Xilinx (XLNX) 10-Q 27 Jul 18 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Jun. 30, 2018	Jul. 13, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2018
Document Fiscal Year Focus	2,019
Document Fiscal Period Focus	Q1
Entity Registrant Name	XILINX INC
Entity Central Index Key	743,988
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Current Fiscal Year End Date	--03-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		252,913,557

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Net revenues	$ 684,370	$ 602,810	[1]
Cost of revenues	206,888	190,824	[1]
Gross margin	477,482	411,986	[1]
Operating expenses:
Research and development	170,826	153,051
Selling, general and administrative	90,532	89,175
Amortization of acquisition-related intangibles	360	705
Total operating expenses	261,718	242,931
Operating income	215,764	169,055	[1]
Interest and other income (expense), net	(2,847)	1,839
Income before income taxes	212,917	170,894	[1]
Provision for income taxes	22,879	13,650	[1]
Net income	$ 190,038	$ 157,244	[1]
Net income per common share:
Basic (in dollars per share)	$ 0.75	$ 0.63	[1]
Diluted (in dollars per share)	0.74	0.59	[1]
Common Stock, Dividends, Per Share, Declared	$ 0.36	$ 0.35
Shares used in per share calculations:
Basic (in shares)	252,682	247,911
Diluted (in shares)	255,935	265,797
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 190,038	$ 157,244	[1]
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on available-for-sale securities	(1,660)	5,250
Reclassification adjustment for (gains) losses on available-for-sale securities	(51)	(48)
Net change in unrealized gains (losses) on hedging transactions	(5,619)	1,425
Reclassification adjustment for gains on hedging transactions	(441)	(338)
Cumulative translation adjustment, net	(2,050)	1,760
Other comprehensive income (loss)	(9,821)	8,049
Total comprehensive income	$ 180,217	$ 165,293
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Current assets:
Cash and cash equivalents at beginning of period	$ 1,677,389	$ 2,179,328
Short-term investments	1,686,809	1,268,242
Accounts receivable, net	456,898	382,246	[1]
Inventories	247,001	236,077
Prepaid expenses and other current assets	57,448	88,695
Total current assets	4,125,545	4,154,588	[1]
Property, plant and equipment, at cost:	871,411	855,023
Accumulated depreciation and amortization	(559,327)	(550,906)
Net property, plant and equipment	312,084	304,117
Long-term investments	91,700	97,896
Goodwill	162,421	162,421
Acquisition-related intangibles, net	3,763	4,123
Other assets	359,679	337,402	[1]
Total Assets	5,055,192	5,060,547	[1]
Current liabilities:
Accounts payable	105,484	98,999
Accrued payroll and related liabilities	198,602	206,367
Income taxes payable	82,410	47,713
Other accrued liabilities	56,696	59,680	[1]
Long-term Debt, Current Maturities	499,407	499,186
Total current liabilities	942,599	911,945	[1]
Long-term Debt, Excluding Current Maturities	1,207,387	1,214,440
Long-term income taxes payable	530,167	523,864
Other long-term liabilities	56,401	49,945
Commitments and contingencies (Note 17)
Stockholders' equity:
Preferred stock, $.01 par value (none issued and outstanding)	0	0
Common stock, $.01 par value	2,515	2,534
Additional paid-in capital	894,588	878,672
Retained earnings	1,457,467	1,513,656	[1]
Accumulated other comprehensive loss	(35,932)	(34,509)
Total stockholders’ equity	2,318,638	2,360,353	[1]
Total Liabilities and Stockholders’ Equity	$ 5,055,192	$ 5,060,547	[1]
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2018	Mar. 31, 2018
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 Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Cash flows from operating activities:
Net income	$ 190,038	$ 157,244	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	15,075	11,232
Amortization	7,333	3,729
Stock-based compensation	35,608	32,036
Amortization of debt discounts	295	1,676
Provision (benefit) for deferred income taxes	(13,532)	24,694	[1]
Others	6,147	(446)
Changes in assets and liabilities:
Accounts receivable, net	(74,652)	(23,654)	[1]
Inventories	(10,924)	11,691
Prepaid expenses and other current assets	2,140	(5,023)
Other assets	(7,770)	(8,690)
Accounts payable	9,320	(3,049)
Accrued liabilities	(32,437)	2,378	[1]
Income taxes payable	49,527	(12,910)
Net cash provided by operating activities	176,168	190,908
Cash flows from investing activities:
Purchases of available-for-sale securities	(559,159)	(832,705)
Proceeds from sale and maturity of available-for-sale securities	155,230	613,396
Purchases of property, plant and equipment and other intangibles	(26,359)	(9,926)
Other investing activities	(13,900)	(3,008)
Net cash used in investing activities	(444,188)	(232,243)
Cash flows from financing activities:
Payments for Repurchase of Common Stock	(137,300)	(67,062)
Payments Related to Tax Withholding for Share-based Compensation	(5,495)	(933)
Proceeds from issuance of common stock through various stock plans	214	2,003
Payment of dividends to stockholders	(90,675)	(87,303)
Repayment of convertible debt	0	(457,918)
Proceeds from Issuance of Long-term Debt	0	745,871
Other financing activities	(663)	(663)
Net cash (used in) provided by financing activities	(233,919)	133,995
Net (decrease) increase in cash and cash equivalents	(501,939)	92,660
Cash and cash equivalents at beginning of period	2,179,328	966,695
Cash and cash equivalents at end of period	1,677,389	1,059,355
Supplemental disclosure of cash flow information:
Interest paid	21,174	5,795
Income taxes (refunded) paid, net	$ (13,328)	$ 1,873
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Basis of Presentation

Basis of Presentation	3 Months Ended
	Jun. 30, 2018
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 31, 2018 . 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 30, 2019 or any future period. The Company uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal 2019 and fiscal 2018 are both 52-week years ending on March 30, 2019 and March 31, 2018 , respectively. The quarters ended June 30, 2018 and July 1, 2017 each consisted of 13 weeks.

Recent Accounting Changes and A

Recent Accounting Changes and Accounting Pronouncements	3 Months Ended
	Jun. 30, 2018
Accounting Changes and Error Corrections [Abstract]
Accounting Changes and Error Corrections [Text Block]	Recent Accounting Changes and Accounting Pronouncements Recent Accounting Pronouncements Adopted Revenue Recognition In April 2014, the Financial Accounting Standards Board (FASB) issued the authoritative guidance, as amended, that outlines a new revenue recognition standard that replaces virtually all existing U.S. GAAP guidance on contracts with customers and the related other assets and deferred costs. The authoritative 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 new guidance 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 new guidance is required to be applied retrospectively to each prior reporting period presented (Full Retrospective), or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application. The Company adopted the new guidance on April 1, 2018, using the Full Retrospective method and restated the comparative prior periods. The Company implemented internal controls and certain system functionality to enable the preparation of financial information on adoption. As a result of the adoption of the authoritative guidance, the Company changed its accounting policy for revenue recognition and the details of the significant changes and quantitative impact of the changes are disclosed below: Revenue from sales to the Company's distributors is recognized upon shipment of the product to the distributors (sell-in) and is reduced by estimated allowances for distributor price adjustments and rights of return. Previously, revenue was recognized upon reported resale of the product by the distributors to their customers (sell-through) as reduced by actual allowances for distributor price adjustments. Revenue from software license agreements, software license renewals, and other contracts are recognized at point of sales, whereas previously these were deferred and recognized over the contractual term before the implementation of the authoritative guidance. Revenue recognition related to the Company's other revenue streams, such as direct customers, remains unchanged. The adoption of this authoritative guidance has an impact on the Company’s condensed consolidated statements of income and balance sheets, but has no impact on net cash provided by or used in operating, financing, or investing activities on the condensed consolidated statements of cash flows. The impact on the Company's previously reported condensed consolidated statement of income resulting from the adoption of the authoritative guidance is as follows: Three months ended July 1, 2017 (In thousands, except per share amounts) As Reported Adjustment As Adjusted Net revenues $ 615,446 $ (12,636 ) $ 602,810 Cost of revenues 192,095 (1,271 ) 190,824 Gross margin 423,351 (11,365 ) 411,986 Operating expenses: Research and development 153,051 — 153,051 Selling, general and administrative 89,175 — 89,175 Amortization of acquisition-related intangibles 705 — 705 Total operating expenses 242,931 — 242,931 Operating income 180,420 (11,365 ) 169,055 Interest and other income, net 1,839 — 1,839 Income before income taxes 182,259 (11,365 ) 170,894 Provision for income taxes 15,014 (1,364 ) 13,650 Net income $ 167,245 $ (10,001 ) $ 157,244 Net income per common share: Basic $ 0.67 $ (0.04 ) $ 0.63 Diluted $ 0.63 $ (0.04 ) $ 0.59 Shares used in per share calculations: Basic 247,911 247,911 Diluted 265,797 265,797 The impact on the Company's previously reported condensed consolidated balance sheet line items affected by the adoption of the authoritative guidance is as follows: March 31, 2018 (In thousands) As Reported Adjustment As Adjusted Accounts receivable $ 372,144 $ 10,102 $ 382,246 Other assets 342,644 (5,242 ) 337,402 Deferred income on shipments to distributors 25,166 (25,166 ) — Other accrued liabilities 59,772 (92 ) 59,680 Retained earnings 1,483,538 30,118 1,513,656 Financial Instruments In January 2016, the FASB issued final authoritative guidance regarding how companies measure equity investments that do not result in consolidation and are not accounted for under the equity method and how they present changes in the fair value of financial liabilities measured under the fair value option that are attributable to their own credit. The authoritative guidance also changes certain disclosure requirements and other aspects of current U.S. GAAP on this matter. The authoritative guidance does not change the guidance for classifying and measuring investments in debt securities and loans. The authoritative guidance is effective for public business entities for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company adopted this authoritative guidance on April 1, 2018 and recorded the balance of the unrealized losses of $11.0 million as of the end of fiscal 2018 from its investment in debt mutual funds and equity securities to retained earnings, less the related deferred taxes of $2.6 million . Subsequent changes in fair value from such investments are recorded in the condensed consolidated statements of income. Income Taxes In October 2016, the FASB issued authoritative guidance on income taxes which eliminates the deferred tax effects of intra-entity asset transfers other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of an asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. The authoritative guidance is effective for public business entities in fiscal years beginning after December 15, 2017 and requires the adoption be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings. The Company adopted this authoritative guidance on April 1, 2018. Accordingly, $13.8 million of prepaid taxes associated with prior period intra-entity asset transfers was reclassified to retained earnings. Recent Accounting Pronouncements Not Yet Adopted Leases In February 2016, the FASB issued authoritative guidance on leases. The new authoritative guidance requires the recognition of assets and liabilities arising from lease transactions on the balance sheet and will also require significant additional disclosures about the amount, timing and uncertainty of cash flows from leases. Accordingly, a lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. The new authoritative guidance is effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, which for Xilinx would be the first quarter of fiscal 2020. Early adoption is permitted. The new authoritative guidance must be adopted using a modified retrospective transition with application of the new authoritative guidance for leases that existed at or are entered into after the beginning of the earliest comparative period presented. To help with the transition to the new guidance, certain practical expedients are provided. The Company is currently evaluating the impact of this new authoritative guidance on its condensed consolidated financial statements.

