Skyworks Solutions (SWKS) 10-Q 5 May 20 2020 Q1 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - $ / shares	6 Months Ended
	Mar. 27, 2020	Apr. 28, 2020
Cover [Abstract]
Document Type	10-Q
Document Period End Date	Mar. 27, 2020
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-05560
Entity Registrant Name	Skyworks Solutions, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	04-2302115
Entity Address, Address Line One	20 Sylvan Road,
Entity Address, City or Town	Woburn
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	01801
City Area Code	(781)
Local Phone Number	376-3000
Title of 12(b) Security	Common Stock, par value $0.25 per share
Trading Symbol	SWKS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		166,835,903
Entity Listing, Par Value Per Share	$ 0.25
Entity Central Index Key	0000004127
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--10-02

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Income Statement [Abstract]
Document Period End Date			Mar. 27, 2020
Net revenue	$ 766.1	$ 810.4	$ 1,662.2	$ 1,782.4
Cost of goods sold	390.5	410.2	842.3	897
Gross profit	375.6	400.2	819.9	885.4
Operating expenses:
Research and development	113.2	107.5	220.8	216.7
Selling, general and administrative	58.6	47.9	114	95.7
Amortization of intangibles	3.1	5.7	6.3	13.1
Restructuring and other charges	1.2	1.5	2	1.4
Total operating expenses	176.1	162.6	343.1	326.9
Operating income	199.5	237.6	476.8	558.5
Other income, net	3.5	3.7	4.9	6.6
Income before income taxes	203	241.3	481.7	565.1
Provision for income taxes	21.9	27.3	43.6	66.3
Net income	$ 181.1	$ 214	$ 438.1	$ 498.8
Earnings per share:
Basic (in dollars per share)	$ 1.07	$ 1.23	$ 2.58	$ 2.85
Diluted (in dollars per share)	$ 1.06	$ 1.23	$ 2.56	$ 2.83
Weighted average shares:
Basic (in shares)	170	173.8	170.1	175.2
Diluted (in shares)	171.1	174.6	171.3	176.1
Common Stock, Dividends, Per Share, Declared	$ 0.44	$ 0.38	$ 0.88	$ 0.76

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Statement of Comprehensive Income [Abstract]
Net income	$ 181.1	$ 214	$ 438.1	$ 498.8
Other comprehensive income, net of tax
Fair value of investments	0.5	0.1	0.4	0.2
Other Comprehensive (Income) Loss, Defined Benefit Plan, before Reclassification Adjustment, after Tax	0	0.5	0	0.5
Comprehensive income	$ 181.6	$ 214.6	$ 438.5	$ 499.5

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Sep. 27, 2019
Statement of Financial Position [Abstract]
Document Period End Date	Mar. 27, 2020
Current assets:
Cash and cash equivalents	$ 912.4	$ 851.3
Marketable Securities, Current	161.5	203.3
Receivables, net of allowance of $0.8 and $0.8, respectively	367.6	465.3
Inventory	648.9	609.7
Other current assets	130.4	105
Total current assets	2,220.8	2,234.6
Property, plant and equipment, net	1,207.9	1,205.6
Operating Lease, Right-of-Use Asset	171.3	0
Goodwill	1,189.8	1,189.8
Intangible assets, net	85.4	107.9
Deferred Income Tax Assets, Net	39.6	40.8
Marketable Securities, Noncurrent	34.1	27.6
Other long-term assets	33	33.3
Total assets	4,981.9	4,839.6
Current liabilities:
Accounts payable	169.5	190.5
Accrued compensation and benefits	78.4	76
Other current liabilities	114.3	107.5
Total current liabilities	362.2	374
Long-term tax liabilities	293	312.4
Operating Lease, Liability, Noncurrent	151.9	0
Other long-term liabilities	32	30.9
Total liabilities	839.1	717.3
Stockholders’ equity:
Preferred stock, no par value: 25.0 shares authorized, no shares issued	0	0
Common stock, $0.25 par value: 525.0 shares authorized; 231.9 shares issued and 167.5 shares outstanding at March 27, 2020, and 230.2 shares issued and 170.1 shares outstanding at September 27, 2019	41.9	42.5
Additional paid-in capital	3,307.2	3,188
Treasury stock, at cost	(3,799.6)	(3,412.9)
Retained earnings	4,600.8	4,312.6
Accumulated other comprehensive loss	(7.5)	(7.9)
Total stockholders’ equity	4,142.8	4,122.3
Total liabilities and stockholders’ equity	$ 4,981.9	$ 4,839.6

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Mar. 27, 2020	Sep. 27, 2019
Current assets:
Allowance for doubtful accounts	$ 0.8	$ 0.8
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, par value (in dollars per share)	$ 0	$ 0
Preferred stock, shares authorized	25	25
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.25	$ 0.25
Common stock, shares authorized	525	525
Common stock, shares issued	231.9	230.2
Common stock, shares outstanding	167.5	170.1

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019
Statement of Cash Flows [Abstract]
Document Period End Date	Mar. 27, 2020
Net income	$ 438.1	$ 498.8
Adjustments to reconcile net income to net cash provided by operating activities:
Share-based compensation	73.8	42.6
Depreciation	160.3	156.4
Amortization of intangible assets, including inventory step-up	22.7	28.6
Deferred income taxes	1.1	(27.6)
Other, net	2.1	0.8
Changes in assets and liabilities:
Receivables, net	97.7	112
Inventory	(37)	(66.9)
Accounts payable	(13.2)	(23.9)
Other current and long-term assets and liabilities	(66.8)	20.3
Net Cash Provided by (Used in) Operating Activities	678.8	741.1
Cash flows from investing activities:
Payments to Acquire Property, Plant, and Equipment	171.9	226.2
Payments to Acquire Marketable Securities	(178.8)	(166.7)
Payments to Acquire Intangible Assets	0.2	12.9
Proceeds from Sale and Maturity of Debt Securities, Available-for-sale	214.4	309.2
Net Cash Provided by (Used in) Investing Activities	(136.5)	(96.6)
Cash flows from financing activities:
Repurchase of common stock - payroll tax withholdings on equity awards	(28.7)	(21)
Repurchase of common stock - stock repurchase program	(358)	(425.5)
Dividends paid	(150)	(133.1)
Net proceeds from exercise of stock options	43.3	6.8
Proceeds from Issuance of Common Stock	12.2	11.3
Net Cash Provided by (Used in) Financing Activities	(481.2)	(561.5)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	61.1	83
Cash and cash equivalents at beginning of period	851.3	733.3
Cash and cash equivalents at end of period	912.4	816.3
Supplemental cash flow disclosures:
Income taxes paid	81.1	87.5
Capital Expenditures Incurred but Not yet Paid	$ 95.4	$ 69.9

