Xilinx (XLNX) 10-Q 25 Oct 18 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Sep. 29, 2018	Oct. 12, 2018
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 29, 2018
Document Fiscal Year Focus	2,019
Document Fiscal Period Focus	Q2
Entity Registrant Name	XILINX INC
Entity Central Index Key	743,988
Current Fiscal Year End Date	--03-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		253,043,435

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017
Net revenues	$ 746,252	$ 627,419	[1]	$ 1,430,622	$ 1,230,229	[1]
Cost of revenues	231,620	185,685	[1]	438,508	376,509	[1]
Gross margin	514,632	441,734	[1]	992,114	853,720	[1]
Operating expenses:
Research and development	183,372	157,985		354,198	311,036
Selling, general and administrative	97,685	91,053		188,217	180,228
Amortization of acquisition-related intangibles	839	510		1,199	1,215
Total operating expenses	281,896	249,548		543,614	492,479
Operating income	232,736	192,186	[1]	448,500	361,241	[1]
Interest and other income, net	6,408	1,831		3,561	3,669
Income before income taxes	239,144	194,017	[1]	452,061	364,910	[1]
Provision for income taxes	23,432	20,266	[1]	46,311	33,915	[1]
Net income	$ 215,712	$ 173,751	[1]	$ 405,750	$ 330,995	[1]
Net income per common share:
Basic (in dollars per share)	$ 0.85	$ 0.70	[1]	$ 1.61	$ 1.33	[1]
Diluted (in dollars per share)	0.84	0.67	[1]	1.59	1.26	[1]
Common Stock, Dividends, Per Share, Declared	$ 0.36	$ 0.35		$ 0.72	$ 0.70
Shares used in per share calculations:
Basic (in shares)	252,988	248,094		252,541	247,960
Diluted (in shares)	255,522	258,217		255,057	261,739
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 215,712	$ 173,751	[1]	$ 405,750	$ 330,995	[1]
Other comprehensive income (loss), net of tax:
Change in net unrealized gains (losses) on available-for-sale securities	(2,125)	763		(3,785)	5,935
Reclassification adjustment for (gains) losses on available-for-sale securities	1	(135)		(50)	(105)
Net change in unrealized gains (losses) on hedging transactions	1,190	756		(4,430)	2,198
Reclassification adjustment for gains on hedging transactions	(1,730)	(1,648)		(2,171)	(2,004)
Cumulative translation adjustment, net	(2,142)	678		(4,192)	2,438
Other comprehensive income (loss)	(4,806)	414		(14,628)	8,462
Total comprehensive income	$ 210,906	$ 174,165		$ 391,122	$ 339,457
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Current assets:
Cash and cash equivalents	$ 1,974,638	$ 2,179,328
Short-term investments	1,305,922	1,268,242
Accounts receivable, net	372,983	382,246	[1]
Inventories	243,642	236,077
Prepaid expenses and other current assets	68,098	88,695
Total current assets	3,965,283	4,154,588	[1]
Property, plant and equipment, at cost:	867,175	855,023
Accumulated depreciation and amortization	(554,365)	(550,906)
Net property, plant and equipment	312,810	304,117
Long-term investments	91,627	97,896
Goodwill	342,456	162,421
Acquisition-related intangibles, net	84,455	4,123
Other assets	350,905	337,402	[1]
Total Assets	5,147,536	5,060,547	[1]
Current liabilities:
Accounts payable	107,099	98,999
Accrued payroll and related liabilities	232,410	206,367
Income taxes payable	31,435	47,713
Other accrued liabilities	60,965	59,680	[1]
Long-term Debt, Current Maturities	499,629	499,186
Total current liabilities	931,538	911,945	[1]
Long-term Debt, Excluding Current Maturities	1,201,884	1,214,440
Long-term income taxes payable	493,655	523,864
Other long-term liabilities	75,573	49,945
Commitments and contingencies (Note 17)
Stockholders' equity:
Preferred stock, $.01 par value (none issued and outstanding)	0	0
Common stock, $.01 par value	2,530	2,534
Additional paid-in capital	906,618	878,672
Retained earnings	1,576,476	1,513,656	[1]
Accumulated other comprehensive loss	(40,738)	(34,509)
Total stockholders’ equity	2,444,886	2,360,353	[1]
Total Liabilities and Stockholders’ Equity	$ 5,147,536	$ 5,060,547	[1]
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 29, 2018	Mar. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares issued (none issued)	0	0
Common stock, par value	$ 0.01	$ 0.01

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017
Cash flows from operating activities:
Net income	$ 405,750	$ 330,995	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	31,123	22,964
Amortization	15,477	7,161
Stock-based compensation	70,553	68,408
Amortization of debt discounts	591	1,964
Provision for deferred income taxes	4,825	37,640	[1]
Others	1,884	744
Changes in assets and liabilities:
Accounts receivable, net	9,263	(42,105)	[1]
Inventories	(6,887)	11,504
Prepaid expenses and other current assets	(5,744)	(18,383)
Other assets	(17,616)	(12,645)
Accounts payable	4,525	(20,585)
Accrued liabilities	13,116	23,346	[1]
Income taxes payable	(37,569)	(17,960)
Net cash provided by operating activities	489,291	393,048
Cash flows from investing activities:
Purchases of available-for-sale securities	(819,512)	(1,367,972)
Proceeds from sale and maturity of available-for-sale securities	780,567	1,257,571
Purchases of property, plant and equipment and other intangibles	(40,533)	(22,149)
Acquisition of business, net of cash acquired	(223,535)	0
Other investing activities	(25,277)	(8,461)
Net cash used in investing activities	(328,290)	(141,011)
Cash flows from financing activities:
Repurchases of common stock	(160,536)	(237,516)
Taxes paid related to net share settlements of restricted stock units	(39,494)	(42,053)
Proceeds from issuance of common stock through various stock plans	18,416	19,358
Payment of dividends to stockholders	(181,752)	(174,260)
Repayment of convertible debt	0	(457,918)
Proceeds from Issuance of Long-term Debt	0	745,175
Other financing activities	(2,325)	(1,325)
Net cash used in financing activities	(365,691)	(148,539)
Net (decrease) increase in cash and cash equivalents	(204,690)	103,498
Cash and cash equivalents at beginning of period	2,179,328	966,695
Cash and cash equivalents at end of period	1,974,638	1,070,193
Supplemental disclosure of cash flow information:
Interest paid	33,986	18,608
Income taxes paid, net	$ 78,948	$ 14,789
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Basis of Presentation

Basis of Presentation	6 Months Ended
	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Basis of Presentation The accompanying interim condensed consolidated financial statements have been prepared in conformity with United States (U.S.) generally accepted accounting principles (GAAP) for interim financial information and the instructions to Form 10-Q and Article 10 of Regulation S-X, and should be read in conjunction with the Xilinx, Inc. (Xilinx or the Company) consolidated financial statements filed with the U.S. Securities and Exchange Commission (SEC) on Form 10-K for the fiscal year ended March 31, 2018 . The interim financial statements are unaudited, but reflect all adjustments which are, in the opinion of management, of a normal, recurring nature necessary to provide a fair statement of results for the interim periods presented. The results of operations for the interim periods shown in this report are not necessarily indicative of the results that may be expected for the fiscal year ending March 30, 2019 or any future period. The Company uses a 52- to 53-week fiscal year ending on the Saturday nearest March 31. Fiscal 2019 and fiscal 2018 are both 52-week years ending on March 30, 2019 and March 31, 2018 , respectively. The quarters ended September 29, 2018 and September 30, 2017 each consisted of 13 weeks.

Recent Accounting Changes and A

Recent Accounting Changes and Accounting Pronouncements	6 Months Ended
	Sep. 29, 2018
Accounting Changes and Error Corrections [Abstract]
Accounting Changes and Error Corrections [Text Block]	Recent Accounting Changes and Accounting Pronouncements Recent Accounting Pronouncements Adopted Revenue Recognition In April 2014, the Financial Accounting Standards Board (FASB) issued the authoritative guidance, as amended, that outlines a new revenue recognition standard that replaces virtually all existing U.S. GAAP guidance on contracts with customers and the related other assets and deferred costs. The authoritative guidance provides a five-step process for recognizing revenue that depicts the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled, in exchange for those goods or services. The new guidance also requires expanded qualitative and quantitative disclosures relating to the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The new guidance is required to be applied retrospectively to each prior reporting period presented (Full Retrospective), or retrospectively with the cumulative effect of initially applying it recognized at the date of initial application. The Company adopted the new guidance on April 1, 2018, using the Full Retrospective method and restated the comparative prior periods. The Company implemented internal controls and certain system functionality to enable the preparation of financial information on adoption. As a result of the adoption of the authoritative guidance, the Company changed its accounting policy for revenue recognition and the details of the significant changes and quantitative impact of the changes are disclosed below: Revenue from sales to the Company's distributors is recognized upon shipment of the product to the distributors (sell-in) and is reduced by estimated allowances for distributor price adjustments and rights of return. Previously, revenue was recognized upon reported resale of the product by the distributors to their customers (sell-through) as reduced by actual allowances for distributor price adjustments. Revenue from software license agreements, software license renewals, and other contracts are recognized at point of sales, whereas previously these were deferred and recognized over the contractual term before the implementation of the authoritative guidance. Revenue recognition related to the Company's other revenue streams, such as direct customers, remains unchanged. The adoption of this authoritative guidance has an impact on the Company’s condensed consolidated statements of income and balance sheets, but has no impact on net cash provided by or used in operating, financing, or investing activities on the condensed consolidated statements of cash flows. The impact on the Company's previously reported condensed consolidated statement of income resulting from the adoption of the authoritative guidance is as follows: Three Months Ended September 30, 2017 Six Months Ended September 30, 2017 (In thousands, except per share amounts) As Reported Adjustment As Adjusted As Reported Adjustment As Adjusted Net revenues $ 619,503 $ 7,916 $ 627,419 $ 1,234,949 $ (4,720 ) $ 1,230,229 Cost of revenues 184,786 899 185,685 376,881 (372 ) 376,509 Gross margin 434,717 7,017 441,734 858,068 (4,348 ) 853,720 Operating expenses: Research and development 157,985 — 157,985 311,036 — 311,036 Selling, general and administrative 91,053 — 91,053 180,228 — 180,228 Amortization of acquisition-related intangibles 510 — 510 1,215 — 1,215 Total operating expenses 249,548 — 249,548 492,479 — 492,479 Operating income 185,169 7,017 192,186 365,589 (4,348 ) 361,241 Interest and other income, net 1,831 — 1,831 3,669 — 3,669 Income before income taxes 187,000 7,017 194,017 369,258 (4,348 ) 364,910 Provision for income taxes 19,468 798 20,266 34,481 (566 ) 33,915 Net income $ 167,532 $ 6,219 $ 173,751 $ 334,777 $ (3,782 ) $ 330,995 Net income per common share: Basic $ 0.68 $ (0.02 ) $ 0.70 $ 1.35 $ (0.02 ) $ 1.33 Diluted $ 0.65 $ (0.02 ) $ 0.67 $ 1.28 $ (0.02 ) $ 1.26 Shares used in per share calculations: Basic 248,094 248,094 247,960 247,960 Diluted 258,217 258,217 261,739 261,739 The impact on the Company's previously reported condensed consolidated balance sheet line items affected by the adoption of the authoritative guidance is as follows: March 31, 2018 (In thousands) As Reported Adjustment As Adjusted Accounts receivable $ 372,144 $ 10,102 $ 382,246 Other assets 342,644 (5,242 ) 337,402 Deferred income on shipments to distributors 25,166 (25,166 ) — Other accrued liabilities 59,772 (92 ) 59,680 Retained earnings 1,483,538 30,118 1,513,656 Financial Instruments In January 2016, the FASB issued final authoritative guidance regarding how companies measure equity investments that do not result in consolidation and are not accounted for under the equity method and how they present changes in the fair value of financial liabilities measured under the fair value option that are attributable to their own credit. The authoritative guidance also changes certain disclosure requirements and other aspects of current U.S. GAAP on this matter. The authoritative guidance does not change the guidance for classifying and measuring investments in debt securities and loans. The authoritative guidance is effective for public business entities for annual periods beginning after December 15, 2017, and interim periods within those annual periods. The Company adopted this authoritative guidance on April 1, 2018 and recorded the balance of the unrealized losses of $11.0 million as of the end of fiscal 2018 from its investment in debt mutual funds and equity securities to retained earnings, less the related deferred taxes of $2.6 million . Subsequent changes in fair value from such investments are recorded in the condensed consolidated statements of income. Income Taxes In October 2016, the FASB issued authoritative guidance on income taxes which eliminates the deferred tax effects of intra-entity asset transfers other than inventory. As a result, a reporting entity would recognize the tax expense from the sale of an asset in the seller’s tax jurisdiction when the transfer occurs, even though the pre-tax effects of that transaction are eliminated in consolidation. The authoritative guidance is effective for public business entities in fiscal years beginning after December 15, 2017 and requires the adoption be applied on a modified retrospective basis through a cumulative-effect adjustment to retained earnings. The Company adopted this authoritative guidance on April 1, 2018. Accordingly, $13.8 million of prepaid taxes associated with prior period intra-entity asset transfers was reclassified to retained earnings. Recent Accounting Pronouncements Not Yet Adopted Leases In February 2016, the FASB issued authoritative guidance on leases. The new authoritative guidance requires the recognition of assets and liabilities arising from lease transactions on the balance sheet and will also require significant additional disclosures about the amount, timing and uncertainty of cash flows from leases. Accordingly, a lessee will recognize a lease asset for its right to use the underlying asset and a lease liability for the corresponding lease obligation. The new authoritative guidance is effective for public business entities for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years, which for Xilinx would be the first quarter of fiscal 2020. Early adoption is permitted. The new authoritative guidance must be adopted using a modified retrospective transition with application of the new authoritative guidance for leases that existed at or are entered after the beginning of the earliest comparative period presented. To help with the transition to the new guidance, certain practical expedients are provided. The Company is currently evaluating the impact of this new authoritative guidance on its condensed consolidated financial statements. On July 30, 2018, The FASB provided entities with an additional (and optional) transition method to adopt the new lease requirements by allowing entities to initially apply the requirements by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, an entity’s reporting for the comparative periods presented in the financial statements in which the entity adopts the new lease requirements would continue to be in accordance with current GAAP. An entity electing this additional (and optional) transition method must provide the required disclosures for all periods that continue to be in accordance with current GAAP. The amendments do not change the existing disclosure requirements in current GAAP. The amendments have the same effective date as the new leases standard, which for Xilinx would be the first quarter of fiscal 2020. The Company is currently evaluating the impact of this new authoritative guidance on its condensed consolidated financial statements. Cloud Computing Arrangements On August 29, 2018, the FASB issued new guidance requiring a customer in a cloud computing arrangement (i.e., hosting arrangement) that is a service contract to follow the internal-use software guidance to determine which implementation costs to capitalize as assets or expense as incurred. Capitalized implementation costs related to a hosting arrangement that is a service contract will be amortized over the term of the hosting arrangement, beginning when the module or component of the hosting arrangement is ready for its intended use. Entities will need to maintain appropriate records to capture the portion of their costs that qualify for capitalization. For public entities, the guidance is effective for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years, which for Xilinx would be the first quarter of fiscal 2021. Early adoption is permitted, including adoption in any interim period. Entities have the option to apply the guidance prospectively to all implementation costs incurred after the date of adoption or retrospectively. The Company is currently evaluating the impact of this new authoritative guidance on its condensed consolidated financial statements.