Significant Customers and Conce

Significant Customers and Concentrations of Credit Risk (Notes)	3 Months Ended
	Jun. 30, 2018
Significant Customers and Concentrations of Credit Risk [Abstract]
Concentration Risk Disclosure [Text Block]	Significant Customers and Concentrations of Credit Risk Avnet, Inc. (Avnet), one of the Company’s distributors, distributes the Company’s products worldwide. As of June 30, 2018 and March 31, 2018 , Avnet accounted for 70% and 61% of the Company’s total net accounts receivable, respectively. Net revenues from Avnet accounted for 51% and 41% of the Company’s worldwide net revenues in the first quarter of fiscal 2019 and 2018 , respectively. The Company expects its accounts receivable to be relatively higher than normal on a temporary basis as the Company partners with its distributors to manage their inventory requirements. 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 condensed 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 distributors. No end customer accounted for more than 10% of the Company’s worldwide net revenues for the first quarter of fiscal 2019 and 2018 . The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 91% of its portfolio in AA (or its equivalent) 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 and interest rate swap contracts. Additionally, Xilinx limits its investments in the debt securities of a single issuer based upon the issuer’s credit rating and attempts to further mitigate credit risk by diversifying risk across geographies and type of issuer. As of June 30, 2018 , approximately 24% of the portfolio consisted of mortgage-backed securities. All of the mortgage-backed securities in the investment portfolio were issued by U.S. government-sponsored enterprises and agencies and are rated AA+ by Standard & Poor’s and Aaa by Moody’s Investors Service.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The authoritative 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. The Company validates the consensus prices by taking random samples from each asset type and corroborating those prices using reported trade activity, benchmark yield curves, binding broker/dealer quotes or other relevant price information. There have not been any changes to the Company’s fair value methodology during the first quarter of fiscal 2019 and the Company did not adjust or override any fair value measurements as of June 30, 2018 . 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 securities, money market funds and marketable equity securities. 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, U.S. agency securities, foreign government and agency securities, mortgage-backed securities, debt mutual funds, asset-backed securities and commercial mortgage-backed securities. The Company’s Level 2 assets and liabilities also include foreign currency forward contracts and interest rate 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 has no Level 3 assets and liabilities measured at fair value on a recurring basis. Assets and Liabilities Measured at Fair Value on a Recurring Basis In instances where the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability. The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of June 30, 2018 and March 31, 2018 : June 30, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 458,706 $ — $ — $ 458,706 Financial institution securities — 349,850 — 349,850 Non-financial institution securities — 350,624 — 350,624 U.S. government and agency securities 114,664 206,945 — 321,609 Foreign government and agency securities — 130,622 — 130,622 Short-term investments: Financial institution securities — 249,982 — 249,982 Non-financial institution securities — 263,922 — 263,922 U.S. government and agency securities 3,647 96,105 — 99,752 Foreign government and agency securities — 43,783 — 43,783 Mortgage-backed securities — 796,953 — 796,953 Asset-backed securities — 89,028 — 89,028 Commercial mortgage-backed securities — 143,389 — 143,389 Long-term investments: Debt mutual funds — 85,633 — 85,633 Marketable equity securities 6,067 — — 6,067 Total assets measured at fair value $ 583,084 $ 2,806,836 $ — $ 3,389,920 Liabilities Derivative financial instruments, net $ — $ 41,289 $ — $ 41,289 Total liabilities measured at fair value $ — $ 41,289 $ — $ 41,289 Net assets measured at fair value $ 583,084 $ 2,765,547 $ — $ 3,348,631 March 31, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities — 359,901 — 359,901 Non-financial institution securities — 242,904 — 242,904 U.S. government and agency securities 996 34,999 — 35,995 Foreign government and agency securities — 179,957 — 179,957 Short-term investments: Financial institution securities — 75,000 — 75,000 Non-financial institution securities — 81,939 — 81,939 U.S. government and agency securities 3,639 19,008 — 22,647 Mortgage-backed securities — 844,397 — 844,397 Asset-backed securities — 91,389 — 91,389 Commercial mortgage-backed securities — 152,870 — 152,870 Long-term investments: Debt mutual funds — 89,670 — 89,670 Marketable equity securities 8,226 — 8,226 Total assets measured at fair value $ 1,304,752 $ 2,172,034 $ — $ 3,476,786 Liabilities Derivative financial instruments, net $ — $ 26,091 $ — $ 26,091 Total liabilities measured at fair value $ — $ 26,091 $ — $ 26,091 Net assets measured at fair value $ 1,304,752 $ 2,145,943 $ — $ 3,450,695 For certain of the Company’s financial instruments, including cash held in banks, accounts receivable and accounts payable, the carrying amounts approximate fair value due to their short maturities, and are therefore excluded from the fair value tables above. As of June 30, 2018 and July 1, 2017 , the Company held no marketable securities measured at fair value using Level 3 inputs. Financial Instruments Not Recorded at Fair Value on a Recurring Basis The Company's $500.0 million principal amount of 2.125% notes due March 15, 2019 (2019 Notes), $500.0 million principal amount of 3.000% notes due March 15, 2021 (2021 Notes) and $750.0 million principal amount of 2.950% senior notes due June 1, 2024 (2024 Notes) are measured at fair value on a quarterly basis for disclosure purposes. The fair values of the 2019 Notes, 2021 Notes and 2024 Notes as of June 30, 2018 were approximately $498.0 million , $495.9 million and $713.4 million , respectively, based on the last trading price for the period (classified as Level 2 in fair value hierarchy due to relatively low trading volume). Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis As of June 30, 2018 , the Company had non-marketable equity securities in private companies of $49.6 million , which were classified as Level 3 assets. The Company’s investments in non-marketable securities of private companies, together with its non-financial assets such as property, plant and equipment, goodwill and acquisition-related intangibles, are recorded at fair value only if the Company recognizes an impairment or an observable price adjustment. Such impairment losses or observable price adjustments were not material during all periods presented.

Financial Instruments

Financial Instruments	3 Months Ended
	Jun. 30, 2018
Investments, All Other Investments [Abstract]
Financial Instruments	Financial Instruments The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented: June 30, 2018 March 31, 2018 (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 $ 458,706 $ — $ — $ 458,706 $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities 599,832 — — 599,832 434,901 — — 434,901 Non-financial institution securities 615,958 1 (1,413 ) 614,546 326,219 — (1,376 ) 324,843 U.S. government and agency securities 421,679 9 (327 ) 421,361 58,913 1 (272 ) 58,642 Foreign government and agency securities 174,405 — — 174,405 179,957 — — 179,957 Mortgage-backed securities 820,305 580 (23,932 ) 796,953 866,048 660 (22,311 ) 844,397 Asset-backed securities 90,426 12 (1,410 ) 89,028 92,751 16 (1,378 ) 91,389 Debt mutual funds 101,350 — (15,717 ) 85,633 101,350 — (11,680 ) 89,670 Commercial mortgage- backed securities 146,984 — (3,595 ) 143,389 156,296 1 (3,427 ) 152,870 Marketable equity securities 7,500 — (1,433 ) 6,067 7,500 726 — 8,226 $ 3,437,145 $ 602 $ (47,827 ) $ 3,389,920 $ 3,515,826 $ 1,404 $ (40,444 ) $ 3,476,786 Financial institution securities include securities issued or managed by financial institutions in various forms, such as commercial paper and time deposits. Substantially all time deposits were issued by institutions outside the U.S. as of June 30, 2018 and March 31, 2018 . The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of June 30, 2018 and March 31, 2018 : June 30, 2018 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 $ 57,501 $ (1,193 ) $ 7,910 $ (220 ) $ 65,411 $ (1,413 ) U.S. government and agency securities 52,351 (224 ) 4,586 (103 ) 56,937 (327 ) Mortgage-backed securities 424,784 (10,639 ) 340,733 (13,293 ) 765,517 (23,932 ) Asset-backed securities 53,832 (944 ) 33,333 (466 ) 87,165 (1,410 ) Debt mutual funds — — 85,633 (15,717 ) 85,633 (15,717 ) Commercial mortgage- backed securities 84,596 (1,830 ) 57,875 (1,765 ) 142,471 (3,595 ) Marketable equity securities 6,067 (1,433 ) — — 6,067 (1,433 ) $ 679,131 $ (16,263 ) $ 530,070 $ (31,564 ) $ 1,209,201 $ (47,827 ) March 31, 2018 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 $ 69,780 $ (1,146 ) $ 8,344 $ (230 ) $ 78,124 $ (1,376 ) U.S. government and agency securities 13,471 (176 ) 9,176 (96 ) 22,647 (272 ) Mortgage-backed securities 510,988 (11,048 ) 299,663 (11,263 ) 810,651 (22,311 ) Asset-backed securities 57,128 (876 ) 32,696 (502 ) 89,824 (1,378 ) Debt mutual funds — — 89,670 (11,680 ) 89,670 (11,680 ) Commercial mortgage- backed securities 95,435 (1,760 ) 56,051 (1,667 ) 151,486 (3,427 ) $ 746,802 $ (15,006 ) $ 495,600 $ (25,438 ) $ 1,242,402 $ (40,444 ) As of June 30, 2018 , the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities due to the general rising of the interest-rate environment, although the percentage of such losses to the total estimated fair value of the mortgage-backed securities was relatively insignificant. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to debt mutual funds and mortgage-backed securities, which were primarily due to the general rising of the interest-rate environment and foreign currency movement. Starting April 1, 2018 , the Company records the change in the fair value of its investment in debt mutual funds and marketable equity securities as part of its interest and other income (expense), net. This change in fair value was a net decrease of $6.2 million for the three months ended June 30, 2018 and resulted in an expense within interest and other income (expense) net for the period. The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of June 30, 2018 and March 31, 2018 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, there have been no defaults on any of these securities and the company has received interest payments as they become due. Therefore, the Company believes that it will be able to collect both principal and interest amount due to the Company. Additionally, in the past several years a portion of the Company's investment in the mortgage-backed securities was redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more was not significant as of June 30, 2018 and March 31, 2018 . 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 amortized cost and estimated fair value of marketable debt securities (financial institution securities, non-financial institution securities, U.S. and foreign government and agency securities, asset-backed securities, mortgage-backed securities and commercial mortgage-backed securities), by contractual maturity, are shown in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties. June 30, 2018 (In thousands) Amortized Estimated Due in one year or less $ 1,758,865 $ 1,758,593 Due after one year through five years 176,391 172,941 Due after five years through ten years 148,349 143,894 Due after ten years 785,984 764,086 $ 2,869,589 $ 2,839,514 As of June 30, 2018 , $1.08 billion of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table does not include investments in money market, debt mutual funds and marketable equity securities because these investments do not have specific contractual maturities. Certain information related to available-for-sale securities is as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Proceeds from sale of available-for-sale securities $ 895 $ 119,922 Gross realized gains on sale of available-for-sale securities $ 96 $ 832 Gross realized losses on sale of available-for-sale securities (47 ) (386 ) Net realized gains on sale of available-for-sale securities $ 49 $ 446 Amortization of premiums on available-for-sale securities $ 2,491 $ 6,823 The cost of securities matured or sold is based on the specific identification method.