Statement of Stockholders Equit

Statement of Stockholders Equity Statement - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Common stock, shares outstanding		177.4
Stockholders' Equity Attributable to Parent	$ 4,097	$ 44.4	$ (2,732.5)	$ 3,061	$ 3,732.9	$ (8.8)
Treasury Stock, Shares			51
Net income	284.9				284.9
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		0.7	0.2
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	(14.4)	$ 0.1	$ (19.6)	5.1
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	21.3			21.3
Treasury Stock, Shares, Acquired		(4)
Treasury Stock, Value, Acquired, Par Value Method	(284)	$ (1)	$ (284)	1
Stock Repurchased During Period, Shares			4
Dividends	(67.1)				(67.1)
Other Comprehensive Income (Loss), Net of Tax	0.6					0.6
Net income	498.8
Common stock, shares outstanding		174.1
Stockholders' Equity Attributable to Parent	4,038.3	$ 43.5	$ (3,036.1)	3,088.4	3,950.7	(8.2)
Treasury Stock, Shares			55.2
Net income	214				214
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		0.3	0.1
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	14.2	$ 0.1	$ (1.5)	15.5
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	21.8			21.8
Treasury Stock, Shares, Acquired		(1.7)
Treasury Stock, Value, Acquired, Par Value Method	(141.5)	$ (0.4)	$ (141.5)	0.5
Stock Repurchased During Period, Shares			1.7
Dividends	(66)				(66)
Other Comprehensive Income (Loss), Net of Tax	0.1					0.1
Common stock, shares outstanding		172.7
Stockholders' Equity Attributable to Parent	$ 4,080.9	$ 43.2	$ (3,179.1)	3,126.2	4,098.7	(8.1)
Treasury Stock, Shares			57
Common stock, shares outstanding	170.1	170.1
Stockholders' Equity Attributable to Parent	$ 4,122.3	$ 42.5	$ (3,412.9)	3,188	4,312.6	(7.9)
Treasury Stock, Shares			60.1
Net income	257.1				257.1
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		1.1	0.3
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	8.2	$ 0.3	$ (26.7)	34.6
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	29.1			29.1
Treasury Stock, Shares, Acquired		(0.7)
Treasury Stock, Value, Acquired, Par Value Method	(74.2)	$ (0.2)		0.2
Stock Repurchased During Period, Shares			0.7
Dividends	(75.1)				(75.1)
Other Comprehensive Income (Loss), Net of Tax	0.1					(0.1)
Net income	$ 438.1
Treasury Stock, Shares, Acquired	(4)
Treasury Stock, Value, Acquired, Par Value Method	$ (358)
Common stock, shares outstanding		170.5
Stockholders' Equity Attributable to Parent	4,267.3	$ 42.6	$ (3,513.8)	3,251.9	4,494.6	(8)
Treasury Stock, Shares			61.1
Net income	181.1				181.1
StockIssuedDuringPeriodSharesShareBasedCompensationNetofRelatedTaxes(inshares)		0.3	0
StockIssuedDuringPeriodValueShareBasedCompensationNetofRelatedTaxes	18.5	$ 0.1	$ (2)	20.4
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	$ 34.1			34.1
Treasury Stock, Shares, Acquired	(3.2)	(3.2)
Treasury Stock, Value, Acquired, Par Value Method	$ (283.8)	$ (0.8)		0.8
Stock Repurchased During Period, Shares			3.2
Dividends	(74.9)				(74.9)
Other Comprehensive Income (Loss), Net of Tax	$ (0.5)					0.5
Common stock, shares outstanding	167.5	167.6
Stockholders' Equity Attributable to Parent	$ 4,142.8	$ 41.9	$ (3,799.6)	$ 3,307.2	$ 4,600.8	$ (7.5)
Treasury Stock, Shares			64.3

Description Of Business and Bas

Description Of Business and Basis Of Presentation	6 Months Ended
	Mar. 27, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION	DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION Skyworks Solutions, Inc., together with its consolidated subsidiaries (“Skyworks” or the “Company”), is empowering the wireless networking revolution. The Company’s analog semiconductors are connecting people, places, and things, spanning a number of new applications within the aerospace, automotive, broadband, cellular infrastructure, connected home, industrial, medical, military, smartphone, tablet and wearable markets. The accompanying unaudited interim consolidated financial statements have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial reporting. Certain information and footnote disclosures, normally included in annual consolidated financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”), have been condensed or omitted pursuant to those rules and regulations. However, in management’s opinion, the financial information reflects all adjustments, including those of a normal recurring nature, necessary to present fairly the results of operations, financial position, and cash flows of the Company for the periods presented. The results of operations, financial position, and cash flows for the Company during the interim periods are not necessarily indicative of those expected for the full year. This information should be read in conjunction with the Company’s financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended September 27, 2019 , filed with the SEC on November 14, 2019, as amended by Amendment No. 1 to such Annual Report on Form 10-K, filed with the SEC on January 27, 2020 (the “2019 10-K”). The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts of assets, liabilities, revenue, expenses, comprehensive income and accumulated other comprehensive loss that are reported in these unaudited consolidated financial statements and accompanying disclosures. The Company evaluates its estimates on an ongoing basis using historical experience and other factors, including the current economic environment. Judgment is required in determining the reserves for, and fair value of, items such as overall fair value assessments of assets and liabilities, particularly those classified as Level 2 or Level 3 in the fair value hierarchy, marketable securities, inventory, intangible assets associated with business combinations, share-based compensation, loss contingencies, and income taxes. In addition, judgment is required in determining whether a potential indicator of impairment of long-lived assets exists and in estimating future cash flows for any necessary impairment testing. Actual results could differ significantly from these estimates. The Company’s fiscal year ends on the Friday closest to September 30. Fiscal 2020 consists of 53 weeks and ends on October 2, 2020 . Fiscal 2019 consisted of 52 weeks and ended on September 27, 2019 . The second quarters of fiscal 2020 and 2019 each consisted of 13 weeks and ended on March 27, 2020 , and March 29, 2019 , respectively. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) (“ASU 2016-02”). This ASU requires lessees to reflect leases with a term greater than one year on their balance sheet as assets and obligations. The Company adopted the standard in the first quarter of fiscal 2020, using the modified retrospective approach, whereby the Company was not required to adjust comparative period financial statements for the new standard. Upon adoption, the Company recorded a right-of-use asset of $141.4 million and a lease liability of $143.1 million . This standard did not have a material impact on the Consolidated Statement of Operations or Consolidated Statement of Cash Flows.

