Leases - Supplemental Balance Sheet (Details) - USD ($) $ in Millions	Jun. 27, 2020	Jun. 29, 2019
Leases [Abstract]
Other non-current assets	$ 40.5
Total operating ROU assets	40.5
Other current liabilities	11.7	$ 0.0
Operating lease liabilities (Note 12)	28.1	$ 0.0
Total operating lease liabilities	$ 39.8
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent	us-gaap:OtherLiabilitiesNoncurrent