Derivative Financial Instrument

Derivative Financial Instruments	3 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company’s primary objective for holding derivative financial instruments is to manage foreign currency exchange rate risk and interest rate risk. As a result of the use of derivative financial instruments, the Company is exposed to the risk that counterparties to derivative contracts may fail to meet their contractual obligations. The Company manages counterparty credit risk in derivative contracts by reviewing counterparty creditworthiness on a regular basis, establishing collateral requirement and limiting exposure to any single counterparty. The right of set-off that exists with certain transactions enables the Company to net amounts due to and from the counterparty, reducing the maximum loss from credit risk in the event of counterparty default. As of June 30, 2018 and March 31, 2018 , the Company had the following outstanding forward currency exchange contracts (in notional amount), which were derivative financial instruments: (In thousands and U.S. dollars) June 30, 2018 March 31, 2018 Singapore Dollar $ 26,392 $ 24,914 Euro 38,591 38,987 Indian Rupee 64,959 62,472 British Pound 8,125 8,155 Japanese Yen 3,882 3,859 Chinese Yuan 13,247 8,260 $ 155,196 $ 146,647 As part of the Company’s strategy to reduce volatility of operating expenses due to foreign exchange rate fluctuations, the Company employs a hedging program with a forward outlook of up to two years for major foreign-currency-denominated operating expenses. The outstanding forward currency exchange contracts expire at various dates through May 2020 . 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 June 30, 2018 , all of the forward foreign currency exchange contracts were designated and qualified as cash flow hedges and the effective portion of the gain or loss on the forward contracts was reported as a component of other comprehensive income (loss) and reclassified into net income in the same period during which the hedged transaction affects earnings. The estimated amount of such gains or losses as of June 30, 2018 that is expected to be reclassified into earnings was not material. The ineffective portion of the gains or losses on the forward contracts was immaterial and 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 entered into interest rate swap contracts with certain independent financial institutions to manage interest rate risks related to fixed interest rate expenses from its 2024 Notes and floating interest rate income from its investments in marketable debt securities. See “Note 10. Debt and Credit Facility” for more discussion related to interest rate swap contracts. The interest rate swap contracts were designated and qualified as fair value hedges of the 2024 Notes, and were separately accounted for as a derivative. The interest rate swap contracts and the 2024 Notes were initially measured at fair value. Any subsequent changes in fair values of the interest rate swap contracts and the 2024 Notes will be recorded in the Company’s consolidated balance sheets. During the three months ended June 30, 2018 , the net change in fair values of the interest rate swap contracts and the underlying 2024 Notes was $7.4 million , which was recorded as a derivative liability for the interest rate swap contacts and also a reduction from the carrying amount of 2024 Notes. There was no ineffectiveness during all periods presented. The Company had the following derivative instruments as of June 30, 2018 and March 31, 2018 , located on the condensed consolidated balance sheets, utilized for risk management purposes detailed above: Foreign Exchange Contracts Asset Derivatives Liability Derivatives (In thousands) Balance Sheet Location Fair Value Balance Sheet Location Fair Value June 30, 2018 Prepaid expenses and other current assets $ 167 Other accrued liabilities $ 5,040 March 31, 2018 Prepaid expenses and other current assets $ 2,922 Other accrued liabilities $ 12 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 sheets for all periods presented. The following table summarizes the effect of derivative instruments on the condensed consolidated statements of income for the first quarter of fiscal 2019 and 2018 : Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging) $ (5,909 ) $ 1,086 Amount of gains (losses) reclassified from accumulated other comprehensive income into income (effective portion) * $ (430 ) $ 357 Amount of gains (losses) recorded (ineffective portion) * $ (11 ) $ (19 ) * Recorded in interest and other income (expense), net within the condensed consolidated statements of income.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	3 Months Ended
	Jun. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company’s equity incentive plans are broad-based, long-term retention programs that cover employees, consultants and non-employee directors of the Company. These plans are intended to attract and retain talented employees, consultants and non-employee directors and to provide such persons with a proprietary interest in the Company. Stock-Based Compensation The following table summarizes stock-based compensation expense related to stock awards granted under the Company’s equity incentive plans and rights to acquire stock granted under the Company’s Employee Stock Purchase Plan (ESPP): Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Stock-based compensation included in: Cost of revenues $ 2,035 $ 2,150 Research and development 20,930 17,466 Selling, general and administrative 12,643 12,420 $ 35,608 $ 32,036 Employee Stock Option Plans The types of awards allowed under the 2007 Equity Incentive Plan (2007 Equity Plan) include incentive stock options, non-qualified stock options, restricted stock units (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; however, there was no issuance of stock options during the first quarter of fiscal 2019 and the entire fiscal 2018 . The Company's stock-based compensation expenses related to options during the first quarter of fiscal 2019 and the number of options outstanding as of June 30, 2018 were not material. As of June 30, 2018 , 11.2 million shares remained available for grant under the 2007 Equity Plan. The total pre-tax intrinsic value of options exercised during the three months ended June 30, 2018 and July 1, 2017 was $220 thousand and $2.8 million , respectively. This intrinsic value represents the difference between the exercise price and the fair market value of the Company’s common stock on the date of exercise. RSU Awards A summary of the Company’s RSU activity and related information is as follows: RSUs Outstanding (Shares in thousands) Number of Shares Weighted-Average Grant-Date Fair Value Per Share April 1, 2017 6,988 $ 42.93 Granted 3,718 $ 60.18 Vested (3,016 ) $ 43.30 Cancelled (701 ) $ 48.16 March 31, 2018 6,989 $ 51.39 Granted 261 $ 65.69 Vested (212 ) $ 53.68 Cancelled (128 ) $ 50.50 June 30, 2018 6,910 $ 51.84 The estimated fair values of RSUs were calculated based on the market price of Xilinx common stock on the date of grant, reduced by the present value of dividends expected to be paid on Xilinx common stock prior to vesting. The per share weighted-average fair value of RSUs granted during the first quarter of fiscal 2019 was $65.69 ( $57.99 for the first quarter of fiscal 2018 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended June 30, 2018 July 1, 2017 Risk-free interest rate 2.7 % 1.7 % Dividend yield 2.1 % 2.3 % For the majority of RSUs 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 the Company pays in cash to the appropriate taxing authorities on behalf of the Company's employees. During the first three months of fiscal 2019 and 2018 , the Company withheld $5.5 million and $25.6 million worth of RSU awards, respectively, to satisfy the employees’ tax obligations. During the first three months of fiscal 2019 , the Company realized an immaterial amount of excess tax benefits in the condensed consolidated statements of income as a component of the provision for income taxes. During the first three months of fiscal 2018 , the Company realized tax benefits of $11.6 million . Employee Stock Purchase Plan The fair values of stock purchase plan rights under the Company’s ESPP were estimated using the Black-Scholes option pricing model. Under the Company’s ESPP, shares are only issued during the second and fourth quarters of each fiscal year. Therefore, no shares were issued during the first quarter of fiscal 2019 or 2018 . The next scheduled purchase under the ESPP is in the second quarter of fiscal 2019 . As of June 30, 2018 , 9.3 million shares were available for future issuance under the Company's ESPP.

Net Income Per Common Share

Net Income Per Common Share	3 Months Ended
	Jun. 30, 2018
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 information on the condensed consolidated statements of income, and there are no reconciling items in the numerator used to compute the diluted net income per common share. The following table summarizes the computation of basic and diluted net income per common share: (In thousands, except per share amounts) June 30, 2018 July 1, 2017 Net income available to common stockholders $ 190,038 $ 157,244 Weighted average common shares outstanding-basic 252,682 247,911 Dilutive effect of employee equity incentive plans 3,253 3,817 Dilutive effect of 2017 Convertible Notes and warrants — 14,069 Weighted average common shares outstanding-diluted 255,935 265,797 Basic net income per common share $ 0.75 $ 0.63 Diluted net income per common share $ 0.74 $ 0.59 The total shares used in the denominator of the diluted net income per common share calculation include potentially dilutive common equivalent shares outstanding that are not included in basic net income per common share calculation. The diluted shares were calculated by applying the treasury stock method to the impact of the equity incentive plans, the incremental shares issuable assuming conversion of the Company's $600.0 million principal amount of 2.625% convertible notes issued in June 2010 (2017 Convertible Notes), before its maturity on June 15, 2017 , and exercise of warrants on a weighted-average outstanding basis, before the final settlements during the third quarter of fiscal 2018. The 2017 Convertible Notes matured during the first quarter of fiscal 2018, and the Company exercised its call options to neutralize the dilutive effect of the incremental shares from the 2017 Convertible Notes. Because the number of diluted shares in the above table for the three months ended July 1, 2017 was calculated based on a weighted-average outstanding basis, it included approximately 6.0 million shares of dilutive impact from the 2017 Convertible Notes through the maturity date. Such impact will no longer be applicable in future periods. Outstanding stock options and RSUs under the Company's stock award plans to purchase approximately 366 thousand and 152 thousand shares for the first quarter of fiscal 2019 and 2018 , respectively, were excluded from the diluted net income per common share calculation by applying the treasury stock method, as their inclusion would have been antidilutive. 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.

Inventories

Inventories	3 Months Ended
	Jun. 30, 2018
Inventory Disclosure [Abstract]
Inventory Disclosure [Text Block]	Inventories Inventories are stated at the lower of actual cost (determined using the first-in, first-out method), or market (estimated net realizable value) and are comprised of the following: (In thousands) June 30, 2018 March 31, 2018 Raw materials $ 17,405 $ 14,674 Work-in-process 169,926 167,039 Finished goods 59,670 54,364 $ 247,001 $ 236,077

