Fair Value Measurements (Tables)

9 Months Ended

12 Months Ended

Jun. 27, 2021

Sep. 27, 2020

Fair Value Disclosures [Abstract]

Assets And Liabilities Measured At Fair Value On A Recurring Basis

			Fair Value Measurements at Reporting Date Using
	Balance at June 27, 2021		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	$	4,753.1	$	4,753.1	$	—	$	—
Short-term investments:
Available-for-sale debt securities
Commercial paper	57.0		—		57.0		—
Corporate debt securities	22.1		—		22.1		—
Total available-for-sale debt securities	79.1		—		79.1		—
Marketable equity securities	74.5		74.5		—		—
Total short-term investments	153.6		74.5		79.1		—
Prepaid expenses and other current assets:
Derivative assets	76.8		63.2		13.6		—
Long-term investments:
Available-for-sale debt securities
Auction rate securities	5.8		—		—		5.8
Corporate debt securities	164.0		—		164.0		—
Foreign government obligations	4.0		—		4.0		—
Mortgage and other asset-backed securities	25.1		—		25.1		—
State and local government obligations	1.5		—		1.5		—
U.S. government treasury securities	85.5		85.5		—		—
Total long-term investments	285.9		85.5		194.6		5.8
Other long-term assets:
Derivative assets	83.6		—		83.6		—
Total assets	$	5,353.0	$	4,976.3	$	370.9	$	5.8
Liabilities:
Accrued liabilities:
Derivative liabilities	$	17.6	$	1.1	$	16.5	$	—
Other long-term liabilities:
Derivative liabilities	16.5		—		16.5		—
Total liabilities	$	34.1	$	1.1	$	33.0	$	—

			Fair Value Measurements at Reporting Date Using
	Balance at September 27, 2020		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	$	4,350.9	$	4,350.9	$	—	$	—
Short-term investments:
Available-for-sale debt securities
Certificates of deposit	1.6		—		1.6		—
Commercial paper	66.8		—		66.8		—
Corporate debt securities	123.6		—		123.6		—
Foreign government obligations	8.5		—		8.5		—
Mortgage and other asset-backed securities	15.8		—		15.8		—
Total available-for-sale debt securities	216.3		—		216.3		—
Marketable equity securities	64.9		64.9		—		—
Total short-term investments	281.2		64.9		216.3		—
Prepaid expenses and other current assets:
Derivative assets	15.6		3.6		12.0		—
Long-term investments:
Available-for-sale debt securities
Auction rate securities	5.7		—		—		5.7
Corporate debt securities	82.6		—		82.6		—
Mortgage and other asset-backed securities	19.3		—		19.3		—
State and local government obligations	3.6		—		3.6		—
U.S. government treasury securities	94.9		94.9		—		—
Total long-term investments	206.1		94.9		105.5		5.7
Other long-term assets:
Derivative assets	87.3		—		87.3		—
Total assets	$	4,941.1	$	4,514.3	$	421.1	$	5.7
Liabilities:
Accrued liabilities:
Derivative liabilities	$	7.3	$	1.9	$	5.4	$	—
Other long-term liabilities:
Derivative liabilities	79.3		0.1		79.2		—
Total liabilities	$	86.6	$	2.0	$	84.6	$	—