Fair Value Measurements (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Jan. 02, 2022	Oct. 03, 2021
Assets:
Total short-term investments	$ 87.4	$ 162.2
Total Assets	4,608.8	7,131.5
Liabilities:
Total liabilities	17.4	16.8
Cash and cash equivalents
Assets:
Cash and cash equivalents	3,969.4	6,455.7
Short-term Investments [Member]
Assets:
Available-for-sale debt securities	8.4	87.8
Marketable equity securities	79.0	74.4
Total short-term investments	87.4	162.2
Prepaid Expenses and Other Current Assets [Member]
Assets:
Derivative assets, Current	154.4	147.6
Long-term Investments [Member]
Assets:
Available-for-sale debt securities	299.6	281.7
Other Long-Term Assets [Member]
Assets:
Derivative assets, Noncurrent	98.0	84.3
Accrued Liabilities [Member]
Liabilities:
Derivative liabilities, Current	11.5	8.6
Other Long-Term Liabilities [Member]
Liabilities:
Derivative liabilities, Noncurrent	5.9	8.2
Auction rate securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		6.0
Commercial paper | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	3.5	63.0
Corporate debt securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	4.8	24.7
Corporate debt securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	148.1	162.0
Foreign government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	4.0
Foreign Government Obligations [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		4.0
Mortgage and other asset-backed securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.1	0.1
Mortgage and other asset-backed securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	59.9	31.9
State and local government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	1.4	1.5
U.S. government treasury securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	86.2	76.3
Fair Value, Inputs, Level 1 [Member]
Assets:
Total Assets	4,258.2	6,737.5
Liabilities:
Total liabilities	4.0	0.3
Fair Value, Inputs, Level 1 [Member] | Cash and cash equivalents
Assets:
Cash and cash equivalents	3,969.4	6,455.7
Fair Value, Inputs, Level 1 [Member] | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Marketable equity securities	79.0	74.4
Total short-term investments	79.0	74.4
Fair Value, Inputs, Level 1 [Member] | Prepaid Expenses and Other Current Assets [Member]
Assets:
Derivative assets, Current	123.6	131.1
Fair Value, Inputs, Level 1 [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	86.2	76.3
Fair Value, Inputs, Level 1 [Member] | Other Long-Term Assets [Member]
Assets:
Derivative assets, Noncurrent	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Accrued Liabilities [Member]
Liabilities:
Derivative liabilities, Current	4.0	0.3
Fair Value, Inputs, Level 1 [Member] | Other Long-Term Liabilities [Member]
Liabilities:
Derivative liabilities, Noncurrent	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Auction rate securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		0.0
Fair Value, Inputs, Level 1 [Member] | Commercial paper | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Corporate debt securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Corporate debt securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Foreign government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0
Fair Value, Inputs, Level 1 [Member] | Foreign Government Obligations [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		0.0
Fair Value, Inputs, Level 1 [Member] | Mortgage and other asset-backed securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | Mortgage and other asset-backed securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | State and local government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 1 [Member] | U.S. government treasury securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	86.2	76.3
Fair Value, Inputs, Level 2 [Member]
Assets:
Total Assets	350.6	388.0
Liabilities:
Total liabilities	13.4	16.5
Fair Value, Inputs, Level 2 [Member] | Cash and cash equivalents
Assets:
Cash and cash equivalents	0.0	0.0
Fair Value, Inputs, Level 2 [Member] | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	8.4	87.8
Marketable equity securities	0.0	0.0
Total short-term investments	8.4	87.8
Fair Value, Inputs, Level 2 [Member] | Prepaid Expenses and Other Current Assets [Member]
Assets:
Derivative assets, Current	30.8	16.5
Fair Value, Inputs, Level 2 [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	213.4	199.4
Fair Value, Inputs, Level 2 [Member] | Other Long-Term Assets [Member]
Assets:
Derivative assets, Noncurrent	98.0	84.3
Fair Value, Inputs, Level 2 [Member] | Accrued Liabilities [Member]
Liabilities:
Derivative liabilities, Current	7.5	8.3
Fair Value, Inputs, Level 2 [Member] | Other Long-Term Liabilities [Member]
Liabilities:
Derivative liabilities, Noncurrent	5.9	8.2
Fair Value, Inputs, Level 2 [Member] | Auction rate securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		0.0
Fair Value, Inputs, Level 2 [Member] | Commercial paper | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	3.5	63.0
Fair Value, Inputs, Level 2 [Member] | Corporate debt securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	4.8	24.7
Fair Value, Inputs, Level 2 [Member] | Corporate debt securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	148.1	162.0
Fair Value, Inputs, Level 2 [Member] | Foreign government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	4.0
Fair Value, Inputs, Level 2 [Member] | Foreign Government Obligations [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		4.0
Fair Value, Inputs, Level 2 [Member] | Mortgage and other asset-backed securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.1	0.1
Fair Value, Inputs, Level 2 [Member] | Mortgage and other asset-backed securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	59.9	31.9
Fair Value, Inputs, Level 2 [Member] | State and local government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	1.4	1.5
Fair Value, Inputs, Level 2 [Member] | U.S. government treasury securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member]
Assets:
Total Assets	0.0	6.0
Liabilities:
Total liabilities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Cash and cash equivalents
Assets:
Cash and cash equivalents	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Marketable equity securities	0.0	0.0
Total short-term investments	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Prepaid Expenses and Other Current Assets [Member]
Assets:
Derivative assets, Current	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	6.0
Fair Value, Inputs, Level 3 [Member] | Other Long-Term Assets [Member]
Assets:
Derivative assets, Noncurrent	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Accrued Liabilities [Member]
Liabilities:
Derivative liabilities, Current	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Other Long-Term Liabilities [Member]
Liabilities:
Derivative liabilities, Noncurrent	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Auction rate securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		6.0
Fair Value, Inputs, Level 3 [Member] | Commercial paper | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Corporate debt securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Corporate debt securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Foreign government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0
Fair Value, Inputs, Level 3 [Member] | Foreign Government Obligations [Member] | Long-term Investments [Member]
Assets:
Available-for-sale debt securities		0.0
Fair Value, Inputs, Level 3 [Member] | Mortgage and other asset-backed securities | Short-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | Mortgage and other asset-backed securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | State and local government obligations | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	0.0	0.0
Fair Value, Inputs, Level 3 [Member] | U.S. government treasury securities | Long-term Investments [Member]
Assets:
Available-for-sale debt securities	$ 0.0	$ 0.0