Income Taxes (Reconciliation of the Statutory U.S. Federal Income Tax Rate With Our Effective Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 27, 2020	Sep. 29, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	24.50%
State income taxes, net of federal tax benefit	2.20%	2.10%	2.10%
Benefits and taxes related to foreign operations	(3.20%)	(0.10%)	(0.10%)
Effective Income Tax Rate Reconciliation, Valuation Allowance, Percent	10.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Tax Expense (Benefit), Share-based Payment Arrangement, Percent	(4.20%)	(2.10%)	(0.90%)
Effective Income Tax Rate Reconciliation, Tax Rate Change, Percent	(2.20%)	0.00%	0.00%
Income Tax Rate Reconciliation, Charitable Contributions, Percent	(1.70%)	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Foreign Derived Intangible Income, Percent	(1.40%)	(1.50%)	0.00%
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Percent	0.00%	1.70%	0.00%
Effective Income Tax Rate Reconciliation, Disposition of Business, Percent	0.00%	(1.30%)	0.00%
Gain resulting from acquisition of joint venture	0.00%	0.00%	(5.80%)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent	0.00%	0.00%	2.80%
Other, net	0.10%	(0.30%)	(0.80%)
Effective tax rate	20.60%	19.50%	21.80%
Subsidiaries [Member]
Tax Credit Carryforward [Line Items]
Gross taxable temporary difference	$ 1,400.0
Deferred Tax Liability Not Recognized, Amount of Unrecognized Deferred Tax Liability, Undistributed Earnings of Foreign Subsidiaries	$ 280.0