Summary of Significant Accounting Policies - Changes in accumulated balances of other comprehensive income (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 29, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	$ (22.9)	$ (41.4)	$ (26.6)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(1.8)	(1.7)	(1.1)
Accumulated other comprehensive Income loss Hedge	(0.9)	(2.7)	2.2
Accumulated Other Comprehensive Income (Loss), Net of Tax	(49.7)	(42.3)	(25.5)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	18.5	(14.8)	(8.1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent	0.1	0.6	(0.5)
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(0.5)	(8.0)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	(9.7)	(19.9)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2.3	3.1
Notional Amount	172.6
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Pension in Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Interest Rate Swap [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated other comprehensive Income loss Hedge	(24.1)	3.5	0.0
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, before Tax	(27.6)	3.5	$ 0.0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.0	0.0
Notional Amount	380.2
Interest rate caps - derivative
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 2.3	$ 3.1