Significant Customers and Conce

Significant Customers and Concentrations of Credit Risk (Notes)	6 Months Ended
	Sep. 29, 2018
Significant Customers and Concentrations of Credit Risk [Abstract]
Concentration Risk Disclosure [Text Block]	Significant Customers and Concentrations of Credit Risk Avnet, Inc. (Avnet), one of the Company’s distributors, distributes the Company’s products worldwide. As of September 29, 2018 and March 31, 2018 , Avnet accounted for 50% and 61% of the Company’s total net accounts receivable, respectively. The Company expects its accounts receivable to fluctuate as the Company partners with its distributors to manage their inventory requirements. For the second quarter and first six months of fiscal 2019, resale of product through Avnet accounted for 46% and 48% of the Company's worldwide net revenues, respectively. For the second quarter and first six months of fiscal 2018, resale of product through Avnet accounted for 46% and 43% 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 condensed consolidated balance sheet. The Company attempts to mitigate the concentration of credit risk in its trade receivables through its credit evaluation process, collection terms, distributor sales to diverse end customers and through geographical dispersion of sales. Xilinx generally does not require collateral for receivables from its end customers or distributors. No end customer accounted for more than 10% of the Company’s worldwide net revenues for the second quarter and first six months of fiscal 2019 and 2018 . The Company mitigates concentrations of credit risk in its investments in debt securities by currently investing approximately 91% of its portfolio in AA (or its equivalent) or higher grade securities as rated by Standard & Poor’s or Moody’s Investors Service. The Company’s methods to arrive at investment decisions are not solely based on the rating agencies’ credit ratings. Xilinx also performs additional credit due diligence and conducts regular portfolio credit reviews, including a review of counterparty credit risk related to the Company’s forward currency exchange and interest rate swap contracts. Additionally, Xilinx limits its investments in the debt securities of a single issuer based upon the issuer’s credit rating and attempts to further mitigate credit risk by diversifying risk across geographies and type of issuer. As of September 29, 2018 , approximately 23% 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. 29, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The authoritative guidance for fair value measurements established by the FASB defines fair value as the exchange price that would be received from selling an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date. When determining the fair value measurements for assets and liabilities required or permitted to be recorded at fair value, the Company considers the principal or most advantageous market in which Xilinx would transact. The Company also considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions and risk of nonperformance. The Company determines the fair value for marketable debt securities using industry standard pricing services, data providers and other third-party sources and by internally performing valuation testing and analysis. The Company primarily uses a consensus price or weighted-average price for its fair value assessment. The Company determines the consensus price using market prices from a variety of industry standard pricing services, data providers, security master files from large financial institutions and other third-party sources and uses those multiple prices as inputs into a distribution-curve-based algorithm to determine the daily market value. The pricing services use multiple inputs to determine market prices, including reportable trades, benchmark yield curves, credit spreads and broker/dealer quotes as well as other industry and economic events. For certain securities with short maturities, such as discount commercial paper and certificates of deposit, the security is accreted from purchase price to face value at maturity. If a subsequent transaction on the same security is observed in the marketplace, the price on the subsequent transaction is used as the current daily market price and the security will be accreted to face value based on the revised price. The Company validates the consensus prices by taking random samples from each asset type and corroborating those prices using reported trade activity, benchmark yield curves, binding broker/dealer quotes or other relevant price information. There have not been any changes to the Company’s fair value methodology during the second quarter and first six months of fiscal 2019 and the Company did not adjust or override any fair value measurements as of September 29, 2018 . Fair Value Hierarchy The fair value framework requires the categorization of assets and liabilities into three levels based upon the assumptions (inputs) used to price the assets or liabilities. The guidance for fair value measurements requires that assets and liabilities carried at fair value be classified and disclosed in one of the following categories: Level 1 — Quoted (unadjusted) prices in active markets for identical assets or liabilities. The Company’s Level 1 assets consist of U.S. government securities, money market funds and marketable equity securities. Level 2 — Observable inputs other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the asset or liability. The Company’s Level 2 assets consist of financial institution securities, non-financial institution securities, U.S. agency securities, foreign government and agency securities, mortgage-backed securities, debt mutual funds, asset-backed securities and commercial mortgage-backed securities. The Company’s Level 2 assets and liabilities also include foreign currency forward contracts and interest rate swap contracts. Level 3 — Unobservable inputs to the valuation methodology that are supported by little or no market activity and that are significant to the measurement of the fair value of the assets or liabilities. Level 3 assets and liabilities include those whose fair value measurements are determined using pricing models, discounted cash flow methodologies or similar valuation techniques, as well as significant management judgment or estimation. The Company has no Level 3 assets and liabilities measured at fair value on a recurring basis. Assets and Liabilities Measured at Fair Value on a Recurring Basis In instances where the inputs used to measure fair value fall into different levels of the fair value hierarchy, the fair value measurement has been determined based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular item to the fair value measurement in its entirety requires judgment, including the consideration of inputs specific to the asset or liability. The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of September 29, 2018 and March 31, 2018 : September 29, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 376,673 $ — $ — $ 376,673 Financial institution securities — 403,980 — 403,980 Non-financial institution securities — 476,957 — 476,957 U.S. government and agency securities 114,891 162,887 — 277,778 Foreign government and agency securities — 370,791 — 370,791 Short-term investments: Financial institution securities — 225,000 — 225,000 Non-financial institution securities — 96,379 — 96,379 U.S. government and agency securities 2,663 12,844 — 15,507 Mortgage-backed securities — 749,426 — 749,426 Asset-backed securities — 85,421 — 85,421 Commercial mortgage-backed securities — 134,189 — 134,189 Long-term investments: Debt mutual funds — 84,926 — 84,926 Marketable equity securities 6,701 — — 6,701 Total assets measured at fair value $ 500,928 $ 2,802,800 $ — $ 3,303,728 Liabilities Derivative financial instruments, net $ — $ 47,791 $ — $ 47,791 Total liabilities measured at fair value $ — $ 47,791 $ — $ 47,791 Net assets measured at fair value $ 500,928 $ 2,755,009 $ — $ 3,255,937 March 31, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities — 359,901 — 359,901 Non-financial institution securities — 242,904 — 242,904 U.S. government and agency securities 996 34,999 — 35,995 Foreign government and agency securities — 179,957 — 179,957 Short-term investments: Financial institution securities — 75,000 — 75,000 Non-financial institution securities — 81,939 — 81,939 U.S. government and agency securities 3,639 19,008 — 22,647 Mortgage-backed securities — 844,397 — 844,397 Asset-backed securities — 91,389 — 91,389 Commercial mortgage-backed securities — 152,870 — 152,870 Long-term investments: Debt mutual funds — 89,670 — 89,670 Marketable equity securities 8,226 — 8,226 Total assets measured at fair value $ 1,304,752 $ 2,172,034 $ — $ 3,476,786 Liabilities Derivative financial instruments, net $ — $ 26,091 $ — $ 26,091 Total liabilities measured at fair value $ — $ 26,091 $ — $ 26,091 Net assets measured at fair value $ 1,304,752 $ 2,145,943 $ — $ 3,450,695 For certain of the Company’s financial instruments, including cash held in banks, accounts receivable and accounts payable, the carrying amounts approximate fair value due to their short maturities, and are therefore excluded from the fair value tables above. 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) and $500.0 million principal amount of 3.000% notes due March 15, 2021 (2021 Notes) are measured at fair value on a quarterly basis for disclosure purposes. The fair values of the 2019 Notes and 2021 Notes as of September 29, 2018 were approximately $498.7 million and $495.2 million , respectively, based on the last trading price for the period (classified as Level 2 in fair value hierarchy due to relatively low trading volume). Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis As of September 29, 2018 , the Company had non-marketable equity securities in private companies of $53.8 million , which were classified as Level 3 assets. The Company’s investments in non-marketable securities of private companies, together with its non-financial assets such as property, plant and equipment, goodwill and acquisition-related intangibles, are recorded at fair value only if the Company recognizes an impairment. The Company’s investments in non-marketable securities of private companies are also recorded at fair value if the Company recognizes an observable price adjustments. Such impairment losses or observable price adjustments were not material during all periods presented.

Financial Instruments

Financial Instruments	6 Months Ended
	Sep. 29, 2018
Investments, All Other Investments [Abstract]
Financial Instruments	Financial Instruments The following is a summary of cash equivalents, available-for-sale securities and equity-type securities as of the end of the periods presented: September 29, 2018 March 31, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds $ 376,673 $ — $ — $ 376,673 $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities 628,965 15 — 628,980 434,901 — — 434,901 Non-financial institution securities 574,630 — (1,294 ) 573,336 326,219 — (1,376 ) 324,843 U.S. government and agency securities 293,600 22 (337 ) 293,285 58,913 1 (272 ) 58,642 Foreign government and agency securities 370,788 3 — 370,791 179,957 — — 179,957 Mortgage-backed securities 775,806 476 (26,856 ) 749,426 866,048 660 (22,311 ) 844,397 Asset-backed securities 86,664 9 (1,252 ) 85,421 92,751 16 (1,378 ) 91,389 Debt mutual funds 101,350 — (16,424 ) 84,926 101,350 — (11,680 ) 89,670 Commercial mortgage- backed securities 137,767 1 (3,579 ) 134,189 156,296 1 (3,427 ) 152,870 Marketable equity securities 7,500 — (799 ) 6,701 7,500 726 — 8,226 $ 3,353,743 $ 526 $ (50,541 ) $ 3,303,728 $ 3,515,826 $ 1,404 $ (40,444 ) $ 3,476,786 Financial institution securities include securities issued or managed by financial institutions in various forms, such as commercial paper and time deposits. Substantially all time deposits were issued by institutions outside the U.S. as of September 29, 2018 and March 31, 2018 . The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of September 29, 2018 and March 31, 2018 : September 29, 2018 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Non-financial institution securities $ 44,067 $ (748 ) $ 19,640 $ (546 ) $ 63,707 $ (1,294 ) U.S. government and agency securities — — 15,507 (337 ) 15,507 (337 ) Mortgage-backed securities 222,604 (5,996 ) 497,433 (20,860 ) 720,037 (26,856 ) Asset-backed securities 18,472 (278 ) 65,425 (974 ) 83,897 (1,252 ) Debt mutual funds — — 84,926 (16,424 ) 84,926 (16,424 ) Commercial mortgage- backed securities 44,231 (950 ) 88,823 (2,629 ) 133,054 (3,579 ) Marketable equity securities 6,701 (799 ) — — 6,701 (799 ) $ 336,075 $ (8,771 ) $ 771,754 $ (41,770 ) $ 1,107,829 $ (50,541 ) March 31, 2018 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Non-financial institution securities $ 69,780 $ (1,146 ) $ 8,344 $ (230 ) $ 78,124 $ (1,376 ) U.S. government and agency securities 13,471 (176 ) 9,176 (96 ) 22,647 (272 ) Mortgage-backed securities 510,988 (11,048 ) 299,663 (11,263 ) 810,651 (22,311 ) Asset-backed securities 57,128 (876 ) 32,696 (502 ) 89,824 (1,378 ) Debt mutual funds — — 89,670 (11,680 ) 89,670 (11,680 ) Commercial mortgage- backed securities 95,435 (1,760 ) 56,051 (1,667 ) 151,486 (3,427 ) $ 746,802 $ (15,006 ) $ 495,600 $ (25,438 ) $ 1,242,402 $ (40,444 ) As of September 29, 2018 , the gross unrealized losses that had been outstanding for less than twelve months were primarily related to mortgage-backed securities due to the general rising of the interest-rate environment, although the percentage of such losses to the total estimated fair value of the mortgage-backed securities was relatively insignificant. The gross unrealized losses that had been outstanding for more than twelve months were primarily related to debt mutual funds and mortgage-backed securities, which were primarily due to the general rising of the interest-rate environment and foreign currency movement. Starting April 1, 2018 , the Company records the change in the fair value of its investment in debt mutual funds and marketable equity securities as part of its interest and other income, net. This change in fair value was a net decrease of $73 thousand and $6.3 million for the three and six months ended September 29, 2018 , respectively, and resulted in an expense within interest and other income, net for the period. The Company reviewed the investment portfolio and determined that the gross unrealized losses on these investments as of September 29, 2018 and March 31, 2018 were temporary in nature as evidenced by the fluctuations in the gross unrealized losses within the investment categories. These investments are highly rated by the credit rating agencies, there have been no defaults on any of these securities and the company has received interest payments as they become due. Therefore, the Company believes that it will be able to collect both principal and interest amount due to the Company. Additionally, in the past several years a portion of the Company's investment in the mortgage-backed securities was redeemed or prepaid by the debtors at par. Furthermore, the aggregate of individual unrealized losses that had been outstanding for twelve months or more was not significant as of September 29, 2018 and March 31, 2018 . The Company neither intends to sell these investments nor concludes that it is more-likely-than-not that it will have to sell them until recovery of their carrying values. The amortized cost and estimated fair value of marketable debt securities (financial institution securities, non-financial institution securities, U.S. and foreign government and agency securities, asset-backed securities, mortgage-backed securities and commercial mortgage-backed securities), by contractual maturity, are shown in the table below. Actual maturities may differ from contractual maturities because issuers may have the right to call or prepay obligations without call or prepayment penalties. September 29, 2018 (In thousands) Amortized Estimated Due in one year or less $ 1,825,385 $ 1,825,113 Due after one year through five years 162,134 158,928 Due after five years through ten years 139,922 135,283 Due after ten years 740,779 716,104 $ 2,868,220 $ 2,835,428 As of September 29, 2018 , $1.01 billion of marketable debt securities with contractual maturities of greater than one year were classified as short-term investments. Additionally, the above table does not include investments in money market, debt mutual funds and marketable equity securities because these investments do not have specific contractual maturities. Certain information related to available-for-sale securities is as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Proceeds from sale of available-for-sale securities $ 7 $ 149,497 $ 903 $ 269,419 Gross realized gains on sale of available-for-sale securities $ — $ 519 $ 96 $ 1,351 Gross realized losses on sale of available-for-sale securities (1 ) (209 ) (48 ) (595 ) Net realized gains (losses) on sale of available-for-sale securities $ (1 ) $ 310 $ 48 $ 756 Amortization of premiums on available-for-sale securities $ 2,645 $ 4,691 $ 5,136 $ 10,213 The cost of securities matured or sold is based on the specific identification method.

