Xilinx (XLNX) 10-Q 26 Oct 17 2018 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Sep. 30, 2017	Oct. 13, 2017
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q2
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	--03-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		250,952,891

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Net revenues	$ 619,503	$ 579,209	$ 1,234,949	$ 1,154,190
Cost of revenues	184,786	175,875	376,881	344,172
Gross margin	434,717	403,334	858,068	810,018
Operating expenses:
Research and development	157,985	141,814	311,036	277,939
Selling, general and administrative	91,053	83,463	180,228	166,573
Amortization of acquisition-related intangibles	510	1,244	1,215	2,488
Total operating expenses	249,548	226,521	492,479	447,000
Operating income	185,169	176,813	365,589	363,018
Interest and other income (expense), net	(1,831)	1,151	(3,669)	5,738
Income before income taxes	187,000	175,662	369,258	357,280
Provision for income taxes	19,468	11,470	34,481	30,039
Net income	$ 167,532	$ 164,192	$ 334,777	$ 327,241
Net income per common share:
Basic (in dollars per share)	$ 0.68	$ 0.65	$ 1.35	$ 1.29
Diluted (in dollars per share)	0.65	0.61	1.28	1.22
Cash dividends per common share	$ 0.35	$ 0.33	$ 0.70	$ 0.66
Shares used in per share calculations:
Basic (in shares)	248,094	253,466	247,960	253,056
Diluted (in shares)	258,217	270,373	261,739	267,885

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 167,532	$ 164,192	$ 334,777	$ 327,241
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on available-for-sale securities	763	(1,496)	5,935	2,230
Reclassification adjustment for (gains) losses on available-for-sale securities	(135)	(368)	(105)	(416)
Change in net unrealized gains (losses) on hedging transactions	756	99	2,198	(683)
Reclassification adjustment for losses on hedging transactions	(1,648)	345	(2,004)	638
Cumulative translation adjustment, net	678	(384)	2,438	(347)
Other comprehensive loss	414	(1,804)	8,462	1,422
Total comprehensive income	$ 167,946	$ 162,388	$ 343,239	$ 328,663

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 01, 2017
Current assets:
Cash and cash equivalents	$ 1,070,193	$ 966,695
Short-term investments	2,490,027	2,354,762
Accounts receivable, net	286,855	243,915
Inventories	215,397	227,033
Prepaid expenses and other current assets	109,758	87,711
Total current assets	4,172,230	3,880,116
Property, plant and equipment, at cost	855,019	839,458
Accumulated depreciation and amortization	(550,901)	(535,633)
Net property, plant and equipment	304,118	303,825
Long-term investments	99,862	116,288
Goodwill	161,287	161,287
Acquisition-related intangibles, net	2,361	3,576
Other assets	290,992	275,440
Total Assets	5,030,850	4,740,532
Current liabilities:
Accounts payable	88,341	108,293
Accrued payroll and related liabilities	192,120	176,601
Income taxes payable	6,766	6,309
Deferred income on shipments to distributors	50,966	54,567
Other accrued liabilities	85,028	95,098
Current portion of long-term debt	0	456,328
Total current liabilities	423,221	897,196
Long-term debt	1,738,666	995,247
Deferred tax liabilities	359,323	317,639
Long-term income taxes payable	5,291	4,503
Other long-term liabilities	18,266	16,908
Commitments and contingencies	0	0
Temporary equity (Note 10)	0	1,406
Stockholders' equity:
Preferred stock, $.01 par value (none issued)	0	0
Common stock, $.01 par value	2,486	2,480
Additional paid-in capital	823,958	803,522
Retained earnings	1,675,858	1,726,312
Accumulated other comprehensive loss	(16,219)	(24,681)
Total stockholders’ equity	2,486,083	2,507,633
Total Liabilities, Temporary Equity and Stockholders’ Equity	$ 5,030,850	$ 4,740,532

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2017	Apr. 01, 2017
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	6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Cash flows from operating activities:
Net income	$ 334,777	$ 327,241
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	22,964	22,807
Amortization	7,161	7,714
Stock-based compensation	68,408	59,206
Net gain on sale of available-for-sale securities	(756)	(823)
Amortization of debt discounts	1,964	6,034
Provision for deferred income taxes	38,206	32,607
Other Operating Activities, Cash Flow Statement	1,500	0
Changes in assets and liabilities:
Accounts receivable, net	(42,940)	79,700
Inventories	11,504	(18,409)
Prepaid expenses and other current assets	(18,383)	(3,765)
Other assets	(12,645)	(5,037)
Accounts payable	(20,585)	1,701
Accrued liabilities	23,434	19,046
Income taxes payable	(17,960)	(11,439)
Deferred income on shipments to distributors	(3,601)	5,646
Net cash provided by operating activities	393,048	522,229
Cash flows from investing activities:
Purchases of available-for-sale securities	(1,367,972)	(1,952,967)
Proceeds from sale and maturity of available-for-sale securities	1,257,571	2,023,314
Purchases of property, plant and equipment	(22,149)	(31,950)
Other investing activities	(8,461)	(15,849)
Net cash provided by (used in) investing activities	(141,011)	22,548
Cash flows from financing activities:
Repurchases of common stock	(237,516)	(200,139)
Restricted stock units withholdings	19,358	37,865
Payments Related to Tax Withholding for Share-based Compensation	(42,053)	(28,352)
Proceeds from issuance of common stock through various stock plans	(174,260)	(167,477)
Repayments of Secured Debt	(457,918)	0
Proceeds from Issuance of Secured Debt	745,175	0
Proceeds from (Payments for) Other Financing Activities	(1,325)	0
Net cash used in financing activities	(148,539)	(358,103)
Net increase in cash and cash equivalents	103,498	186,674
Cash and cash equivalents at beginning of period	966,695	503,816
Cash and cash equivalents at end of period	1,070,193
Supplemental disclosure of cash flow information:
Interest paid	18,608	20,688
Income taxes paid, net	$ 14,789	$ 9,118

Basis of Presentation

Basis of Presentation	6 Months Ended
	Sep. 30, 2017
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 April 1, 2017 . 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 31, 2018 or any future period. The Company uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal year 2018 and fiscal year 2017 are both 52-week years ending on March 31, 2018 and April 1, 2017, respectively. The quarters ended on September 30, 2017 and October 1, 2016 each consisted of 13 weeks.

Recent Accounting Changes and A

Recent Accounting Changes and Accounting Pronouncements	6 Months Ended
	Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
Accounting Changes and Error Corrections [Text Block]	Recent Accounting Changes and Accounting Pronouncements In April 2014, the Financial Accounting Standards Board (FASB) issued the authoritative guidance, as amended, that outlines a new global 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 authoritative 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 authoritative guidance is required to be applied retrospectively to each prior reporting period presented, or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application. The Company is currently evaluating the full impact of this new authoritative guidance on its consolidated financial statements, including selection of the transition method. However, assuming all other revenue recognition criteria have been met, it is expected that the new authoritative guidance would require the Company to recognize revenue and cost relating to distributor sales upon product delivery (Sell-In), subject to estimated allowance for distributor price adjustments and rights of return, rather than deferring the distributor sales upon product delivery and subsequently recognizing revenue when the product is sold by the distributor to the end customer (Sell-Through). Upon adoption, the Company currently expects that it will record the balance of the deferred revenue (subject to true-ups) under Sell-Through to retained earnings, and the impact would be offset by the recognition of revenue on shipments post adoption under Sell-In. The Company continues to evaluate the impact to revenues and related disclosures related to the pending adoption of the new guidance and the preliminary assessments are subject to change. Depending on timing of customer orders, timing of shipment to distributors and to end customers, distributor inventory strategies and other factors that may be beyond the Company's control, the difference in revenue recognized under Sell-Through and Sell-In could be material in the future. The authoritative guidance will be effective for the Company beginning in fiscal year 2019 as the Company decided not to early adopt it in fiscal year 2018. In January 2016, the FASB issued the 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. The new authoritative guidance also changes certain disclosure requirements and other aspects of current U.S. GAAP. It 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, which for Xilinx would be the first quarter of fiscal year 2019. Upon adoption, the Company would record all of the unrealized gains or losses from its investment in mutual funds to retained earnings, and subsequent changes in fair value from such investments will be recorded under its consolidated statements of income. In February 2016, the FASB issued the 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 year 2020. Early adoption is permitted. The new authoritative guidance must be adopted using a modified retrospective transition, and provides for certain practical expedients. In addition, the transition will require application of the new authoritative guidance at the beginning of the earliest comparative period presented. The Company is currently evaluating the impact of this new authoritative guidance on its consolidated financial statements. In August 2016, the FASB issued authoritative guidance for cash flow classification. The new authoritative guidance is intended to reduce diversity in practice in how cash receipts and cash payments are classified in the statement of cash flows. The new authoritative guidance will be effective for public business entities in fiscal years beginning after December 15, 2017, including interim periods within those years, which for Xilinx would be the first quarter of fiscal year 2019. Early adoption is permitted. The Company is currently evaluating the impact of this new authoritative guidance on its consolidated financial statements. In October 2016, the FASB issued authoritative guidance for accounting for 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 new authoritative guidance will be effective for public business entities in fiscal years beginning after December 15, 2017, which for Xilinx would be the first quarter of fiscal year 2019. Early adoption is permitted as of the beginning of the annual period. The authoritative guidance will be effective for the Company beginning in fiscal year 2019 as the Company decided not to early adopt it in fiscal year 2018. The Company is currently evaluating the impact of this new authoritative guidance on its consolidated financial statements. In May 2017, the FASB issued authoritative guidance that clarifies the scope of modification accounting for share-based compensation. Under the new guidance, modification accounting is required only if the fair value, the vesting conditions, or the classification of the award (as equity or liability) changes as a result of the change in terms or conditions. The new guidance will reduce diversity in practice and result in fewer changes to the terms of an award being accounted for as modifications. The new authoritative guidance will be effective for public business entities in fiscal years beginning after December 15, 2017, which for Xilinx would be the first quarter of fiscal year 2019. Early adoption is permitted as of the beginning of the annual period. The authoritative guidance will be effective for the Company beginning in fiscal year 2019 as the Company decided not to early adopt it in fiscal year 2018. The Company is currently evaluating the impact of this new authoritative guidance on its consolidated financial statements. In August 2017, the FASB issued authoritative guidance that amended the accounting for hedging activities. The guidance permits more hedging strategies to be eligible for hedge accounting and simplifies the application of hedge accounting guidance in areas where practice issues exist. The new authoritative guidance will be effective for public business entities for annual periods, and interim periods within those annual periods, beginning after December 15, 2018, which for Xilinx would be the first quarter of fiscal year 2020. Early adoption is permitted, including adoption in any interim periods after issuance of the authoritative guidance. The Company is currently evaluating the impact of this new authoritative guidance on its consolidated financial statements.

