contingencies_Details

Contingencies (Details)	9 Months Ended
	Dec. 27, 2014
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought For Each Unspecified Claim	11000

Goodwill_and_AcquisitionRelate2

Goodwill and Acquisition-Related Intangibles (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 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	-116,876	-109,709
Total	21,700	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	-70,301	-63,267
Total	21,559	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	-46,575	-46,442
Total	$141	$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		9 Months Ended
In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013	Mar. 29, 2014
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquisition-related intangibles	$2,371	$2,589	$7,167	$7,425
Schedule of expected annual amortization expense for acquisition-related intangibles
2015 (remaining six months)	2,371		2,371
2016	8,935		8,935
2017	7,131		7,131
2018	2,660		2,660
2019	603		603
Total	$21,700		$21,700		$28,867

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended		9 Months Ended
	Dec. 27, 2014	Dec. 28, 2013	Dec. 27, 2014	Dec. 28, 2013
Subsequent Events [Abstract]
Common Stock, Dividends, Per Share, Declared	$0.29	$0.25	$0.87	$0.75