Marketable Securities

Marketable Securities	6 Months Ended
	Mar. 27, 2020
Investments, Debt and Equity Securities [Abstract]
MARKETABLE SECURITIES	MARKETABLE SECURITIES The Company's portfolio of available-for-sale marketable securities consists of the following (in millions): Current Noncurrent Available for sale: March 27, 2020 September 27, March 27, 2020 September 27, U.S. Treasury and government $ 56.5 $ 34.2 $ 27.7 $ 20.0 Corporate bonds and notes 83.4 66.2 6.4 5.9 Municipal bonds 21.6 102.9 — 1.7 Total $ 161.5 $ 203.3 $ 34.1 $ 27.6 The contractual maturities of noncurrent available-for-sale marketable securities were due within two years or less. There were gross unrealized gains of $0.7 million on U.S. Treasury securities and $0.1 million on corporate bonds and notes as of March 27, 2020 , and $0.1 million in gross unrealized losses on municipal bonds as of September 27, 2019

Fair Value

Fair Value	6 Months Ended
	Mar. 27, 2020
Fair Value Disclosures [Abstract]
FAIR VALUE	4. FAIR VALUE Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis The Company groups its financial assets and liabilities measured at fair value on a recurring basis in three levels, based on the markets in which the assets and liabilities are traded and the reliability of the assumptions used to determine fair value. These levels are: • Level 1 - Quoted prices in active markets for identical assets or liabilities. • Level 2 - Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices in markets with insufficient volume or infrequent transactions (less active markets), or model-driven valuations in which all significant inputs are observable or can be derived principally from, or corroborated with, observable market data. • Level 3 - Fair value is derived from valuation techniques in which one or more significant inputs are unobservable, including assumptions and judgments made by the Company. Assets and liabilities recorded at fair value on a recurring basis consisted of the following (in millions): As of March 27, 2020 As of September 27, 2019 Fair Value Measurements Fair Value Measurements Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Assets Cash and cash equivalents* $ 912.4 $ 772.7 $ 139.7 $ — $ 851.3 $ 809.5 $ 41.8 $ — U.S. Treasury and government securities 84.2 40.3 43.9 — 54.2 28.4 25.8 — Corporate bonds and notes 89.8 — 89.8 — 72.1 — 72.1 — Municipal bonds 21.6 — 21.6 — 104.6 — 104.6 — Total $ 1,108.0 $ 813.0 $ 295.0 $ — $ 1,082.2 $ 837.9 $ 244.3 $ — * Cash equivalents included in Levels 1 and 2 consist of money market funds and corporate bonds and notes, foreign government bonds, commercial paper, and agency securities purchased with less than ninety days until maturity. Assets Measured and Recorded at Fair Value on a Nonrecurring Basis The Company’s non-financial assets and liabilities, such as goodwill, intangible assets, and other long-lived assets resulting from business combinations, are measured at fair value using income approach valuation methodologies at the date of acquisition and are subsequently re-measured if there are indicators of impairment. There were no indicators of impairment identified during the three and six months ended March 27, 2020

Inventory

Inventory	6 Months Ended
	Mar. 27, 2020
Inventory, Net [Abstract]
INVENTORY	INVENTORY Inventory consists of the following (in millions): As of March 27, September 27, Raw materials $ 22.2 $ 24.4 Work-in-process 387.0 336.2 Finished goods 236.8 245.7 Finished goods held on consignment by customers 2.9 3.4 Total inventory $ 648.9 $ 609.7

Property, Plant And Equipment

Property, Plant And Equipment	6 Months Ended
	Mar. 27, 2020
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT	PROPERTY, PLANT AND EQUIPMENT, NET Property, plant and equipment, net consists of the following (in millions): As of March 27, September 27, Land and improvements $ 11.8 $ 11.7 Buildings and improvements 402.9 354.4 Furniture and fixtures 43.7 33.8 Machinery and equipment 2,353.3 2,311.5 Construction in progress 207.7 172.5 Total property, plant and equipment, gross 3,019.4 2,883.9 Accumulated depreciation (1,811.5 ) (1,678.3 ) Total property, plant and equipment, net $ 1,207.9 $ 1,205.6

Goodwill And Intangible Assets

Goodwill And Intangible Assets	6 Months Ended
	Mar. 27, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL AND INTANGIBLE ASSETS	GOODWILL AND INTANGIBLE ASSETS There were no changes to the carrying amount of goodwill during the three and six months ended March 27, 2020 . The Company tests its goodwill for impairment annually as of the first day of its fourth fiscal quarter and in interim periods if certain events occur indicating the carrying value of goodwill may be impaired. There were no indicators of impairment noted during the three and six months ended March 27, 2020 . Intangible assets consist of the following (in millions): As of As of Weighted March 27, 2020 September 27, 2019 Gross Accumulated Net Gross Accumulated Net Customer relationships 5.0 $ 18.2 $ (13.9 ) $ 4.3 $ 25.6 $ (19.5 ) $ 6.1 Developed technology and other 4.1 94.4 (65.0 ) 29.4 94.4 (48.9 ) 45.5 Trademarks 3.0 1.6 (1.6 ) — 1.6 (1.3 ) 0.3 Technology licenses 3.1 25.1 (9.3 ) 15.8 24.9 (4.8 ) 20.1 IPR&D 35.9 — 35.9 35.9 — 35.9 Total intangible assets $ 175.2 $ (89.8 ) $ 85.4 $ 182.4 $ (74.5 ) $ 107.9 Fully amortized intangible assets are eliminated from both the gross and accumulated amortization amounts in the first quarter of each fiscal year. Accrued technology licenses payable of $14.2 million and $20.1 million have been included in other current liabilities within the consolidated balance sheets as of March 27, 2020 , and September 27, 2019 , respectively. Annual amortization expense for the next five fiscal years related to definite-lived intangible assets, excluding IPR&D, is expected to be as follows (in millions): Remaining 2020 2021 2022 2023 2024 Thereafter Amortization expense, cost of goods sold $ 9.6 $ 2.7 $ 0.1 $ 0.1 $ 0.1 $ 1.8 Amortization expense, operating expense $ 10.9 $ 15.3 $ 5.0 $ 1.0 $ 1.0 $ 1.9 Total amortization expense $ 20.5 $ 18.0 $ 5.1 $ 1.1 $ 1.1 $ 3.7

Income Taxes

Income Taxes	6 Months Ended
	Mar. 27, 2020
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The provision for income taxes consists of the following components (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, United States income taxes $ 11.8 $ 21.3 $ 23.3 $ 50.9 Foreign income taxes 10.1 6.0 20.3 15.4 Provision for income taxes $ 21.9 $ 27.3 $ 43.6 $ 66.3 Effective tax rate 10.8 % 11.4 % 9.0 % 11.8 % The difference between the Company’s effective tax rate and the 21.0% United States federal statutory rate for the three and six months ended March 27, 2020 and March 29, 2019 , respectively, resulted primarily from foreign earnings taxed at rates lower than the federal statutory rate, a benefit from foreign-derived intangible income deduction (“FDII”), and research and experimentation and foreign tax credits earned, partially offset by a tax on global intangible low-taxed income (“GILTI”), and an increase in tax expense related to a change in the reserve for uncertain tax positions. The Company operates under a tax holiday in Singapore, which is effective through September 30, 2030. The current tax holiday is conditioned upon the Company’s compliance with certain employment and investment thresholds in Singapore. Accrued taxes of $23.4 million and $29.7 million have been included in other current liabilities within the consolidated balance sheets as of March 27, 2020 , and September 27, 2019