Significant Customers and Conce

Significant Customers and Concentrations of Credit Risk (Notes)	6 Months Ended
	Sep. 30, 2017
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 September 30, 2017 and April 1, 2017 , Avnet accounted for 67% and 59% of the Company’s total net accounts receivable, respectively. For the second quarter and first six months of fiscal year 2018 , resale of product through Avnet accounted for 44% and 42% of the Company’s worldwide net revenues, respectively. For the second quarter and the first six months of fiscal year 2017 , resale of product through Avnet accounted for 43% and 50% of the Company’s worldwide net revenues, respectively. Xilinx is subject to concentrations of credit risk primarily in its trade accounts receivable and investments in debt securities to the extent of the amounts recorded on the consolidated balance sheet. The Company attempts to mitigate the concentration of credit risk in its trade receivables through its credit evaluation process, collection terms, distributor sales to diverse end customers and through geographical dispersion of sales. Xilinx generally does not require collateral for receivables from its end customers or from distributors. No end customer accounted for more than 10% of the Company’s worldwide net revenues for the second quarter as well as the first six months of fiscal years 2018 and 2017 . The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 84% 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 September 30, 2017 , approximately 33% 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	6 Months Ended
	Sep. 30, 2017
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 activities, 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 six months of fiscal year 2018 and the Company did not adjust or override any fair value measurements as of September 30, 2017 . 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 and money market funds. Level 2 — Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. The Company’s Level 2 assets consist of financial institution securities, non-financial institution securities, U.S. agency securities, foreign government and agency securities, mortgage-backed securities, debt mutual funds, bank loans, 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. 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 September 30, 2017 and April 1, 2017 : September 30, 2017 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 323,034 $ — $ — $ 323,034 Financial institution securities — 255,864 — 255,864 Non-financial institution securities — 192,800 — 192,800 U.S. government and agency securities 13,880 31,528 — 45,408 Foreign government and agency securities — 184,868 — 184,868 Short-term investments: Financial institution securities — 324,853 — 324,853 Non-financial institution securities — 226,546 — 226,546 U.S. government and agency securities 27,098 23,158 — 50,256 Foreign government and agency securities — 79,920 — 79,920 Asset-backed securities — 217,827 — 217,827 Mortgage-backed securities — 1,154,680 — 1,154,680 Debt mutual fund — 34,029 — 34,029 Bank loans — 157,899 — 157,899 Commercial mortgage-backed securities — 244,017 — 244,017 Long-term investments: Asset-backed securities — 1,430 — 1,430 Mortgage-backed securities — 41,971 — 41,971 Debt mutual fund — 56,461 — 56,461 Total assets measured at fair value $ 364,012 $ 3,227,851 $ — $ 3,591,863 Liabilities Derivative financial instruments, net $ — $ 1,462 $ — $ 1,462 Total liabilities measured at fair value $ — $ 1,462 $ — $ 1,462 Net assets measured at fair value $ 364,012 $ 3,226,389 $ — $ 3,590,401 April 1, 2017 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 298,307 $ — $ — $ 298,307 Non-financial institution securities — 205,322 — 205,322 Foreign government and agency securities — 177,310 — 177,310 Financial institution securities — 158,962 — 158,962 U.S government and agency securities 2,998 50,984 — 53,982 Short-term investments: Financial institution securities — 189,835 — 189,835 Non-financial institution securities — 203,938 — 203,938 U.S. government and agency securities 31,732 44,820 — 76,552 Foreign government and agency securities — 144,811 — 144,811 Mortgage-backed securities — 1,115,403 — 1,115,403 Debt mutual fund — 34,068 — 34,068 Bank loans — 154,014 — 154,014 Asset-backed securities — 218,170 — 218,170 Commercial mortgage-backed securities — 217,971 — 217,971 Long-term investments: Mortgage-backed securities — 60,099 — 60,099 Debt mutual fund — 54,608 — 54,608 Asset-backed securities — 1,581 — 1,581 Derivative financial instruments, net — 1,661 — 1,661 Total assets measured at fair value $ 333,037 $ 3,033,557 $ — $ 3,366,594 Changes in Level 3 Instruments Measured at Fair Value on a Recurring Basis The following table is a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3): Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Balance as of beginning of period $ — $ 10,068 $ — $ 9,977 Total unrealized gains (losses): Included in other comprehensive income (loss) — 92 — 183 Balance as of end of period $ — $ 10,160 $ — $ 10,160 As of September 30, 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 September 30, 2017 were approximately $501.3 million , $509.6 million and $750.1 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).

Financial Instruments

Financial Instruments	6 Months Ended
	Sep. 30, 2017
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: September 30, 2017 April 1, 2017 (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 $ 323,034 $ — $ — $ 323,034 $ 298,307 $ — $ — $ 298,307 Financial institution securities 580,717 — — 580,717 348,797 — — 348,797 Non-financial institution securities 418,879 744 (277 ) 419,346 409,109 647 (496 ) 409,260 U.S. government and — agency securities 95,793 5 (134 ) 95,664 130,749 8 (223 ) 130,534 Foreign government and agency securities 264,788 — — 264,788 322,172 — (51 ) 322,121 Mortgage-backed securities 1,201,005 5,409 (9,763 ) 1,196,651 1,186,732 3,527 (14,757 ) 1,175,502 Asset-backed securities 219,255 480 (478 ) 219,257 220,033 404 (686 ) 219,751 Debt mutual funds 101,350 — (10,860 ) 90,490 101,350 — (12,674 ) 88,676 Bank loans 157,510 643 (254 ) 157,899 153,281 839 (106 ) 154,014 Commercial mortgage- backed securities 247,390 199 (3,572 ) 244,017 221,504 146 (3,679 ) 217,971 $ 3,609,721 $ 7,480 $ (25,338 ) $ 3,591,863 $ 3,392,034 $ 5,571 $ (32,672 ) $ 3,364,933 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 September 30, 2017 and April 1, 2017 : September 30, 2017 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 $ 62,033 $ (210 ) $ 5,606 $ (67 ) $ 67,639 $ (277 ) U.S. government and agency securities 34,015 (125 ) 5,130 (9 ) 39,145 (134 ) Mortgage-backed securities 730,974 (6,516 ) 157,026 (3,247 ) 888,000 (9,763 ) Asset-backed securities 135,560 (464 ) 4,757 (14 ) 140,317 (478 ) Debt mutual funds — — 90,490 (10,860 ) 90,490 (10,860 ) Bank loans 30,107 (254 ) — — 30,107 (254 ) Commercial mortgage- backed securities 119,843 (893 ) 60,028 (2,679 ) 179,871 (3,572 ) $ 1,112,532 $ (8,462 ) $ 323,037 $ (16,876 ) $ 1,435,569 $ (25,338 ) April 1, 2017 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 $ 68,850 $ (492 ) $ 1,022 $ (4 ) $ 69,872 $ (496 ) U.S. government and agency securities 64,895 (223 ) — — 64,895 (223 ) Mortgage-backed securities 811,058 (11,872 ) 139,931 (2,885 ) 950,989 (14,757 ) Asset-backed securities 119,845 (651 ) 4,689 (35 ) 124,534 (686 ) Debt mutual funds — — 88,676 (12,674 ) 88,676 (12,674 ) Bank loans 15,139 (106 ) — — 15,139 (106 ) Foreign government and agency securities 64,857 (51 ) — — 64,857 (51 ) Commercial mortgage- backed securities 165,393 (1,706 ) 24,362 (1,973 ) 189,755 (3,679 ) $ 1,310,037 $ (15,101 ) $ 258,680 $ (17,571 ) $ 1,568,717 $ (32,672 ) As of September 30, 2017 , 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, mortgage-backed securities and commercial mortgage-backed securities, which were primarily due to the general rising of the interest-rate environment and foreign currency movement. The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of September 30, 2017 and April 1, 2017 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 we have 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 were redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more were not significant as of September 30, 2017 and April 1, 2017 , the majority of which were related to debt mutual funds due to foreign currency and interest rate fluctuations. 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, bank loans, 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. September 30, 2017 (In thousands) Amortized Estimated Due in one year or less $ 1,200,344 $ 1,200,345 Due after one year through five years 469,451 467,424 Due after five years through ten years 312,956 312,503 Due after ten years 1,202,586 1,198,067 $ 3,185,337 $ 3,178,339 As of September 30, 2017 , $1.93 billion of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table did not include investments in money market and mutual funds because these funds do not have specific contractual maturities. Certain information related to available-for-sale securities is as follows: Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Proceeds from sale of available-for-sale securities $ 149,497 $ 153,871 $ 269,419 $ 253,345 Gross realized gains on sale of available-for-sale securities $ 519 $ 762 $ 1,351 $ 1,427 Gross realized losses on sale of available-for-sale securities (209 ) (92 ) (595 ) (604 ) Net realized gains on sale of available-for-sale securities $ 310 $ 670 $ 756 $ 823 Amortization of premiums on available-for-sale securities $ 4,691 $ 7,414 $ 10,213 $ 14,175 The cost of securities matured or sold is based on the specific identification method.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Sep. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments 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 six months ended September 30, 2017 , the net change in fair values of the interest rate swap contracts and the underlying 2024 Notes was $ 2.8 million , which was recorded as a derivative liability for the interest rate swap contacts (as a component of other long-term liabilities on the condensed consolidated balance sheets) and also a reduction from the carrying amount of 2024 Notes. There was no ineffectiveness during all periods presented. Other than this arrangement, there have been no material changes to the Company's derivative financial instruments since April 1, 2017 .