Debt and Credit Facility

Debt and Credit Facility	3 Months Ended
	Jun. 30, 2018
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt and Credit Facility 2019 Notes and 2021 Notes On March 12, 2014, the Company issued the 2019 Notes and 2021 Notes at a discounted price of 99.477% and 99.281% of par, respectively. Interest on the 2019 Notes and 2021 Notes is payable semi-annually on March 15 and September 15. The Company received net proceeds of $990.1 million from issuance of the 2019 Notes and 2021 Notes, after the debt discount and deduction of debt issuance costs. The debt discounts and issuance costs are amortized to interest expense over the terms of the 2019 Notes and 2021 Notes. As of June 30, 2018 , the remaining term of the 2019 Notes and 2021 Notes are 0.7 years and 2.7 years respectively. The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of June 30, 2018 and March 31, 2018 : (In thousands) June 30, 2018 March 31, 2018 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (365 ) (501 ) Unamortized debt issuance costs associated with 2019 Notes (228 ) (313 ) Carrying value of the 2019 Notes 499,407 499,186 Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,461 ) (1,593 ) Unamortized debt issuance costs associated with 2021 Notes (651 ) (711 ) Carrying value of the 2021 Notes $ 497,888 $ 497,696 Total carrying value $ 997,295 $ 996,882 Interest expense related to the 2019 Notes and 2021 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Contractual coupon interest $ 6,406 $ 6,406 Amortization of debt issuance costs 146 146 Amortization of debt discount, net 268 260 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,820 $ 6,812 2024 Notes On May 30, 2017, the Company issued the 2024 Notes at a discounted price of 99.887% of par. Interest on the 2024 Notes is payable semi-annually on June 1 and December 1. The Company received $745.2 million from the issuance of the 2024 Notes, after the debt discount and deduction of debt issuance costs. The debt discounts and issuance costs are amortized to interest expense over the term of the 2024 Notes. As of June 30, 2018 , the remaining term of the 2024 Notes is approximately 6.0 years. In relation to the issuance of the 2024 Notes, the Company entered into interest rate swap contracts with certain independent financial institutions, whereby the Company pays on a semi-annual basis, a variable interest rate equal to the three-month London Interbank Offered Rate (LIBOR) plus 91.43 bps , and receives on a semi-annual basis, interest income at a fixed interest rate of 2.950% . The Company incurred a net interest expense of $851 thousand for the three months ended June 30, 2018 and earned a net interest income of $643 thousand for the three months ended July 1, 2017 , from the interest rate swap contracts, which was included in interest and other income (expense), net on the condensed consolidated statements of income. As of June 30, 2018 , the fair value of the interest rate swap contracts was $36.4 million , which was recorded in other long-term liabilities. The following table summarizes the carrying value of the 2024 Notes as of June 30, 2018 and March 31, 2018 : (In thousands) June 30, 2018 March 31, 2018 Principal amount of the 2024 Notes $ 750,000 $ 750,000 Unamortized discount of the 2024 Notes (727 ) (755 ) Unamortized debt issuance costs associated with 2024 Notes (3,358 ) (3,500 ) Carrying Value of the 2024 Notes $ 745,915 $ 745,745 Fair value hedge adjustment — interest rate swap contracts (36,416 ) (29,001 ) Net carrying value of the 2024 Notes $ 709,499 $ 716,744 Interest expense related to the 2024 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Contractual coupon interest (including interest rate swap, net) $ 6,382 $ 1,322 Amortization of debt issuance costs 142 47 Amortization of debt discount, net 28 10 Total interest expense related to the 2024 Notes $ 6,552 $ 1,379 Revolving Credit Facility On December 7, 2016 , the Company entered into a $400.0 million senior unsecured revolving credit facility that, upon certain conditions, may be extended by an additional $150.0 million , with a syndicate of banks (expiring in December 2021 ). Borrowings under the credit facility will bear interest at a benchmark rate plus an applicable margin based upon the Company’s credit rating. In connection with the credit facility, the Company is required to maintain certain financial and nonfinancial covenants. As of June 30, 2018 , the Company had made no borrowings under this credit facility and was not in violation of any of the covenants.

Common Stock Repurchase Program

Common Stock Repurchase Program	3 Months Ended
	Jun. 30, 2018
Stockholders' Equity Note [Abstract]
Common Stock and Debentures Repurchase Program [Text Block]	Common Stock Repurchase Program The Board of Directors (Board) 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. On May 16, 2016, the Board authorized the repurchase of up to $1.00 billion of the Company's common stock and debentures (2016 Repurchase Program). The 2016 Repurchase Program has no stated expiration date. On May 16, 2018, the Board authorized the 2018 Repurchase Program to repurchase the Company's common stock and debentures up to $500.0 million . Through June 30, 2018 , the Company had used $929.4 million of the $1.00 billion authorized under the 2016 Repurchase Program, leaving $70.6 million available for future repurchases. The Company’s current policy is to retire all repurchased shares, and consequently, no treasury shares were held as of June 30, 2018 and March 31, 2018 . During the first quarter of fiscal 2019 , the Company repurchased 2.1 million shares of common stock for a total of $136.8 million and during the first quarter of fiscal 2018 , the Company repurchased 1.0 million shares of common stock for a total of $67.1 million .

Interest and Other Expense, Net

Interest and Other Expense, Net	3 Months Ended
	Jun. 30, 2018
Other Income and Expenses [Abstract]
Interest and Other Expense, Net	Interest and Other Income (Expense), Net The components of interest and other income (expense), net are as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Interest income $ 17,397 $ 13,414 Interest expense (13,372 ) (12,081 ) Other income (expense), net (6,872 ) 506 Total interest and other income (expense), net $ (2,847 ) $ 1,839

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Loss Comprehensive income (loss) is defined as the change in equity of a company during a period from transactions and other events and circumstances from non-owner sources. The components of the Company's accumulated other comprehensive loss are as follows: (In thousands) June 30, 2018 March 31, 2018 Accumulated unrealized losses on available-for-sale securities, net of tax $ (23,156 ) $ (29,844 ) Accumulated unrealized gains (losses) on hedging transactions, net of tax (4,386 ) 1,674 Accumulated cumulative translation adjustment, net of tax (8,390 ) (6,339 ) Total accumulated other comprehensive loss $ (35,932 ) $ (34,509 ) The related tax effects of other comprehensive income (loss) were not material for all periods presented.

Income Taxes

Income Taxes	3 Months Ended
	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a tax provision of $22.9 million for the first quarter of fiscal 2019 as compared to $13.7 million in the same prior year period, representing effective tax rates of 11% and 8% , respectively. The prior year balance has been restated to reflect the retrospective application of the current authoritative guidance for revenue recognition. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements" for additional detail. On December 22, 2017, the Tax Cuts and Jobs Act (TCJA) was enacted into law. The TCJA provides numerous significant tax law changes including the reduction of the U.S. federal corporate income tax rate from 35% to 21%, the requirement for companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and the creation of new taxes on certain foreign-sourced earnings. Some provisions of the TCJA began to impact the Company in fiscal 2018, while other provisions impact the Company beginning in fiscal 2019. In accordance with Staff Accounting Bulletin (SAB) 118, the Company has recorded provisional amounts recognizing the effect of the tax law changes in prior periods, but may adjust those provisional amounts during a measurement period that is similar to the measurement period used when accounting for business combinations. As of June 30, 2018, the Company has not adjusted the provisional estimate recorded in prior periods for effects from the one-time transition tax. The amount recorded for the one-time transition tax remains provisional as the Company has not yet finalized its calculation of the total post-1986 earnings and profits (E&P) for its foreign subsidiaries. Additionally, the Company will continue to evaluate the impact of the tax law change as it relates to providing U.S. taxes on its investments in foreign subsidiaries. Since U.S. federal taxes have been recognized through the one-time transition tax on all accumulated and previously untaxed foreign earnings through December 31, 2017, the Company does not intend to permanently reinvest those earnings. The difference between the U.S. federal statutory tax rate of 21% and the Company's effective tax rate in the first quarter of fiscal 2019 was primarily due to the beneficial impact of income earned in lower tax rate jurisdictions, which was partially offset by the new tax on low-taxed income from foreign subsidiaries. The difference between the U.S. federal statutory tax rate of 35% and the Company’s effective tax rate in the first quarter of fiscal 2018 was primarily due to income earned in lower tax rate jurisdictions, for which no U.S. income tax had been provided, as the Company had intended to permanently reinvest the earnings outside of the U.S. The Company’s total gross unrecognized tax benefits as of June 30, 2018 , determined in accordance with FASB authoritative guidance for measuring uncertain tax positions, increased by $825 thousand in the first quarter of fiscal 2019 to $126.0 million . The total amount of unrecognized tax benefits that, if realized in a future period, would favorably affect the effective tax rate was $16.0 million as of June 30, 2018 . Another $85.5 million would increase additional paid-in capital. The $85.5 million relates to an additional deduction claimed on federal and state amended tax returns for fiscal 2014 for repurchase premium paid in that year in connection with the early redemption of the Company’s 3.125% Junior Convertible debenture due March 15, 2037. It is reasonably possible that changes to the Company's 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 statutes of limitations have closed for U.S. federal income tax purposes for years through fiscal 2014, for U.S. state income tax purposes for years through fiscal 2010, and for Ireland income tax purposes for years through fiscal 2013.

Commitments

Commitments	3 Months Ended
	Jun. 30, 2018
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 April 2029 . 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. Xilinx also leases cars under non-cancelable operating leases that expire at various dates through May 2022. Approximate future minimum lease payments under non-cancelable operating leases are as follows: Fiscal (In thousands) 2019 (remaining nine months) $ 6,115 2020 9,216 2021 7,198 2022 5,923 2023 4,798 Thereafter 30,708 Total $ 63,958 Aggregate future rental income to be received, which includes rents from both owned and leased property, totaled $12.0 million as of June 30, 2018 . Rent expense, net of rental income, under all operating leases was $1.0 million and $1.2 million for the three months ended June 30, 2018 and July 1, 2017 , respectively. Rental income was not material for the first quarter of fiscal 2019 or 2018 . Other commitments as of June 30, 2018 totaled $136.5 million and consisted of purchases of inventory and other non-cancelable purchase obligations related to subcontractors that manufacture silicon wafers and provide assembly and some test services. The Company expects to receive and pay for these materials and services in the next three to six months, as the products meet delivery and quality specifications. Additionally, as of June 30, 2018 , the Company also had $18.9 million of non-cancelable license obligations to providers of electronic design automation software and hardware/software maintenance and $33.7 million commitments primarily related to open purchase orders from ordinary operations. These commitments expire at various dates through December 2022 .

Product Warranty and Indemnific

Product Warranty and Indemnification (Notes)	3 Months Ended
	Jun. 30, 2018
Product Warranties Disclosures [Abstract]
Product Warranty Disclosure [Text Block]	Product Warranty and Indemnification The Company generally sells products with a limited warranty for product quality. The Company provides an accrual for known product issues if a loss is probable and can be reasonably estimated. As of the end of the first quarter of fiscal 2019 and the end of fiscal 2018 , the accrual balances of the product warranty liability were 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 the Company's hardware products experience epidemic failure. To a lesser extent, the Company may from time-to-time offer limited indemnification with respect to its software products. The terms and conditions of these indemnity obligations are limited by contract, which obligations are typically perpetual from the effective date of the agreement. The Company has historically received only a limited number of requests for indemnification under these provisions and has not made any significant payments pursuant to these provisions. The Company cannot estimate the maximum amount of potential future payments, if any, that the Company may be required to make as a result of these obligations due to the limited history of indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim and indemnification provision. However, there can be no assurances that the Company will not incur any financial liabilities in the future as a result of these obligations.