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Mar. 27, 2020
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Legal Matters From time to time, various lawsuits, claims and proceedings have been, and may in the future be, instituted or asserted against the Company, including those pertaining to patent infringement, intellectual property, environmental hazards, product liability and warranty, safety and health, employment and contractual matters. The semiconductor industry is characterized by vigorous protection and pursuit of intellectual property rights. From time to time, third parties have asserted and may in the future assert patent, copyright, trademark and other intellectual property rights to technologies that are important to the Company’s business and have demanded and may in the future demand that the Company license their technology. The outcome of any such litigation cannot be predicted with certainty and some such lawsuits, claims or proceedings may be disposed of unfavorably to the Company. Generally speaking, intellectual property disputes often have a risk of injunctive relief, which, if imposed against the Company, could materially and adversely affect the Company’s financial condition or results of operations. From time to time the Company may also be involved in legal proceedings in the ordinary course of business. The Company monitors the status of legal proceedings and other contingencies on an ongoing basis to ensure loss contingencies are recognized and/or disclosed in its financial statements and footnotes. The Company does not believe there are any pending legal proceedings that are reasonably possible to result in a material loss. The Company is engaged in various legal actions in the normal course of business and, while there can be no assurances, the Company believes the outcome of all pending litigation involving the Company will not have, individually or in the aggregate, a material adverse effect on its business or financial statements. Guarantees and Indemnities The Company has made no significant contractual guarantees for the benefit of third parties. However, the Company generally indemnifies its customers from third-party intellectual property infringement litigation claims related to its products and, on occasion, also provides other indemnities related to product sales. In connection with certain facility leases, the Company has indemnified its lessors for certain claims arising from the facility or the lease. The Company indemnifies its directors and officers to the maximum extent permitted under the laws of the state of Delaware. The duration of the indemnities varies and in many cases is indefinite. The indemnities to customers in connection with product sales generally are subject to limits based upon the amount of the related product sales and in many cases are subject to geographic and other restrictions. In certain instances, the Company’s indemnities do not provide for any limitation of the maximum potential future payments the Company could be obligated to make. The Company has not recorded any liability for these indemnities in the accompanying consolidated balance sheets and does not expect that such obligations will have a material adverse impact on its financial statements.

Stockholder's Equity

Stockholder's Equity	6 Months Ended
	Mar. 27, 2020
Stockholders' Equity Note [Abstract]
STOCKHOLDERS' EQUITY	STOCKHOLDERS’ EQUITY Stock Repurchase Program On January 30, 2019 , the Board of Directors approved a stock repurchase program, pursuant to which the Company is authorized to repurchase up to $2.0 billion of its common stock from time to time prior to January 30, 2021 , on the open market or in privately negotiated transactions, as permitted by securities laws and other legal requirements. The timing and amount of any shares of the Company’s common stock that are repurchased under the repurchase program are determined by the Company’s management based on its evaluation of market conditions and other factors. During the three months ended March 27, 2020 , the Company paid $283.8 million (including commissions) in connection with the repurchase of 3.2 million shares of its common stock (paying an average price of $87.61 per share). During the six months ended March 27, 2020 , the Company paid $358.0 million (including commissions) in connection with the repurchase of 4.0 million shares of its common stock (paying an average price of $89.92 per share). As of March 27, 2020 , $1.3 billion remained available under the existing stock repurchase authorization. Dividends On May 4, 2020 , the Company announced that the Board of Directors had declared a cash dividend on the Company’s common stock of $0.44 per share. This dividend is payable on June 11, 2020 , to the Company’s stockholders of record as of the close of business on May 21, 2020 . During the three and six months ended March 27, 2020 , dividends charged to retained earnings were as follows (in millions, except per share data): 2020 Per Share Total Amount First quarter $ 0.44 $ 75.1 Second quarter 0.44 74.9 Total $ 0.88 $ 150.0 Share-based Compensation The following table summarizes the share-based compensation expense by line item in the Statements of Operations (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, Cost of goods sold $ 7.2 $ 3.3 $ 11.4 $ 6.9 Research and development 17.2 9.9 32.0 22.4 Selling, general and administrative 15.8 8.6 30.4 13.3 Total share-based compensation $ 40.2 $ 21.8 $ 73.8 $ 42.6

Earnings Per Share

Earnings Per Share	6 Months Ended
	Mar. 27, 2020
Earnings Per Share [Abstract]
EARNINGS PER SHARE	EARNINGS PER SHARE The following table sets forth the computation of basic and diluted earnings per share (in millions, except per share amounts): Three Months Ended Six Months Ended March 27, March 29, March 27, March 29, Net income $ 181.1 $ 214.0 $ 438.1 $ 498.8 Weighted average shares outstanding – basic 170.0 173.8 170.1 175.2 Dilutive effect of equity-based awards 1.1 0.8 1.2 0.9 Weighted average shares outstanding – diluted 171.1 174.6 171.3 176.1 Net income per share – basic $ 1.07 $ 1.23 $ 2.58 $ 2.85 Net income per share – diluted $ 1.06 $ 1.23 $ 2.56 $ 2.83 Anti-dilutive common stock equivalents 0.5 1.9 1.5 1.8 Basic earnings per share are calculated by dividing net income by the weighted average number of shares of the Company’s common stock outstanding during the period. The calculation of diluted earnings per share includes the dilutive effect of equity-based awards that were outstanding during the three and six months ended March 27, 2020 , and March 29, 2019 , using the treasury stock method. Certain of the Company’s outstanding share-based awards, noted in the table above, were excluded because they were anti-dilutive, but they could become dilutive in the future.

Revenue Recognition (Notes)

Revenue Recognition (Notes)	6 Months Ended
	Mar. 27, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	2. REVENUE RECOGNITION The Company presents net revenue by geographic area based upon the location of the original equipment manufacturers’ (“OEMs”) headquarters as it believes that doing so best depicts how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. Net revenue by geographic area is as follows (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, United States $ 415.4 $ 403.1 $ 1,005.8 $ 1,003.2 China 178.0 199.4 346.4 394.0 South Korea 73.9 106.0 133.0 205.0 Taiwan 59.1 64.1 101.0 104.8 Europe, Middle East and Africa 32.7 31.1 63.0 63.8 Other Asia-Pacific 7.0 6.7 13.0 11.6 Total $ 766.1 $ 810.4 $ 1,662.2 $ 1,782.4 The Company’s revenue from external customers is generated principally from the sale of semiconductor products that facilitate various wireless communication applications. Accordingly, the Company considers its product offerings to be similar in nature and therefore not segregated for reporting purposes. Accrued customer liabilities of $40.5 million and $38.5 million have been included in other current liabilities within the consolidated balance sheets as of March 27, 2020 , and September 27, 2019 , respectively. Concentrations Financial instruments that potentially subject the Company to concentration of credit risk consist principally of trade accounts receivable. Trade accounts receivable are primarily derived from sales to electronic component distributors and manufacturers of communication products. The Company performs ongoing credit evaluations of its customers. At March 27, 2020 , and September 27, 2019 , the Company's three largest accounts receivable balances comprised 57% and 67% , respectively, of aggregate gross accounts receivable. Significant portions of the Company's sales are concentrated among a limited number of customers. The duration, severity, and future impact of the COVID-19 pandemic are highly uncertain and could result in significant disruptions to the business operations of the Company's customers. If one or more of these major customers significantly decreased its orders for the Company's products, the Company's business could be materially and adversely affected.

