UNAUDITED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Millions	Total	Total Equity - Controlled Interest	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income	Non-controlling Interest
Balance at beginning of period (shares) at Jun. 24, 2018			101,488
Balance at beginning of period at Jun. 24, 2018	$ 2,072.1	$ 2,067.1	$ 0.1	$ 2,549.1	$ (482.7)	$ 0.6	$ 5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(11.1)	(11.1)			(11.1)
Currency translation gain (loss)	0.3	0.3				0.3
Unrealized gain on available-for-sale securities	(0.3)	(0.3)				(0.3)
Comprehensive (loss) income	(11.1)	(11.1)
Tax withholding on vested equity awards	(10.8)	(10.8)		(10.8)
Stock-based compensation	12.1	12.1		12.1
Exercise of stock options and issuance of shares (shares)			1,032
Exercise of stock options and issuance of shares	15.5	15.5		15.5
Convertible note issuance	110.6	110.6		110.6
Balance at end of period (shares) at Sep. 23, 2018			102,520
Balance at end of period at Sep. 23, 2018	2,198.7	2,193.7	$ 0.1	2,676.5	(483.5)	0.6	5.0
Balance at beginning of period (shares) at Jun. 24, 2018			101,488
Balance at beginning of period at Jun. 24, 2018	2,072.1	2,067.1	$ 0.1	2,549.1	(482.7)	0.6	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(241.3)
Currency translation gain (loss)	(0.8)
Unrealized gain on available-for-sale securities	2.8
Comprehensive (loss) income	(239.3)
Balance at end of period (shares) at Mar. 31, 2019			104,515
Balance at end of period at Mar. 31, 2019	2,065.9	2,060.8	$ 0.1	2,772.0	(713.8)	2.5	5.1
Balance at beginning of period (shares) at Sep. 23, 2018			102,520
Balance at beginning of period at Sep. 23, 2018	2,198.7	2,193.7	$ 0.1	2,676.5	(483.5)	0.6	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(2.5)	(2.5)			(2.5)
Currency translation gain (loss)	(0.9)	(0.9)				(0.9)
Unrealized gain on available-for-sale securities	1.1	1.1				1.1
Comprehensive (loss) income	(2.3)	(2.3)
Tax withholding on vested equity awards	(1.1)	(1.1)		(1.1)
Stock-based compensation	13.6	13.6		13.6
Exercise of stock options and issuance of shares (shares)			553
Exercise of stock options and issuance of shares	14.6	14.6		14.6
Balance at end of period (shares) at Dec. 30, 2018			103,073
Balance at end of period at Dec. 30, 2018	2,223.5	2,218.5	$ 0.1	2,703.6	(486.0)	0.8	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(227.7)	(227.8)			(227.8)		0.1
Currency translation gain (loss)	(0.3)	(0.3)				(0.3)
Unrealized gain on available-for-sale securities	2.0	2.0				2.0
Comprehensive (loss) income	(226.0)	(226.1)					0.1
Tax withholding on vested equity awards	(0.5)	(0.5)		(0.5)
Stock-based compensation	15.6	15.6		15.6
Exercise of stock options and issuance of shares (shares)			1,442
Exercise of stock options and issuance of shares	53.3	53.3		53.3
Balance at end of period (shares) at Mar. 31, 2019			104,515
Balance at end of period at Mar. 31, 2019	$ 2,065.9	2,060.8	$ 0.1	2,772.0	(713.8)	2.5	5.1
Balance at beginning of period (shares) at Jun. 30, 2019	106,570		106,570
Balance at beginning of period at Jun. 30, 2019	$ 2,041.2	2,036.2	$ 0.1	2,874.1	(847.5)	9.5	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(37.8)	(37.8)			(37.8)
Unrealized gain on available-for-sale securities	0.5	0.5				0.5
Comprehensive (loss) income	(37.3)	(37.3)
Tax withholding on vested equity awards	(14.3)	(14.3)		(14.3)
Stock-based compensation	17.4	17.4		17.4
Exercise of stock options and issuance of shares (shares)			1,127
Exercise of stock options and issuance of shares	18.6	18.6		18.6
Balance at end of period (shares) at Sep. 29, 2019			107,697
Balance at end of period at Sep. 29, 2019	$ 2,025.6	2,020.6	$ 0.1	2,895.8	(885.3)	10.0	5.0
Balance at beginning of period (shares) at Jun. 30, 2019	106,570		106,570
Balance at beginning of period at Jun. 30, 2019	$ 2,041.2	2,036.2	$ 0.1	2,874.1	(847.5)	9.5	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(151.7)
Currency translation gain (loss)	0.0
Unrealized gain on available-for-sale securities	(1.7)
Comprehensive (loss) income	$ (153.4)
Balance at end of period (shares) at Mar. 29, 2020	108,153		108,153
Balance at end of period at Mar. 29, 2020	$ 1,945.0	1,939.5	$ 0.1	2,931.3	(999.7)	7.8	5.5
Balance at beginning of period (shares) at Sep. 29, 2019			107,697
Balance at beginning of period at Sep. 29, 2019	2,025.6	2,020.6	$ 0.1	2,895.8	(885.3)	10.0	5.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(52.5)	(52.8)			(52.8)		0.3
Unrealized gain on available-for-sale securities	(0.3)	(0.3)				(0.3)
Comprehensive (loss) income	(52.8)	(53.1)					0.3
Tax withholding on vested equity awards	(0.4)	(0.4)		(0.4)
Stock-based compensation	13.4	13.4		13.4
Exercise of stock options and issuance of shares (shares)			334
Exercise of stock options and issuance of shares	10.7	10.7		10.7
Balance at end of period (shares) at Dec. 29, 2019			108,031
Balance at end of period at Dec. 29, 2019	1,996.5	1,991.2	$ 0.1	2,919.5	(938.1)	9.7	5.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net (loss) income	(61.4)	(61.6)			(61.6)		0.2
Currency translation gain (loss)	0.0
Unrealized gain on available-for-sale securities	(1.9)	(1.9)				(1.9)
Comprehensive (loss) income	(63.3)	(63.5)					0.2
Tax withholding on vested equity awards	(1.5)	(1.5)		(1.5)
Stock-based compensation	11.6	11.6		11.6
Exercise of stock options and issuance of shares (shares)			122
Exercise of stock options and issuance of shares	$ 1.7	1.7		1.7
Balance at end of period (shares) at Mar. 29, 2020	108,153		108,153
Balance at end of period at Mar. 29, 2020	$ 1,945.0	$ 1,939.5	$ 0.1	$ 2,931.3	$ (999.7)	$ 7.8	$ 5.5