Derivative Financial Instrument

Derivative Financial Instruments	6 Months Ended
	Sep. 29, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments	Derivative Financial Instruments The Company’s primary objective for holding derivative financial instruments is to manage foreign currency exchange rate risk and interest rate risk. As a result of the use of derivative financial instruments, the Company is exposed to the risk that counterparties to derivative contracts may fail to meet their contractual obligations. The Company manages counterparty credit risk in derivative contracts by reviewing counterparty creditworthiness on a regular basis, establishing collateral requirement and limiting exposure to any single counterparty. The right of set-off that exists with certain transactions enables the Company to net amounts due to and from the counterparty, reducing the maximum loss from credit risk in the event of counterparty default. 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 29, 2018 , the net change in fair values of the interest rate swap contracts and the underlying 2024 Notes was $13.3 million , which was recorded as a derivative liability for the interest rate swap contacts and as a reduction from the carrying amount of the 2024 Notes. There was no ineffectiveness during all periods presented.

Stock-Based Compensation Plans

Stock-Based Compensation Plans	6 Months Ended
	Sep. 29, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans The Company’s equity incentive plans are broad-based, long-term retention programs that cover employees, consultants and non-employee directors of the Company. These plans are intended to attract and retain talented employees, consultants and non-employee directors and to provide such persons with a proprietary interest in the Company. Stock-Based Compensation The following table summarizes stock-based compensation expense related to stock awards granted under the Company’s equity incentive plans and rights to acquire stock granted under the Company’s Employee Stock Purchase Plan (ESPP): Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Stock-based compensation included in: Cost of revenues $ 2,249 $ 2,147 $ 4,284 $ 4,297 Research and development 20,047 20,096 40,977 37,562 Selling, general and administrative 12,649 14,129 25,292 26,549 $ 34,945 $ 36,372 $ 70,553 $ 68,408 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 2019 and the entire fiscal 2018 . The Company's stock-based compensation expenses related to options during the first six months of fiscal 2019 and the number of options outstanding as of September 29, 2018 were not material. On August 1, 2018, the stockholders approved an amendment to increase the authorized number of shares reserved for issuance under the 2007 Equity Plan by 3.0 million shares. As of September 29, 2018 , 11.6 million shares remained available for grant under the 2007 Equity Plan. RSU Awards A summary of the Company’s RSU activity and related information is as follows: RSUs Outstanding (Shares in thousands) Number of Shares Weighted-Average Grant-Date Fair Value Per Share April 1, 2017 6,988 $ 42.93 Granted 3,718 $ 60.18 Vested (3,016 ) $ 43.30 Cancelled (701 ) $ 48.16 March 31, 2018 6,989 $ 51.39 Granted 2,964 $ 63.00 Vested (2,293 ) $ 48.60 Cancelled (251 ) $ 52.20 September 29, 2018 7,409 The estimated fair values of RSUs were calculated based on the market price of Xilinx common stock on the date of grant, reduced by the present value of dividends expected to be paid on Xilinx common stock prior to vesting. The per share weighted-average fair value of RSUs granted during the second quarter of fiscal 2019 was $62.79 ( $59.99 for the second quarter of fiscal 2018 ), and for the first six months of fiscal 2019 was $63.00 ( $59.89 for the first six months of fiscal 2018 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended Six Months Ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Risk-free interest rate 2.7 % 1.7 % 2.7 % 1.7 % Dividend yield 2.2 % 2.2 % 2.2 % 2.2 % For the majority of RSUs granted, the number of shares of common stock issued on the date the RSU awards vest is net of the minimum statutory withholding requirements that the Company pays in cash to the appropriate taxing authorities on behalf of the Company's employees. During the first six months of fiscal 2019 and 2018 , the Company withheld $39.5 million and $42.1 million worth of RSU awards, respectively, to satisfy the employees’ tax obligations. During the second quarter and the first six months of fiscal 2019 , the Company realized excess tax benefits of $7.8 million and $8.7 million , respectively, primarily from RSU vesting. During the second quarter and the first six months of fiscal 2018 , the Company realized excess tax benefits of $6.3 million and $17.9 million , respectively. These tax 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 359 thousand shares for $18.0 million during the second quarter of fiscal 2019 and 355 thousand shares for $16.9 million during the second quarter of fiscal 2018 . The per-share weighted-average fair value of stock purchase rights granted under the ESPP during the second quarter of fiscal 2019 and 2018 was $19.06 and $16.46 , respectively. The fair values of stock purchase plan rights granted in the second quarter of fiscal years 2019 and 2018 were estimated using the Black-Scholes option pricing model at the date of grant using the following assumptions: 2019 2018 Expected life of options (years) 1.25 1.25 Expected stock price volatility 0.29 0.28 Risk-free interest rate 2.5 % 1.3 % Dividend yield 2.0 % 2.2 % The next scheduled purchase under the ESPP is in the fourth quarter of fiscal 2019 . On August 1, 2018, the stockholders approved an amendment to increase the authorized number of shares reserved for issuance under the ESPP by 3.0 million shares. As of September 29, 2018 , 12.0 million shares were available for future issuance under the ESPP.

Net Income Per Common Share

Net Income Per Common Share	6 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Net Income Per Common Share	Net Income Per Common Share The computation of basic net income per common share for all periods presented is derived from information on the condensed consolidated statements of income, and there are no reconciling items in the numerator used to compute the diluted net income per common share. The following table summarizes the computation of basic and diluted net income per common share: Three Months Ended Six Months Ended (In thousands, except per share amounts) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Net income available to common stockholders $ 215,712 $ 173,751 $ 405,750 $ 330,995 Weighted average common shares outstanding-basic 252,988 248,094 252,541 247,960 Dilutive effect of employee equity incentive plans 2,534 2,532 2,516 2,949 Dilutive effect of 2017 Convertible Notes — — — 2,986 Dilutive effect of warrants — 7,591 — 7,844 Weighted average common shares outstanding-diluted 255,522 258,217 255,057 261,739 Basic net income per common share $ 0.85 $ 0.70 $ 1.61 $ 1.33 Diluted net income per common share $ 0.84 $ 0.67 $ 1.59 $ 1.26 The total shares used in the denominator of the diluted net income per common share calculation include potentially dilutive common equivalent shares outstanding that are not included in basic net income per common share calculation. The diluted shares were calculated by applying the treasury stock method to the impact of the equity incentive plans, the incremental shares issuable assuming conversion of the Company's $600.0 million principal amount of 2.625% convertible notes issued in June 2010 (2017 Convertible Notes), before its maturity on June 15, 2017 , and exercise of warrants on a weighted-average outstanding basis, before the final settlements during the third quarter of fiscal 2018. The 2017 Convertible Notes matured during the first quarter of fiscal 2018, and the Company exercised its call options to neutralize the dilutive effect of the incremental shares from the 2017 Convertible Notes. Because the number of diluted shares in the above table for the 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. Such impact will no longer be applicable in future periods. Outstanding stock options and RSUs under the Company's stock award plans to purchase approximately 1.8 million and 3.0 million shares for the second quarter and first six months of fiscal 2019 , respectively, were excluded from the diluted net income per common share calculation by applying the treasury stock method, as their inclusion would have been antidilutive. These options and RSUs could be dilutive in the future if the Company’s average share price increases and is greater than the combined exercise prices and the unamortized fair values of these options and RSUs.

Inventories

Inventories	6 Months Ended
	Sep. 29, 2018
Inventory Disclosure [Abstract]
Inventory Disclosure [Text Block]	Inventories Inventories are stated at the lower of actual cost (determined using the first-in, first-out method), or market (estimated net realizable value) and are comprised of the following: (In thousands) September 29, 2018 March 31, 2018 Raw materials $ 21,296 $ 14,674 Work-in-process 175,213 167,039 Finished goods 47,133 54,364 $ 243,642 $ 236,077

Debt and Credit Facility

Debt and Credit Facility	6 Months Ended
	Sep. 29, 2018
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	Debt and Credit Facility 2019 Notes and 2021 Notes On March 12, 2014, the Company issued the 2019 Notes and 2021 Notes at a discounted price of 99.477% and 99.281% of par, respectively. Interest on the 2019 Notes and 2021 Notes is payable semi-annually on March 15 and September 15. The Company received net proceeds of $990.1 million from issuance of the 2019 Notes and 2021 Notes, after the debt discount and deduction of debt issuance costs. The debt discounts and issuance costs are amortized to interest expense over the terms of the 2019 Notes and 2021 Notes. As of September 29, 2018 , the remaining term of the 2019 Notes and 2021 Notes are 0.5 years and 2.5 years respectively. The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of September 29, 2018 and March 31, 2018 : (In thousands) September 29, 2018 March 31, 2018 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (229 ) (501 ) Unamortized debt issuance costs associated with 2019 Notes (142 ) (313 ) Carrying value of the 2019 Notes 499,629 499,186 Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,330 ) (1,593 ) Unamortized debt issuance costs associated with 2021 Notes (590 ) (711 ) Carrying value of the 2021 Notes $ 498,080 $ 497,696 Total carrying value $ 997,709 $ 996,882 Interest expense related to the 2019 Notes and 2021 Notes was included in interest and other income, net on the condensed consolidated statements of income as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Contractual coupon interest $ 6,406 $ 6,406 $ 12,813 $ 12,813 Amortization of debt issuance costs 146 146 292 293 Amortization of debt discount, net 269 262 535 520 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,821 $ 6,814 $ 13,640 $ 13,626 2024 Notes On May 30, 2017, the Company issued the $750.0 million principal amount of 2.950% senior notes due June 1, 2024 (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 29, 2018 , the remaining term of the 2024 Notes is approximately 5.7 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 incurred a net interest expense of $642 thousand and $1.5 million for the three and six months ended September 29, 2018 , respectively, from the interest rate swap contracts, which was included in interest and other income (expense), net on the condensed consolidated statements of income. Net interest income of $1.5 million and $2.1 million was earned on the contracts for the three and six months ended September 30, 2017 , respectively. As of September 29, 2018 , the fair value of the interest rate swap contracts was $42.3 million , which was recorded in other long-term liabilities. The following table summarizes the carrying value of the 2024 Notes as of September 29, 2018 and March 31, 2018 : (In thousands) September 29, 2018 March 31, 2018 Principal amount of the 2024 Notes $ 750,000 $ 750,000 Unamortized discount of the 2024 Notes (699 ) (755 ) Unamortized debt issuance costs associated with 2024 Notes (3,216 ) (3,500 ) Carrying Value of the 2024 Notes $ 746,085 $ 745,745 Fair value hedge adjustment — interest rate swap contracts (42,281 ) (29,001 ) Net carrying value of the 2024 Notes $ 703,804 $ 716,744 Interest expense related to the 2024 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Contractual coupon interest (including interest rate swap, net) $ 6,174 $ 4,046 $ 12,556 $ 5,368 Amortization of debt issuance costs 142 142 284 189 Amortization of debt discount, net 27 27 56 37 Total interest expense related to the 2024 Notes $ 6,343 $ 4,215 $ 12,896 $ 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 29, 2018 , the Company had made no borrowings under this credit facility and was not in violation of any of the covenants.

