Fair Value Measurements (Tables)

6 Months Ended

Mar. 31, 2024

Apr. 02, 2023

Fair Value Disclosures [Abstract]

Assets And Liabilities Measured At Fair Value On A Recurring Basis

			Fair Value Measurements at Reporting Date Using
	Balance at March 31, 2024		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant  Other Observable Inputs (Level 2)		Significant Unobservable  Inputs (Level 3)
Assets:
Cash and cash equivalents	$	2,764.1	$	2,764.1	$	—	$	—
Short-term investments:
Available-for-sale debt securities
Corporate debt securities	37.7		—		37.7		—
Foreign corporate bonds	0.2		—		0.2		—
Mortgage and other asset-backed securities	0.3		—		0.3		—
State and local government obligations	1.4		—		1.4		—
U.S. government treasury securities	16.5		16.5		—		—
Total available-for-sale debt securities	56.1		16.5		39.6		—
Structured deposits	221.9		—		221.9		—
Marketable equity securities	84.5		84.5		—		—
Total short-term investments	362.5		101.0		261.5		—
Prepaid expenses and other current assets:
Derivative assets	48.1		—		48.1		—
Long-term investments:
Available-for-sale debt securities
Corporate debt securities	127.4		—		116.9		10.5
Mortgage and other asset-backed securities	52.6		—		52.6		—
State and local government obligations	2.7		—		2.7		—
U.S. government treasury securities	97.5		97.5		—		—
Total available-for-sale debt securities	280.2		97.5		172.2		10.5
Structured deposits	0.2		—		0.2		—
Total long-term investments	280.4		97.5		172.4		10.5
Other long-term assets:
Derivative assets	181.2		—		181.2		—
Total assets	$	3,636.3	$	2,962.6	$	663.2	$	10.5
Liabilities:
Accrued liabilities:
Derivative liabilities	$	5.5	$	—	$	5.5	$	—
Other long-term liabilities:
Derivative liabilities	35.1		—		35.1		—
Total liabilities	$	40.6	$	—	$	40.6	$	—

			Fair Value Measurements at Reporting Date Using
	Balance at October 1, 2023		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable  Inputs (Level 3)
Assets:
Cash and cash equivalents	$	3,551.5	$	3,551.5	$	—	$	—
Short-term investments:
Available-for-sale debt securities
Corporate debt securities	64.0		—		64.0		—
U.S. government treasury securities	2.8		2.8		—		—
Foreign government obligations	3.9		—		3.9		—
Total available-for-sale debt securities	70.7		2.8		67.9		—
Structured deposits	261.2		—		261.2		—
Marketable equity securities	69.6		69.6		—		—
Total short-term investments	401.5		72.4		329.1		—
Prepaid expenses and other current assets:
Derivative assets	41.0		—		41.0		—
Long-term investments:
Available-for-sale debt securities
Corporate debt securities	91.1		—		91.1		—
Mortgage and other asset-backed securities	50.2		—		50.2		—
State and local government obligations	1.3		—		1.3		—
U.S. government treasury securities	104.7		104.7		—		—
Total long-term investments	247.3		104.7		142.6		—
Other long-term assets:
Derivative assets	153.0		—		153.0		—
Total assets	$	4,394.3	$	3,728.6	$	665.7	$	—
Liabilities:
Accrued liabilities:
Derivative liabilities	$	3.6	$	—	$	3.6	$	—
Other long-term liabilities:
Derivative liabilities	43.2		—		43.2		—
Total liabilities	$	46.8	$	—	$	46.8	$	—