Contingencies

Contingencies	3 Months Ended
	Jun. 30, 2018
Loss Contingency [Abstract]
Contingencies	Contingencies Patent Litigation On February 1, 2017, a patent infringement lawsuit was filed by Godo Kaisha IP Bridge 1 (IP Bridge) against the Company in the U.S. District Court for the Eastern District of Texas (Godo Kaisha IP Bridge 1 v. Xilinx, Inc., Case. No. 2:17-cv-00100). The lawsuit pertains to two patents and IP Bridge seeks unspecified damages, interest, attorneys’ fees, costs, and a permanent injunction or an on-going royalty. On September 14, 2017, the court granted the Company’s motion to transfer venue and the matter is now pending before the U.S. District Court for the Northern District of California. The Company is unable to estimate its range of possible loss, if any, in this matter at this time. On March 17, 2017, a patent infringement lawsuit was filed by Anza Technology, Inc. (Anza) against the Company in the U.S. District Court for the District of Colorado (Anza Technology, Inc. v. Xilinx, Inc., Case No. 1:17-cv-00687). The lawsuit pertains to three patents and Anza seeks unspecified damages, attorney fees, interest, costs, and expenses. On October 27, 2017, the court granted the Company’s motion to transfer venue and the matter is now pending before the U.S. District Court for the Northern District of California. The Company is unable to estimate its range of possible loss, if any, in this matter at this time. The Company intends to continue to protect and defend its IP vigorously. Other Matters On June 11, 2015, John P. Neblett, as Chapter 7 Trustee of Valley Forge Composite Technologies, Inc., filed a complaint against Xilinx and others in the U.S. Bankruptcy Court for the Middle District of Pennsylvania (Bankruptcy No. 1:13-bk-05253-JJT). The complaint alleges causes of actions against Xilinx for negligence and civil conspiracy relating to alleged violations of U.S. export laws. It seeks at least $50.0 million in damages, together with punitive damages, from the defendants. On September 21, 2015, the action was withdrawn from the U.S. Bankruptcy Court for the Middle District of Pennsylvania and transferred to the U.S. District Court for the Eastern District of Kentucky. On November 2, 2015, Xilinx, along with other defendants, filed a motion to dismiss the complaint. On November 3, 2015, Xilinx filed a motion for sanctions pursuant to Federal Rule of Civil Procedure 11. On June 27, 2016, the Court denied both motions. On September 11, 2017, Xilinx, along with other defendants, filed motions for summary judgment seeking to dispose of all claims against them. On July 3, 2018, the Court granted both of Xilinx’s Motions for Summary Judgment, disposing of all claims asserted against Xilinx. 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 Acquisition-Relate

Goodwill and Acquisition-Related Intangibles	3 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquisition-Related Intangibles	Goodwill and Acquisition-Related Intangibles As of June 30, 2018 and March 31, 2018 , the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows: Weighted-Average (In thousands) June 30, 2018 March 31, 2018 Amortization Life Goodwill $ 162,421 $ 162,421 Core technology, gross 82,480 82,480 Less accumulated amortization (78,885 ) (78,562 ) Core technology, net 3,595 3,918 4.8 years Other intangibles, gross 46,966 46,966 Less accumulated amortization (46,798 ) (46,761 ) Other intangibles, net 168 205 2.6 years Total acquisition-related intangibles, gross 129,446 129,446 Less accumulated amortization (125,683 ) (125,323 ) Total acquisition-related intangibles, net $ 3,763 $ 4,123 Amortization expense for acquisition-related intangibles for the three months ended June 30, 2018 and July 1, 2017 was $360 thousand and $705 thousand , respectively. Based on the carrying value of acquisition-related intangibles recorded as of June 30, 2018 , and assuming no subsequent acquisition or impairment of the underlying assets, the annual amortization expense for acquisition-related intangibles is expected to be as follows: Fiscal (In thousands) 2019 (remaining nine months) $ 893 2020 1,160 2021 1,137 2022 573 Total $ 3,763

Subsequent Events (Notes)

Subsequent Events (Notes)	3 Months Ended
	Jun. 30, 2018
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On July 17, 2018, the Company announced the acquisition of DeePhi Technology Co., Ltd, a leading artificial intelligence and machine learning company. On July 24, 2018, the U.S. Court of Appeals for the Ninth Circuit reversed a 2015 decision of the U.S. Tax Court that had found U.S. Treasury Regulations requiring the inclusion of stock-based compensation in intercompany cost-sharing arrangements to be invalid. The case at issue was Altera Corp. v. Commissioner. The Company is currently evaluating the impact of this decision on its financial statements and is unable to estimate the impact at this time. On July 24, 2018 , the Company’s Board of Directors declared a cash dividend of $0.36 per common share for the second quarter of fiscal 2019 . The dividend is payable on August 28, 2018 to stockholders of record on August 8, 2018 .

Derivative Financial Instrume26

Derivative Financial Instruments Derivative Financial Instruments (Policies)	3 Months Ended
	Jun. 30, 2018
Accounting Policies [Abstract]
Derivatives	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.

Recent Accounting Changes and27

Recent Accounting Changes and Accounting Pronouncements Recent Accounting Standards (Tables)	3 Months Ended
	Jun. 30, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The impact on the Company's previously reported condensed consolidated statement of income resulting from the adoption of the authoritative guidance is as follows: Three months ended July 1, 2017 (In thousands, except per share amounts) As Reported Adjustment As Adjusted Net revenues $ 615,446 $ (12,636 ) $ 602,810 Cost of revenues 192,095 (1,271 ) 190,824 Gross margin 423,351 (11,365 ) 411,986 Operating expenses: Research and development 153,051 — 153,051 Selling, general and administrative 89,175 — 89,175 Amortization of acquisition-related intangibles 705 — 705 Total operating expenses 242,931 — 242,931 Operating income 180,420 (11,365 ) 169,055 Interest and other income, net 1,839 — 1,839 Income before income taxes 182,259 (11,365 ) 170,894 Provision for income taxes 15,014 (1,364 ) 13,650 Net income $ 167,245 $ (10,001 ) $ 157,244 Net income per common share: Basic $ 0.67 $ (0.04 ) $ 0.63 Diluted $ 0.63 $ (0.04 ) $ 0.59 Shares used in per share calculations: Basic 247,911 247,911 Diluted 265,797 265,797 The impact on the Company's previously reported condensed consolidated balance sheet line items affected by the adoption of the authoritative guidance is as follows: March 31, 2018 (In thousands) As Reported Adjustment As Adjusted Accounts receivable $ 372,144 $ 10,102 $ 382,246 Other assets 342,644 (5,242 ) 337,402 Deferred income on shipments to distributors 25,166 (25,166 ) — Other accrued liabilities 59,772 (92 ) 59,680 Retained earnings 1,483,538 30,118 1,513,656

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of June 30, 2018 and March 31, 2018 : June 30, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 458,706 $ — $ — $ 458,706 Financial institution securities — 349,850 — 349,850 Non-financial institution securities — 350,624 — 350,624 U.S. government and agency securities 114,664 206,945 — 321,609 Foreign government and agency securities — 130,622 — 130,622 Short-term investments: Financial institution securities — 249,982 — 249,982 Non-financial institution securities — 263,922 — 263,922 U.S. government and agency securities 3,647 96,105 — 99,752 Foreign government and agency securities — 43,783 — 43,783 Mortgage-backed securities — 796,953 — 796,953 Asset-backed securities — 89,028 — 89,028 Commercial mortgage-backed securities — 143,389 — 143,389 Long-term investments: Debt mutual funds — 85,633 — 85,633 Marketable equity securities 6,067 — — 6,067 Total assets measured at fair value $ 583,084 $ 2,806,836 $ — $ 3,389,920 Liabilities Derivative financial instruments, net $ — $ 41,289 $ — $ 41,289 Total liabilities measured at fair value $ — $ 41,289 $ — $ 41,289 Net assets measured at fair value $ 583,084 $ 2,765,547 $ — $ 3,348,631 March 31, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities — 359,901 — 359,901 Non-financial institution securities — 242,904 — 242,904 U.S. government and agency securities 996 34,999 — 35,995 Foreign government and agency securities — 179,957 — 179,957 Short-term investments: Financial institution securities — 75,000 — 75,000 Non-financial institution securities — 81,939 — 81,939 U.S. government and agency securities 3,639 19,008 — 22,647 Mortgage-backed securities — 844,397 — 844,397 Asset-backed securities — 91,389 — 91,389 Commercial mortgage-backed securities — 152,870 — 152,870 Long-term investments: Debt mutual funds — 89,670 — 89,670 Marketable equity securities 8,226 — 8,226 Total assets measured at fair value $ 1,304,752 $ 2,172,034 $ — $ 3,476,786 Liabilities Derivative financial instruments, net $ — $ 26,091 $ — $ 26,091 Total liabilities measured at fair value $ — $ 26,091 $ — $ 26,091 Net assets measured at fair value $ 1,304,752 $ 2,145,943 $ — $ 3,450,695
Changes in Level 3 instruments measured at fair value on a recurring basis	As of June 30, 2018 and July 1, 2017 , the Company held no marketable securities measured at fair value using Level 3 inputs.

Financial Instruments (Tables)

Financial Instruments (Tables)	3 Months Ended
	Jun. 30, 2018
Investments, All Other Investments [Abstract]
Available-for-sale securities	The following is a summary of cash equivalents and available-for-sale securities as of the end of the periods presented: June 30, 2018 March 31, 2018 (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 $ 458,706 $ — $ — $ 458,706 $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities 599,832 — — 599,832 434,901 — — 434,901 Non-financial institution securities 615,958 1 (1,413 ) 614,546 326,219 — (1,376 ) 324,843 U.S. government and agency securities 421,679 9 (327 ) 421,361 58,913 1 (272 ) 58,642 Foreign government and agency securities 174,405 — — 174,405 179,957 — — 179,957 Mortgage-backed securities 820,305 580 (23,932 ) 796,953 866,048 660 (22,311 ) 844,397 Asset-backed securities 90,426 12 (1,410 ) 89,028 92,751 16 (1,378 ) 91,389 Debt mutual funds 101,350 — (15,717 ) 85,633 101,350 — (11,680 ) 89,670 Commercial mortgage- backed securities 146,984 — (3,595 ) 143,389 156,296 1 (3,427 ) 152,870 Marketable equity securities 7,500 — (1,433 ) 6,067 7,500 726 — 8,226 $ 3,437,145 $ 602 $ (47,827 ) $ 3,389,920 $ 3,515,826 $ 1,404 $ (40,444 ) $ 3,476,786
Fair values and gross unrealized losses of the investments	The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of June 30, 2018 and March 31, 2018 : June 30, 2018 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 $ 57,501 $ (1,193 ) $ 7,910 $ (220 ) $ 65,411 $ (1,413 ) U.S. government and agency securities 52,351 (224 ) 4,586 (103 ) 56,937 (327 ) Mortgage-backed securities 424,784 (10,639 ) 340,733 (13,293 ) 765,517 (23,932 ) Asset-backed securities 53,832 (944 ) 33,333 (466 ) 87,165 (1,410 ) Debt mutual funds — — 85,633 (15,717 ) 85,633 (15,717 ) Commercial mortgage- backed securities 84,596 (1,830 ) 57,875 (1,765 ) 142,471 (3,595 ) Marketable equity securities 6,067 (1,433 ) — — 6,067 (1,433 ) $ 679,131 $ (16,263 ) $ 530,070 $ (31,564 ) $ 1,209,201 $ (47,827 ) March 31, 2018 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 $ 69,780 $ (1,146 ) $ 8,344 $ (230 ) $ 78,124 $ (1,376 ) U.S. government and agency securities 13,471 (176 ) 9,176 (96 ) 22,647 (272 ) Mortgage-backed securities 510,988 (11,048 ) 299,663 (11,263 ) 810,651 (22,311 ) Asset-backed securities 57,128 (876 ) 32,696 (502 ) 89,824 (1,378 ) Debt mutual funds — — 89,670 (11,680 ) 89,670 (11,680 ) Commercial mortgage- backed securities 95,435 (1,760 ) 56,051 (1,667 ) 151,486 (3,427 ) $ 746,802 $ (15,006 ) $ 495,600 $ (25,438 ) $ 1,242,402 $ (40,444 )
Amortized cost and estimated fair value of marketable debt securities	June 30, 2018 (In thousands) Amortized Estimated Due in one year or less $ 1,758,865 $ 1,758,593 Due after one year through five years 176,391 172,941 Due after five years through ten years 148,349 143,894 Due after ten years 785,984 764,086 $ 2,869,589 $ 2,839,514
Information on sale of available-for-sale securities	Certain information related to available-for-sale securities is as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Proceeds from sale of available-for-sale securities $ 895 $ 119,922 Gross realized gains on sale of available-for-sale securities $ 96 $ 832 Gross realized losses on sale of available-for-sale securities (47 ) (386 ) Net realized gains on sale of available-for-sale securities $ 49 $ 446 Amortization of premiums on available-for-sale securities $ 2,491 $ 6,823