Leases (Notes)

Leases (Notes)	6 Months Ended
	Mar. 27, 2020
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	11. LEASES The Company determines if an arrangement is a lease at its inception. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its estimated incremental borrowing rate in determining the present value of lease payments considering the term of the lease, which is derived from information available at the lease commencement date. The lease term includes renewal options when it is reasonably certain that the option will be exercised and excludes termination options. To the extent that the Company’s agreements have variable lease payments, the Company includes variable lease payments that depend on an index or a rate and excludes those that depend on facts or circumstances occurring after the commencement date, other than the passage of time. Lease expense for these leases is recognized on a straight-line basis over the lease term. The Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. Operating leases are included in operating lease ROU assets, other current liabilities, and long-term operating lease liabilities in the Company's condensed consolidated balance sheet. The Company’s lease arrangements consist primarily of corporate, manufacturing and other facility agreements as well as various machinery and office equipment agreements. The leases expire at various dates through 2033, some of which include options to extend the lease term. The options with the longest potential total lease term consist of options for extension of up to three five-year periods following expiration of the original lease term. During the three and six months ended March 27, 2020 , the Company recorded $6.3 million and $12.3 million of operating lease expense and $3.3 million and $4.0 million of variable lease expense, respectively. During the three and six months ended March 29, 2019 , the Company recorded $4.7 million and $9.4 million of rent expense, respectively. The Company's finance leases and short-term leases are immaterial. Supplemental cash information and non-cash activities related to operating leases are as follows (in millions): Six Months Ended March 27, 2020 Operating cash outflows from operating leases $ 11.4 Operating lease assets obtained in exchange for new lease liabilities $ 29.8 Maturities of lease liabilities under operating leases by fiscal year are as follows (in millions): March 27, 2020 2020 (remainder) $ 9.9 2021 23.7 2022 24.4 2023 23.8 2024 21.4 Thereafter 97.7 Total lease payments 200.9 Less: imputed interest (28.3 ) Present value of lease liabilities 172.6 Less: current portion (included in other current liabilities) (20.7 ) Total $ 151.9 Future minimum lease liabilities under non-cancelable operating leases are as follows (in millions): September 27, 2020 $ 26.7 2021 25.9 2022 24.8 2023 23.3 2024 21.5 Thereafter 97.7 Total $ 219.9 Weighted-average remaining lease term and discount rate related to operating leases are as follows: March 27, 2020 Weighted-average remaining lease term (years) 8.5 Weighted-average discount rate 3.3 %

Subsequent Events (Notes)

Subsequent Events (Notes)	3 Months Ended
	Mar. 27, 2020
Subsequent Events [Abstract]
Subsequent Events [Text Block]	13. SUBSEQUENT EVENTS The Company continues to monitor its supply chain in light of the COVID-19 pandemic. On April 13, 2020, state and local government officials from the state of Baja California, Mexico, informed the Company of their decision to temporarily suspend the Company's operations in Mexicali, Mexico (the “Mexicali Operations”), pursuant to the Mexican Ministry of Health’s Executive Order dated March 31, 2020, which suspended all non-essential public and private sector business in order to mitigate the spread of COVID-19. In compliance with this decision, the Company temporarily suspended its Mexicali Operations until April 27, 2020, when the Company received permission from state and local officials in Mexicali to resume the Mexicali Operations. The Company does not expect that the temporary suspension of its Mexicali Operations will have a significant impact on the Company's business operations. However, a renewed suspension of the Mexicali Operations for an extended period of time would likely impact the Company’s ability to meet customer demand and would likely impact its operating results.

Description Of Business and B_2

Description Of Business and Basis Of Presentation (Policies)	6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Lessee, Leases [Policy Text Block]		The Company determines if an arrangement is a lease at its inception. Right-of-use (“ROU”) assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. The Company uses its estimated incremental borrowing rate in determining the present value of lease payments considering the term of the lease, which is derived from information available at the lease commencement date. The lease term includes renewal options when it is reasonably certain that the option will be exercised and excludes termination options. To the extent that the Company’s agreements have variable lease payments, the Company includes variable lease payments that depend on an index or a rate and excludes those that depend on facts or circumstances occurring after the commencement date, other than the passage of time. Lease expense for these leases is recognized on a straight-line basis over the lease term. The Company has elected not to recognize ROU assets and lease liabilities that arise from short-term (12 months or less) leases for any class of underlying asset. Operating leases are included in operating lease ROU assets, other current liabilities, and long-term operating lease liabilities in the Company's condensed consolidated balance sheet. The Company’s lease arrangements consist primarily of corporate, manufacturing and other facility agreements as well as various machinery and office equipment agreements. The leases expire at various dates through 2033, some of which include options to extend the lease term. The options with the longest potential total lease term consist of options for extension of up to three five-year periods following expiration of the original lease term.
Fiscal Period	The Company’s fiscal year ends on the Friday closest to September 30. Fiscal 2020 consists of 53 weeks and ends on October 2, 2020 . Fiscal 2019 consisted of 52 weeks and ended on September 27, 2019 . The second quarters of fiscal 2020 and 2019 each consisted of 13 weeks and ended on March 27, 2020 , and March 29, 2019 , respectively.
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2016-02, Leases (Topic 842) (“ASU 2016-02”). This ASU requires lessees to reflect leases with a term greater than one year on their balance sheet as assets and obligations. The Company adopted the standard in the first quarter of fiscal 2020, using the modified retrospective approach, whereby the Company was not required to adjust comparative period financial statements for the new standard. Upon adoption, the Company recorded a right-of-use asset of $141.4 million and a lease liability of $143.1 million . This standard did not have a material impact on the Consolidated Statement of Operations or Consolidated Statement of Cash Flows.