Common Stock Repurchase Program

Common Stock Repurchase Program	6 Months Ended
	Sep. 29, 2018
Stockholders' Equity Note [Abstract]
Common Stock and Debentures Repurchase Program [Text Block]	Common Stock Repurchase Program The Board of Directors (Board) has approved stock repurchase programs enabling the Company to repurchase its common stock in the open market or through negotiated transactions with independent financial institutions. On May 16, 2016, the Board authorized the repurchase of up to $1.00 billion of the Company's common stock and debentures (2016 Repurchase Program). The 2016 Repurchase Program has no stated expiration date. On May 16, 2018, the Board authorized the 2018 Repurchase Program to repurchase the Company's common stock and debentures up to $500.0 million (2018 Repurchase Program). Through September 29, 2018 , the Company had used $952.7 million of the $1.00 billion authorized under the 2016 Repurchase Program, leaving $47.3 million available for future repurchases. The Company has not used any of the amount authorized under the 2018 Repurchase Program. The Company’s current policy is to retire all repurchased shares, and consequently, no treasury shares were held as of September 29, 2018 and March 31, 2018 . During the first six months of fiscal 2019 , the Company repurchased 2.4 million shares of common stock in the open market with independent financial institutions for a total of $160.0 million and during the first six months of fiscal 2018 , the Company repurchased 3.7 million shares of common stock in the open market and through accelerated share repurchase agreements with an independent financial institution for a total of $237.5 million .

Interest and Other Expense, Net

Interest and Other Expense, Net	6 Months Ended
	Sep. 29, 2018
Other Income and Expenses [Abstract]
Interest and Other Expense, Net	Interest and Other Income, Net The components of interest and other income, net are as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Interest income $ 17,350 $ 13,832 $ 34,748 $ 27,246 Interest expense (13,164 ) (11,029 ) (26,536 ) (23,110 ) Other income (expense), net 2,222 (972 ) (4,651 ) (467 ) Total interest and other income, net $ 6,408 $ 1,831 $ 3,561 $ 3,669

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	6 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Loss Comprehensive income (loss) is defined as the change in equity of a company during a period from transactions and other events and circumstances from non-owner sources. The components of the Company's accumulated other comprehensive loss are as follows: (In thousands) September 29, 2018 March 31, 2018 Accumulated unrealized losses on available-for-sale securities, net of tax $ (25,280 ) $ (29,844 ) Accumulated unrealized gains (losses) on hedging transactions, net of tax (4,926 ) 1,674 Accumulated cumulative translation adjustment, net of tax (10,532 ) (6,339 ) Total accumulated other comprehensive loss $ (40,738 ) $ (34,509 ) The related tax effects of other comprehensive income (loss) were not material for all periods presented.

Income Taxes

Income Taxes	6 Months Ended
	Sep. 29, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company recorded a tax provision of $23.4 million and $46.3 million for the second quarter and the first six months of fiscal 2019 , respectively, representing effective tax rates of 9.8% and 10.2% , respectively. The Company recorded tax provisions of $20.3 million and $33.9 million for the second quarter and the first six months of fiscal 2018, respectively, representing effective tax rates of 10.4% and 9.3% , respectively. The prior year amounts have been restated to reflect the retrospective application of the current authoritative guidance for revenue recognition. Refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements" for additional detail. On December 22, 2017, the Tax Cuts and Jobs Act (TCJA) was enacted into law. The TCJA provides numerous significant tax law changes including the reduction of the U.S. federal corporate income tax rate from 35% to 21%, the requirement for companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred and the creation of new taxes on certain foreign-sourced earnings. Some provisions of the TCJA began to impact the Company in fiscal 2018, while other provisions impact the Company beginning in fiscal 2019. In accordance with Staff Accounting Bulletin (SAB) 118, the Company has recorded provisional amounts recognizing the effect of the tax law changes in prior periods, but may adjust those provisional amounts during a measurement period that is similar to the measurement period used when accounting for business combinations. As a result of updated technical guidance related to the TCJA, the Company revised its provisional estimate recorded in prior periods. The application of this guidance resulted in an increase to tax expense of $9.4 million in the second quarter of fiscal 2019. The amount recorded for the one-time transition tax remains provisional as the Company has not yet finalized its calculation of the total post-1986 earnings and profits (E&P) for its foreign subsidiaries. Additionally, the Company will continue to evaluate the impact of the tax law change as it relates to providing U.S. taxes on its investments in foreign subsidiaries. Since U.S. federal taxes have been recognized through the one-time transition tax on all accumulated and previously untaxed foreign earnings through December 31, 2017, the Company does not intend to permanently reinvest those earnings. The difference between the U.S. federal statutory tax rate of 21% and the Company's effective tax rate in the second quarter and the first six months of fiscal 2019 was primarily due to the favorable impact of income earned in lower tax rate jurisdictions, which was partially offset by the new tax on low-taxed income from foreign subsidiaries. The difference between the U.S. federal statutory tax rate of 35% and the Company’s effective tax rate in the second quarter and the first six months of fiscal 2018 was primarily due to income earned in lower tax rate jurisdictions, for which no U.S. income tax had been provided, as the Company had intended to permanently reinvest the earnings outside of the U.S. The Company’s total gross unrecognized tax benefits for the second quarter and the first six months of fiscal 2019, determined in accordance with FASB authoritative guidance for measuring uncertain tax positions, increased by an immaterial amount to $126.1 million . The total amount of unrecognized tax benefits that, if realized in a future period, would favorably affect the effective tax rate was $16.1 million as of September 29, 2018 . Another $85.5 million would increase additional paid-in capital. The $85.5 million relates to an additional deduction claimed on federal and state amended tax returns for fiscal 2014 for repurchase premium paid in that year in connection with the early redemption of the Company’s 3.125% Junior Convertible debenture due March 15, 2037. It is reasonably possible that changes to the Company's unrecognized tax benefits could be significant in the next twelve months due to tax audit settlements and lapses of statutes of limitation. As a result of uncertainties regarding tax audit settlements and their possible outcomes, an estimate of the range of increase or decrease that could occur in the next twelve months cannot be made. The Company’s policy is to include interest and penalties related to income tax liabilities within the provision for income taxes on the condensed consolidated statements of income. The balance of accrued interest and penalties recorded in the condensed consolidated balance sheets and the amounts of interest and penalties included in the Company's provision for income taxes were not material for all periods presented. The statutes of limitations have closed for U.S. federal income tax purposes for years through fiscal 2014, for U.S. state income tax purposes for years through fiscal 2010, and for Ireland income tax purposes for years through fiscal 2013.

Commitments

Commitments	6 Months Ended
	Sep. 29, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments	Commitments Xilinx leases some of its facilities and office buildings under non-cancelable operating leases that expire at various dates through April 2029 . Additionally, Xilinx entered into a land lease in conjunction with the Company’s building in Singapore, which will expire in November 2035 and the lease cost was settled in an up-front payment in June 2006. Some of the operating leases for facilities and office buildings require payment of operating costs, including property taxes, repairs, maintenance and insurance. Most of the Company’s leases contain renewal options for varying terms. Xilinx also leases cars under non-cancelable operating leases that expire at various dates through May 2022. Approximate future minimum lease payments under non-cancelable operating leases are as follows: Fiscal (In thousands) 2019 (remaining six months) $ 4,613 2020 10,124 2021 7,231 2022 5,891 2023 4,699 Thereafter 30,708 Total $ 63,266 Aggregate future rental income to be received, which includes rents from both owned and leased property, totaled $11.0 million as of September 29, 2018 . Rent expense, net of rental income, under all operating leases was $816 thousand and $1.8 million for the three and six months ended September 29, 2018 , respectively. 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. Rental income was not material for the second quarter and the first six months of fiscal 2019 or 2018 . Other commitments as of September 29, 2018 totaled $200.2 million and consisted of purchases of inventory and other non-cancelable purchase obligations related to subcontractors that manufacture silicon wafers and provide assembly and some test services. The Company expects to receive and pay for these materials and services in the next three to six months, as the products meet delivery and quality specifications. Additionally, as of September 29, 2018 , the Company also had $8.9 million of non-cancelable license obligations to providers of electronic design automation software and hardware/software maintenance and $25.1 million commitments primarily related to open purchase orders from ordinary operations. These commitments expire at various dates through December 2022 .

Product Warranty and Indemnific

Product Warranty and Indemnification (Notes)	6 Months Ended
	Sep. 29, 2018
Product Warranties Disclosures [Abstract]
Product Warranty Disclosure [Text Block]	Product Warranty and Indemnification The Company generally sells products with a limited warranty for product quality. The Company provides an accrual for known product issues if a loss is probable and can be reasonably estimated. As of the end of the second quarter of fiscal 2019 and the end of fiscal 2018 , the accrual balances of the product warranty liability were immaterial. The Company offers, subject to certain terms and conditions, to indemnify customers and distributors for costs and damages awarded against these parties in the event the Company’s hardware products are found to infringe third-party intellectual property rights, including patents, copyrights or trademarks, and to compensate certain customers for limited specified costs they actually incur in the event the Company's hardware products experience epidemic failure. To a lesser extent, the Company may from time-to-time offer limited indemnification with respect to its software products. The terms and conditions of these indemnity obligations are limited by contract, which obligations are typically perpetual from the effective date of the agreement. The Company has historically received only a limited number of requests for indemnification under these provisions and has not made any significant payments pursuant to these provisions. The Company cannot estimate the maximum amount of potential future payments, if any, that the Company may be required to make as a result of these obligations due to the limited history of indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim and indemnification provision. However, there can be no assurances that the Company will not incur any financial liabilities in the future as a result of these obligations.

Contingencies

Contingencies	6 Months Ended
	Sep. 29, 2018
Loss Contingency [Abstract]
Contingencies	Contingencies Patent Litigation On February 1, 2017, a patent infringement lawsuit was filed by Godo Kaisha IP Bridge 1 (IP Bridge) against the Company in the U.S. District Court for the Eastern District of Texas (Godo Kaisha IP Bridge 1 v. Xilinx, Inc., Case. No. 2:17-cv-00100). The lawsuit pertains to two patents and IP Bridge seeks unspecified damages, interest, attorneys’ fees, costs, and a permanent injunction or an on-going royalty. On September 14, 2017, the court granted the Company’s motion to transfer venue and the matter is now pending before the U.S. District Court for the Northern District of California. The Company is unable to estimate its range of possible loss, if any, in this matter at this time. On March 17, 2017, a patent infringement lawsuit was filed by Anza Technology, Inc. (Anza) against the Company in the U.S. District Court for the District of Colorado (Anza Technology, Inc. v. Xilinx, Inc., Case No. 1:17-cv-00687). The lawsuit pertains to three patents and Anza seeks unspecified damages, attorney fees, interest, costs, and expenses. On October 27, 2017, the court granted the Company’s motion to transfer venue to the U.S. District Court for the Northern District of California. The parties reached an agreement to settle the lawsuit and it was dismissed with prejudice on July 23, 2018. The amount of the settlement did not have a material impact on the Company's financial position or results of operations. The Company intends to continue to protect and defend its IP vigorously. Other Matters On June 11, 2015, John P. Neblett, as Chapter 7 Trustee of Valley Forge Composite Technologies, Inc., filed a complaint against Xilinx and others in the U.S. Bankruptcy Court for the Middle District of Pennsylvania (Bankruptcy No. 1:13-bk-05253-JJT). The complaint alleges causes of actions against Xilinx for negligence and civil conspiracy relating to alleged violations of U.S. export laws. It seeks at least $50.0 million in damages, together with punitive damages, from the defendants. On September 21, 2015, the action was withdrawn from the U.S. Bankruptcy Court for the Middle District of Pennsylvania and transferred to the U.S. District Court for the Eastern District of Kentucky. On November 2, 2015, Xilinx, along with other defendants, filed a motion to dismiss the complaint. On November 3, 2015, Xilinx filed a motion for sanctions pursuant to Federal Rule of Civil Procedure 11. On June 27, 2016, the Court denied both motions. On September 11, 2017, Xilinx, along with other defendants, filed motions for summary judgment seeking to dispose of all claims against them. On July 3, 2018, the Court granted both of Xilinx’s Motions for Summary Judgment, disposing of all claims asserted against Xilinx. On August 1, 2018, the Trustee filed a Notice of Appeal. On August 9, 2018, the Court of Appeals for the Sixth Circuit issued an Order to Show Cause requesting that the appellant address a possible jurisdictional defect. On August 29, 2018, the appellant responded to the Order to Show Cause. On September 10, 2018, the appellees, including Xilinx, filed a joint reply. The Court of Appeals has not issued a further order. 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. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Acquisition-Related Intangibles	Goodwill and Acquisition-Related Intangibles As of September 29, 2018 and March 31, 2018 , the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows: Weighted-Average (In thousands) September 29, 2018 March 31, 2018 Amortization Life Goodwill $ 342,456 $ 162,421 Core technology, gross 107,250 82,480 Less accumulated amortization (79,587 ) (78,562 ) Core technology, net 27,663 3,918 5.0 years Other intangibles, gross 51,016 46,966 3.0 years Less accumulated amortization (46,934 ) (46,761 ) In-process research and development 52,710 — N/A Other intangibles, net 56,792 205 Total acquisition-related intangibles, gross 210,976 129,446 Less accumulated amortization (126,521 ) (125,323 ) Total acquisition-related intangibles, net $ 84,455 $ 4,123 Amortization expense for acquisition-related intangibles for the three and six months ended September 29, 2018 was $839 thousand and $1.2 million , respectively. Amortization expense for acquisition-related intangibles for the three and six months ended September 30, 2017 was $510 thousand and $1.2 million , respectively. During the second quarter of fiscal 2019, the Company recorded $180.0 million of goodwill and $81.5 million of intangibles attributable to the acquisition of Deephi Technology Co., Ltd (Deephi Tech). See "Note 19. Business Combination" to our condensed consolidated financial statements. Based on the carrying value of acquisition-related intangibles recorded as of September 29, 2018 , assuming no subsequent acquisition or impairment of the underlying assets, and the expected timing of completion of in-process research and development, the annual amortization expense for acquisition-related intangibles is expected to be as follows: Fiscal (In thousands) 2019 (remaining six months) $ 3,732 2020 13,613 2021 17,983 2022 16,631 Thereafter 32,496 Total $ 84,455