Stock-Based Compensation Plans

Stock-Based Compensation Plans	6 Months Ended
	Sep. 30, 2017
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Stock-based compensation included in: Cost of revenues $ 2,147 $ 1,930 $ 4,297 $ 4,049 Research and development 20,096 16,529 37,562 31,649 Selling, general and administrative 14,129 11,343 26,549 23,508 $ 36,372 $ 29,802 $ 68,408 $ 59,206 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 six months of fiscal year 2018 and the entire fiscal year 2017 . The Company's stock-based compensation expenses related to options during the first six months of fiscal year 2018 and the number of options outstanding as of September 30, 2017 were not material. On August 9, 2017, the stockholders approved an amendment to increase the authorized number of shares reserved for issuance under the 2007 Equity Plan by 1.9 million shares. As of September 30, 2017 , 11.4 million shares remained available for grant under the 2007 Equity Plan. The total pre-tax intrinsic value of options exercised during the three and six months ended September 30, 2017 was $465 thousand and $3.2 million , respectively. The total pre-tax intrinsic value of options exercised during the three and six months ended October 1, 2016 was $8.8 million and $21.4 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 2, 2016 6,619 $ 40.74 Granted 3,398 $ 44.38 Vested (2,619 ) $ 39.49 Cancelled (410 ) $ 41.63 April 1, 2017 6,988 $ 42.93 Granted 3,262 $ 59.89 Vested (2,288 ) $ 41.99 Cancelled (314 ) $ 46.76 September 30, 2017 7,648 $ 49.91 The estimated fair values of RSU awards were calculated based on the market price of Xilinx common stock on the date of grant, reduced by the present value of dividends expected to be paid on Xilinx common stock prior to vesting. The per share weighted-average fair value of RSUs granted during the second quarter of fiscal year 2018 was $59.99 ( $42.89 for the second quarter of fiscal year 2017 ), and for the first six months of fiscal year 2018 was $59.89 ( $42.87 for the first six months of fiscal year 2017 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended Six Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Risk-free interest rate 1.7 % 0.8 % 1.7 % 0.8 % Dividend yield 2.2 % 2.9 % 2.2 % 2.9 % 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 its employees. During the second quarter and the first six months of fiscal year 2018 , the Company realized excess tax benefits of $6.3 million and $17.9 million , respectively. During the second quarter and the first six months of fiscal year 2017 , the Company realized excess tax benefits of $2.9 million and $9.7 million , respectively. These benefits were recorded in the condensed consolidated statements of income as a component of the provision for income taxes. Employee Stock Purchase Plan Under the ESPP, shares are only issued during the second and fourth quarters of each fiscal year. Employees purchased 355 thousand shares for $16.9 million during the second quarter of fiscal year 2018 and 446 thousand shares for $15.0 million during the second quarter of fiscal year 2017 . The per-share weighted-average fair value of stock purchase rights granted under the ESPP during the second quarter of fiscal years 2018 and 2017 was $16.46 and $11.64 , respectively. The fair values of stock purchase plan rights granted in the second quarter of fiscal years 2018 and 2017 were estimated using the Black-Scholes option pricing model at the date of grant using the following assumptions: 2018 2017 Expected life of options (years) 1.25 1.25 Expected stock price volatility 0.28 0.23 Risk-free interest rate 1.3 % 0.5 % Dividend yield 2.2 % 2.6 % The next scheduled purchase under the ESPP is in the fourth quarter of fiscal year 2018. On August 9, 2017, the stockholders approved an amendment to increase the authorized number of shares reserved for issuance under the ESPP by 2.0 million shares. As of September 30, 2017 , 9.9 million shares were available for future issuance under the ESPP.

Net Income Per Common Share

Net Income Per Common Share	6 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Net Income Per Common Share	Net Income Per Common Share The computation of basic net income per common share for all periods presented is derived from the information on the condensed consolidated statements of income, and there are no reconciling items in the numerator used to compute diluted net income per common share. The following table summarizes the computation of basic and diluted net income per common share: Three Months Ended Six Months Ended (In thousands, except per share amounts) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Net income available to common stockholders $ 167,532 $ 164,192 $ 334,777 $ 327,241 Weighted average common shares outstanding-basic 248,094 253,466 247,960 253,056 Dilutive effect of employee equity incentive plans 2,532 2,126 2,949 2,319 Dilutive effect of 2017 Convertible Notes — 9,587 2,986 8,736 Dilutive effect of warrants 7,591 5,194 7,844 3,774 Weighted average common shares outstanding-diluted 258,217 270,373 261,739 267,885 Basic earnings per common share $ 0.68 $ 0.65 $ 1.35 $ 1.29 Diluted earnings per common share $ 0.65 $ 0.61 $ 1.28 $ 1.22 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. The 2017 Convertible Notes matured during the first quarter of fiscal year 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 six months ended September 30, 2017 was calculated based on a weighted-average outstanding basis, it included approximately 3.0 million shares of dilutive impact from the 2017 Convertible Notes through the maturity date. See "Note 10. Debt and Credit Facility" for more discussion of the Company's debt, call options and warrants. Outstanding stock options and RSUs under the Company's stock award plans to purchase approximately 1.0 million and 3.2 million shares, for the second quarter and the first six months of fiscal year 2018 , respectively, were excluded from diluted net income per common share by applying the treasury stock method, as their inclusion would have been anti-dilutive. These options and RSUs could be dilutive in the future if the Company’s average share price increases and is greater than the combined exercise prices and the unamortized fair values of these options and RSUs.

Inventories

Inventories	6 Months Ended
	Sep. 30, 2017
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) September 30, 2017 April 1, 2017 Raw materials $ 16,699 $ 14,517 Work-in-process 152,252 161,120 Finished goods 46,446 51,396 $ 215,397 $ 227,033

Debt and Credit Facility

Debt and Credit Facility	6 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt and Credit Facility [Text Block]	Debt and Credit Facility 2017 Convertible Notes During the first quarter of fiscal year 2018, the Company received conversion requests from the remaining holders of the 2017 Convertible Notes. Upon settlement, the holders received a cash payment equal to the par value of the 2017 Convertible Notes of $457.9 million , as well as 9.0 million shares of the Company's common stock. In conjunction with the settlement, the Company exercised its call options on its shares of common stock that it purchased to hedge against the dilution from the conversion of the 2017 Convertible Notes, and received 9.0 million shares from the hedge counterparties. As of the end of the first quarter of fiscal year 2018, the 2017 Convertible Notes were no longer outstanding. The carrying values of the liability and equity components of the 2017 Convertible Notes are reflected in the Company’s condensed consolidated balance sheets as follows: (In thousands) September 30, 2017 April 1, 2017 Liability component: Principal amount of the 2017 Convertible Notes $ — $ 457,918 Unamortized discount of liability component — (1,977 ) Hedge accounting adjustment – sale of interest rate swap — 571 Unamortized debt issuance costs associated with 2017 Convertible Notes — (184 ) Net carrying value of the 2017 Convertible Notes $ — $ 456,328 Equity component (including temporary equity) – net carrying value $ — $ 50,688 Prior to the conversion, interest expense related to the 2017 Convertible Notes was included in interest and other income (expense), net on the condensed consolidated statements of income, and was recognized as follows: Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ — $ 3,938 $ 2,300 $ 7,875 Amortization of debt issuance costs — 362 184 724 Amortization of debt discount, net — 2,763 1,406 5,526 Total interest expense related to the 2017 Convertible Notes $ — $ 7,063 $ 3,890 $ 14,125 To reduce the hedging costs of purchasing the call options on its common stock as described above, the Company, under separate transactions, sold warrants to independent counterparties, which give the counterparties the right to purchase up to 21.1 million shares of the Company's common stock at $40.26 per share. Portions of the warrants were exercised during the quarter ended September 30, 2017 and the Company issued 2.2 million shares of its common stock as part of the settlement. The remainder of the warrants will expire and settle on a gradual basis through November 2017. Subsequent to the quarter-end, as of October 26, 2017, the Company issued 2.3 million shares of its common stock as part of the settlement of additional warrant exercises. 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 September 30, 2017 , the remaining term of the 2019 Notes and 2021 Notes are 1.5 years and 3.5 years, respectively. The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of September 30, 2017 and April 1, 2017 : (In thousands) September 30, 2017 April 1, 2017 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (770 ) (1,037 ) Unamortized debt issuance costs associated with the 2019 Notes (484 ) (654 ) Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,852 ) (2,107 ) Unamortized debt issuance costs associated with the 2021 Notes (833 ) (955 ) Total carrying value $ 996,061 $ 995,247 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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ 6,406 $ 6,406 $ 12,813 $ 12,813 Amortization of debt issuance costs 146 146 293 293 Amortization of debt discount, net 262 255 520 507 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,814 $ 6,807 $ 13,626 $ 13,613 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 September 30, 2017 , the remaining term of the 2024 Notes is approximately 6.7 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 earned a net interest income of $1.5 million and $2.1 million during the three and six months ended September 30, 2017 , respectively, from the interest rate swap contracts, which was included in interest and other income (expense), net on the condensed consolidated statements of income as a reduction to interest expense. As of September 30, 2017 , the fair value of the interest rate swap contracts was $2.8 million , which was recorded in other long-term liabilities on the condensed consolidated balance sheets. The following table summarizes the carrying value of the 2024 Notes as of September 30, 2017 and April 1, 2017 : (In thousands) September 30, 2017 April 1, 2017 Principal amount of the 2024 Notes $ 750,000 $ — Unamortized discount of the 2024 Notes (810 ) — Unamortized debt issuance costs associated with 2024 Notes (3,789 ) — Carrying value of the 2024 Notes $ 745,401 $ — Fair value hedge adjustment - interest rate swap contracts (2,796 ) — Net carrying value of the 2024 Notes $ 742,605 $ — 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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ 4,046 $ — $ 5,368 $ — Amortization of debt issuance costs 142 — 189 — Amortization of debt discount, net 27 — 37 — Total interest expense related to the 2024 Notes $ 4,215 $ — $ 5,594 $ — 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 September 30, 2017 , 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	6 Months Ended
	Sep. 30, 2017
Common Stock Repurchase Program [Abstract]
Common Stock and Debentures Repurchase Program [Text Block]	Common Stock Repurchase Program The Board of Directors has approved stock repurchase programs enabling the Company to repurchase its common stock in the open market or through negotiated transactions with independent financial institutions. 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. Through September 30, 2017 , the Company had used $555.4 million of the $1.00 billion authorized under the 2016 Repurchase Program, leaving $444.6 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 September 30, 2017 and April 1, 2017 . During the first six months of fiscal year 2018 , the Company repurchased 3.7 million shares of common stock in the open market and through an accelerated share repurchase agreement with an independent financial institution for a total of $237.5 million . During the first six months of fiscal year 2017 , the Company repurchased 4.1 million shares of common stock in the open market for a total of $200.1 million .

