Retirement Plans Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 30, 2016 USD ($)	Dec. 29, 2017 USD ($) contract	Sep. 30, 2016 USD ($)	Sep. 25, 2015 USD ($)
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of Life Insurance Contract Held in Rabbi Trust | contract		124
Deferred Compensation Plan Assets	$ 59.9	$ 58.1
Deferred Compensation Plan Assets, Death Benefit on Insurance Contracts	150.7	145.8
Deferred Compensation Plan Assets, Loans Outstanding Against Insurance Contracts	44.0	44.5
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan		212.9
Defined Benefit Plan, Plan Assets, Payment for Settlement		62.3
Employer contributions	0.8	68.0	$ 16.7
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Settlement		70.5
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	(45.0)	(71.1)	$ (8.1)	$ (5.9)
Moody's, Aa1 Rating [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Lower Threshold for Discount Rate Basis, Corporate Bonds		$ 250.0
United States
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Percentage of Projected Benefit Obligation		38.60%
OUS
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Deferred Compensation Plan Assets, Collateral For Plan Benefits	$ 7.7	$ 8.8