Consolidated Statements Of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Sep. 27, 2019		Sep. 28, 2018		Sep. 29, 2017
Income Statement [Abstract]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 3,376.8		$ 3,868.0		$ 3,651.4
Cost of Goods and Services Sold	1,773.0		1,917.3		1,809.6
Gross profit	1,603.8		1,950.7		1,841.8
Operating expenses:
Research and development	424.1		404.5		355.2
Selling, general and administrative	198.3		207.8		204.6
Amortization of intangibles	22.6		18.3		27.6
Restructuring and other charges	6.8		0.8		0.6
Total operating expenses	651.8		631.4		588.0
Operating income	952.0		1,319.3		1,253.8
Other income (expense), net	9.0		12.8		3.2
Income before income taxes	961.0		1,332.1		1,257.0
Provision for income taxes	107.4		413.7		246.8
Net income	$ 853.6		$ 918.4		$ 1,010.2
Earnings per share:
Basic (in dollars per share)	$ 4.92	[1]	$ 5.06	[1]	$ 5.48
Diluted (in dollars per share)	$ 4.89	[1]	$ 5.01	[1]	$ 5.41
Weighted average shares:
Basic (in shares)	173.5		181.3		184.3
Diluted (in shares)	174.5		183.2		186.7
Cash dividends declared and paid per share (in dollars per share)	$ 1.58		$ 1.34		$ 1.16

[1] Earnings per share calculations for each of the quarters are based on the weighted average number of shares outstanding and included common stock equivalents in each period. Therefore, the sums of the quarters do not necessarily equal the full year earnings per share.