Fair Value (Schedule Of Financial Instruments Measured At Fair Value On Recurring Basis) (Details) - USD ($) $ in Millions	Apr. 01, 2022	Oct. 01, 2021
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt	$ 2,187.3	$ 2,235.6
Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents*	656.4	882.9
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	778.2	1,027.2
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents*	634.6	882.9
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	634.6	885.5
Fair Value, Inputs, Level 2 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt, Fair Value	1,401.4	1,523.1
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents*	21.8	0.0
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	143.6	141.7
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents*	0.0	0.0
Assets, Fair Value Disclosure, Recurring (Deprecated 2018-01-31)	0.0	0.0
2023 Notes
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt	498.5	498.2
2023 Notes | Fair Value, Inputs, Level 2 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt, Fair Value	489.8	501.0
2026 Notes
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt	496.4	496.2
2026 Notes | Fair Value, Inputs, Level 2 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt, Fair Value	463.1	507.5
2031 Notes
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt	494.2	494.0
2031 Notes | Fair Value, Inputs, Level 2 [Member]
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt, Fair Value	448.5	514.6
Senior Notes
Fair Value Disclosure, Asset and Liability, Not Measured at Fair Value [Line Items]
Long-term Debt	1,489.1	1,488.4
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	10.5	13.6
US Treasury and Government [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.0	2.6
US Treasury and Government [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	10.5	11.0
US Treasury and Government [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.0	0.0
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	103.4	117.0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.0	0.0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	103.4	117.0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.0	0.0
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	7.9	13.7
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	0.0	0.0
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	7.9	13.7
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 0.0	$ 0.0