Leases - Effects of New Accounting Pronouncement (Details) - USD ($) $ in Millions	Jun. 29, 2019	Dec. 30, 2018	Dec. 29, 2018
ASSETS
Finance lease liabilities	$ 8.4	$ 7.8	$ 7.8
Operating lease right-of-use assets	55.4	60.5	0.0
Current liabilities:
Other accrued liabilities	1.5	1.2	1.2
Other accrued liabilities	20.8	20.2
Non-current:
Other long-term liabilities	7.1	6.6	$ 6.6
Operating lease liabilities	$ 35.7	40.4
Topic 842 Adjustments
ASSETS
Finance lease liabilities		0.0
Operating lease right-of-use assets		60.5
Current liabilities:
Other accrued liabilities		0.0
Other accrued liabilities		20.2
Non-current:
Other long-term liabilities		0.0
Operating lease liabilities		$ 40.4