Derivative Financial Instrume30

Derivative Financial Instruments (Tables)	3 Months Ended
	Jun. 30, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Forward currency exchange contracts outstanding	As of June 30, 2018 and March 31, 2018 , the Company had the following outstanding forward currency exchange contracts (in notional amount), which were derivative financial instruments: (In thousands and U.S. dollars) June 30, 2018 March 31, 2018 Singapore Dollar $ 26,392 $ 24,914 Euro 38,591 38,987 Indian Rupee 64,959 62,472 British Pound 8,125 8,155 Japanese Yen 3,882 3,859 Chinese Yuan 13,247 8,260 $ 155,196 $ 146,647
Derivative Instruments Located on Condensed Consolidated Balance Sheet	The Company had the following derivative instruments as of June 30, 2018 and March 31, 2018 , located on the condensed consolidated balance sheets, utilized for risk management purposes detailed above: Foreign Exchange Contracts Asset Derivatives Liability Derivatives (In thousands) Balance Sheet Location Fair Value Balance Sheet Location Fair Value June 30, 2018 Prepaid expenses and other current assets $ 167 Other accrued liabilities $ 5,040 March 31, 2018 Prepaid expenses and other current assets $ 2,922 Other accrued liabilities $ 12
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 first quarter of fiscal 2019 and 2018 : Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging) $ (5,909 ) $ 1,086 Amount of gains (losses) reclassified from accumulated other comprehensive income into income (effective portion) * $ (430 ) $ 357 Amount of gains (losses) recorded (ineffective portion) * $ (11 ) $ (19 ) * Recorded in interest and other income (expense), net within the condensed consolidated statements of income.

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	3 Months Ended
	Jun. 30, 2018
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 (In thousands) June 30, 2018 July 1, 2017 Stock-based compensation included in: Cost of revenues $ 2,035 $ 2,150 Research and development 20,930 17,466 Selling, general and administrative 12,643 12,420 $ 35,608 $ 32,036
Schedule of Share-based compensation, restricted stock units, valuation assumption [Table Text Block]	The per share weighted-average fair value of RSUs granted during the first quarter of fiscal 2019 was $65.69 ( $57.99 for the first quarter of fiscal 2018 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended June 30, 2018 July 1, 2017 Risk-free interest rate 2.7 % 1.7 % Dividend yield 2.1 % 2.3 %
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 April 1, 2017 6,988 $ 42.93 Granted 3,718 $ 60.18 Vested (3,016 ) $ 43.30 Cancelled (701 ) $ 48.16 March 31, 2018 6,989 $ 51.39 Granted 261 $ 65.69 Vested (212 ) $ 53.68 Cancelled (128 ) $ 50.50 June 30, 2018 6,910 $ 51.84

Net Income Per Common Share Net

Net Income Per Common Share Net Income Per Common Share (Tables)	3 Months Ended
	Jun. 30, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table summarizes the computation of basic and diluted net income per common share: (In thousands, except per share amounts) June 30, 2018 July 1, 2017 Net income available to common stockholders $ 190,038 $ 157,244 Weighted average common shares outstanding-basic 252,682 247,911 Dilutive effect of employee equity incentive plans 3,253 3,817 Dilutive effect of 2017 Convertible Notes and warrants — 14,069 Weighted average common shares outstanding-diluted 255,935 265,797 Basic net income per common share $ 0.75 $ 0.63 Diluted net income per common share $ 0.74 $ 0.59

Inventories Inventories (Tables

Inventories Inventories (Tables)	3 Months Ended
	Jun. 30, 2018
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) June 30, 2018 March 31, 2018 Raw materials $ 17,405 $ 14,674 Work-in-process 169,926 167,039 Finished goods 59,670 54,364 $ 247,001 $ 236,077

Debt and Credit Facility (Table

Debt and Credit Facility (Tables)	3 Months Ended
	Jun. 30, 2018
2019 and 2021 Notes Payable [Member]
Schedule of Debt Instruments [Line Items]
Carrying values of liability and equity components of debentures	The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of June 30, 2018 and March 31, 2018 : (In thousands) June 30, 2018 March 31, 2018 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (365 ) (501 ) Unamortized debt issuance costs associated with 2019 Notes (228 ) (313 ) Carrying value of the 2019 Notes 499,407 499,186 Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,461 ) (1,593 ) Unamortized debt issuance costs associated with 2021 Notes (651 ) (711 ) Carrying value of the 2021 Notes $ 497,888 $ 497,696 Total carrying value $ 997,295 $ 996,882
Interest Expense Related to Debentures [Table Text Block]	Interest expense related to the 2019 Notes and 2021 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Contractual coupon interest $ 6,406 $ 6,406 Amortization of debt issuance costs 146 146 Amortization of debt discount, net 268 260 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,820 $ 6,812
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Schedule of Debt Instruments [Line Items]
Carrying values of liability and equity components of debentures	The following table summarizes the carrying value of the 2024 Notes as of June 30, 2018 and March 31, 2018 : (In thousands) June 30, 2018 March 31, 2018 Principal amount of the 2024 Notes $ 750,000 $ 750,000 Unamortized discount of the 2024 Notes (727 ) (755 ) Unamortized debt issuance costs associated with 2024 Notes (3,358 ) (3,500 ) Carrying Value of the 2024 Notes $ 745,915 $ 745,745 Fair value hedge adjustment — interest rate swap contracts (36,416 ) (29,001 ) Net carrying value of the 2024 Notes $ 709,499 $ 716,744
Interest Expense Related to Debentures [Table Text Block]	Interest expense related to the 2024 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Contractual coupon interest (including interest rate swap, net) $ 6,382 $ 1,322 Amortization of debt issuance costs 142 47 Amortization of debt discount, net 28 10 Total interest expense related to the 2024 Notes $ 6,552 $ 1,379

Interest And Other Expense, N35

Interest And Other Expense, Net (Tables)	3 Months Ended
	Jun. 30, 2018
Other Income and Expenses [Abstract]
Components of interest and other expense, net	The components of interest and other income (expense), net are as follows: Three Months Ended (In thousands) June 30, 2018 July 1, 2017 Interest income $ 17,397 $ 13,414 Interest expense (13,372 ) (12,081 ) Other income (expense), net (6,872 ) 506 Total interest and other income (expense), net $ (2,847 ) $ 1,839

Accumulated Other Comprehensi36

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Jun. 30, 2018
Equity [Abstract]
Components of accumulated other comprehensive income (loss)	The components of the Company's accumulated other comprehensive loss are as follows: (In thousands) June 30, 2018 March 31, 2018 Accumulated unrealized losses on available-for-sale securities, net of tax $ (23,156 ) $ (29,844 ) Accumulated unrealized gains (losses) on hedging transactions, net of tax (4,386 ) 1,674 Accumulated cumulative translation adjustment, net of tax (8,390 ) (6,339 ) Total accumulated other comprehensive loss $ (35,932 ) $ (34,509 )

Commitments (Tables)

Commitments (Tables)	3 Months Ended
	Jun. 30, 2018
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) 2019 (remaining nine months) $ 6,115 2020 9,216 2021 7,198 2022 5,923 2023 4,798 Thereafter 30,708 Total $ 63,958

Goodwill and Acquisition-Rela38

Goodwill and Acquisition-Related Intangibles (Tables)	3 Months Ended
	Jun. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Gross and net amounts of goodwill and of acquisition-related intangibles	As of June 30, 2018 and March 31, 2018 , the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows: Weighted-Average (In thousands) June 30, 2018 March 31, 2018 Amortization Life Goodwill $ 162,421 $ 162,421 Core technology, gross 82,480 82,480 Less accumulated amortization (78,885 ) (78,562 ) Core technology, net 3,595 3,918 4.8 years Other intangibles, gross 46,966 46,966 Less accumulated amortization (46,798 ) (46,761 ) Other intangibles, net 168 205 2.6 years Total acquisition-related intangibles, gross 129,446 129,446 Less accumulated amortization (125,683 ) (125,323 ) Total acquisition-related intangibles, net $ 3,763 $ 4,123
Schedule of expected annual amortization expense for acquisition-related intangibles	Based on the carrying value of acquisition-related intangibles recorded as of June 30, 2018 , and assuming no subsequent acquisition or impairment of the underlying assets, the annual amortization expense for acquisition-related intangibles is expected to be as follows: Fiscal (In thousands) 2019 (remaining nine months) $ 893 2020 1,160 2021 1,137 2022 573 Total $ 3,763

Recent Accounting Changes and39

Recent Accounting Changes and Accounting Pronouncements Recent Accounting Standards (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017		Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net	$ 684,370	$ 602,810	[1]
Cost of Goods and Services Sold	206,888	190,824	[1]
Gross margin	477,482	411,986	[1]
Research and Development Expense	170,826	153,051
Selling, General and Administrative Expense	90,532	89,175
Amortization of acquisition-related intangibles	360	705
Operating Expenses	261,718	242,931
Operating income	215,764	169,055	[1]
Other Nonoperating Income (Expense)	(2,847)	1,839
Income before income taxes	212,917	170,894	[1]
Provision for income taxes	22,879	13,650	[1]
Net income	$ 190,038	$ 157,244	[1]
Earnings Per Share, Basic	$ 0.75	$ 0.63	[1]
Earnings Per Share, Diluted	$ 0.74	$ 0.59	[1]
Weighted Average Number of Shares Outstanding, Basic	252,682	247,911
Weighted Average Number of Shares Outstanding, Diluted	255,935	265,797
Accounts Receivable, Net, Current	$ 456,898			$ 382,246	[1]
Other assets	359,679			337,402	[1]
Deferred Income On Shipments To Distributors				0
Other accrued liabilities	56,696			59,680	[1]
Retained Earnings (Accumulated Deficit)	$ 1,457,467			1,513,656	[1]
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net		$ 615,446
Cost of Goods and Services Sold		192,095
Gross margin		423,351
Research and Development Expense		153,051
Selling, General and Administrative Expense		89,175
Amortization of acquisition-related intangibles		705
Operating Expenses		242,931
Operating income		180,420
Other Nonoperating Income (Expense)		1,839
Income before income taxes		182,259
Provision for income taxes		15,014
Net income		$ 167,245
Earnings Per Share, Basic		$ 0.67
Earnings Per Share, Diluted		$ 0.63
Accounts Receivable, Net, Current				372,144
Other assets				342,644
Deferred Income On Shipments To Distributors				25,166
Other accrued liabilities				59,772
Retained Earnings (Accumulated Deficit)				1,483,538
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net		$ (12,636)
Cost of Goods and Services Sold		(1,271)
Gross margin		(11,365)
Research and Development Expense		0
Selling, General and Administrative Expense		0
Amortization of acquisition-related intangibles		0
Operating Expenses		0
Operating income		(11,365)
Other Nonoperating Income (Expense)		0
Income before income taxes		(11,365)
Provision for income taxes		(1,364)
Net income		$ (10,001)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share		$ (0.04)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share		$ (0.04)
Accounts Receivable, Net, Current				10,102
Other assets				(5,242)
Deferred Income On Shipments To Distributors				(25,166)
Other accrued liabilities				(92)
Retained Earnings (Accumulated Deficit)				$ 30,118
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Recent Accounting Changes and40

