Employee Pension and Other Benefit Plans - Amounts Recognized on Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 30, 2018
Amount recognized in the Consolidated Balance Sheets at end of year:
Non-current liabilities	$ 102.7	$ 103.2
Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income:
Net actuarial gain (loss)	(5.4)	(7.3)	$ (2.8)
Amortization of accumulated net actuarial losses	2.8	1.8	$ 1.5
Pension Benefit Plans
Amount recognized in the Consolidated Balance Sheets at end of year:
Current liabilities	7.6	7.3
Non-current liabilities	102.3	102.8
Net amount recognized at end of year	109.9	110.1
Amount recognized in accumulated other comprehensive (loss) income at end of year:
Actuarial losses, net of tax	(31.2)	(28.6)
Net amount recognized at end of year	(31.2)	(28.6)
Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income:
Net actuarial gain (loss)	(5.4)	(7.3)
Amortization of accumulated net actuarial losses	2.8	1.8
Total recognized in other comprehensive (loss) income	$ (2.6)	$ (5.5)