Retirement Plans (Schedule of Benefit Obligation, Plan Assets and Funded Status of Plans) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Pension Benefits
Change in benefit obligation:
Projected benefit obligations at beginning of year	$ 375.5	$ 400.8
Service cost	1.8	2.4	$ 2.7
Interest cost	13.2	14.5	15.4
Actuarial (gain) loss	65.5	(0.8)
Benefits and administrative expenses paid	(20.1)	(17.8)
Plan settlements	(26.5)	(23.6)
Defined Benefit Plan, Plan Amendments	(0.4)	0.0
Net transfer in/(out)	0.0	0.7
Currency translation	0.1	(0.7)
Projected benefit obligations at end of year	409.1	375.5	400.8
Change in plan assets:
Fair value of plan assets at beginning of year	309.9	339.0
Actual return on plan assets	29.5	1.9
Employer contributions	16.7	10.4
Benefits and administrative expenses paid	(20.1)	(17.8)
Plan settlements	(26.5)	(23.6)
Currency translation	0.0	0.0
Fair value of plan assets at end of year	309.5	309.9	339.0
Funded status at end of year	(99.6)	(65.6)
Postretirement Benefits
Change in benefit obligation:
Projected benefit obligations at beginning of year	52.2	52.0
Service cost	0.1	0.1	0.1
Interest cost	2.0	1.9	2.1
Actuarial (gain) loss	0.5	2.1
Benefits and administrative expenses paid	(4.0)	(3.9)
Plan settlements	0.0	0.0
Defined Benefit Plan, Plan Amendments	0.0	0.0
Net transfer in/(out)	0.0	0.0
Currency translation	0.0	0.0
Projected benefit obligations at end of year	50.8	52.2	52.0
Change in plan assets:
Fair value of plan assets at beginning of year	0.0	0.0
Actual return on plan assets	0.0	0.0
Employer contributions	4.0	3.9
Benefits and administrative expenses paid	(4.0)	(3.9)
Plan settlements	0.0	0.0
Currency translation	0.0	0.0
Fair value of plan assets at end of year	0.0	0.0	$ 0.0
Funded status at end of year	$ (50.8)	$ (52.2)