Retirement Plans - Schedule of Net Periodic Benefit Costs (Detail) - Defined Benefit Plans - USD ($) $ in Millions	12 Months Ended
	Oct. 02, 2015	Sep. 26, 2014	Sep. 27, 2013
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5.7	$ 4.1	$ 4.8
Interest cost	4.4	6.1	5.2
Loss due to settlement or curtailment	1.1	1.8	1.0
Expected return on assets	(7.1)	(7.8)	(5.7)
Amortization of prior service cost	0.1	0.2	0.2
Recognized actuarial loss	2.5	2.1	2.7
Net periodic benefit cost	6.7	6.5	8.2
New prior service (credit) cost	(1.1)	0.0	0.5
Net (gain) loss arising during the year	6.7	10.3	(6.6)
Amortization of prior service cost	(0.1)	(0.2)	(0.2)
Amortization, settlement and curtailment of net actuarial loss	(3.6)	(3.9)	(3.7)
Total recognized in other comprehensive (earnings) loss	1.9	6.2	(10.0)
Total recognized in net periodic benefit cost and other comprehensive (earnings) loss	$ 8.6	$ 12.7	$ (1.8)