Derivatives Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 01, 2017	Mar. 26, 2016	Apr. 01, 2017	Mar. 26, 2016	Sep. 26, 2015	Sep. 24, 2016
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Interest Rate Cap Agreements Aggregate Premium Payable					$ 13.2
Principal Amount Of Borrowings	$ 1,000.0		$ 1,000.0
Interest Payment Duration	three-year
Loss reclassified from accumulated other comprehensive loss to the statement of income	$ (1.2)	$ (0.7)	(3.3)	$ (1.0)
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred			6.0
Interest Rate Cash Flow Hedge Asset at Fair Value	3.2		3.2			$ 1.4
Gain (Loss) on Foreign Currency Derivative Instruments Not Designated as Hedging Instruments	1.8	0.6	3.0	1.0
Unrealized Gain (Loss) on Foreign Currency Derivatives, Net, before Tax	3.9	$ 0.7	4.5	$ 0.3
Notional Amount	$ 80.5		$ 80.5