Leases - Costs (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Dec. 28, 2019	Dec. 28, 2019
Leases [Abstract]
Amortization of right-of-use assets	$ 0.2	$ 0.4
Interest on lease liabilities	0.1	0.3
Total finance lease cost	0.3	0.7
Operating lease cost	105.5	217.3
Short-term lease cost	1.9	3.6
Variable lease cost	61.1	112.1
Operating lease right-of-use impairment	0.0	35.8
Less: sublease income	(5.3)	(10.7)
Total net lease cost	$ 163.5	$ 358.8