Recent Accounting Changes and Accounting Pronouncements Accounting Standard Update 2016-01 (Details) - Accounting Standards Update 2016-01 [Member] $ in Millions	3 Months Ended
	Jun. 30, 2018USD ($)
Other Comprehensive Income (Loss) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 11
Deferred Tax Asset [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 2.6

Recent Accounting Changes and41

Recent Accounting Changes and Accounting Pronouncements Accounting Standards Update 2016 -16 (Details) $ in Millions	3 Months Ended
	Jun. 30, 2018USD ($)
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 13.8

Significant Customers and Con42

Significant Customers and Concentrations of Credit Risk (Details) - Customer	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018
Significant Customers and Concentrations of Credit Risk [Abstract]
Percentage of Accounts Receivable Accounted From Company Distributor One	70.00%		61.00%
Percentage of net revenues through resale of product from Company Distributor One	51.00%	41.00%
Number of End Customers Accounted For 10% or More of Net Revenues	0	0
Percentage of higher grade security investment in debt securities	91.00%
Percentage of Mortgage Backed Securities In Investment Portfolio	24.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Available-for-sale Securities, Noncurrent	$ 91,700	$ 97,896
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	3,389,920	3,476,786
Fair Value, Net Asset (Liability)	3,348,631	3,450,695
Fair Value, Measurements, Recurring [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	41,289	26,091
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	583,084	1,304,752
Fair Value, Net Asset (Liability)	583,084	1,304,752
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	2,806,836	2,172,034
Fair Value, Net Asset (Liability)	2,765,547	2,145,943
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	41,289	26,091
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Net Asset (Liability)	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
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
Assets measured at fair value	458,706	1,291,891
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
Assets measured at fair value	349,850	359,901
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
Assets measured at fair value	350,624	242,904
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
Assets measured at fair value	321,609	35,995
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
Assets measured at fair value	130,622	179,957
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
Assets measured at fair value	458,706	1,291,891
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	114,664	996
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	349,850	359,901
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
Assets measured at fair value	350,624	242,904
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
Assets measured at fair value	206,945	34,999
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
Assets measured at fair value	130,622	179,957
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	249,982	75,000
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
Assets measured at fair value	263,922	81,939
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
Assets measured at fair value	99,752	22,647
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
Assets measured at fair value	43,783
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	796,953	844,397
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	89,028	91,389
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	143,389	152,870
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	3,647	3,639
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
Assets measured at fair value	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
Assets measured at fair value	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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
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
Assets measured at fair value	249,982	75,000
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
Assets measured at fair value	263,922	81,939
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
Assets measured at fair value	96,105	19,008
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
Assets measured at fair value	43,783
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
Assets measured at fair value	796,953	844,397
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
Assets measured at fair value	89,028	91,389
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	143,389	152,870
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	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
Assets measured at fair value	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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	85,633	89,670
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	6,067	8,226
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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	6,067	8,226
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
Assets measured at fair value	85,633	89,670
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	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
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	41,289	26,091
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	41,289	26,091
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	$ 0	$ 0

Fair Value Measurements (Deta44

Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Noncurrent	$ 91,700	$ 97,896
Cost Method Investments, Fair Value Disclosure	49,600
Two And One Two Five Percent 2019 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000
Debt Instrument, Interest Rate, Stated Percentage	2.125%
Debt Instrument, Maturity Date	Mar. 15, 2019
Fair value of convertible notes	$ 498,000
Three Point Zero Percent 2021 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Debt Instrument, Maturity Date	Mar. 15, 2021
Fair value of convertible notes	$ 495,900
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 750,000
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Debt Instrument, Maturity Date	Jun. 1, 2024
Fair value of convertible notes	$ 713,400
Three Point Zero Percent 2021 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	500,000	500,000
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 750,000	750,000
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Two And One Two Five Percent 2019 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000	$ 500,000

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Available-for-sale securities
Amortized Cost	$ 3,437,145	$ 3,515,826
Gross Unrealized Gains	602	1,404
Gross Unrealized Losses	(47,827)	(40,444)
Estimated Fair Value	3,389,920	3,476,786
Money Market Funds [Member]
Available-for-sale securities
Amortized Cost	458,706	1,291,891
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	458,706	1,291,891
Financial institution securities [Member]
Available-for-sale securities
Amortized Cost	599,832	434,901
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	599,832	434,901
Non-financial institution securities [Member]
Available-for-sale securities
Amortized Cost	615,958	326,219
Gross Unrealized Gains	1	0
Gross Unrealized Losses	(1,413)	(1,376)
Estimated Fair Value	614,546	324,843
U.S. Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	421,679	58,913
Gross Unrealized Gains	9	1
Gross Unrealized Losses	(327)	(272)
Estimated Fair Value	421,361	58,642
Foreign Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	174,405	179,957
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	174,405	179,957
Mortgage-Backed Securities [Member]
Available-for-sale securities
Amortized Cost	820,305	866,048
Gross Unrealized Gains	580	660
Gross Unrealized Losses	(23,932)	(22,311)
Estimated Fair Value	796,953	844,397
Asset-backed Securities [Member]
Available-for-sale securities
Amortized Cost	90,426	92,751
Gross Unrealized Gains	12	16
Gross Unrealized Losses	(1,410)	(1,378)
Estimated Fair Value	89,028	91,389
Debt Mutual Fund [Member]
Available-for-sale securities
Amortized Cost	101,350	101,350
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(15,717)	(11,680)
Estimated Fair Value	85,633	89,670
Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	146,984	156,296
Gross Unrealized Gains	0	1
Gross Unrealized Losses	(3,595)	(3,427)
Estimated Fair Value	143,389	152,870
Equity Securities [Member]
Available-for-sale securities
Amortized Cost	7,500	7,500
Gross Unrealized Gains	0	726
Gross Unrealized Losses	(1,433)	0
Estimated Fair Value	$ 6,067	$ 8,226

Financial Instruments (Details

Financial Instruments (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Gross Unrealized Loss	$ 6,200
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	679,131	$ 746,802
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(16,263)	(15,006)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	530,070	495,600
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(31,564)	(25,438)
Available-for-Sale Securities, Fair Value, Total	1,209,201	1,242,402
Available-for-Sale Securities, Gross Unrealized Losses, Total	(47,827)	(40,444)
Non-financial institution securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	57,501	69,780
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(1,193)	(1,146)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	7,910	8,344
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(220)	(230)
Available-for-Sale Securities, Fair Value, Total	65,411	78,124
Available-for-Sale Securities, Gross Unrealized Losses, Total	(1,413)	(1,376)
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	52,351	13,471
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(224)	(176)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	4,586	9,176
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(103)	(96)
Available-for-Sale Securities, Fair Value, Total	56,937	22,647
Available-for-Sale Securities, Gross Unrealized Losses, Total	(327)	(272)
Mortgage-Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	424,784	510,988
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(10,639)	(11,048)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	340,733	299,663
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(13,293)	(11,263)
Available-for-Sale Securities, Fair Value, Total	765,517	810,651
Available-for-Sale Securities, Gross Unrealized Losses, Total	(23,932)	(22,311)
Asset-backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	53,832	57,128
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(944)	(876)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	33,333	32,696
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(466)	(502)
Available-for-Sale Securities, Fair Value, Total	87,165	89,824
Available-for-Sale Securities, Gross Unrealized Losses, Total	(1,410)	(1,378)
Debt Mutual Fund [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	85,633	89,670
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(15,717)	(11,680)
Available-for-Sale Securities, Fair Value, Total	85,633	89,670
Available-for-Sale Securities, Gross Unrealized Losses, Total	(15,717)	(11,680)
Commercial Mortgage Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	84,596	95,435
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(1,830)	(1,760)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	57,875	56,051
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(1,765)	(1,667)
Available-for-Sale Securities, Fair Value, Total	142,471	151,486
Available-for-Sale Securities, Gross Unrealized Losses, Total	(3,595)	$ (3,427)
Equity Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	6,067
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(1,433)
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	6,067
Available-for-Sale Securities, Gross Unrealized Losses, Total	$ (1,433)

Financial Instruments (Detail47

Financial Instruments (Details 2) $ in Thousands	Jun. 30, 2018USD ($)
Amortized Cost
Due in one year or less	$ 1,758,865
Due after one year through five years	176,391
Due after five years through ten years	148,349
Due after ten years	785,984
Amortized Cost Total	2,869,589
Estimated Fair Value
Due in one year or less	1,758,593
Due after one year through five years	172,941
Due after five years through ten years	143,894
Due after ten years	764,086
Estimated Fair Value Total	2,839,514
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$ 1,080,000

Financial Instruments (Detail48

Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Investments, All Other Investments [Abstract]
Proceeds from sale of available-for-sale securities	$ 895	$ 119,922
Gross realized gains on sale of available-for-sale securities	96	832
Gross realized losses on sale of available-for-sale securities	(47)	(386)
Net realized gains on sale of available-for-sale securities	49	446
Amortization of premiums on available-for-sale securities	$ 2,491	$ 6,823

Derivative Financial Instrume49

Derivative Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 155,196	$ 146,647
Singapore Dollar [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	26,392	24,914
Euro [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	38,591	38,987
Indian Rupee [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	64,959	62,472
British Pound [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	8,125	8,155
Japanese Yen [Member]
Derivative [Line Items]
Derivative Asset, Notional Amount	3,882	3,859
China, Yuan Renminbi
Derivative [Line Items]
Derivative Asset, Notional Amount	$ 13,247	$ 8,260

Derivative Financial Instrume50

Derivative Financial Instruments (Details 1) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Prepaid expenses and other current assets
Derivatives, Fair Value [Line Items]
Asset Derivatives, Fair Value	$ 167	$ 2,922
Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives, Fair Value	$ 5,040	$ 12

Derivative Financial Instrume51

Derivative Financial Instruments (Details 2) - Cash Flow Hedging [Member] - USD ($) $ in Thousands		3 Months Ended
		Jun. 30, 2018	Jul. 01, 2017
Foreign Exchange Contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gains (losses) recognized in other comprehensive income on derivative (effective portion of cash flow hedging)		$ (5,909)	$ 1,086
Interest And Other Expense, Net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gains (losses) reclassified from accumulated other comprehensive income into income (effective portion)	[1]	430	(357)
Amount of gains (losses) recorded (ineffective portion)	[1]	$ (11)	$ (19)
[1]	Recorded in interest and other income (expense), net within the condensed consolidated statements of income.