Interest and Other Expense, Net

Interest and Other Expense, Net	6 Months Ended
	Sep. 30, 2017
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Interest income $ 13,832 $ 12,098 $ 27,246 $ 23,564 Interest expense (11,029 ) (13,870 ) (23,110 ) (27,738 ) Other income (expense), net (972 ) 621 (467 ) (1,564 ) Interest and other income (expense), net $ 1,831 $ (1,151 ) $ 3,669 $ (5,738 )

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Sep. 30, 2017
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 accumulated other comprehensive loss are as follows: (In thousands) September 30, 2017 April 1, 2017 Accumulated unrealized losses on available-for-sale securities, net of tax $ (11,260 ) $ (17,091 ) Accumulated unrealized gains on hedging transactions, net of tax 854 661 Accumulated cumulative translation adjustment, net of tax (5,813 ) (8,251 ) Accumulated other comprehensive loss $ (16,219 ) $ (24,681 ) The related tax effects of other comprehensive loss were not material for all periods presented.

Income Taxes

Income Taxes	6 Months Ended
	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded tax provisions of $19.5 million and $34.5 million for the second quarter and the first six months of fiscal year 2018 , respectively, representing an effective tax rate of 10% and 9% , respectively. The Company recorded tax provisions of $11.5 million and $30.0 million for the second quarter and the first six months of fiscal year 2017 , respectively, representing an effective tax rate of 7% and 8% , respectively. The difference between the U.S. federal statutory tax rate of 35% and the Company’s effective tax rate in all periods was primarily due to income earned in lower tax rate jurisdictions, for which no U.S. income tax has been provided, as the Company intends to permanently reinvest these earnings outside of the U.S. The Company’s total gross unrecognized tax benefits as of September 30, 2017 increased by $90.6 million in the first six months of fiscal year 2018 to $121.0 million . The increase is primarily attributable to an additional deduction claimed on federal and state amended returns for repurchase premium paid in connection with the early redemption of the Company’s 3.125% Junior Convertible debenture due March 15, 2037 (2037 Convertible Notes) in fiscal year 2014. As of September 30, 2017 , the total amount of unrecognized tax benefits that, if realized in a future period, would favorably affect the effective tax rate is $13.7 million . Another $85.5 million related to the 2037 Convertible Notes would increase additional paid-in capital. It is reasonably possible that changes to our unrecognized tax benefits could be significant in the next twelve months due to tax audit settlements and lapses of statutes of limitation. As a result of uncertainties regarding tax audit settlements and their possible outcomes, an estimate of the range of increase or decrease that could occur in the next twelve months cannot be determined at this time. The Company’s policy is to include interest and penalties related to income tax liabilities within the provision for income taxes on the condensed consolidated statements of income. The balance of accrued interest and penalties recorded in the condensed consolidated balance sheets and the amounts of interest and penalties included in the Company's provision for income taxes were not material for all periods presented. The Company is no longer subject to U.S. federal audits by taxing authorities for years through fiscal year 2013, U.S. state audits for years through fiscal year 2010 and tax audits in Ireland for years through fiscal year 2011.

Commitments

Commitments	6 Months Ended
	Sep. 30, 2017
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. Approximate future minimum lease payments under non-cancelable operating leases are as follows: Fiscal (In thousands) 2018 (remaining six months) $ 2,916 2019 4,856 2020 6,680 2021 5,659 2022 5,696 Thereafter 29,444 Total $ 55,251 Aggregate future rental income to be received from owned property totaled $9.2 million as of September 30, 2017 . Rent expense, net of rental income, under all operating leases was $900 thousand and $2.1 million for the three and six months ended September 30, 2017 , respectively. Rent expense, net of rental income, under all operating leases was $1.3 million and $2.5 million for the three and six months ended October 1, 2016 , respectively. Rental income was not material for the second quarter and the first six months of fiscal years 2018 and 2017 . Other commitments as of September 30, 2017 totaled $127.1 million and consisted of purchases of inventory and other non-cancelable purchase obligations related to subcontractors that manufacture silicon wafers and provide assembly and test services. The Company expects to receive and pay for these materials and services in the next three to six months, as the products meet delivery and quality specifications. As of September 30, 2017 , the Company had $35.3 million of non-cancelable license obligations to providers of electronic design automation software and hardware/software maintenance expiring at various dates through December 2019 .

Product Warranty and Indemnific

Product Warranty and Indemnification	6 Months Ended
	Sep. 30, 2017
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 second quarter of fiscal year 2018 and the end of fiscal year 2017 , the accrual balance of the product warranty liability was immaterial. The Company offers, subject to certain terms and conditions, to indemnify customers and distributors for costs and damages awarded against these parties in the event the Company’s hardware products are found to infringe third-party intellectual property rights, including patents, copyrights or trademarks, and to compensate certain customers for limited specified costs they actually incur in the event our hardware products experience epidemic failure. To a lesser extent, the Company may from time-to-time offer limited indemnification with respect to its software products. The terms and conditions of these indemnity obligations are limited by contract, which obligations are typically perpetual from the effective date of the agreement. The Company has historically received only a limited number of requests for indemnification under these provisions and has not made any significant payments pursuant to these provisions. The Company cannot estimate the maximum amount of potential future payments, if any, that the Company may be required to make as a result of these obligations due to the limited history of indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim and indemnification provision. However, there can be no assurances that the Company will not incur any financial liabilities in the future as a result of these obligations.

Contingencies

Contingencies	6 Months Ended
	Sep. 30, 2017
Loss Contingency [Abstract]
Contingencies	Contingencies Patent Litigation On July 17, 2014, a patent infringement lawsuit was filed by PLL Technologies, Inc. (PTI) against the Company in the U.S. District Court for the District of Delaware (PLL Technologies, Inc. v. Xilinx, Inc., Case No. 1:14-CV-00945). On April 28, 2015, the U.S. Patent Trial and Appeal Board (PTAB) granted Xilinx's request for inter partes review (IPR) with respect to all claims in the litigation. On May 5, 2015, the Court ordered the litigation be stayed pending final resolution of the IPR. On April 18, 2016, the PTAB issued a final written decision in which all of the asserted claims were found unpatentable. On June 14, 2016, PTI filed notice of appeal from the final written decision. On June 13, 2017, the Federal Circuit affirmed the PTAB’s findings of invalidity. On July 19, 2017, the U.S. District Court case was dismissed with prejudice. 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 the same date, the Company filed a complaint for declaratory judgment of patent non-infringement against IP Bridge in the U.S. District Court for the Northern District of California (Xilinx, Inc. v. Godo Kaisha IP Bridge 1, Case No. 5:17-cv-00509). The complaint filed by the Company pertained to twelve other patents and sought judgment of non-infringement by Xilinx, as well as costs, expenses and attorneys’ fees. On June 15, 2017, IP Bridge granted Xilinx a royalty-free covenant not to sue for infringement of those twelve patents, and on June 16, 2017, the parties filed a stipulated dismissal without prejudice of the declaratory judgment action in California. The Company is unable to estimate its range of possible loss, if any, in the remaining action in Texas 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. 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 our 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 the action in its entirety. The motions are not yet fully briefed and the Court has therefore not ruled on them. The Company intends to vigorously defend the case and is unable to estimate its range of possible loss, if any, in this matter at this time. On April 4, 2017, Mountjoy Chilton Medley, LLP filed a third-party complaint against Xilinx and others in the U.S. District Court for the Middle District of Pennsylvania (Case No. 4:15-cv-01622-MWB). The complaint alleges that to the extent the third-party plaintiff is found liable, that the actions or inactions of Xilinx and others entitles the third-party plaintiff to apportionment of damages based on the allegations against Xilinx in the case filed by the Chapter 7 Trustee of Valley Forge Composite Technologies, Inc. On August 28, 2017, Xilinx, along with other third party defendants, filed a motion to dismiss the complaint. On October 10, 2017, the Court granted the motion to dismiss. 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	6 Months Ended
	Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquisition-Related Intangibles	Goodwill and Acquisition-Related Intangibles As of September 30, 2017 , there have been no material changes to the Company's goodwill and acquisition-related intangibles since April 1, 2017 .

