Fair Value Measurements (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 28, 2019	Dec. 28, 2019	Jun. 30, 2019	Jun. 29, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, net		$ 886.3		$ 938.8
Operating lease right-of-use assets		$ 1,996.5	$ 2,133.7
Level 3
Property, Plant and Equipment [Line Items]
Operating lease right-of-use assets	$ 119.3
Level 3 | Store Assets
Property, Plant and Equipment [Line Items]
Tangible asset impairment charges	39.8
Property and equipment, net	10.1
Level 3 | Operating Lease Right-of-use Assets
Property, Plant and Equipment [Line Items]
Tangible asset impairment charges	$ 35.8