Summary of Significant Accounting Policies - Schedule of Other Assets (Detail) - USD ($) $ in Millions	Sep. 26, 2015	Sep. 27, 2014
Accounting Policies [Abstract]
Deferred financing costs	$ 27.0	$ 44.9
Life insurance contracts	27.5	22.4
Cash Flow Hedge Derivative Instrument Assets at Fair Value	6.9	0.0
Mutual funds	5.6	15.4
Manufacturing access fees	11.6	14.1
Cost-method equity investments	4.2	5.2
Other	17.9	16.2
Other assets	$ 115.2	$ 142.6