Subsequent Events (Notes)

Subsequent Events (Notes)	6 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On October 24, 2017 , the Company’s Board of Directors declared a cash dividend of $0.35 per common share for the third quarter of fiscal year 2018 . The dividend is payable on December 6, 2017 to stockholders of record on November 15, 2017 .

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Policies)	6 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Share based compensation, Restricted Stock and Restricted Stock Units Policy [Policy Text Block]	The estimated fair values of RSU awards were calculated based on the market price of Xilinx common stock on the date of grant, reduced by the present value of dividends expected to be paid on Xilinx common stock prior to vesting.

Inventories Inventories (Polici

Inventories Inventories (Policies)	6 Months Ended
	Sep. 30, 2017
Inventory Disclosure [Abstract]
Inventory, Policy [Policy Text Block]	Inventories are stated at the lower of actual cost (determined using the first-in, first-out method) or market (estimated net realizable value)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Sep. 30, 2017
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 September 30, 2017 and April 1, 2017 : September 30, 2017 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 323,034 $ — $ — $ 323,034 Financial institution securities — 255,864 — 255,864 Non-financial institution securities — 192,800 — 192,800 U.S. government and agency securities 13,880 31,528 — 45,408 Foreign government and agency securities — 184,868 — 184,868 Short-term investments: Financial institution securities — 324,853 — 324,853 Non-financial institution securities — 226,546 — 226,546 U.S. government and agency securities 27,098 23,158 — 50,256 Foreign government and agency securities — 79,920 — 79,920 Asset-backed securities — 217,827 — 217,827 Mortgage-backed securities — 1,154,680 — 1,154,680 Debt mutual fund — 34,029 — 34,029 Bank loans — 157,899 — 157,899 Commercial mortgage-backed securities — 244,017 — 244,017 Long-term investments: Asset-backed securities — 1,430 — 1,430 Mortgage-backed securities — 41,971 — 41,971 Debt mutual fund — 56,461 — 56,461 Total assets measured at fair value $ 364,012 $ 3,227,851 $ — $ 3,591,863 Liabilities Derivative financial instruments, net $ — $ 1,462 $ — $ 1,462 Total liabilities measured at fair value $ — $ 1,462 $ — $ 1,462 Net assets measured at fair value $ 364,012 $ 3,226,389 $ — $ 3,590,401 April 1, 2017 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 298,307 $ — $ — $ 298,307 Non-financial institution securities — 205,322 — 205,322 Foreign government and agency securities — 177,310 — 177,310 Financial institution securities — 158,962 — 158,962 U.S government and agency securities 2,998 50,984 — 53,982 Short-term investments: Financial institution securities — 189,835 — 189,835 Non-financial institution securities — 203,938 — 203,938 U.S. government and agency securities 31,732 44,820 — 76,552 Foreign government and agency securities — 144,811 — 144,811 Mortgage-backed securities — 1,115,403 — 1,115,403 Debt mutual fund — 34,068 — 34,068 Bank loans — 154,014 — 154,014 Asset-backed securities — 218,170 — 218,170 Commercial mortgage-backed securities — 217,971 — 217,971 Long-term investments: Mortgage-backed securities — 60,099 — 60,099 Debt mutual fund — 54,608 — 54,608 Asset-backed securities — 1,581 — 1,581 Derivative financial instruments, net — 1,661 — 1,661 Total assets measured at fair value $ 333,037 $ 3,033,557 $ — $ 3,366,594
Changes in Level 3 instruments measured at fair value on a recurring basis	The following table is a reconciliation of all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3): Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Balance as of beginning of period $ — $ 10,068 $ — $ 9,977 Total unrealized gains (losses): Included in other comprehensive income (loss) — 92 — 183 Balance as of end of period $ — $ 10,160 $ — $ 10,160

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Sep. 30, 2017
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: September 30, 2017 April 1, 2017 (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 $ 323,034 $ — $ — $ 323,034 $ 298,307 $ — $ — $ 298,307 Financial institution securities 580,717 — — 580,717 348,797 — — 348,797 Non-financial institution securities 418,879 744 (277 ) 419,346 409,109 647 (496 ) 409,260 U.S. government and — agency securities 95,793 5 (134 ) 95,664 130,749 8 (223 ) 130,534 Foreign government and agency securities 264,788 — — 264,788 322,172 — (51 ) 322,121 Mortgage-backed securities 1,201,005 5,409 (9,763 ) 1,196,651 1,186,732 3,527 (14,757 ) 1,175,502 Asset-backed securities 219,255 480 (478 ) 219,257 220,033 404 (686 ) 219,751 Debt mutual funds 101,350 — (10,860 ) 90,490 101,350 — (12,674 ) 88,676 Bank loans 157,510 643 (254 ) 157,899 153,281 839 (106 ) 154,014 Commercial mortgage- backed securities 247,390 199 (3,572 ) 244,017 221,504 146 (3,679 ) 217,971 $ 3,609,721 $ 7,480 $ (25,338 ) $ 3,591,863 $ 3,392,034 $ 5,571 $ (32,672 ) $ 3,364,933
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 September 30, 2017 and April 1, 2017 : September 30, 2017 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 $ 62,033 $ (210 ) $ 5,606 $ (67 ) $ 67,639 $ (277 ) U.S. government and agency securities 34,015 (125 ) 5,130 (9 ) 39,145 (134 ) Mortgage-backed securities 730,974 (6,516 ) 157,026 (3,247 ) 888,000 (9,763 ) Asset-backed securities 135,560 (464 ) 4,757 (14 ) 140,317 (478 ) Debt mutual funds — — 90,490 (10,860 ) 90,490 (10,860 ) Bank loans 30,107 (254 ) — — 30,107 (254 ) Commercial mortgage- backed securities 119,843 (893 ) 60,028 (2,679 ) 179,871 (3,572 ) $ 1,112,532 $ (8,462 ) $ 323,037 $ (16,876 ) $ 1,435,569 $ (25,338 ) April 1, 2017 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 $ 68,850 $ (492 ) $ 1,022 $ (4 ) $ 69,872 $ (496 ) U.S. government and agency securities 64,895 (223 ) — — 64,895 (223 ) Mortgage-backed securities 811,058 (11,872 ) 139,931 (2,885 ) 950,989 (14,757 ) Asset-backed securities 119,845 (651 ) 4,689 (35 ) 124,534 (686 ) Debt mutual funds — — 88,676 (12,674 ) 88,676 (12,674 ) Bank loans 15,139 (106 ) — — 15,139 (106 ) Foreign government and agency securities 64,857 (51 ) — — 64,857 (51 ) Commercial mortgage- backed securities 165,393 (1,706 ) 24,362 (1,973 ) 189,755 (3,679 ) $ 1,310,037 $ (15,101 ) $ 258,680 $ (17,571 ) $ 1,568,717 $ (32,672 )
Amortized cost and estimated fair value of marketable debt securities	September 30, 2017 (In thousands) Amortized Estimated Due in one year or less $ 1,200,344 $ 1,200,345 Due after one year through five years 469,451 467,424 Due after five years through ten years 312,956 312,503 Due after ten years 1,202,586 1,198,067 $ 3,185,337 $ 3,178,339
Information on sale of available-for-sale securities	Certain information related to available-for-sale securities is as follows: Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Proceeds from sale of available-for-sale securities $ 149,497 $ 153,871 $ 269,419 $ 253,345 Gross realized gains on sale of available-for-sale securities $ 519 $ 762 $ 1,351 $ 1,427 Gross realized losses on sale of available-for-sale securities (209 ) (92 ) (595 ) (604 ) Net realized gains on sale of available-for-sale securities $ 310 $ 670 $ 756 $ 823 Amortization of premiums on available-for-sale securities $ 4,691 $ 7,414 $ 10,213 $ 14,175

Stock-Based Compensation Plan30

Stock-Based Compensation Plans (Tables)	6 Months Ended
	Sep. 30, 2017
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Stock-based compensation included in: Cost of revenues $ 2,147 $ 1,930 $ 4,297 $ 4,049 Research and development 20,096 16,529 37,562 31,649 Selling, general and administrative 14,129 11,343 26,549 23,508 $ 36,372 $ 29,802 $ 68,408 $ 59,206
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	The per share weighted-average fair value of RSUs granted during the second quarter of fiscal year 2018 was $59.99 ( $42.89 for the second quarter of fiscal year 2017 ), and for the first six months of fiscal year 2018 was $59.89 ( $42.87 for the first six months of fiscal year 2017 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended Six Months Ended September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Risk-free interest rate 1.7 % 0.8 % 1.7 % 0.8 % Dividend yield 2.2 % 2.9 % 2.2 % 2.9 %
Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]	The fair values of stock purchase plan rights granted in the second quarter of fiscal years 2018 and 2017 were estimated using the Black-Scholes option pricing model at the date of grant using the following assumptions: 2018 2017 Expected life of options (years) 1.25 1.25 Expected stock price volatility 0.28 0.23 Risk-free interest rate 1.3 % 0.5 % Dividend yield 2.2 % 2.6 %
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 2, 2016 6,619 $ 40.74 Granted 3,398 $ 44.38 Vested (2,619 ) $ 39.49 Cancelled (410 ) $ 41.63 April 1, 2017 6,988 $ 42.93 Granted 3,262 $ 59.89 Vested (2,288 ) $ 41.99 Cancelled (314 ) $ 46.76 September 30, 2017 7,648 $ 49.91

