v3.26.1
Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)
$ in Millions
Jun. 28, 2026
Sep. 28, 2025
Assets [Abstract]    
Cash and cash equivalents $ 3,449.8 $ 3,219.8
Other Long-Term Investments 313.2 246.9
Total short-term investments 160.5 247.2
Derivative assets, Current 30.1 15.9
Derivative assets, Noncurrent 422.4 278.6
Total Assets 4,376.0 4,008.4
Liabilities:    
Derivative liabilities, Current 0.8 7.1
Derivative liabilities, Noncurrent 19.3 20.9
Total liabilities 20.1 28.0
Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 313.2 246.9
Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 76.8 151.9
Marketable equity securities 83.7 95.3
Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 153.2 132.2
Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 50.6 67.8
Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 69.2 75.7
Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.3 0.4
State and local government obligations | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities:   2.7
State and local government obligations | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 2.8 1.1
U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 90.8 36.3
U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 23.1 82.6
Fair Value, Inputs, Level 1 [Member]    
Assets [Abstract]    
Cash and cash equivalents 3,449.8 3,219.8
Other Long-Term Investments 90.8 36.3
Total short-term investments 106.8 177.9
Derivative assets, Current 0.0 0.0
Derivative assets, Noncurrent 0.0 0.0
Total Assets 3,647.4 3,434.0
Liabilities:    
Derivative liabilities, Current 0.0 0.0
Derivative liabilities, Noncurrent 0.0 0.0
Total liabilities 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 90.8 36.3
Fair Value, Inputs, Level 1 [Member] | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 23.1 82.6
Marketable equity securities 83.7 95.3
Fair Value, Inputs, Level 1 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities:   0.0
Fair Value, Inputs, Level 1 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 1 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 90.8 36.3
Fair Value, Inputs, Level 1 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 23.1 82.6
Fair Value, Inputs, Level 2 [Member]    
Assets [Abstract]    
Cash and cash equivalents 0.0 0.0
Other Long-Term Investments 193.4 183.9
Total short-term investments 41.1 57.4
Derivative assets, Current 30.1 15.9
Derivative assets, Noncurrent 422.4 278.6
Total Assets 687.0 535.8
Liabilities:    
Derivative liabilities, Current 0.8 7.1
Derivative liabilities, Noncurrent 19.3 20.9
Total liabilities 20.1 28.0
Fair Value, Inputs, Level 2 [Member] | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 193.4 183.9
Fair Value, Inputs, Level 2 [Member] | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 41.1 57.4
Marketable equity securities 0.0 0.0
Fair Value, Inputs, Level 2 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 124.2 105.5
Fair Value, Inputs, Level 2 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 38.0 55.9
Fair Value, Inputs, Level 2 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 69.2 75.7
Fair Value, Inputs, Level 2 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.3 0.4
Fair Value, Inputs, Level 2 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities:   2.7
Fair Value, Inputs, Level 2 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 2.8 1.1
Fair Value, Inputs, Level 2 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 2 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 3 [Member]    
Assets [Abstract]    
Cash and cash equivalents 0.0 0.0
Other Long-Term Investments 29.0 26.7
Total short-term investments 12.6 11.9
Derivative assets, Current 0.0 0.0
Derivative assets, Noncurrent 0.0 0.0
Total Assets 41.6 38.6
Liabilities:    
Derivative liabilities, Current 0.0 0.0
Derivative liabilities, Noncurrent 0.0 0.0
Total liabilities 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 29.0 26.7
Fair Value, Inputs, Level 3 [Member] | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 12.6 11.9
Marketable equity securities 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 29.0 26.7
Fair Value, Inputs, Level 3 [Member] | Corporate debt securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 12.6 11.9
Fair Value, Inputs, Level 3 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | Mortgage and other asset-backed securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities:   0.0
Fair Value, Inputs, Level 3 [Member] | State and local government obligations | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:OtherLongTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: 0.0 0.0
Fair Value, Inputs, Level 3 [Member] | U.S. government treasury securities | Balance Sheet Location [Axis]: us-gaap:ShortTermInvestments    
Assets [Abstract]    
Available-for-sale debt securities: $ 0.0 $ 0.0