UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative Effect, Period of Adoption, Adjustment	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Balance at beginning of period (in shares) at Jun. 26, 2022			123,795
Balance at beginning of period at Jun. 26, 2022	$ 2,439.3	$ (303.3)	$ 0.2	$ 4,228.4	$ (333.0)	$ (1,764.0)	$ 29.7	$ (25.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(26.2)					(26.2)
Unrealized gain on available-for-sale securities	(7.0)							(7.0)
Tax withholding on vested equity awards	(16.9)			(16.9)
Stock-based compensation (in shares)			395
Stock-based compensation	23.2			23.2
Exercise of stock options and issuance of shares (in shares)			20
Exercise of stock options and issuance of shares	0.5			0.5
Balance at end of period (in shares) at Sep. 25, 2022			124,210
Balance at end of period at Sep. 25, 2022	$ 2,109.6		$ 0.2	3,902.2		(1,760.5)		(32.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of ASU 2020-06 [Extensible Enumeration]	Accounting Standards Update 2020-06 [Member]
Balance at beginning of period (in shares) at Jun. 26, 2022			123,795
Balance at beginning of period at Jun. 26, 2022	$ 2,439.3	$ (303.3)	$ 0.2	4,228.4	$ (333.0)	(1,764.0)	$ 29.7	(25.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(216.6)
Unrealized gain on available-for-sale securities	2.2
Comprehensive loss	(214.4)
Balance at end of period (in shares) at Mar. 26, 2023			124,437
Balance at end of period at Mar. 26, 2023	1,706.8		$ 0.2	3,680.6		(1,950.9)		(23.1)
Balance at beginning of period (in shares) at Sep. 25, 2022			124,210
Balance at beginning of period at Sep. 25, 2022	2,109.6		$ 0.2	3,902.2		(1,760.5)		(32.3)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(90.9)					(90.9)
Unrealized gain on available-for-sale securities	3.7							3.7
Tax withholding on vested equity awards	(0.4)			(0.4)
Stock-based compensation	21.4			21.4
Exercise of stock options and issuance of shares (in shares)			203
Exercise of stock options and issuance of shares	10.7			10.7
Capped call transactions related to the issuance of convertible notes due December 1, 2029	(273.9)			(273.9)
Balance at end of period (in shares) at Dec. 25, 2022			124,413
Balance at end of period at Dec. 25, 2022	1,780.2		$ 0.2	3,660.0		(1,851.4)		(28.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(99.5)					(99.5)
Unrealized gain on available-for-sale securities	5.5							5.5
Comprehensive loss	(94.0)
Tax withholding on vested equity awards	(0.4)			(0.4)
Stock-based compensation	20.8			20.8
Exercise of stock options and issuance of shares (in shares)			24
Exercise of stock options and issuance of shares	0.2			0.2
Balance at end of period (in shares) at Mar. 26, 2023			124,437
Balance at end of period at Mar. 26, 2023	$ 1,706.8		$ 0.2	3,680.6		(1,950.9)		(23.1)
Balance at beginning of period (in shares) at Jun. 25, 2023	124,794		124,794
Balance at beginning of period at Jun. 25, 2023	$ 1,621.9		$ 0.2	3,711.0		(2,064.2)		(25.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(395.7)					(395.7)
Unrealized gain on available-for-sale securities	1.9							1.9
Tax withholding on vested equity awards	(15.0)			(15.0)
Stock-based compensation (in shares)			506
Stock-based compensation	32.1			32.1
Exercise of stock options and issuance of shares (in shares)			21
Exercise of stock options and issuance of shares	0.5			0.5
Balance at end of period (in shares) at Sep. 24, 2023			125,321
Balance at end of period at Sep. 24, 2023	$ 1,245.7		$ 0.2	3,728.6		(2,459.9)		(23.2)
Balance at beginning of period (in shares) at Jun. 25, 2023	124,794		124,794
Balance at beginning of period at Jun. 25, 2023	$ 1,621.9		$ 0.2	3,711.0		(2,064.2)		(25.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(689.3)
Unrealized gain on available-for-sale securities	12.4
Comprehensive loss	$ (676.9)
Balance at end of period (in shares) at Mar. 31, 2024	125,833		125,833
Balance at end of period at Mar. 31, 2024	$ 1,022.6		$ 0.2	3,788.6		(2,753.5)		(12.7)
Balance at beginning of period (in shares) at Sep. 24, 2023			125,321
Balance at beginning of period at Sep. 24, 2023	1,245.7		$ 0.2	3,728.6		(2,459.9)		(23.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(144.7)					(144.7)
Unrealized gain on available-for-sale securities	11.0							11.0
Tax withholding on vested equity awards	(2.0)			(2.0)
Stock-based compensation (in shares)			104
Stock-based compensation	29.8			29.8
Exercise of stock options and issuance of shares (in shares)			360
Exercise of stock options and issuance of shares	10.4			10.4
Balance at end of period (in shares) at Dec. 31, 2023			125,785
Balance at end of period at Dec. 31, 2023	1,150.2		$ 0.2	3,766.8		(2,604.6)		(12.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(148.9)					(148.9)
Unrealized gain on available-for-sale securities	(0.5)							(0.5)
Comprehensive loss	(149.4)
Tax withholding on vested equity awards (in shares)			0
Tax withholding on vested equity awards	(0.7)			(0.7)
Stock-based compensation (in shares)			48
Stock-based compensation	$ 22.5			22.5
Balance at end of period (in shares) at Mar. 31, 2024	125,833		125,833
Balance at end of period at Mar. 31, 2024	$ 1,022.6		$ 0.2	$ 3,788.6		$ (2,753.5)		$ (12.7)