Marketable Securities (Tables)

Marketable Securities (Tables)	6 Months Ended
	Mar. 27, 2020
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	The Company's portfolio of available-for-sale marketable securities consists of the following (in millions): Current Noncurrent Available for sale: March 27, 2020 September 27, March 27, 2020 September 27, U.S. Treasury and government $ 56.5 $ 34.2 $ 27.7 $ 20.0 Corporate bonds and notes 83.4 66.2 6.4 5.9 Municipal bonds 21.6 102.9 — 1.7 Total $ 161.5 $ 203.3 $ 34.1 $ 27.6

Fair Value (Tables)

Fair Value (Tables)	6 Months Ended
	Mar. 27, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value Assets and Liabilities Measured on Recurring Basis	Assets and liabilities recorded at fair value on a recurring basis consisted of the following (in millions): As of March 27, 2020 As of September 27, 2019 Fair Value Measurements Fair Value Measurements Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Assets Cash and cash equivalents* $ 912.4 $ 772.7 $ 139.7 $ — $ 851.3 $ 809.5 $ 41.8 $ — U.S. Treasury and government securities 84.2 40.3 43.9 — 54.2 28.4 25.8 — Corporate bonds and notes 89.8 — 89.8 — 72.1 — 72.1 — Municipal bonds 21.6 — 21.6 — 104.6 — 104.6 — Total $ 1,108.0 $ 813.0 $ 295.0 $ — $ 1,082.2 $ 837.9 $ 244.3 $ —

Inventory (Tables)

Inventory (Tables)	6 Months Ended
	Mar. 27, 2020
Inventory, Net [Abstract]
Schedule Of Inventories	Inventory consists of the following (in millions): As of March 27, September 27, Raw materials $ 22.2 $ 24.4 Work-in-process 387.0 336.2 Finished goods 236.8 245.7 Finished goods held on consignment by customers 2.9 3.4 Total inventory $ 648.9 $ 609.7

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	6 Months Ended
	Mar. 27, 2020
Property, Plant and Equipment [Abstract]
Schedule Of Property, Plant And Equipment	Property, plant and equipment, net consists of the following (in millions): As of March 27, September 27, Land and improvements $ 11.8 $ 11.7 Buildings and improvements 402.9 354.4 Furniture and fixtures 43.7 33.8 Machinery and equipment 2,353.3 2,311.5 Construction in progress 207.7 172.5 Total property, plant and equipment, gross 3,019.4 2,883.9 Accumulated depreciation (1,811.5 ) (1,678.3 ) Total property, plant and equipment, net $ 1,207.9 $ 1,205.6

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	6 Months Ended
	Mar. 27, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets Excluding Goodwill	Intangible assets consist of the following (in millions): As of As of Weighted March 27, 2020 September 27, 2019 Gross Accumulated Net Gross Accumulated Net Customer relationships 5.0 $ 18.2 $ (13.9 ) $ 4.3 $ 25.6 $ (19.5 ) $ 6.1 Developed technology and other 4.1 94.4 (65.0 ) 29.4 94.4 (48.9 ) 45.5 Trademarks 3.0 1.6 (1.6 ) — 1.6 (1.3 ) 0.3 Technology licenses 3.1 25.1 (9.3 ) 15.8 24.9 (4.8 ) 20.1 IPR&D 35.9 — 35.9 35.9 — 35.9 Total intangible assets $ 175.2 $ (89.8 ) $ 85.4 $ 182.4 $ (74.5 ) $ 107.9
Schedule Of Expected Annual Amortization Expense Related To Intangible Assets For The Next Five Years	Annual amortization expense for the next five fiscal years related to definite-lived intangible assets, excluding IPR&D, is expected to be as follows (in millions): Remaining 2020 2021 2022 2023 2024 Thereafter Amortization expense, cost of goods sold $ 9.6 $ 2.7 $ 0.1 $ 0.1 $ 0.1 $ 1.8 Amortization expense, operating expense $ 10.9 $ 15.3 $ 5.0 $ 1.0 $ 1.0 $ 1.9 Total amortization expense $ 20.5 $ 18.0 $ 5.1 $ 1.1 $ 1.1 $ 3.7

Income Taxes (Tables)

Income Taxes (Tables)	6 Months Ended
	Mar. 27, 2020
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	The provision for income taxes consists of the following components (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, United States income taxes $ 11.8 $ 21.3 $ 23.3 $ 50.9 Foreign income taxes 10.1 6.0 20.3 15.4 Provision for income taxes $ 21.9 $ 27.3 $ 43.6 $ 66.3 Effective tax rate 10.8 % 11.4 % 9.0 % 11.8 %

Stockholder's Equity (Tables)

Stockholder's Equity (Tables)	6 Months Ended
	Mar. 27, 2020
Stockholders' Equity Note [Abstract]
Dividends Declared	During the three and six months ended March 27, 2020 , dividends charged to retained earnings were as follows (in millions, except per share data): 2020 Per Share Total Amount First quarter $ 0.44 $ 75.1 Second quarter 0.44 74.9 Total $ 0.88 $ 150.0
Schedule of share-based compensation expense	The following table summarizes the share-based compensation expense by line item in the Statements of Operations (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, Cost of goods sold $ 7.2 $ 3.3 $ 11.4 $ 6.9 Research and development 17.2 9.9 32.0 22.4 Selling, general and administrative 15.8 8.6 30.4 13.3 Total share-based compensation $ 40.2 $ 21.8 $ 73.8 $ 42.6

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Mar. 27, 2020
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share	The following table sets forth the computation of basic and diluted earnings per share (in millions, except per share amounts): Three Months Ended Six Months Ended March 27, March 29, March 27, March 29, Net income $ 181.1 $ 214.0 $ 438.1 $ 498.8 Weighted average shares outstanding – basic 170.0 173.8 170.1 175.2 Dilutive effect of equity-based awards 1.1 0.8 1.2 0.9 Weighted average shares outstanding – diluted 171.1 174.6 171.3 176.1 Net income per share – basic $ 1.07 $ 1.23 $ 2.58 $ 2.85 Net income per share – diluted $ 1.06 $ 1.23 $ 2.56 $ 2.83 Anti-dilutive common stock equivalents 0.5 1.9 1.5 1.8

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Mar. 27, 2020
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	The Company presents net revenue by geographic area based upon the location of the original equipment manufacturers’ (“OEMs”) headquarters as it believes that doing so best depicts how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. Net revenue by geographic area is as follows (in millions): Three Months Ended Six Months Ended March 27, 2020 March 29, March 27, 2020 March 29, United States $ 415.4 $ 403.1 $ 1,005.8 $ 1,003.2 China 178.0 199.4 346.4 394.0 South Korea 73.9 106.0 133.0 205.0 Taiwan 59.1 64.1 101.0 104.8 Europe, Middle East and Africa 32.7 31.1 63.0 63.8 Other Asia-Pacific 7.0 6.7 13.0 11.6 Total $ 766.1 $ 810.4 $ 1,662.2 $ 1,782.4

Leases (Tables)

Leases (Tables)	6 Months Ended
	Mar. 27, 2020
Leases [Abstract]
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Maturities of lease liabilities under operating leases by fiscal year are as follows (in millions): March 27, 2020 2020 (remainder) $ 9.9 2021 23.7 2022 24.4 2023 23.8 2024 21.4 Thereafter 97.7 Total lease payments 200.9 Less: imputed interest (28.3 ) Present value of lease liabilities 172.6 Less: current portion (included in other current liabilities) (20.7 ) Total $ 151.9 Future minimum lease liabilities under non-cancelable operating leases are as follows (in millions): September 27, 2020 $ 26.7 2021 25.9 2022 24.8 2023 23.3 2024 21.5 Thereafter 97.7 Total $ 219.9
Lease, Cost [Table Text Block]	Weighted-average remaining lease term and discount rate related to operating leases are as follows: March 27, 2020 Weighted-average remaining lease term (years) 8.5 Weighted-average discount rate 3.3 % Supplemental cash information and non-cash activities related to operating leases are as follows (in millions): Six Months Ended March 27, 2020 Operating cash outflows from operating leases $ 11.4 Operating lease assets obtained in exchange for new lease liabilities $ 29.8

