Investments - Short-term Investments by Type (Details) - USD ($)	Sep. 26, 2021	Jun. 27, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 592,000,000.0	$ 770,500,000
Gross Unrealized Gains	4,500,000	5,500,000
Gross Unrealized Losses	(200,000)	(400,000)
Credit Loss Allowance	0	0
Estimated Fair Value	596,300,000	775,600,000
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	135,700,000	139,400,000
Gross Unrealized Gains	1,700,000	1,900,000
Gross Unrealized Losses	0	0
Credit Loss Allowance	0	0
Estimated Fair Value	137,400,000	141,300,000
Corporate bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	366,900,000	456,500,000
Gross Unrealized Gains	2,600,000	3,300,000
Gross Unrealized Losses	(200,000)	(300,000)
Credit Loss Allowance	0	0
Estimated Fair Value	369,300,000	459,500,000
U.S. agency securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	13,800,000	15,800,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Credit Loss Allowance	0	0
Estimated Fair Value	13,800,000	15,800,000
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	46,100,000	72,300,000
Gross Unrealized Gains	200,000	300,000
Gross Unrealized Losses	0	(100,000)
Credit Loss Allowance	0	0
Estimated Fair Value	46,300,000	72,500,000
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	9,500,000	16,500,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Credit Loss Allowance	0	0
Estimated Fair Value	9,500,000	16,500,000
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		50,000,000.0
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Credit Loss Allowance		0
Estimated Fair Value		50,000,000.0
Variable rate demand notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	20,000,000.0	20,000,000.0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Credit Loss Allowance	0	0
Estimated Fair Value	$ 20,000,000.0	$ 20,000,000.0