Net Income Per Common Share Net

Net Income Per Common Share Net Income Per Common Share (Tables)	6 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table summarizes the computation of basic and diluted net income per common share: Three Months Ended Six Months Ended (In thousands, except per share amounts) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Net income available to common stockholders $ 167,532 $ 164,192 $ 334,777 $ 327,241 Weighted average common shares outstanding-basic 248,094 253,466 247,960 253,056 Dilutive effect of employee equity incentive plans 2,532 2,126 2,949 2,319 Dilutive effect of 2017 Convertible Notes — 9,587 2,986 8,736 Dilutive effect of warrants 7,591 5,194 7,844 3,774 Weighted average common shares outstanding-diluted 258,217 270,373 261,739 267,885 Basic earnings per common share $ 0.68 $ 0.65 $ 1.35 $ 1.29 Diluted earnings per common share $ 0.65 $ 0.61 $ 1.28 $ 1.22

Inventories Inventories (Tables

Inventories Inventories (Tables)	6 Months Ended
	Sep. 30, 2017
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) September 30, 2017 April 1, 2017 Raw materials $ 16,699 $ 14,517 Work-in-process 152,252 161,120 Finished goods 46,446 51,396 $ 215,397 $ 227,033

Debt and Credit Facility (Table

Debt and Credit Facility (Tables)	6 Months Ended
	Sep. 30, 2017
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Schedule of Debt Instruments [Line Items]
Carrying values of liability and equity components of debentures	The carrying values of the liability and equity components of the 2017 Convertible Notes are reflected in the Company’s condensed consolidated balance sheets as follows: (In thousands) September 30, 2017 April 1, 2017 Liability component: Principal amount of the 2017 Convertible Notes $ — $ 457,918 Unamortized discount of liability component — (1,977 ) Hedge accounting adjustment – sale of interest rate swap — 571 Unamortized debt issuance costs associated with 2017 Convertible Notes — (184 ) Net carrying value of the 2017 Convertible Notes $ — $ 456,328 Equity component (including temporary equity) – net carrying value $ — $ 50,688
Interest Expense Related to Debentures [Table Text Block]	nterest expense related to the 2017 Convertible Notes was included in interest and other income (expense), net on the condensed consolidated statements of income, and was recognized as follows: Three Months Ended Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ — $ 3,938 $ 2,300 $ 7,875 Amortization of debt issuance costs — 362 184 724 Amortization of debt discount, net — 2,763 1,406 5,526 Total interest expense related to the 2017 Convertible Notes $ — $ 7,063 $ 3,890 $ 14,125
2019 and 2021 Notes Payable [Member]
Schedule of Debt Instruments [Line Items]
Schedule of Long-term Debt Instruments [Table Text Block]	The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of September 30, 2017 and April 1, 2017 : (In thousands) September 30, 2017 April 1, 2017 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (770 ) (1,037 ) Unamortized debt issuance costs associated with the 2019 Notes (484 ) (654 ) Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,852 ) (2,107 ) Unamortized debt issuance costs associated with the 2021 Notes (833 ) (955 ) Total carrying value $ 996,061 $ 995,247
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ 6,406 $ 6,406 $ 12,813 $ 12,813 Amortization of debt issuance costs 146 146 293 293 Amortization of debt discount, net 262 255 520 507 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,814 $ 6,807 $ 13,626 $ 13,613
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 September 30, 2017 and April 1, 2017 : (In thousands) September 30, 2017 April 1, 2017 Principal amount of the 2024 Notes $ 750,000 $ — Unamortized discount of the 2024 Notes (810 ) — Unamortized debt issuance costs associated with 2024 Notes (3,789 ) — Carrying value of the 2024 Notes $ 745,401 $ — Fair value hedge adjustment - interest rate swap contracts (2,796 ) — Net carrying value of the 2024 Notes $ 742,605 $ —
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Contractual coupon interest $ 4,046 $ — $ 5,368 $ — Amortization of debt issuance costs 142 — 189 — Amortization of debt discount, net 27 — 37 — Total interest expense related to the 2024 Notes $ 4,215 $ — $ 5,594 $ —

Interest And Other Expense, N34

Interest And Other Expense, Net (Tables)	6 Months Ended
	Sep. 30, 2017
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 Six Months Ended (In thousands) September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016 Interest income $ 13,832 $ 12,098 $ 27,246 $ 23,564 Interest expense (11,029 ) (13,870 ) (23,110 ) (27,738 ) Other income (expense), net (972 ) 621 (467 ) (1,564 ) Interest and other income (expense), net $ 1,831 $ (1,151 ) $ 3,669 $ (5,738 )

Accumulated Other Comprehensi35

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Components of accumulated other comprehensive income (loss)	The components of accumulated other comprehensive loss are as follows: (In thousands) September 30, 2017 April 1, 2017 Accumulated unrealized losses on available-for-sale securities, net of tax $ (11,260 ) $ (17,091 ) Accumulated unrealized gains on hedging transactions, net of tax 854 661 Accumulated cumulative translation adjustment, net of tax (5,813 ) (8,251 ) Accumulated other comprehensive loss $ (16,219 ) $ (24,681 )

Commitments (Tables)

Commitments (Tables)	6 Months Ended
	Sep. 30, 2017
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) 2018 (remaining six months) $ 2,916 2019 4,856 2020 6,680 2021 5,659 2022 5,696 Thereafter 29,444 Total $ 55,251

Significant Customers and Con37

Significant Customers and Concentrations of Credit Risk (Details) - Customer	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Apr. 01, 2017
Significant Customers and Concentrations of Credit Risk [Abstract]
Percentage of Accounts Receivable Accounted From Company Distributor One	67.00%		67.00%		59.00%
Percentage of net revenues through resale of product from Company Distributor One	44.00%	43.00%	42.00%	50.00%
Number of End Customers Accounted For 10% or More of Net Revenues	0	0	0	0
Percentage of higher grade securities investment in debt securities	84.00%		84.00%
Percentage of Mortgage Backed Securities In Investment Portfolio	33.00%		33.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Jul. 01, 2017	Apr. 01, 2017	Jul. 02, 2016	Apr. 02, 2016
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 0	$ 10,160	$ 0	$ 10,160	$ 0	$ 0	$ 10,068	$ 9,977
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	0	$ 92	0	$ 183
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	3,591,863		3,591,863			3,366,594
Liabilities, Fair Value Disclosure, Recurring	1,462		1,462
Fair Value, Net Asset (Liability)	3,590,401		3,590,401
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	364,012		364,012			333,037
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Net Asset (Liability)	364,012		364,012
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	3,227,851		3,227,851			3,033,557
Liabilities, Fair Value Disclosure, Recurring	1,462		1,462
Fair Value, Net Asset (Liability)	3,226,389		3,226,389
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Net Asset (Liability)	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, Fair Value Disclosure, Recurring	323,034		323,034			298,307
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, Fair Value Disclosure, Recurring	255,864		255,864			158,962
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, Fair Value Disclosure, Recurring	192,800		192,800			205,322
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, Fair Value Disclosure, Recurring	45,408		45,408			53,982
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, Fair Value Disclosure, Recurring	184,868		184,868			177,310
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, Fair Value Disclosure, Recurring	323,034		323,034			298,307
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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	13,880		13,880			2,998
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	255,864		255,864			158,962
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, Fair Value Disclosure, Recurring	192,800		192,800			205,322
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, Fair Value Disclosure, Recurring	31,528		31,528			50,984
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, Fair Value Disclosure, Recurring	184,868		184,868			177,310
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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	324,853		324,853			189,835
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, Fair Value Disclosure, Recurring	226,546		226,546			203,938
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, Fair Value Disclosure, Recurring	50,256		50,256			76,552
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, Fair Value Disclosure, Recurring	79,920		79,920			144,811
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, Fair Value Disclosure, Recurring	217,827		217,827			218,170
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, Fair Value Disclosure, Recurring	1,154,680		1,154,680			1,115,403
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	34,029		34,029			34,068
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	157,899		157,899			154,014
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, Fair Value Disclosure, Recurring	244,017		244,017			217,971
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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	27,098		27,098			31,732
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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		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, Fair Value Disclosure, Recurring	0		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, Fair Value Disclosure, Recurring	324,853		324,853			189,835
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, Fair Value Disclosure, Recurring	226,546		226,546			203,938
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, Fair Value Disclosure, Recurring	23,158		23,158			44,820
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, Fair Value Disclosure, Recurring	79,920		79,920			144,811
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, Fair Value Disclosure, Recurring	217,827		217,827			218,170
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, Fair Value Disclosure, Recurring	1,154,680		1,154,680			1,115,403
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	34,029		34,029			34,068
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	157,899		157,899			154,014
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, Fair Value Disclosure, Recurring	244,017		244,017			217,971
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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		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, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,430		1,430			1,581
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	41,971		41,971			60,099
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, Fair Value Disclosure, Recurring	56,461		56,461			54,608
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						1,661
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,430		1,430			1,581
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	41,971		41,971			60,099
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, Fair Value Disclosure, Recurring	56,461		56,461			54,608
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						1,661
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	$ 0		$ 0			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						$ 0

Fair Value Measurements (Deta39

Fair Value Measurements (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Changes in Level 3 instruments measured at fair value on a recurring basis
Balance as of beginning of period	$ 0	$ 10,068	$ 0	$ 9,977
Total realized and unrealized gains (losses) included in other comprehensive income	0	92	0	183
Balance as of end of period	$ 0	$ 10,160	$ 0	$ 10,160

Fair Value Measurements (Deta40

Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Sep. 30, 2017	Apr. 01, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 3,591,863	$ 3,364,933
2.125% 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 debentures	$ 501,300
3.0% 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 debentures	$ 509,600
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 debentures	$ 750,100