Business Combination (Notes)

Business Combination (Notes)	6 Months Ended
	Sep. 29, 2018
Business Combinations [Abstract]
Business Combination	Business Combination During the second quarter of fiscal 2019, the Company completed the acquisition of Deephi Tech by acquiring all its outstanding ordinary shares. Deephi Tech was a privately held start-up with industry-leading capabilities in machine learning and focusing on system-level neural network optimization. This acquisition strengthens the Company's capabilities in artificial intelligence applications. Total purchase consideration to acquire Deephi Tech was $251.9 million , including $11.5 million of fair value from the Company's preexisting investment in Deephi Tech, $10.6 million unsettled payments to Deephi Tech equity holders and $6.3 million of cash acquired. The Company incurred $3.4 million of acquisition related costs, which was recorded in the operating expenses of condensed consolidated statements of income. Additionally, the Company was required to assess the fair value of its preexisting investment in Deephi Tech and recorded $6.5 million gain in its condensed consolidated statements of income as part of interest and other income, net. Subsequent to the acquisition, the financial results for Deephi Tech are included in the Company's condensed consolidated financial statements. Prior to the acquisition, the financial results for Deephi Tech were not significant for proforma financial information. The company allocated the purchase price to tangible and identified intangible assets acquired and liabilities assumed based on estimated fair values. As additional information becomes available, the company may further update the preliminary purchase price allocation during the remainder of the measurement period (up to one year from the acquisition date). The preliminary fair values of the assets acquired and liabilities assumed in the acquisition of Deephi Tech, by major class, were recognized as follows: Amount (In thousands) Cash and cash equivalents $ 6,263 Tangible assets 2,485 Identifiable intangible assets 81,530 Goodwill 180,035 Deferred tax liabilities (15,257 ) Other liabilities (3,146 ) Total $ 251,910 The goodwill of $180.0 million arising from the acquisition is attributed to the expected synergies and other benefits that will be generated from the combination of the Company and Deephi Tech. The goodwill recognized is not expected to be deductible for tax purposes. The identified intangible assets assumed in the acquisition of Deephi Tech were recognized as follows based upon the preliminary fair values as of the closing date of the acquisition. Amount Amortization Life (In thousands) Trade Names & Trademarks $ 1,020 3.0 years Developed Technology 24,770 5.0 years Customer Relationships 3,030 3.0 years In-Process Research and Development 52,710 N/A Total identifiable intangible assets $ 81,530

Subsequent Events (Notes)

Subsequent Events (Notes)	6 Months Ended
	Sep. 29, 2018
Subsequent Events [Abstract]
Subsequent Events [Text Block]	Subsequent Events On October 23, 2018 , the Company’s Board of Directors declared a cash dividend of $0.36 per common share for the third quarter of fiscal 2019 . The dividend is payable on December 4, 2018 to stockholders of record on November 13, 2018 .

Recent Accounting Changes and_2

Recent Accounting Changes and Accounting Pronouncements Recent Accounting Standards (Tables)	6 Months Ended
	Sep. 29, 2018
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]	The impact on the Company's previously reported condensed consolidated statement of income resulting from the adoption of the authoritative guidance is as follows: Three Months Ended September 30, 2017 Six Months Ended September 30, 2017 (In thousands, except per share amounts) As Reported Adjustment As Adjusted As Reported Adjustment As Adjusted Net revenues $ 619,503 $ 7,916 $ 627,419 $ 1,234,949 $ (4,720 ) $ 1,230,229 Cost of revenues 184,786 899 185,685 376,881 (372 ) 376,509 Gross margin 434,717 7,017 441,734 858,068 (4,348 ) 853,720 Operating expenses: Research and development 157,985 — 157,985 311,036 — 311,036 Selling, general and administrative 91,053 — 91,053 180,228 — 180,228 Amortization of acquisition-related intangibles 510 — 510 1,215 — 1,215 Total operating expenses 249,548 — 249,548 492,479 — 492,479 Operating income 185,169 7,017 192,186 365,589 (4,348 ) 361,241 Interest and other income, net 1,831 — 1,831 3,669 — 3,669 Income before income taxes 187,000 7,017 194,017 369,258 (4,348 ) 364,910 Provision for income taxes 19,468 798 20,266 34,481 (566 ) 33,915 Net income $ 167,532 $ 6,219 $ 173,751 $ 334,777 $ (3,782 ) $ 330,995 Net income per common share: Basic $ 0.68 $ (0.02 ) $ 0.70 $ 1.35 $ (0.02 ) $ 1.33 Diluted $ 0.65 $ (0.02 ) $ 0.67 $ 1.28 $ (0.02 ) $ 1.26 Shares used in per share calculations: Basic 248,094 248,094 247,960 247,960 Diluted 258,217 258,217 261,739 261,739 The impact on the Company's previously reported condensed consolidated balance sheet line items affected by the adoption of the authoritative guidance is as follows: March 31, 2018 (In thousands) As Reported Adjustment As Adjusted Accounts receivable $ 372,144 $ 10,102 $ 382,246 Other assets 342,644 (5,242 ) 337,402 Deferred income on shipments to distributors 25,166 (25,166 ) — Other accrued liabilities 59,772 (92 ) 59,680 Retained earnings 1,483,538 30,118 1,513,656

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Sep. 29, 2018
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	The following tables present information about the Company’s assets and liabilities measured at fair value on a recurring basis as of September 29, 2018 and March 31, 2018 : September 29, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 376,673 $ — $ — $ 376,673 Financial institution securities — 403,980 — 403,980 Non-financial institution securities — 476,957 — 476,957 U.S. government and agency securities 114,891 162,887 — 277,778 Foreign government and agency securities — 370,791 — 370,791 Short-term investments: Financial institution securities — 225,000 — 225,000 Non-financial institution securities — 96,379 — 96,379 U.S. government and agency securities 2,663 12,844 — 15,507 Mortgage-backed securities — 749,426 — 749,426 Asset-backed securities — 85,421 — 85,421 Commercial mortgage-backed securities — 134,189 — 134,189 Long-term investments: Debt mutual funds — 84,926 — 84,926 Marketable equity securities 6,701 — — 6,701 Total assets measured at fair value $ 500,928 $ 2,802,800 $ — $ 3,303,728 Liabilities Derivative financial instruments, net $ — $ 47,791 $ — $ 47,791 Total liabilities measured at fair value $ — $ 47,791 $ — $ 47,791 Net assets measured at fair value $ 500,928 $ 2,755,009 $ — $ 3,255,937 March 31, 2018 (In thousands) Quoted Significant Significant Total Fair Assets Cash equivalents: Money market funds $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities — 359,901 — 359,901 Non-financial institution securities — 242,904 — 242,904 U.S. government and agency securities 996 34,999 — 35,995 Foreign government and agency securities — 179,957 — 179,957 Short-term investments: Financial institution securities — 75,000 — 75,000 Non-financial institution securities — 81,939 — 81,939 U.S. government and agency securities 3,639 19,008 — 22,647 Mortgage-backed securities — 844,397 — 844,397 Asset-backed securities — 91,389 — 91,389 Commercial mortgage-backed securities — 152,870 — 152,870 Long-term investments: Debt mutual funds — 89,670 — 89,670 Marketable equity securities 8,226 — 8,226 Total assets measured at fair value $ 1,304,752 $ 2,172,034 $ — $ 3,476,786 Liabilities Derivative financial instruments, net $ — $ 26,091 $ — $ 26,091 Total liabilities measured at fair value $ — $ 26,091 $ — $ 26,091 Net assets measured at fair value $ 1,304,752 $ 2,145,943 $ — $ 3,450,695

Financial Instruments (Tables)

Financial Instruments (Tables)	6 Months Ended
	Sep. 29, 2018
Investments, All Other Investments [Abstract]
Available-for-sale securities	The following is a summary of cash equivalents, available-for-sale securities and equity-type securities as of the end of the periods presented: September 29, 2018 March 31, 2018 (In thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Money market funds $ 376,673 $ — $ — $ 376,673 $ 1,291,891 $ — $ — $ 1,291,891 Financial institution securities 628,965 15 — 628,980 434,901 — — 434,901 Non-financial institution securities 574,630 — (1,294 ) 573,336 326,219 — (1,376 ) 324,843 U.S. government and agency securities 293,600 22 (337 ) 293,285 58,913 1 (272 ) 58,642 Foreign government and agency securities 370,788 3 — 370,791 179,957 — — 179,957 Mortgage-backed securities 775,806 476 (26,856 ) 749,426 866,048 660 (22,311 ) 844,397 Asset-backed securities 86,664 9 (1,252 ) 85,421 92,751 16 (1,378 ) 91,389 Debt mutual funds 101,350 — (16,424 ) 84,926 101,350 — (11,680 ) 89,670 Commercial mortgage- backed securities 137,767 1 (3,579 ) 134,189 156,296 1 (3,427 ) 152,870 Marketable equity securities 7,500 — (799 ) 6,701 7,500 726 — 8,226 $ 3,353,743 $ 526 $ (50,541 ) $ 3,303,728 $ 3,515,826 $ 1,404 $ (40,444 ) $ 3,476,786
Fair values and gross unrealized losses of the investments	The following tables show the fair values and gross unrealized losses of the Company’s investments, aggregated by investment category, for individual securities that have been in a continuous unrealized loss position for the length of time specified, as of September 29, 2018 and March 31, 2018 : September 29, 2018 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Non-financial institution securities $ 44,067 $ (748 ) $ 19,640 $ (546 ) $ 63,707 $ (1,294 ) U.S. government and agency securities — — 15,507 (337 ) 15,507 (337 ) Mortgage-backed securities 222,604 (5,996 ) 497,433 (20,860 ) 720,037 (26,856 ) Asset-backed securities 18,472 (278 ) 65,425 (974 ) 83,897 (1,252 ) Debt mutual funds — — 84,926 (16,424 ) 84,926 (16,424 ) Commercial mortgage- backed securities 44,231 (950 ) 88,823 (2,629 ) 133,054 (3,579 ) Marketable equity securities 6,701 (799 ) — — 6,701 (799 ) $ 336,075 $ (8,771 ) $ 771,754 $ (41,770 ) $ 1,107,829 $ (50,541 ) March 31, 2018 Less Than 12 Months 12 Months or Greater Total (In thousands) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Non-financial institution securities $ 69,780 $ (1,146 ) $ 8,344 $ (230 ) $ 78,124 $ (1,376 ) U.S. government and agency securities 13,471 (176 ) 9,176 (96 ) 22,647 (272 ) Mortgage-backed securities 510,988 (11,048 ) 299,663 (11,263 ) 810,651 (22,311 ) Asset-backed securities 57,128 (876 ) 32,696 (502 ) 89,824 (1,378 ) Debt mutual funds — — 89,670 (11,680 ) 89,670 (11,680 ) Commercial mortgage- backed securities 95,435 (1,760 ) 56,051 (1,667 ) 151,486 (3,427 ) $ 746,802 $ (15,006 ) $ 495,600 $ (25,438 ) $ 1,242,402 $ (40,444 )
Amortized cost and estimated fair value of marketable debt securities	September 29, 2018 (In thousands) Amortized Estimated Due in one year or less $ 1,825,385 $ 1,825,113 Due after one year through five years 162,134 158,928 Due after five years through ten years 139,922 135,283 Due after ten years 740,779 716,104 $ 2,868,220 $ 2,835,428
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 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Proceeds from sale of available-for-sale securities $ 7 $ 149,497 $ 903 $ 269,419 Gross realized gains on sale of available-for-sale securities $ — $ 519 $ 96 $ 1,351 Gross realized losses on sale of available-for-sale securities (1 ) (209 ) (48 ) (595 ) Net realized gains (losses) on sale of available-for-sale securities $ (1 ) $ 310 $ 48 $ 756 Amortization of premiums on available-for-sale securities $ 2,645 $ 4,691 $ 5,136 $ 10,213

