Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Jun. 27, 2020	Mar. 28, 2020	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 27, 2020	Jun. 29, 2019	Jun. 30, 2018
Reconciliation of the Company's income tax expense (benefit) at the federal statutory rate to the income tax expense (benefit) at the effective tax rate
Income tax (benefit) expense computed at federal statutory rate									$ 36.6	$ (7.0)	$ 36.3
Foreign rate differential									(24.6)	(17.8)	(24.3)
Change in valuation allowance									13.4	7.4	(206.0)
Change in Tax law									0.0	0.0	80.5
Tax credits									(10.2)	(7.1)	(11.0)
Stock-based compensation									4.8	5.9	(1.0)
Subpart F and GILTI									22.9	13.4	2.0
Unrecognized tax benefits									(1.7)	4.8	7.9
Other									(2.4)	0.5	(3.1)
Audit settlement									0.0	3.0	0.0
Total income tax (benefit) expense	$ 19.2	$ 5.2	$ 8.6	$ 5.8	$ 4.7	$ (8.2)	$ 1.4	$ 5.2	$ 38.8	$ 3.1	$ (118.7)