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 01, 2017
Available-for-sale securities
Amortized Cost	$ 3,609,721	$ 3,392,034
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	7,480	5,571
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(25,338)	(32,672)
Estimated Fair Value	3,591,863	3,364,933
Money Market Funds [Member]
Available-for-sale securities
Amortized Cost	323,034	298,307
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Estimated Fair Value	323,034	298,307
Financial institution securities [Member]
Available-for-sale securities
Amortized Cost	580,717	348,797
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Estimated Fair Value	580,717	348,797
Non-financial institution securities [Member]
Available-for-sale securities
Amortized Cost	418,879	409,109
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	744	647
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(277)	(496)
Estimated Fair Value	419,346	409,260
Auction Rate Securities [Member]
Available-for-sale securities
Estimated Fair Value	0
U.S. Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	95,793	130,749
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	5	8
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(134)	(223)
Estimated Fair Value	95,664	130,534
Foreign Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	264,788	322,172
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	0	(51)
Estimated Fair Value	264,788	322,121
Mortgage-Backed Securities [Member]
Available-for-sale securities
Amortized Cost	1,201,005	1,186,732
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	5,409	3,527
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(9,763)	(14,757)
Estimated Fair Value	1,196,651	1,175,502
Asset-backed Securities [Member]
Available-for-sale securities
Amortized Cost	219,255	220,033
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	480	404
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(478)	(686)
Estimated Fair Value	219,257	219,751
Debt Mutual Fund [Member]
Available-for-sale securities
Amortized Cost	101,350	101,350
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(10,860)	(12,674)
Estimated Fair Value	90,490	88,676
Bank Loans [Member]
Available-for-sale securities
Amortized Cost	157,510	153,281
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	643	839
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(254)	(106)
Estimated Fair Value	157,899	154,014
Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	247,390	221,504
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	199	146
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax	(3,572)	(3,679)
Estimated Fair Value	$ 244,017	$ 217,971

Financial Instruments (Details

Financial Instruments (Details 1) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 01, 2017
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	$ 1,112,532	$ 1,310,037
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(8,462)	(15,101)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	323,037	258,680
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(16,876)	(17,571)
Available-for-Sale Securities, Fair Value, Total	1,435,569	1,568,717
Available-for-Sale Securities, Gross Unrealized Losses, Total	(25,338)	(32,672)
Non-financial institution securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	62,033	68,850
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(210)	(492)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	5,606	1,022
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(67)	(4)
Available-for-Sale Securities, Fair Value, Total	67,639	69,872
Available-for-Sale Securities, Gross Unrealized Losses, Total	(277)	(496)
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	34,015	64,895
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(125)	(223)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	5,130	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(9)	0
Available-for-Sale Securities, Fair Value, Total	39,145	64,895
Available-for-Sale Securities, Gross Unrealized Losses, Total	(134)	(223)
Foreign Government Debt Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value		64,857
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses		(51)
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		64,857
Available-for-Sale Securities, Gross Unrealized Losses, Total		(51)
Mortgage-Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	730,974	811,058
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(6,516)	(11,872)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	157,026	139,931
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(3,247)	(2,885)
Available-for-Sale Securities, Fair Value, Total	888,000	950,989
Available-for-Sale Securities, Gross Unrealized Losses, Total	(9,763)	(14,757)
Asset-backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	135,560	119,845
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(464)	(651)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	4,757	4,689
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(14)	(35)
Available-for-Sale Securities, Fair Value, Total	140,317	124,534
Available-for-Sale Securities, Gross Unrealized Losses, Total	(478)	(686)
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	90,490	88,676
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(10,860)	(12,674)
Available-for-Sale Securities, Fair Value, Total	90,490	88,676
Available-for-Sale Securities, Gross Unrealized Losses, Total	(10,860)	(12,674)
Bank Loans [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	30,107	15,139
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(254)	(106)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	0	0
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	0	0
Available-for-Sale Securities, Fair Value, Total	30,107	15,139
Available-for-Sale Securities, Gross Unrealized Losses, Total	(254)	(106)
Commercial Mortgage Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	119,843	165,393
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(893)	(1,706)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	60,028	24,362
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(2,679)	(1,973)
Available-for-Sale Securities, Fair Value, Total	179,871	189,755
Available-for-Sale Securities, Gross Unrealized Losses, Total	$ (3,572)	$ (3,679)

Financial Instruments (Detail43

Financial Instruments (Details 2) $ in Thousands	Sep. 30, 2017USD ($)
Amortized cost and estimated fair value of marketable debt securities
Amortized Cost Due in one year or less	$ 1,200,344
Amortized Cost Due after one year through five years	469,451
Amortized Cost Due after five years through ten years	312,956
Amortized Cost Due after ten years	1,202,586
Amortized Cost Total	3,185,337
Estimated Fair Value Due in one year or less	1,200,345
Estimated Fair Value Due after one year through five years	467,424
Estimated Fair Value Due after five years through ten years	312,503
Estimated Fair Value Due after ten years	1,198,067
Estimated Fair Value Total	3,178,339
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$ 1,930,000

Financial Instruments (Detail44

Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Investments, All Other Investments [Abstract]
Proceeds from Sale of Available-for-sale Securities	$ 149,497	$ 153,871	$ 269,419	$ 253,345
Gross realized gains on sale of available-for-sale securities	519	762	1,351	1,427
Gross realized losses on sale of available-for-sale securities	(209)	(92)	(595)	(604)
Net realized gains (losses) on sale of available-for-sale securities	310	670	756	823
Amortization of premiums on available-for-sale securities	$ 4,691	$ 7,414	$ 10,213	$ 14,175

Derivative Financial Instrume45

Derivative Financial Instruments (Details Textual) $ in Millions	6 Months Ended
	Sep. 30, 2017USD ($)
Interest Rate Swap [Member]
Derivative [Line Items]
Change in fair value of interest rate derivative	$ 2.8

Stock-Based Compensation Plan46

Stock-Based Compensation Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 36,372	$ 29,802	$ 68,408	$ 59,206
Cost of Sales [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	2,147	1,930	4,297	4,049
Research and Development [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	20,096	16,529	37,562	31,649
Selling, General and Administrative Expenses [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 14,129	$ 11,343	$ 26,549	$ 23,508

Stock-Based Compensation Plan47

Stock-Based Compensation Plans (Details 1)	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Weighted average assumptions in estimation of fair value of stock options
Risk-free interest rate	1.70%	0.80%	1.70%	0.80%
Dividend yield	2.20%	2.90%	2.20%	2.90%

Stock-Based Compensation Plan48

Stock-Based Compensation Plans (Details 3) - $ / shares shares in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Apr. 01, 2017
Summary Of Restricted Stock Unit Activity and Related Information
Number of Shares, Beginning Balance			6,988	6,619	6,619
Number of Shares, Granted			3,262		3,398
Number of Shares, Vested			(2,288)		(2,619)
Number of Shares, Forfeited/Cancelled			(314)		(410)
Number of Shares, Ending Balance	7,648		7,648		6,988
Weighted-Average Grant-Date Fair Value, Beginning Balance			$ 42.93	$ 40.74	$ 40.74
Weighted-Average Grant-Date Fair Value, Vested			41.99		39.49
Weighted-Average Grant-Date Fair Value, Forfeited/Cancelled			46.76		41.63
Weighted-Average Grant-Date Fair Value, Ending Balance	$ 49.91		49.91		42.93
Restricted Stock Units (RSUs) [Member]
Summary Of Restricted Stock Unit Activity and Related Information
Weighted-Average Grant-Date Fair Value, Granted	$ 59.99	$ 42.89	$ 59.89	$ 42.87	$ 44.38

Stock-Based Compensation Plan49

Stock-Based Compensation Plans (Details Textual) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Apr. 01, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Payments Related to Tax Withholding for Share-based Compensation			$ 42,053	$ 28,352
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 6,300	$ 2,900	17,900	9,700
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period, Intrinsic Value	$ 465	$ 8,800	$ 3,200	$ 21,400
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	1.70%	0.80%	1.70%	0.80%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.20%	2.90%	2.20%	2.90%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted	$ 59.99	$ 42.89	$ 59.89	$ 42.87	$ 44.38
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Shares, Employee Stock Purchase Plans	355	446
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 16,900	$ 15,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term	1 year 3 months	1 year 3 months
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate	28.00%	23.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	1.30%	0.50%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.20%	2.60%
Equity Plan Two Thousand Seven [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			1,900
Shares Available for Grant	11,400		11,400
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized			2,000
Weighted-Average Grant-Date Fair Value, Granted	$ 16.46	$ 11.64
Shares Available for Grant	9,900		9,900

Net Income Per Common Share (De

Net Income Per Common Share (Details) - USD ($) shares in Thousands		3 Months Ended			6 Months Ended
		Sep. 30, 2017	Jul. 01, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Apr. 01, 2017
Schedule of Debt Instruments [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	[1]	0		9,587	2,986	8,736
Antidilutive shares excluded from computation of dilutive net income per common share		1,000			3,200
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Schedule of Debt Instruments [Line Items]
Debt Instrument, Face Amount		$ 0	$ 0		$ 0		$ 457,918,000
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Schedule of Debt Instruments [Line Items]
Debt Instrument, Face Amount			$ 600,000,000
Debt Instrument, Interest Rate, Stated Percentage			2.625%
Debt Instrument, Maturity Date			Jun. 15, 2017
[1]	Three Months Ended Six Months Ended(In thousands, except per share amounts)September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016Net income available to common stockholders$167,532 $164,192 $334,777 $327,241Weighted average common shares outstanding-basic248,094 253,466 247,960 253,056Dilutive effect of employee equity incentive plans2,532 2,126 2,949 2,319Dilutive effect of 2017 Convertible Notes— 9,587 2,986 8,736Dilutive effect of warrants7,591 5,194 7,844 3,774Weighted average common shares outstanding-diluted258,217 270,373 261,739 267,885Basic earnings per common share$0.68 $0.65 $1.35 $1.29Diluted earnings per common share$0.65 $0.61 $1.28 $1.22

