Financial Statement Details - Other Operating Expense (Income) (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 30, 2019	Jun. 24, 2018	Jun. 25, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Factory optimization restructuring	$ 4.1	$ 0.0	$ 0.0
Severance and other restructuring	4.2	3.8	0.0
Total restructuring costs	8.3	3.8	0.0
Project and transaction costs	16.9	8.5	0.0
Executive severance	1.3	4.5	2.2
Factory optimization start up costs	1.5	0.0	0.0
Gain from termination of Wolfspeed transaction, net	0.0	0.0	(2.8)
Other operating expense (income)	$ 28.0	$ 16.8	$ (0.6)