Stock-Based Compensation Plans

Stock-Based Compensation Plans (Tables)	6 Months Ended
	Sep. 29, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
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 2019 and 2018 were estimated using the Black-Scholes option pricing model at the date of grant using the following assumptions: 2019 2018 Expected life of options (years) 1.25 1.25 Expected stock price volatility 0.29 0.28 Risk-free interest rate 2.5 % 1.3 % Dividend yield 2.0 % 2.2 %
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 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Stock-based compensation included in: Cost of revenues $ 2,249 $ 2,147 $ 4,284 $ 4,297 Research and development 20,047 20,096 40,977 37,562 Selling, general and administrative 12,649 14,129 25,292 26,549 $ 34,945 $ 36,372 $ 70,553 $ 68,408
Schedule of Share-based compensation, restricted stock units, valuation assumption [Table Text Block]	The per share weighted-average fair value of RSUs granted during the second quarter of fiscal 2019 was $62.79 ( $59.99 for the second quarter of fiscal 2018 ), and for the first six months of fiscal 2019 was $63.00 ( $59.89 for the first six months of fiscal 2018 ), which were calculated based on estimates at the date of grant using the following weighted-average assumptions: Three Months Ended Six Months Ended September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Risk-free interest rate 2.7 % 1.7 % 2.7 % 1.7 % Dividend yield 2.2 % 2.2 % 2.2 % 2.2 %
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of restricted stock unit activity and related information	A summary of the Company’s RSU activity and related information is as follows: RSUs Outstanding (Shares in thousands) Number of Shares Weighted-Average Grant-Date Fair Value Per Share April 1, 2017 6,988 $ 42.93 Granted 3,718 $ 60.18 Vested (3,016 ) $ 43.30 Cancelled (701 ) $ 48.16 March 31, 2018 6,989 $ 51.39 Granted 2,964 $ 63.00 Vested (2,293 ) $ 48.60 Cancelled (251 ) $ 52.20 September 29, 2018 7,409

Net Income Per Common Share Net

Net Income Per Common Share Net Income Per Common Share (Tables)	6 Months Ended
	Sep. 29, 2018
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table summarizes the computation of basic and diluted net income per common share: Three Months Ended Six Months Ended (In thousands, except per share amounts) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Net income available to common stockholders $ 215,712 $ 173,751 $ 405,750 $ 330,995 Weighted average common shares outstanding-basic 252,988 248,094 252,541 247,960 Dilutive effect of employee equity incentive plans 2,534 2,532 2,516 2,949 Dilutive effect of 2017 Convertible Notes — — — 2,986 Dilutive effect of warrants — 7,591 — 7,844 Weighted average common shares outstanding-diluted 255,522 258,217 255,057 261,739 Basic net income per common share $ 0.85 $ 0.70 $ 1.61 $ 1.33 Diluted net income per common share $ 0.84 $ 0.67 $ 1.59 $ 1.26

Inventories Inventories (Tables

Inventories Inventories (Tables)	6 Months Ended
	Sep. 29, 2018
Inventory Disclosure [Abstract]
Schedule of Inventory, Current [Table Text Block]	Inventories are stated at the lower of actual cost (determined using the first-in, first-out method), or market (estimated net realizable value) and are comprised of the following: (In thousands) September 29, 2018 March 31, 2018 Raw materials $ 21,296 $ 14,674 Work-in-process 175,213 167,039 Finished goods 47,133 54,364 $ 243,642 $ 236,077

Debt and Credit Facility (Table

Debt and Credit Facility (Tables)	6 Months Ended
	Sep. 29, 2018
2019 and 2021 Notes Payable [Member]
Schedule of Debt Instruments [Line Items]
Carrying values of liability and equity components of debentures	The following table summarizes the carrying value of the 2019 Notes and 2021 Notes as of September 29, 2018 and March 31, 2018 : (In thousands) September 29, 2018 March 31, 2018 Principal amount of the 2019 Notes $ 500,000 $ 500,000 Unamortized discount of the 2019 Notes (229 ) (501 ) Unamortized debt issuance costs associated with 2019 Notes (142 ) (313 ) Carrying value of the 2019 Notes 499,629 499,186 Principal amount of the 2021 Notes 500,000 500,000 Unamortized discount of the 2021 Notes (1,330 ) (1,593 ) Unamortized debt issuance costs associated with 2021 Notes (590 ) (711 ) Carrying value of the 2021 Notes $ 498,080 $ 497,696 Total carrying value $ 997,709 $ 996,882
Interest Expense Related to Debentures [Table Text Block]	Interest expense related to the 2019 Notes and 2021 Notes was included in interest and other income, net on the condensed consolidated statements of income as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Contractual coupon interest $ 6,406 $ 6,406 $ 12,813 $ 12,813 Amortization of debt issuance costs 146 146 292 293 Amortization of debt discount, net 269 262 535 520 Total interest expense related to the 2019 Notes and 2021 Notes $ 6,821 $ 6,814 $ 13,640 $ 13,626
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 29, 2018 and March 31, 2018 : (In thousands) September 29, 2018 March 31, 2018 Principal amount of the 2024 Notes $ 750,000 $ 750,000 Unamortized discount of the 2024 Notes (699 ) (755 ) Unamortized debt issuance costs associated with 2024 Notes (3,216 ) (3,500 ) Carrying Value of the 2024 Notes $ 746,085 $ 745,745 Fair value hedge adjustment — interest rate swap contracts (42,281 ) (29,001 ) Net carrying value of the 2024 Notes $ 703,804 $ 716,744
Interest Expense Related to Debentures [Table Text Block]	Interest expense related to the 2024 Notes was included in interest and other income (expense), net on the condensed consolidated statements of income as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Contractual coupon interest (including interest rate swap, net) $ 6,174 $ 4,046 $ 12,556 $ 5,368 Amortization of debt issuance costs 142 142 284 189 Amortization of debt discount, net 27 27 56 37 Total interest expense related to the 2024 Notes $ 6,343 $ 4,215 $ 12,896 $ 5,594

Interest And Other Expense, N_2

Interest And Other Expense, Net (Tables)	6 Months Ended
	Sep. 29, 2018
Other Income and Expenses [Abstract]
Components of interest and other expense, net	The components of interest and other income, net are as follows: Three Months Ended Six Months Ended (In thousands) September 29, 2018 September 30, 2017 September 29, 2018 September 30, 2017 Interest income $ 17,350 $ 13,832 $ 34,748 $ 27,246 Interest expense (13,164 ) (11,029 ) (26,536 ) (23,110 ) Other income (expense), net 2,222 (972 ) (4,651 ) (467 ) Total interest and other income, net $ 6,408 $ 1,831 $ 3,561 $ 3,669

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Sep. 29, 2018
Equity [Abstract]
Components of accumulated other comprehensive income (loss)	The components of the Company's accumulated other comprehensive loss are as follows: (In thousands) September 29, 2018 March 31, 2018 Accumulated unrealized losses on available-for-sale securities, net of tax $ (25,280 ) $ (29,844 ) Accumulated unrealized gains (losses) on hedging transactions, net of tax (4,926 ) 1,674 Accumulated cumulative translation adjustment, net of tax (10,532 ) (6,339 ) Total accumulated other comprehensive loss $ (40,738 ) $ (34,509 )

Commitments (Tables)

Commitments (Tables)	6 Months Ended
	Sep. 29, 2018
Commitments and Contingencies Disclosure [Abstract]
Future minimum lease payments under non-cancelable operating leases	Approximate future minimum lease payments under non-cancelable operating leases are as follows: Fiscal (In thousands) 2019 (remaining six months) $ 4,613 2020 10,124 2021 7,231 2022 5,891 2023 4,699 Thereafter 30,708 Total $ 63,266

Goodwill and Acquisition-Rela_2

Goodwill and Acquisition-Related Intangibles (Tables)	6 Months Ended
	Sep. 29, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Gross and net amounts of goodwill and of acquisition-related intangibles	As of September 29, 2018 and March 31, 2018 , the gross and net amounts of goodwill and of acquisition-related intangibles for all acquisitions were as follows: Weighted-Average (In thousands) September 29, 2018 March 31, 2018 Amortization Life Goodwill $ 342,456 $ 162,421 Core technology, gross 107,250 82,480 Less accumulated amortization (79,587 ) (78,562 ) Core technology, net 27,663 3,918 5.0 years Other intangibles, gross 51,016 46,966 3.0 years Less accumulated amortization (46,934 ) (46,761 ) In-process research and development 52,710 — N/A Other intangibles, net 56,792 205 Total acquisition-related intangibles, gross 210,976 129,446 Less accumulated amortization (126,521 ) (125,323 ) Total acquisition-related intangibles, net $ 84,455 $ 4,123
Schedule of expected annual amortization expense for acquisition-related intangibles	Based on the carrying value of acquisition-related intangibles recorded as of September 29, 2018 , assuming no subsequent acquisition or impairment of the underlying assets, and the expected timing of completion of in-process research and development, the annual amortization expense for acquisition-related intangibles is expected to be as follows: Fiscal (In thousands) 2019 (remaining six months) $ 3,732 2020 13,613 2021 17,983 2022 16,631 Thereafter 32,496 Total $ 84,455

Business Combination (Tables)

Business Combination (Tables)	6 Months Ended
	Sep. 29, 2018
Business Combinations [Abstract]
Schedule of Assets Acquired and Liabilities Assumed	The preliminary fair values of the assets acquired and liabilities assumed in the acquisition of Deephi Tech, by major class, were recognized as follows: Amount (In thousands) Cash and cash equivalents $ 6,263 Tangible assets 2,485 Identifiable intangible assets 81,530 Goodwill 180,035 Deferred tax liabilities (15,257 ) Other liabilities (3,146 ) Total $ 251,910
Schedule of Finite-Lived Intangible Assets Acquired	The identified intangible assets assumed in the acquisition of Deephi Tech were recognized as follows based upon the preliminary fair values as of the closing date of the acquisition. Amount Amortization Life (In thousands) Trade Names & Trademarks $ 1,020 3.0 years Developed Technology 24,770 5.0 years Customer Relationships 3,030 3.0 years In-Process Research and Development 52,710 N/A Total identifiable intangible assets $ 81,530
Schedule of Indefinite-lived Intangible Assets Acquired	The identified intangible assets assumed in the acquisition of Deephi Tech were recognized as follows based upon the preliminary fair values as of the closing date of the acquisition. Amount Amortization Life (In thousands) Trade Names & Trademarks $ 1,020 3.0 years Developed Technology 24,770 5.0 years Customer Relationships 3,030 3.0 years In-Process Research and Development 52,710 N/A Total identifiable intangible assets $ 81,530

Recent Accounting Changes and_3

Recent Accounting Changes and Accounting Pronouncements Recent Accounting Standards (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017		Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net	$ 746,252	$ 627,419	[1]	$ 1,430,622	$ 1,230,229	[1]
Cost of Goods and Services Sold	231,620	185,685	[1]	438,508	376,509	[1]
Gross margin	514,632	441,734	[1]	992,114	853,720	[1]
Operating Expenses [Abstract]
Research and Development Expense	183,372	157,985		354,198	311,036
Selling, General and Administrative Expense	97,685	91,053		188,217	180,228
Amortization of acquisition-related intangibles	839	510		1,199	1,215
Operating Expenses	281,896	249,548		543,614	492,479
Operating income	232,736	192,186	[1]	448,500	361,241	[1]
Other Nonoperating Income (Expense)	6,408	1,831		3,561	3,669
Income before income taxes	239,144	194,017	[1]	452,061	364,910	[1]
Provision for income taxes	23,432	20,266	[1]	46,311	33,915	[1]
Net income	$ 215,712	$ 173,751	[1]	$ 405,750	$ 330,995	[1]
Earnings Per Share [Abstract]
Earnings Per Share, Basic	$ 0.85	$ 0.70	[1]	$ 1.61	$ 1.33	[1]
Earnings Per Share, Diluted	0.84	0.67	[1]	1.59	1.26	[1]
Common Stock, Dividends, Per Share, Declared	$ 0.36	$ 0.35		$ 0.72	$ 0.70
Weighted Average Number of Shares Outstanding, Basic	252,988	248,094		252,541	247,960
Weighted Average Number of Shares Outstanding, Diluted	255,522	258,217		255,057	261,739
Accounts Receivable, Net, Current	$ 372,983			$ 372,983			$ 382,246	[1]
Other assets	350,905			350,905			337,402	[1]
Deferred Income On Shipments To Distributors							0
Other accrued liabilities	60,965			60,965			59,680	[1]
Retained Earnings (Accumulated Deficit)	$ 1,576,476			$ 1,576,476			1,513,656	[1]
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net		$ 619,503			$ 1,234,949
Cost of Goods and Services Sold		184,786			376,881
Gross margin		434,717			858,068
Operating Expenses [Abstract]
Research and Development Expense		157,985			311,036
Selling, General and Administrative Expense		91,053			180,228
Amortization of acquisition-related intangibles		510			1,215
Operating Expenses		249,548			492,479
Operating income		185,169			365,589
Other Nonoperating Income (Expense)		1,831			3,669
Income before income taxes		187,000			369,258
Provision for income taxes		19,468			34,481
Net income		$ 167,532			$ 334,777
Earnings Per Share [Abstract]
Earnings Per Share, Basic		$ 0.68			$ 1.35
Earnings Per Share, Diluted		$ 0.65			$ 1.28
Accounts Receivable, Net, Current							372,144
Other assets							342,644
Deferred Income On Shipments To Distributors							25,166
Other accrued liabilities							59,772
Retained Earnings (Accumulated Deficit)							1,483,538
Difference between Revenue Guidance in Effect before and after Topic 606 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue, Net		$ 7,916			$ (4,720)
Cost of Goods and Services Sold		899			(372)
Gross margin		7,017			(4,348)
Operating Expenses [Abstract]
Research and Development Expense		0			0
Selling, General and Administrative Expense		0			0
Amortization of acquisition-related intangibles		0			0
Operating Expenses		0			0
Operating income		7,017			(4,348)
Other Nonoperating Income (Expense)		0			0
Income before income taxes		7,017			(4,348)
Provision for income taxes		798			(566)
Net income		$ 6,219			$ (3,782)
Earnings Per Share [Abstract]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Basic Earnings Per Share		$ (0.02)			$ (0.02)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Diluted Earnings Per Share		$ (0.02)			$ (0.02)
Accounts Receivable, Net, Current							10,102
Other assets							(5,242)
Deferred Income On Shipments To Distributors							(25,166)
Other accrued liabilities							(92)
Retained Earnings (Accumulated Deficit)							$ 30,118
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Recent Accounting Changes and_4

