v3.25.1
Fair Value Measurements (Schedule Of Available For Sale Securities) (Details) - USD ($)
$ in Millions
 6 Months Ended
Mar. 29, 2025
Sep. 28, 2024
Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available For Sale Securities Debt Maturity Period 45 years  
Short Term Investment Maturity Period 12 months  
Other Current Assets [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Current   $ 10
Other Current Assets [Member] | Level 1 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Current   0
Other Current Assets [Member] | Level 2 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Current   10
Other Current Assets [Member] | Level 3 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Current   0
Other Assets [Member] | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Noncurrent $ 114 103
Other Assets [Member] | Level 1 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Noncurrent 0 0
Other Assets [Member] | Level 2 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Noncurrent 89 75
Other Assets [Member] | Level 3 | Fair Value, Recurring [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-Sale, Noncurrent 25 28
U.S. treasury and agency    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax (2) (1)
Debt Securities, Available-for-sale 89 85
Debt Securities, Available-for-Sale, Amortized Cost, Total 91 86
Corporate and asset-backed    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax 0 0
Debt Securities, Available-for-sale 25 28
Debt Securities, Available-for-Sale, Amortized Cost, Total $ 25 $ 28