Investments - Schedule of Gross Unrealized Losses and Fair Value of Short-term Investments by Type and Length of Time (Details) $ in Millions	Sep. 29, 2024 USD ($) security	Jun. 30, 2024 USD ($) security
Fair Value
Less than 12 Months	$ 31.6	$ 666.5
Greater than 12 Months	235.3	303.6
Total	266.9	970.1
Unrealized Loss
Less than 12 Months	0.0	(0.6)
Greater than 12 Months	(4.4)	(8.7)
Total	$ (4.4)	$ (9.3)
Number of securities with an unrealized loss
Less than 12 Months | security	68	141
Greater than 12 Months | security	44	66
Total | security	112	207
Corporate bonds
Fair Value
Less than 12 Months	$ 9.2	$ 135.2
Greater than 12 Months	161.7	183.4
Total	170.9	318.6
Unrealized Loss
Less than 12 Months	0.0	(0.2)
Greater than 12 Months	(3.3)	(6.5)
Total	(3.3)	(6.7)
U.S. treasury securities
Fair Value
Less than 12 Months	19.9	507.4
Greater than 12 Months	5.9	35.9
Total	25.8	543.3
Unrealized Loss
Less than 12 Months	0.0	(0.4)
Greater than 12 Months	(0.1)	(0.2)
Total	(0.1)	(0.6)
Municipal bonds
Fair Value
Less than 12 Months	2.5	9.0
Greater than 12 Months	67.7	74.3
Total	70.2	83.3
Unrealized Loss
Less than 12 Months	0.0	0.0
Greater than 12 Months	(1.0)	(2.0)
Total	$ (1.0)	(2.0)
U.S. agency securities
Fair Value
Less than 12 Months		14.9
Greater than 12 Months		10.0
Total		24.9
Unrealized Loss
Less than 12 Months		0.0
Greater than 12 Months		0.0
Total		$ 0.0