Description Of Business and B_3

Description Of Business and Basis Of Presentation (Details)	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of weeks in fiscal year			1 year	1 year
Number of weeks in fiscal quarter	3 months	3 months

Description Of Business and B_4

Description Of Business and Basis Of Presentation (New Accounting Pronouncements) (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Sep. 28, 2019	Sep. 27, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 171.3		$ 0
Operating Lease, Liability	$ 172.6
Document Period End Date	Mar. 27, 2020
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset		$ 141.4
Operating Lease, Liability		$ 143.1

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Millions	Mar. 27, 2020	Sep. 27, 2019
Other Current Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	$ 161.5	$ 203.3
Other Noncurrent Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	34.1	27.6
US Treasury and Government [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	84.2
US Treasury and Government [Member] | Other Current Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	56.5	34.2
US Treasury and Government [Member] | Other Noncurrent Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	27.7	20
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	89.8
Corporate Debt Securities [Member] | Other Current Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	83.4	66.2
Corporate Debt Securities [Member] | Other Noncurrent Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	6.4	5.9
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	21.6
US States and Political Subdivisions Debt Securities [Member] | Other Current Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	21.6	102.9
US States and Political Subdivisions Debt Securities [Member] | Other Noncurrent Assets [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	$ 0	$ 1.7

Marketable Securities Schedule

Marketable Securities Schedule of Available-for-sale Securities (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Sep. 27, 2019
Debt Securities, Available-for-sale [Line Items]
Document Period End Date	Mar. 27, 2020
US Treasury and Government [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	$ 0.7
Available-for-sale Securities	84.2
Corporate Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0.1
Available-for-sale Securities	89.8
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Available-for-sale Securities	$ 21.6
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax		$ (0.1)

Marketable Securities Contractu

Marketable Securities Contractual Maturity (Details)	6 Months Ended
	Mar. 27, 2020
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Debt Maturities, Date	2 years

Fair Value (Fair value transfer

Fair Value (Fair value transfers) (Details)	6 Months Ended
	Mar. 27, 2020USD ($)
Fair Value Disclosures [Abstract]
Transfer of assets from L1 to L2	$ 0
Transfers of assets from L2 to L1	0
Transfers of assets into L3	0
Transfer of liabilities from L1 to L2	0
Transfers of liabilities from L2 to L1	$ 0

Fair Value (Schedule Of Financi

Fair Value (Schedule Of Financial Instruments Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions	Mar. 27, 2020	Sep. 27, 2019
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 912.4	$ 851.3
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	1,108	1,082.2
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	772.7	809.5
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	813	837.9
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	139.7	41.8
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	295	244.3
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	0	0
US Treasury and Government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	84.2
US Treasury and Government [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		54.2
US Treasury and Government [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	40.3	28.4
US Treasury and Government [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	43.9	25.8
US Treasury and Government [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Corporate Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	89.8
Corporate Debt Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		72.1
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	89.8	72.1
Corporate Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
US States and Political Subdivisions Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	21.6
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities		104.6
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0	0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	21.6	104.6
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 0	$ 0

Inventory (Schedule Of Inventor

Inventory (Schedule Of Inventories) (Details) - USD ($) $ in Millions	Mar. 27, 2020	Sep. 27, 2019
Inventory, Net [Abstract]
Raw materials	$ 22.2	$ 24.4
Work-in-process	387	336.2
Finished goods	236.8	245.7
Finished goods held on consignment by customers	2.9	3.4
Total inventory	$ 648.9	$ 609.7

Property, Plant and Equipment_2

Property, Plant and Equipment (Schedule Of Property, Plant And Equipment) (Details) - USD ($) $ in Millions	Mar. 27, 2020	Sep. 27, 2019
Property, Plant and Equipment
Total property, plant and equipment, gross	$ 3,019.4	$ 2,883.9
Accumulated depreciation	(1,811.5)	(1,678.3)
Total property, plant and equipment, net	1,207.9	1,205.6
Land and improvements [Member]
Property, Plant and Equipment
Total property, plant and equipment, gross	11.8	11.7
Building and improvements [Member]
Property, Plant and Equipment
Total property, plant and equipment, gross	402.9	354.4
Furniture and fixtures [Member]
Property, Plant and Equipment
Total property, plant and equipment, gross	43.7	33.8
Machinery and equipment [Member]
Property, Plant and Equipment
Total property, plant and equipment, gross	2,353.3	2,311.5
Construction in progress [Member]
Property, Plant and Equipment
Total property, plant and equipment, gross	$ 207.7	$ 172.5

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets (Schedule Of Intangible Assets Subject To Amortization) (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Sep. 27, 2019
Finite-Lived Intangible Assets [Line Items]
Document Period End Date	Mar. 27, 2020
Accumulated Amortization	$ (89.8)	$ (74.5)
Total intangible assets, Gross Carrying Amount	175.2	182.4
Total intangible assets, Net Carrying Amount	$ 85.4	107.9
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	5 years
Finite-Lived Intangible Assets, Gross	$ 18.2	25.6
Accumulated Amortization	(13.9)	(19.5)
Net Carrying Amount	$ 4.3	6.1
Technology-Based Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	4 years 1 month 6 days
Finite-Lived Intangible Assets, Gross	$ 94.4	94.4
Accumulated Amortization	(65)	(48.9)
Net Carrying Amount	$ 29.4	45.5
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	3 years
Finite-Lived Intangible Assets, Gross	$ 1.6	1.6
Accumulated Amortization	(1.6)	(1.3)
Net Carrying Amount	0	0.3
Computer Software, Intangible Asset [Member]
Finite-Lived Intangible Assets [Line Items]
Accrued Liabilities	$ 14.2	20.1
Weighted Average Amortization Period (Years)	3 years 1 month 6 days
Finite-Lived Intangible Assets, Gross	$ 25.1	24.9
Accumulated Amortization	(9.3)	(4.8)
Net Carrying Amount	$ 15.8	20.1
In Process Research and Development [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Amortization Period (Years)	0 years
Finite-Lived Intangible Assets, Gross	$ 35.9	35.9
Accumulated Amortization	0	0
Net Carrying Amount	$ 35.9	$ 35.9

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets (Schedule Of Expected Annual Amortization Expense Related To Intangible Assets For The Next Five Years) (Details) $ in Millions	Mar. 27, 2020USD ($)
Expected Annual Amortization Expense related to intangible assets for the next five years [Line Items]
Remaining 2019	$ 20.5
2020	18
2021	5.1
2022	1.1
2023	1.1
Thereafter	3.7
Cost of sales [Member]
Expected Annual Amortization Expense related to intangible assets for the next five years [Line Items]
Remaining 2019	9.6
2020	2.7
2021	0.1
2022	0.1
2023	0.1
Thereafter	1.8
Operating Expense [Member]
Expected Annual Amortization Expense related to intangible assets for the next five years [Line Items]
Remaining 2019	10.9
2020	15.3
2021	5
2022	1
2023	1
Thereafter	$ 1.9