Net Income Per Common Share N51

Net Income Per Common Share Net Income Per Common Share (Details 2) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
		Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Earnings Per Share [Abstract]
Net income		$ 167,532	$ 164,192	$ 334,777	$ 327,241
Weighted Average Number of Shares Outstanding, Basic		248,094	253,466	247,960	253,056
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements		2,532	2,126	2,949	2,319
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	[1]	0	9,587	2,986	8,736
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants		7,591	5,194	7,844	3,774
Weighted Average Number of Shares Outstanding, Diluted		258,217	270,373	261,739	267,885
Earnings Per Share, Basic		$ 0.68	$ 0.65	$ 1.35	$ 1.29
Earnings Per Share, Diluted		$ 0.65	$ 0.61	$ 1.28	$ 1.22
[1]	Three Months Ended Six Months Ended(In thousands, except per share amounts)September 30, 2017 October 1, 2016 September 30, 2017 October 1, 2016Net income available to common stockholders$167,532 $164,192 $334,777 $327,241Weighted average common shares outstanding-basic248,094 253,466 247,960 253,056Dilutive effect of employee equity incentive plans2,532 2,126 2,949 2,319Dilutive effect of 2017 Convertible Notes— 9,587 2,986 8,736Dilutive effect of warrants7,591 5,194 7,844 3,774Weighted average common shares outstanding-diluted258,217 270,373 261,739 267,885Basic earnings per common share$0.68 $0.65 $1.35 $1.29Diluted earnings per common share$0.65 $0.61 $1.28 $1.22

Inventories Inventories (Detail

Inventories Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 01, 2017
Inventory Disclosure [Abstract]
Inventory, Raw Materials, Gross	$ 16,699	$ 14,517
Inventory, Work in Process, Gross	152,252	161,120
Inventory, Finished Goods, Gross	46,446	51,396
Inventory, Net	$ 215,397	$ 227,033

Debt and Credit Facility (Detai

Debt and Credit Facility (Details 1) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Mar. 29, 2014	Apr. 01, 2017
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis			three-month London Interbank Offered Rate (LIBOR) plus 91.43 bps
Net interest rate received (paid) from interest rate swap	$ 1,500,000		$ 2,100,000
Long-term debt	$ 1,738,666,000		1,738,666,000			$ 995,247,000
Amortization of Debt Discount (Premium)			$ 1,964,000	$ 6,034,000
2.125% 2019 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent Of Par	99.477%		99.477%
Debt instrument, long term debt, remaining discount amortization period			1 year 5 months 15 days
Debt Instrument, Face Amount	$ 500,000,000		$ 500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(770,000)		(770,000)			(1,037,000)
Unamortized Debt Issuance Expense	$ 484,000		$ 484,000			654,000
3.0% 2021 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent Of Par	99.281%		99.281%
Debt instrument, long term debt, remaining discount amortization period			3 years 5 months 15 days
Debt Instrument, Face Amount	$ 500,000,000		$ 500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(1,852,000)		(1,852,000)			(2,107,000)
Unamortized Debt Issuance Expense	833,000		833,000			955,000
2019 and 2021 Notes Payable [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Long-term Debt					$ 990,100,000
Long-term debt	996,061,000		996,061,000			995,247,000
Interest Expense, Debt, Excluding Amortization	6,406,000	$ 6,406,000	12,813,000	12,813,000
Amortization of Debt Issuance Costs	146,000	146,000	293,000	293,000
Amortization of Debt Discount (Premium)	262,000	255,000	520,000	507,000
Interest Expense, Debt	$ 6,814,000	6,807,000	$ 13,626,000	13,613,000
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent Of Par	99.887%		99.887%
Proceeds from Issuance of Long-term Debt			$ 745,200,000
Debt instrument, long term debt, remaining discount amortization period			6 years 8 months
Debt Instrument, Interest Rate, Stated Percentage	2.95%		2.95%
Debt Instrument, Face Amount	$ 750,000,000		$ 750,000,000			0
Debt Instrument, Unamortized Discount	(810,000)		(810,000)			0
Unamortized Debt Issuance Expense	(3,789,000)		(3,789,000)			0
Long Term Debt, Carrying Value before Hedging Adjustment	745,401,000		745,401,000			0
Fair Value Adjustment to Long-term Debt, Related to Interest Rate Swap	(2,796,000)		(2,796,000)
Derivative, Amount of Hedged Item						0
Long-term debt	742,605,000		742,605,000			$ 0
Interest Expense, Debt, Excluding Amortization	4,046,000	0	5,368,000	0
Amortization of Debt Issuance Costs	142,000	0	189,000	0
Amortization of Debt Discount (Premium)	27,000	0	37,000	0
Interest Expense, Debt	4,215,000	$ 0	$ 5,594,000	$ 0
two thousand and sixteen credit line [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Initiation Date			Dec. 7, 2016
Line of Credit Facility, Maximum Borrowing Capacity	400,000,000		$ 400,000,000
AdditionalborrowingcapacityfromRevolvingCreditFacility	150,000,000		$ 150,000,000
Line of Credit Facility, Expiration Date			Dec. 31, 2021
Line of Credit Facility, Average Outstanding Amount			$ 0
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	$ 2,800,000		$ 2,800,000

Debt and Credit Facility (Det54

Debt and Credit Facility (Details 2) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended			6 Months Ended
	Sep. 30, 2017	Jul. 01, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016	Oct. 26, 2017	Apr. 01, 2017
Short-term Debt [Line Items]
Stock Issued During Period, Shares, Conversion of Convertible Securities		9
Shares received from exercise of call options		9
Amortization of Debt Discount (Premium)				$ 1,964,000	$ 6,034,000
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Short-term Debt [Line Items]
Debt Instrument, Face Amount	$ 0	$ 0		0			$ 457,918,000
Debt Instrument, Unamortized Discount	0			0			1,977,000
Hedge Accounting Adjustment - Sale Of Interest Rate Swap	0			0			571,000
Unamortized Debt Issuance Expense	0			0			(184,000)
Convertible Debt	0			0			456,328,000
Debt Instrument, Convertible, Carrying Amount of Equity Component	0			0			$ 50,688,000
Interest Expense, Debt, Excluding Amortization	0		$ 3,938,000	2,300,000	7,875,000
Amortization of Debt Issuance Costs	0		362,000	184,000	724,000
Amortization of Debt Discount (Premium)	0		2,763,000	1,406,000	5,526,000
Interest Expense, Debt	$ 0		$ 7,063,000	$ 3,890,000	$ 14,125,000
Warrants, number of shares the holders have the right to purchase	21.1			21.1
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 40.26			$ 40.26
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right	2.2			2.2
Subsequent Event [Member]
Short-term Debt [Line Items]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right						2.3

Common Stock Repurchase Progr55

Common Stock Repurchase Program (Details) - USD ($)	5 Months Ended	6 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Oct. 01, 2016	Apr. 01, 2017	May 16, 2016
Accelerated Share Repurchases [Line Items]
Stock Repurchased and Retired During Period, Value		$ 237,500,000	$ 200,100,000
Stock Repurchased and Retired During Period, Shares		3,700,000	4,100,000
Treasury shares	0	0		0
Repurchase Program Two Thousand Sixteen [Member] [Domain]
Accelerated Share Repurchases [Line Items]
Stock Repurchase Program, Authorized Amount					$ 1,000,000,000
Stock Repurchased During Period, Value	$ 555,400,000
Total amount available for future repurchases	$ 444,600,000	$ 444,600,000

Interest and Other Expense, N56

Interest and Other Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Components of interest and other expense
Interest income	$ 13,832	$ 12,098	$ 27,246	$ 23,564
Interest expense	(11,029)	(13,870)	(23,110)	(27,738)
Other income (expense), net	(972)	621	(467)	(1,564)
Interest and other expense, net	$ 1,831	$ (1,151)	$ 3,669	$ (5,738)

Accumulated Other Comprehensi57

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Apr. 01, 2017
Components of accumulated other comprehensive income (loss)
Accumulated unrealized losses on available-for-sale securities, net of tax	$ (11,260)	$ (17,091)
Accumulated unrealized losses on hedging transactions, net of tax	854	661
Accumulated cumulative translation adjustment, net of tax	(5,813)	(8,251)
Accumulated other comprehensive loss	$ (16,219)	$ (24,681)

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$ 19,468	$ 11,470	$ 34,481	$ 30,039
Effective Income Tax Rate Reconciliation, Percent	10.00%	7.00%	9.00%	8.00%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			35.00%
Unrecognized Tax Benefits, Period Increase (Decrease)			$ 90,600
Unrecognized Tax Benefits	$ 121,000		121,000
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	13,700		13,700
Unrecognized Tax Benefits That Would Impact Additional Paid-in Capital	$ 85,500		$ 85,500

Commitments (Details)

Commitments (Details) $ in Thousands	Sep. 30, 2017USD ($)
Future Minimum Lease Payments Under Non-Cancelable Operating Leases [Abstract]
2017 (remaining 3 months)	$ 2,916
2,018	4,856
2,019	6,680
2,020	5,659
2,021	5,696
Thereafter	29,444
Total	$ 55,251

Commitments (Details Textual)

Commitments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Commitments [Line Items]
Lease Expiration Date			Apr. 30, 2029
Aggregate future rental income to be received	$ 9,200		$ 9,200
Rent expense, net of rental income	900	$ 1,300	2,100	$ 2,500
Non-cancelable license obligations	35,300		$ 35,300
Software and Maintenance License Obligations Expiration Date			Dec. 28, 2019
Purchase Obligation	$ 127,100		$ 127,100
Minimum [Member]
Commitments [Line Items]
Purchase Commitments, Period for Payment			3 months
Maximum [Member]
Commitments [Line Items]
Purchase Commitments, Period for Payment			6 months
Capital Lease Obligations [Member]
Commitments [Line Items]
Lease Expiration Date			Nov. 30, 2035

Contingencies (Details)

Contingencies (Details) $ in Millions	6 Months Ended
	Sep. 30, 2017USD ($)
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 50

Subsequent Events (Details)

Subsequent Events (Details)	Oct. 24, 2017$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.35