Recent Accounting Changes and Accounting Pronouncements Accounting Standard Update 2016-01 (Details) - Accounting Standards Update 2016-01 [Member] $ in Millions	6 Months Ended
	Sep. 29, 2018USD ($)
Other Comprehensive Income (Loss) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 11
Deferred Tax Asset [Domain]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 2.6

Recent Accounting Changes and_5

Recent Accounting Changes and Accounting Pronouncements Accounting Standards Update 2016 -16 (Details) $ in Millions	6 Months Ended
	Sep. 29, 2018USD ($)
Accounting Standards Update 2016-16 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 13.8

Significant Customers and Con_2

Significant Customers and Concentrations of Credit Risk (Details) - Customer	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Mar. 31, 2018
Significant Customers and Concentrations of Credit Risk [Abstract]
Percentage of Accounts Receivable Accounted From Company Distributor One	50.00%		50.00%		61.00%
Percentage of net revenues through resale of product from Company Distributor One	46.00%	46.00%	48.00%	43.00%
Number of End Customers Accounted For 10% or More of Net Revenues	0	0
Percentage of higher grade security investment in debt securities	91.00%		91.00%
Percentage of Mortgage Backed Securities In Investment Portfolio	23.00%		23.00%

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Available-for-sale Securities, Noncurrent	$ 91,627	$ 97,896
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	3,303,728	3,476,786
Fair Value, Net Asset (Liability)	3,255,937	3,450,695
Fair Value, Measurements, Recurring [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	47,791	26,091
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	500,928	1,304,752
Fair Value, Net Asset (Liability)	500,928	1,304,752
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	2,802,800	2,172,034
Fair Value, Net Asset (Liability)	2,755,009	2,145,943
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	47,791	26,091
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Net Asset (Liability)	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	376,673	1,291,891
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	403,980	359,901
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	476,957	242,904
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	277,778	35,995
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	370,791	179,957
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	376,673	1,291,891
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	114,891	996
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	403,980	359,901
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	476,957	242,904
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	162,887	34,999
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	370,791	179,957
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	225,000	75,000
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	96,379	81,939
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	15,507	22,647
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	749,426	844,397
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	85,421	91,389
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	134,189	152,870
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	2,663	3,639
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	225,000	75,000
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	96,379	81,939
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	12,844	19,008
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	749,426	844,397
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	85,421	91,389
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	134,189	152,870
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	84,926	89,670
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	6,701	8,226
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	6,701	8,226
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	84,926	89,670
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Equity Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets measured at fair value	0	0
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	47,791	26,091
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0	0
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	47,791	26,091
Other Noncurrent Liabilities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	$ 0	$ 0

Fair Value Measurements (Deta_2

Fair Value Measurements (Details Textual) - USD ($) $ in Thousands	6 Months Ended
	Sep. 29, 2018	Mar. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities, Noncurrent	$ 91,627	$ 97,896
Cost Method Investments, Fair Value Disclosure	53,800
Two And One Two Five Percent 2019 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000
Debt Instrument, Interest Rate, Stated Percentage	2.125%
Debt Instrument, Maturity Date	Mar. 15, 2019
Fair value of convertible notes	$ 498,700
Three Point Zero Percent 2021 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000
Debt Instrument, Interest Rate, Stated Percentage	3.00%
Debt Instrument, Maturity Date	Mar. 15, 2021
Fair value of convertible notes	$ 495,200
Three Point Zero Percent 2021 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	500,000	500,000
Two And One Two Five Percent 2019 Senior Debentures [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt Instrument, Face Amount	$ 500,000	$ 500,000

Financial Instruments (Details)

Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Available-for-sale securities
Amortized Cost	$ 3,353,743	$ 3,515,826
Gross Unrealized Gains	526	1,404
Gross Unrealized Losses	(50,541)	(40,444)
Estimated Fair Value	3,303,728	3,476,786
Money Market Funds [Member]
Available-for-sale securities
Amortized Cost	376,673	1,291,891
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	376,673	1,291,891
Financial institution securities [Member]
Available-for-sale securities
Amortized Cost	628,965	434,901
Gross Unrealized Gains	15	0
Gross Unrealized Losses	0	0
Estimated Fair Value	628,980	434,901
Non-financial institution securities [Member]
Available-for-sale securities
Amortized Cost	574,630	326,219
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1,294)	(1,376)
Estimated Fair Value	573,336	324,843
U.S. Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	293,600	58,913
Gross Unrealized Gains	22	1
Gross Unrealized Losses	(337)	(272)
Estimated Fair Value	293,285	58,642
Foreign Government and Agency Securities [Member]
Available-for-sale securities
Amortized Cost	370,788	179,957
Gross Unrealized Gains	3	0
Gross Unrealized Losses	0	0
Estimated Fair Value	370,791	179,957
Mortgage-Backed Securities [Member]
Available-for-sale securities
Amortized Cost	775,806	866,048
Gross Unrealized Gains	476	660
Gross Unrealized Losses	(26,856)	(22,311)
Estimated Fair Value	749,426	844,397
Asset-backed Securities [Member]
Available-for-sale securities
Amortized Cost	86,664	92,751
Gross Unrealized Gains	9	16
Gross Unrealized Losses	(1,252)	(1,378)
Estimated Fair Value	85,421	91,389
Debt Mutual Fund [Member]
Available-for-sale securities
Amortized Cost	101,350	101,350
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(16,424)	(11,680)
Estimated Fair Value	84,926	89,670
Commercial Mortgage Backed Securities [Member]
Available-for-sale securities
Amortized Cost	137,767	156,296
Gross Unrealized Gains	1	1
Gross Unrealized Losses	(3,579)	(3,427)
Estimated Fair Value	134,189	152,870
Equity Securities [Member]
Available-for-sale securities
Amortized Cost	7,500	7,500
Gross Unrealized Gains	0	726
Gross Unrealized Losses	(799)	0
Estimated Fair Value	$ 6,701	$ 8,226

Financial Instruments (Details

Financial Instruments (Details 1) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Sep. 29, 2018	Sep. 29, 2018	Mar. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Equity Securities, Gross Unrealized Loss	$ 73	$ 6,300
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	336,075	336,075	$ 746,802
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(8,771)	(8,771)	(15,006)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	771,754	771,754	495,600
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(41,770)	(41,770)	(25,438)
Available-for-Sale Securities, Fair Value, Total	1,107,829	1,107,829	1,242,402
Available-for-Sale Securities, Gross Unrealized Losses, Total	(50,541)	(50,541)	(40,444)
Non-financial institution securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	44,067	44,067	69,780
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(748)	(748)	(1,146)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	19,640	19,640	8,344
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(546)	(546)	(230)
Available-for-Sale Securities, Fair Value, Total	63,707	63,707	78,124
Available-for-Sale Securities, Gross Unrealized Losses, Total	(1,294)	(1,294)	(1,376)
U.S. Government and Agency Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	0	0	13,471
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	0	0	(176)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	15,507	15,507	9,176
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(337)	(337)	(96)
Available-for-Sale Securities, Fair Value, Total	15,507	15,507	22,647
Available-for-Sale Securities, Gross Unrealized Losses, Total	(337)	(337)	(272)
Mortgage-Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	222,604	222,604	510,988
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(5,996)	(5,996)	(11,048)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	497,433	497,433	299,663
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(20,860)	(20,860)	(11,263)
Available-for-Sale Securities, Fair Value, Total	720,037	720,037	810,651
Available-for-Sale Securities, Gross Unrealized Losses, Total	(26,856)	(26,856)	(22,311)
Asset-backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	18,472	18,472	57,128
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(278)	(278)	(876)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	65,425	65,425	32,696
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(974)	(974)	(502)
Available-for-Sale Securities, Fair Value, Total	83,897	83,897	89,824
Available-for-Sale Securities, Gross Unrealized Losses, Total	(1,252)	(1,252)	(1,378)
Debt Mutual Fund [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	0	0	0
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	0	0	0
Available-for-Sale Securities, 12 Months or Greater, Fair Value	84,926	84,926	89,670
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(16,424)	(16,424)	(11,680)
Available-for-Sale Securities, Fair Value, Total	84,926	84,926	89,670
Available-for-Sale Securities, Gross Unrealized Losses, Total	(16,424)	(16,424)	(11,680)
Commercial Mortgage Backed Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	44,231	44,231	95,435
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(950)	(950)	(1,760)
Available-for-Sale Securities, 12 Months or Greater, Fair Value	88,823	88,823	56,051
Available-for-Sale Securities, 12 Months or Greater, Gross Unrealized Losses	(2,629)	(2,629)	(1,667)
Available-for-Sale Securities, Fair Value, Total	133,054	133,054	151,486
Available-for-Sale Securities, Gross Unrealized Losses, Total	(3,579)	(3,579)	$ (3,427)
Equity Securities [Member]
Fair values and gross unrealized losses of the investments
Available-for-Sale Securities, Less Than 12 Months, Fair Value	6,701	6,701
Available-for-Sale Securities, Less Than 12 Months, Gross Unrealized Losses	(799)	(799)
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	6,701	6,701
Available-for-Sale Securities, Gross Unrealized Losses, Total	$ (799)	$ (799)

Financial Instruments (Detail_2

Financial Instruments (Details 2) $ in Thousands	Sep. 29, 2018USD ($)
Amortized Cost
Due in one year or less	$ 1,825,385
Due after one year through five years	162,134
Due after five years through ten years	139,922
Due after ten years	740,779
Amortized Cost Total	2,868,220
Estimated Fair Value
Due in one year or less	1,825,113
Due after one year through five years	158,928
Due after five years through ten years	135,283
Due after ten years	716,104
Estimated Fair Value Total	2,835,428
Marketable debt securities with contractual maturities greater than one year but classified as short-term investment	$ 1,010,000

Financial Instruments (Detail_3

Financial Instruments (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Investments, All Other Investments [Abstract]
Proceeds from sale of available-for-sale securities	$ 7	$ 149,497	$ 903	$ 269,419
Gross realized gains on sale of available-for-sale securities	0	519	96	1,351
Gross realized losses on sale of available-for-sale securities	(1)	(209)	(48)	(595)
Net realized gains (losses) on sale of available-for-sale securities	(1)	310	48	756
Amortization of premiums on available-for-sale securities	$ 2,645	$ 4,691	$ 5,136	$ 10,213

Derivative Financial Instrume_2

Derivative Financial Instruments (Details Textual)	6 Months Ended
	Sep. 29, 2018USD ($)
Derivative [Line Items]
Gain (Loss) on Fair Value Hedge Ineffectiveness, Net	$ 0
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 13,300,000

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 34,945	$ 36,372	$ 70,553	$ 68,408
Cost of Revenues [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	2,249	2,147	4,284	4,297
Research and Development [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	20,047	20,096	40,977	37,562
Selling, General and Administrative Expenses [Member]
Stock Based compensation expense
Stock-based compensation effect on income before taxes	$ 12,649	$ 14,129	$ 25,292	$ 26,549

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 1)	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.70%	1.70%	2.70%	1.70%
Weighted average assumptions in estimation of fair value of stock options
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.20%	2.20%	2.20%	2.20%

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans Stock-Based Compensation Plans (Details 3) - Restricted Stock Units (RSUs) [Member] - $ / shares shares in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Mar. 31, 2018
Number of Shares
Number of Shares, Beginning Balance (shares)			6,989	6,988	6,988
Number of Shares, Granted (shares)			2,964		3,718
Number of Shares, Vested (shares)			2,293		3,016
Number of Shares, Forfeited/Cancelled (shares)			251		701
Number of Shares, Ending Balance (shares)	7,409		7,409		6,989
Weighted-Average Grant-Date Fair Value Per Share
Weighted-Average Grant-Date Fair Value, Beginning Balance (usd per share)			$ 51.39	$ 42.93	$ 42.93
Weighted-Average Grant-Date Fair Value, Granted (usd per share)	$ 62.79	$ 59.99	63	$ 59.89	60.18
Weighted-Average Grant-Date Fair Value, Vested (usd per share)			48.60		43.30
Weighted-Average Grant-Date Fair Value, Forfeited/Cancelled (usd per share)			52.20		48.16
Weighted-Average Grant-Date Fair Value, Ending Balance (usd per share)					$ 51.39

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans (Details Textual) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Mar. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax benefit from compensation expense	$ 7.8	$ 6.3	$ 8.7	$ 17.9
Adjustments Related to Tax Withholding for Share-based Compensation			$ 39.5	$ 42.1
Options, grants in period (shares)			0		0
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.70%	1.70%	2.70%	1.70%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.20%	2.20%	2.20%	2.20%
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Issued During Period, Value, Employee Stock Purchase Plan	$ 18	$ 16.9
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	29.00%	28.00%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate	2.50%	1.30%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.00%	2.20%
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted (usd per share)	$ 62.79	$ 59.99	$ 63	$ 59.89	$ 60.18
Equity Plan 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			3,000,000
Shares available for grant (shares)	11,600,000		11,600,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-Average Grant-Date Fair Value, Granted (usd per share)	$ 19.06	$ 16.46
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized			3,000,000
ESPP shares issued during period (shares)	359,000	355,000
Shares available for grant (shares)	12,000,000		12,000,000