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Income Tax Disclosure [Abstract]
Document Period End Date			Mar. 27, 2020
United States income taxes	$ 11.8	$ 21.3	$ 23.3	$ 50.9
Foreign income taxes	10.1	6	20.3	15.4
Provision for income taxes	$ 21.9	$ 27.3	$ 43.6	$ 66.3
Effective tax rate	10.80%	11.40%	9.00%	11.80%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Mar. 27, 2020	Sep. 27, 2019
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%
Accrued income taxes, current	$ 23.4	$ 29.7

Stockholder's Equity (Share Rep

Stockholder's Equity (Share Repurchase) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	Jan. 30, 2019	Mar. 27, 2020	Dec. 27, 2019	Mar. 29, 2019	Dec. 28, 2018	Mar. 27, 2020
Equity, Class of Treasury Stock [Line Items]
Share repurchase authorized date	Jan. 30, 2019
Authorized amount of stock for repurchase	$ 2,000
Stock repurchase program expiration date	Jan. 30, 2021
Stock repurchased		$ 283.8	$ 74.2	$ 141.5	$ 284	$ 358
Treasury Stock, Shares, Acquired		3.2				4
Average price of stock repurchased (in dollars per share)		$ 87.61				$ 89.92
Remaining amount authorized fro stock repurchase		$ 1,300				$ 1,300

Stockholder's Equity (Dividend)

Stockholder's Equity (Dividend) (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 11, 2020	May 21, 2020	May 04, 2020	Mar. 27, 2020	Dec. 27, 2019	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Dividends Payable [Line Items]
Document Period End Date							Mar. 27, 2020
Payments of Ordinary Dividends							$ 150	$ 133.1
Payments of ordinary dividends				$ 74.9	$ 75.1		$ 150
Common Stock, Dividends, Per Share, Declared				$ 0.44	$ 0.44	$ 0.38	$ 0.88	$ 0.76
Subsequent Event [Member] | Dividend Declared [Member]
Dividends Payable [Line Items]
Dividend declaration date			May 4, 2020
dividends date to be paid	Jun. 11, 2020
Dividends date of record		May 21, 2020
Cash dividends declared and paid per share (usd per share)	$ 0.44

Stockholder's Equity (Share Bas

Stockholder's Equity (Share Based Compensation) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Document Period End Date			Mar. 27, 2020
Share-based compensation expense	$ 40.2	$ 21.8	$ 73.8	$ 42.6
Cost of sales [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	7.2	3.3	11.4	6.9
Research and development [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	17.2	9.9	32	22.4
Selling, general and administrative [Member]
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation expense	$ 15.8	$ 8.6	$ 30.4	$ 13.3

Earnings Per Share (Schedule Of

Earnings Per Share (Schedule Of Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Mar. 27, 2020	Dec. 27, 2019	Mar. 29, 2019	Dec. 28, 2018	Mar. 27, 2020	Mar. 29, 2019
Earnings Per Share [Abstract]
Net income	$ 181.1	$ 257.1	$ 214	$ 284.9	$ 438.1	$ 498.8
Weighted average shares outstanding - basic (shares)	170		173.8		170.1	175.2
Dilutive effect of equity based awards (shares)	1.1		0.8		1.2	0.9
Weighted average shares outstanding - diluted (shares)	171.1		174.6		171.3	176.1
Net income per share - basic (usd per share)	$ 1.07		$ 1.23		$ 2.58	$ 2.85
Net income per share - diluted (usd per share)	$ 1.06		$ 1.23		$ 2.56	$ 2.83
Anti-dilutive common stock equivalents (shares)	0.5		1.9		1.5	1.8

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019	Sep. 27, 2019
Disaggregation of Revenue [Line Items]
Contract with Customer, Refund Liability	$ 40.5		$ 40.5		$ 38.5
Document Period End Date			Mar. 27, 2020
Revenues	766.1	$ 810.4	$ 1,662.2	$ 1,782.4
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenues	415.4	403.1	1,005.8	1,003.2
CHINA
Disaggregation of Revenue [Line Items]
Revenues	178	199.4	346.4	394
KOREA, REPUBLIC OF
Disaggregation of Revenue [Line Items]
Revenues	73.9	106	133	205
TAIWAN, PROVINCE OF CHINA
Disaggregation of Revenue [Line Items]
Revenues	59.1	64.1	101	104.8
EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenues	32.7	31.1	63	63.8
Asia, Other [Member]
Disaggregation of Revenue [Line Items]
Revenues	$ 7	$ 6.7	$ 13	$ 11.6

Revenue Recognition concentrati

Revenue Recognition concentrations (Details)	6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019
Accounts Receivable [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	57.00%	67.00%

Leases (Details)

Leases (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 27, 2020	Mar. 29, 2019	Mar. 27, 2020	Mar. 29, 2019	Sep. 27, 2019
Leases [Abstract]
Document Period End Date			Mar. 27, 2020
Operating Leases, Future Minimum Payments Due, Next Twelve Months					$ 26.7
Operating Lease, Payments			$ 11.4
Operating Lease, Weighted Average Remaining Lease Term	8 years 6 months		8 years 6 months
Lessee, Operating Lease, Liability, Payments, Remainder of Fiscal Year	$ 9.9		$ 9.9
Operating Lease, Expense	6.3	$ 4.7	12.3	$ 9.4
Variable Lease, Cost	3.3		4
Lessee, Operating Lease, Liability, Payments, Due Year Two	23.7		23.7
Lessee, Operating Lease, Liability, Payments, Due Year Three	24.4		24.4
Lessee, Operating Lease, Liability, Payments, Due Year Four	23.8		23.8
Lessee, Operating Lease, Liability, Payments, Due Year Five	21.4		21.4
Lessee, Operating Lease, Liability, Payments, Due after Year Five	97.7		97.7
Lessee, Operating Lease, Liability, Payments, Due	200.9		200.9
Lessee, Operating Lease, Liability, Undiscounted Excess Amount	(28.3)		(28.3)
Operating Lease, Liability	172.6		172.6
Operating Lease, Liability, Current	(20.7)		(20.7)
Operating Lease, Liability, Noncurrent	$ 151.9		$ 151.9		0
Operating Lease, Weighted Average Discount Rate, Percent	3.30%		3.30%
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability			$ 29.8
Operating Leases, Future Minimum Payments, Due in Two Years					25.9
Operating Leases, Future Minimum Payments, Due in Three Years					24.8
Operating Leases, Future Minimum Payments, Due in Four Years					23.3
Operating Leases, Future Minimum Payments, Due in Five Years					21.5
Operating Leases, Future Minimum Payments, Due Thereafter					97.7
Operating Leases, Future Minimum Payments Due					$ 219.9