Derivative Financial Instrume52

Derivative Financial Instruments (Details Textual)	3 Months Ended
	Jun. 30, 2018USD ($)
Derivative [Line Items]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	$ 0
Hedging Program number of years	2 years
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 7,400,000

Stock-Based Compensation Plan53

Stock-Based Compensation Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 35,608	$ 32,036
Cost of Revenues [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	2,035	2,150
Research and Development [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	20,930	17,466
Selling, General and Administrative Expenses [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 12,643	$ 12,420

Stock-Based Compensation Plan54

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 1)	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.67%	1.70%
Weighted average assumptions in estimation of fair value of stock options
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.08%	2.30%

Stock-Based Compensation Plan55

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 3) - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018
Number of Shares
Number of Shares, Beginning Balance (shares)	6,989	6,988	6,988
Number of Shares, Granted (shares)	261		3,718
Number of Shares, Vested (shares)	212		3,016
Number of Shares, Forfeited/Cancelled (shares)	128		701
Number of Shares, Ending Balance (shares)	6,910		6,989
Weighted-Average Grant-Date Fair Value Per Share
Weighted-Average Grant-Date Fair Value, Beginning Balance (usd per share)	$ 51.39	$ 42.93	$ 42.93
Weighted-Average Grant-Date Fair Value, Granted (usd per share)	65.69	$ 57.99	60.18
Weighted-Average Grant-Date Fair Value, Vested (usd per share)	53.68		43.30
Weighted-Average Grant-Date Fair Value, Forfeited/Cancelled (usd per share)	50.50		48.16
Weighted-Average Grant-Date Fair Value, Ending Balance (usd per share)	$ 51.84		$ 51.39

Stock-Based Compensation Plan56

Stock-Based Compensation Plans (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from compensation expense		$ 11,600
Adjustments Related to Tax Withholding for Share-based Compensation	$ 5,500	25,600
Options, grants in period (shares)	0		0
Options, intrinsic value of shares exercised in the period	$ 220	$ 2,800
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted (usd per share)	$ 65.69	$ 57.99	$ 60.18
Equity Plan 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant (shares)	11,200,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP shares issued during period (shares)	0
Shares available for grant (shares)	9,300,000

Net Income Per Common Share N57

Net Income Per Common Share Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Debt Conversion [Line Items]
Net income	$ 190,038	$ 157,244	[1]
Weighted Average Number of Shares Outstanding, Basic	252,682	247,911
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	3,253	3,817
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities and Warrants	0	14,069
Weighted Average Number of Shares Outstanding, Diluted	255,935	265,797
Antidilutive shares excluded from computation of dilutive net income per common share	366	152
Earnings Per Share, Basic	$ 0.75	$ 0.63	[1]
Earnings Per Share, Diluted	$ 0.74	$ 0.59	[1]
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Debt Conversion [Line Items]
Debt Instrument, Face Amount		$ 600,000
Debt Instrument, Interest Rate, Stated Percentage		2.625%
Debt Instrument, Maturity Date		Jun. 15, 2017
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Inventories Inventories (Detail

Inventories Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventory, Raw Materials, Gross	$ 17,405	$ 14,674
Inventory, Work in Process, Gross	169,926	167,039
Inventory, Finished Goods, Gross	59,670	54,364
Inventory, Net	$ 247,001	$ 236,077

Debt and Credit Facility (Detai

Debt and Credit Facility (Details 1) - USD ($)	3 Months Ended		12 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 29, 2014	Mar. 31, 2018	May 30, 2017	Mar. 12, 2014
Debt Instrument [Line Items]
Net interest rate received (paid) from interest rate swap	$ (851,000)	$ 643,000
Long-term Debt, Current Maturities	499,407,000			$ 499,186,000
Amortization of Debt Discount (Premium)	295,000	1,676,000
Proceeds from Issuance of Long-term Debt	$ 0	745,871,000
Debt Instrument, Description of Variable Rate Basis	three-month London Interbank Offered Rate (LIBOR) plus 91.43 bps
Line of Credit Facility, Expiration Date	Dec. 14, 2021
Line of Credit Facility, Maximum Borrowing Capacity	$ 400,000,000
AdditionalborrowingcapacityfromRevolvingCreditFacility	150,000,000
Line of Credit Facility, Average Outstanding Amount	0
Long-term Debt, Excluding Current Maturities	1,207,387,000			1,214,440,000
Two And One Two Five Percent 2019 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par						99.477%
Debt Instrument, Face Amount	500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(365,000)			(501,000)
Debt Issuance Costs, Current, Net	228,000			313,000
Long-term Debt, Current Maturities	$ 499,407,000			499,186,000
Debt instrument, long term debt, remaining discount amortization period	8 months 15 days
2019 and 2021 Notes Payable [Member]
Debt Instrument [Line Items]
Interest Expense, Debt, Excluding Amortization	$ 6,406,000	6,406,000
Amortization of Debt Issuance Costs	146,000	146,000
Amortization of Debt Discount (Premium)	268,000	260,000
Interest Expense, Debt	6,820,000	6,812,000
Proceeds from Issuance of Long-term Debt			$ 990,100,000
Debt, Long-term and Short-term, Combined Amount	997,295,000			996,882,000
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par					99.887%
Debt Instrument, Face Amount	$ 750,000,000			750,000,000
Debt Instrument, Interest Rate, Stated Percentage	2.95%
Debt Instrument, Unamortized Discount	$ (727,000)			(755,000)
Debt Issuance Costs, Noncurrent, Net	3,358,000			3,500,000
Long Term Debt, Carrying Value before Hedging Adjustment	745,915,000			745,745,000
Derivative, Amount of Hedged Item	(36,416,000)			(29,001,000)
Interest Expense, Debt, Excluding Amortization	6,382,000	1,322,000
Amortization of Debt Issuance Costs	142,000	47,000
Amortization of Debt Discount (Premium)	28,000	10,000
Interest Expense, Debt	$ 6,552,000	1,379,000
Proceeds from Issuance of Long-term Debt		$ 745,200,000
Debt instrument, long term debt, remaining discount amortization period	6 years
Long-term Debt, Excluding Current Maturities	$ 709,499,000			716,744,000
Three Point Zero Percent 2021 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par						99.281%
Debt Instrument, Face Amount	500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(1,461,000)			(1,593,000)
Debt Issuance Costs, Noncurrent, Net	$ 651,000			711,000
Debt instrument, long term debt, remaining discount amortization period	2 years 8 months 15 days
Long-term Debt, Excluding Current Maturities	$ 497,888,000			$ 497,696,000
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	$ 36,400,000

Debt and Credit Facility (Det60

Debt and Credit Facility (Details 2) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018
Short-term Debt [Line Items]
Repayments of Convertible Debt	$ 0	$ 457,918
Amortization of Debt Discount (Premium)	295	$ 1,676
Long-term Debt, Excluding Current Maturities	$ 1,207,387		$ 1,214,440

Common Stock Repurchase Progr61

Common Stock Repurchase Program (Details) - USD ($)	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	May 16, 2018	Mar. 31, 2018	May 16, 2016
Accelerated Share Repurchases [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities		6,000,000
Preferred stock, shares issued (none issued)	0			0
Preferred Stock, Shares Outstanding	0			0
Stock Repurchased and Retired During Period, Value	$ 136,800,000	$ 67,100,000
Treasury shares	0			0
Stock Repurchased During Period, Shares	(2,100,000)	(1,000,000)
Repurchase Program Two Thousand Sixteen [Member] [Domain]
Accelerated Share Repurchases [Line Items]
Amount authorized for common stock repurchase					$ 1,000,000,000
Stock Repurchased During Period, Value	$ 929,400,000
Total amount available for future repurchases	$ 70,600,000
Repurchase Program Two Thousand Eighteen [Domain]
Accelerated Share Repurchases [Line Items]
Amount authorized for common stock repurchase			$ 500,000,000

Interest and Other Expense, N62

Interest and Other Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Other Income and Expenses [Abstract]
Net interest rate received (paid) from interest rate swap	$ 851	$ (643)
Components of interest and other expense
Interest income	17,397	13,414
Interest expense	(13,372)	(12,081)
Other income (expense), net	(6,872)	506
Interest and other expense, net	$ (2,847)	$ 1,839

Accumulated Other Comprehensi63

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Mar. 31, 2018
Components of accumulated other comprehensive income (loss)
Accumulated unrealized losses on available-for-sale securities, net of tax	$ (23,156)	$ (29,844)
Accumulated unrealized losses on hedging transactions, net of tax	(4,386)	1,674
Accumulated cumulative translation adjustment, net of tax	(8,390)	(6,339)
Accumulated other comprehensive income (loss)	$ (35,932)	$ (34,509)

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$ 22,879	$ 13,650	[1]
Effective Income Tax Rate Reconciliation, Percent	11.00%	8.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Unrecognized Tax Benefits, Period Increase (Decrease)	$ 825
Unrecognized Tax Benefits	126,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	16,000
Unrecognized Tax Benefits That Would Impact Additional Paid-in Capital	$ 85,500
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Commitments (Details)

Commitments (Details) $ in Thousands	Jun. 30, 2018USD ($)
Future Minimum Lease Payments Under Non-Cancelable Operating Leases
2019 (remaining nine months)	$ 6,115
2,020	9,216
2,021	7,198
2,022	5,923
2,023	4,798
Thereafter	30,708
Total	$ 63,958

Commitments (Details Textual)

Commitments (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017
Other Commitments [Line Items]
Aggregate future rental income to be received	$ 12
Rent expense, net of rental income	1	$ 1.2
Other commitments	$ 136.5
Software and Maintenance License Obligations Expiration Date	Dec. 28, 2022
Minimum [Member]
Other Commitments [Line Items]
Purchase Commitments, Period for Payment	3 months
Maximum [Member]
Other Commitments [Line Items]
Purchase Commitments, Period for Payment	6 months
Capital Lease Obligations [Member]
Other Commitments [Line Items]
Lease Expiration Date	Nov. 30, 2035
Electronic Design Automation Software And Hardware/Software Maintenance [Member]
Other Commitments [Line Items]
Non-cancelable license obligations	$ 18.9
Leasing Arrangement [Member]
Other Commitments [Line Items]
Lease Expiration Date	Apr. 30, 2029
Open purchase Orders From Ordinary Operations [Member]
Other Commitments [Line Items]
Non-cancelable license obligations	$ 33.7

Contingencies Contingencies (De

Contingencies Contingencies (Details) $ in Millions	3 Months Ended
	Jun. 30, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency, Damages Sought, Value	$ 50

Goodwill and Acquisition-Rela68

Goodwill and Acquisition-Related Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Gross and net amounts of goodwill and of acquisition-related intangibles
Goodwill	$ 162,421	$ 162,421
Total acquisition-related intangibles, gross	129,446	129,446
Less accumulated amortization	(125,683)	(125,323)
Total	3,763	4,123
Core Technology [Member]
Gross and net amounts of goodwill and of acquisition-related intangibles
Total acquisition-related intangibles, gross	82,480	82,480
Less accumulated amortization	(78,885)	(78,562)
Total	$ 3,595	3,918
Weighted-Average Amortization Life	4 years 9 months 18 days
Other Intangibles [Member]
Gross and net amounts of goodwill and of acquisition-related intangibles
Total acquisition-related intangibles, gross	$ 46,966	46,966
Less accumulated amortization	(46,798)	(46,761)
Total	$ 168	$ 205
Weighted-Average Amortization Life	2 years 7 months 6 days

Goodwill and Acquisition-Rela69

Goodwill and Acquisition-Related Intangibles (Details 1) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquisition-related intangibles	$ 360	$ 705
Schedule of expected annual amortization expense for acquisition-related intangibles
2019 (remaining nine months)	893
2,020	1,160
2,021	1,137
2,022	573
Total	$ 3,763		$ 4,123

Subsequent Events (Details)

Subsequent Events (Details)	Jul. 24, 2018$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.36