Net Income Per Common Share N_2

Net Income Per Common Share Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017		Jul. 01, 2017
Debt Conversion [Line Items]
Net income	$ 215,712	$ 173,751	[1]	$ 405,750	$ 330,995	[1]
Weighted Average Number of Shares Outstanding, Basic	252,988	248,094		252,541	247,960
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	2,534	2,532		2,516	2,949
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities and Warrants	0	7,591		0	7,844
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities	0	0		0	2,986
Weighted Average Number of Shares Outstanding, Diluted	255,522	258,217		255,057	261,739
Antidilutive shares excluded from computation of dilutive net income per common share	1,800			3,000
Earnings Per Share, Basic	$ 0.85	$ 0.70	[1]	$ 1.61	$ 1.33	[1]
Earnings Per Share, Diluted	$ 0.84	$ 0.67	[1]	$ 1.59	$ 1.26	[1]
Two And Six Two Five Percent Senior Convertible Debentures [Member]
Debt Conversion [Line Items]
Debt Instrument, Face Amount							$ 600,000
Debt Instrument, Interest Rate, Stated Percentage							2.625%
Debt Instrument, Maturity Date		Jun. 15, 2017
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Inventories Inventories (Detail

Inventories Inventories (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Inventory Disclosure [Abstract]
Inventory, Raw Materials, Gross	$ 21,296	$ 14,674
Inventory, Work in Process, Gross	175,213	167,039
Inventory, Finished Goods, Gross	47,133	54,364
Inventory, Net	$ 243,642	$ 236,077

Debt and Credit Facility (Detai

Debt and Credit Facility (Details 1) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Mar. 29, 2014	Mar. 31, 2018	May 30, 2017	Mar. 12, 2014
Debt Instrument [Line Items]
Net interest rate received (paid) from interest rate swap	$ (642,000)	$ 1,500,000	$ (1,500,000)	$ 2,100,000
Long-term Debt, Current Maturities	499,629,000		499,629,000			$ 499,186,000
Amortization of Debt Discount (Premium)			591,000	1,964,000
Proceeds from Issuance of Long-term Debt			$ 0	745,175,000
Debt Instrument, Description of Variable Rate Basis			three-month London Interbank Offered Rate (LIBOR) plus 91.43 bps
Line of Credit Facility, Expiration Date			Dec. 14, 2021
Line of Credit Facility, Maximum Borrowing Capacity	400,000,000		$ 400,000,000
AdditionalborrowingcapacityfromRevolvingCreditFacility	150,000,000		150,000,000
Line of Credit Facility, Average Outstanding Amount			0
Long-term Debt, Excluding Current Maturities	1,201,884,000		1,201,884,000			1,214,440,000
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 750,000,000		$ 750,000,000
Debt Instrument, Interest Rate, Stated Percentage	2.95%		2.95%
Two And One Two Five Percent 2019 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par								99.477%
Debt Instrument, Face Amount	$ 500,000,000		$ 500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(229,000)		(229,000)			(501,000)
Debt Issuance Costs, Current, Net	142,000		142,000			313,000
Long-term Debt, Current Maturities	$ 499,629,000		499,629,000			499,186,000
Debt instrument, long term debt, remaining discount amortization period	5 months 15 days
2019 and 2021 Notes Payable [Member]
Debt Instrument [Line Items]
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	292,000	293,000
Amortization of Debt Discount (Premium)	269,000	262,000	535,000	520,000
Interest Expense, Debt	6,821,000	6,814,000	13,640,000	13,626,000
Proceeds from Issuance of Long-term Debt					$ 990,100,000
Debt, Long-term and Short-term, Combined Amount	997,709,000		997,709,000			996,882,000
Two Point and Nine Five Percent 2024 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par							99.887%
Debt Instrument, Face Amount	$ 750,000,000		$ 750,000,000			750,000,000
Debt Instrument, Interest Rate, Stated Percentage	2.95%		2.95%
Debt Instrument, Unamortized Discount	$ (699,000)		$ (699,000)			(755,000)
Debt Issuance Costs, Noncurrent, Net	3,216,000		3,216,000			3,500,000
Long Term Debt, Carrying Value before Hedging Adjustment	746,085,000		746,085,000			745,745,000
Derivative, Amount of Hedged Item	(42,281,000)		(42,281,000)			(29,001,000)
Interest Expense, Debt, Excluding Amortization	6,174,000	4,046,000	12,556,000	5,368,000
Amortization of Debt Issuance Costs	142,000	142,000	284,000	189,000
Amortization of Debt Discount (Premium)	27,000	27,000	56,000	37,000
Interest Expense, Debt	$ 6,343,000	$ 4,215,000	12,896,000	$ 5,594,000
Proceeds from Issuance of Long-term Debt			745,200,000
Debt instrument, long term debt, remaining discount amortization period	5 years 8 months
Long-term Debt, Excluding Current Maturities	$ 703,804,000		703,804,000			716,744,000
Three Point Zero Percent 2021 Senior Debentures [Member]
Debt Instrument [Line Items]
Discount Percent of Par								99.281%
Debt Instrument, Face Amount	500,000,000		500,000,000			500,000,000
Debt Instrument, Unamortized Discount	(1,330,000)		(1,330,000)			(1,593,000)
Debt Issuance Costs, Noncurrent, Net	$ 590,000		590,000			711,000
Debt instrument, long term debt, remaining discount amortization period	2 years 5 months 15 days
Long-term Debt, Excluding Current Maturities	$ 498,080,000		498,080,000			$ 497,696,000
Interest Rate Swap [Member]
Debt Instrument [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	$ 42,300,000		$ 42,300,000

Debt and Credit Facility (Det_2

Debt and Credit Facility (Details 2) - USD ($) $ in Thousands	6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Mar. 31, 2018
Short-term Debt [Line Items]
Repayments of Convertible Debt	$ 0	$ 457,918
Amortization of Debt Discount (Premium)	591	$ 1,964
Long-term Debt, Excluding Current Maturities	$ 1,201,884		$ 1,214,440

Common Stock Repurchase Progr_2

Common Stock Repurchase Program (Details) - USD ($)	6 Months Ended		28 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	May 16, 2018	Mar. 31, 2018	May 16, 2016
Accelerated Share Repurchases [Line Items]
Preferred stock, shares issued (none issued)	0		0		0
Preferred Stock, Shares Outstanding	0		0		0
Stock Repurchased and Retired During Period, Value	$ 160,000,000	$ 237,500,000
Treasury shares	0		0		0
Stock Repurchased During Period, Shares	(2,400,000)	(3,700,000)
Repurchase Program Two Thousand Sixteen [Member] [Domain]
Accelerated Share Repurchases [Line Items]
Amount authorized for common stock repurchase						$ 1,000,000,000
Stock Repurchased During Period, Value			$ 952,700,000
Total amount available for future repurchases	$ 47,300,000		$ 47,300,000
Repurchase Program Two Thousand Eighteen [Domain]
Accelerated Share Repurchases [Line Items]
Amount authorized for common stock repurchase				$ 500,000,000

Interest and Other Expense, N_3

Interest and Other Expense, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Other Income and Expenses [Abstract]
Net interest rate received (paid) from interest rate swap	$ (642)	$ 1,500	$ (1,500)	$ 2,100
Components of interest and other expense
Interest income	17,350	13,832	34,748	27,246
Interest expense	(13,164)	(11,029)	(26,536)	(23,110)
Other income (expense), net	2,222	(972)	(4,651)	(467)
Interest and other expense, net	$ 6,408	$ 1,831	$ 3,561	$ 3,669

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Components of accumulated other comprehensive income (loss)
Accumulated unrealized losses on available-for-sale securities, net of tax	$ (25,280)	$ (29,844)
Accumulated unrealized losses on hedging transactions, net of tax	(4,926)	1,674
Accumulated cumulative translation adjustment, net of tax	(10,532)	(6,339)
Accumulated other comprehensive income (loss)	$ (40,738)	$ (34,509)

Income Taxes (Details Textual)

Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended			6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017		Sep. 29, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)	$ 23,432	$ 20,266	[1]	$ 46,311	$ 33,915	[1]
Tax Cuts and Jobs Act of 2017, Incomplete Accounting, Provisional Income Tax Expense	$ 9,400
Effective Income Tax Rate Reconciliation, Percent	9.80%	10.40%		10.20%	9.30%
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Unrecognized Tax Benefits	$ 126,100			$ 126,100
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	16,100			16,100
Unrecognized Tax Benefits That Would Impact Additional Paid-in Capital	$ 85,500			$ 85,500
[1]	Prior year balances have been restated to reflect the retrospective application of the new revenue recognition accounting standard. Please refer to "Note 2. Recent Accounting Changes and Accounting Pronouncements."

Commitments (Details)

Commitments (Details) $ in Thousands	Sep. 29, 2018USD ($)
Future Minimum Lease Payments Under Non-Cancelable Operating Leases
2019 (remaining six months)	$ 4,613
2,020	10,124
2,021	7,231
2,022	5,891
2,023	4,699
Thereafter	30,708
Total	$ 63,266

Commitments (Details Textual)

Commitments (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Other Commitments [Line Items]
Aggregate future rental income to be received	$ 11,000		$ 11,000
Rent expense, net of rental income	816	$ 900	1,800	$ 2,100
Other commitments	200,200		$ 200,200
Software and Maintenance License Obligations Expiration Date			Dec. 28, 2022
Minimum [Member]
Other Commitments [Line Items]
Purchase Commitments, Period for Payment			3 months
Maximum [Member]
Other Commitments [Line Items]
Purchase Commitments, Period for Payment			6 months
Capital Lease Obligations [Member]
Other Commitments [Line Items]
Lease Expiration Date			Nov. 30, 2035
Electronic Design Automation Software And Hardware/Software Maintenance [Member]
Other Commitments [Line Items]
Non-cancelable license obligations	8,900		$ 8,900
Leasing Arrangement [Member]
Other Commitments [Line Items]
Lease Expiration Date			Apr. 30, 2029
Open purchase Orders From Ordinary Operations [Member]
Other Commitments [Line Items]
Non-cancelable license obligations	$ 25,100		$ 25,100

Contingencies Contingencies (De

Contingencies Contingencies (Details) $ in Millions	6 Months Ended
	Sep. 29, 2018USD ($)
Commitments and Contingencies Disclosure [Abstract]
Loss Contingency, Damages Sought, Value	$ 50

Goodwill and Acquisition-Rela_3

Goodwill and Acquisition-Related Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 29, 2018	Mar. 31, 2018
Gross and net amounts of goodwill and of acquisition-related intangibles
Goodwill	$ 342,456	$ 162,421
Total acquisition-related intangibles, gross	210,976	129,446
Less accumulated amortization	(126,521)	(125,323)
Total	84,455	4,123
Core Technology [Member]
Gross and net amounts of goodwill and of acquisition-related intangibles
Total acquisition-related intangibles, gross	107,250	82,480
Less accumulated amortization	(79,587)	(78,562)
Total	$ 27,663	3,918
Weighted-Average Amortization Life	5 years
Other Intangibles [Member]
Gross and net amounts of goodwill and of acquisition-related intangibles
Total acquisition-related intangibles, gross	$ 51,016	46,966
Less accumulated amortization	(46,934)	(46,761)
Indefinite-lived Intangible Assets Acquired	52,710	0
Total	$ 56,792	$ 205
Weighted-Average Amortization Life	3 years
Deephi Tech Acquisition [Member]
Gross and net amounts of goodwill and of acquisition-related intangibles
Goodwill	$ 180,035
Identifiable intangible assets	$ 81,530

Goodwill and Acquisition-Rela_4

Goodwill and Acquisition-Related Intangibles (Details 1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization of acquisition-related intangibles	$ 839	$ 510	$ 1,199	$ 1,215
Schedule of expected annual amortization expense for acquisition-related intangibles
2019 (remaining six months)	3,732		3,732
2,020	13,613		13,613
2,021	17,983		17,983
2,022	16,631		16,631
Thereafter	32,496		32,496
Total	$ 84,455		$ 84,455		$ 4,123

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 29, 2018	Mar. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 342,456	$ 162,421
Deephi Tech Acquisition [Member]
Business Acquisition [Line Items]
Purchase consideration	251,900
Fair value of preexisting investment	11,500
Unsettled payments	10,600
Cash acquired	6,263
Acquisition related costs	3,400
Remeasurement gain	6,500
Goodwill	$ 180,035

Business Combination Schedule o

Business Combination Schedule of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Mar. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 342,456	$ 162,421
Deephi Tech Acquisition [Member]
Business Acquisition [Line Items]
Cash and cash equivalents	6,263
Tangible assets	2,485
Identifiable intangible assets	81,530
Goodwill	180,035
Deferred tax liabilities	(15,257)
Other liabilities	(3,146)
Total	$ 251,910

Business Combination Schedule_2

Business Combination Schedule of Intangible Assets Acquired (Details) - Deephi Tech Acquisition [Member] $ in Thousands	3 Months Ended
	Sep. 29, 2018USD ($)
Acquired Indefinite-lived Intangible Assets [Line Items]
Identifiable intangible assets	$ 81,530
In Process Research and Development [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets acquired	52,710
Trademarks and Trade Names [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 1,020
Amortization Life	3 years
Developed Technology Rights [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 24,770
Amortization Life	5 years
Customer Relationships [Member]
Acquired Indefinite-lived Intangible Assets [Line Items]
Finite-lived intangible assets acquired	$ 3,030
Amortization Life	3 years

Subsequent Events (Details)

Subsequent Events (Details)	Oct. 23, 2018$ / shares
Subsequent Event [Member]
Subsequent Event [Line Items]
Common Stock, Dividends, Per Share, Declared	$ 0.36