Restructuring and Severance Charges - Restructuring Activities and Accrued Liabilities (Details) $ in Millions	9 Months Ended
	Jul. 02, 2017 USD ($)
Restructuring Reserve [Roll Forward]
Beginning Balance	$ 7.5
Provisions	19.4
Cash expenditures	(8.6)
Other non-cash settlement	(0.1)
Ending Balance	18.4
Employee Severance
Restructuring Reserve [Roll Forward]
Beginning Balance	2.5
Provisions	11.9
Cash expenditures	(6.3)
Other non-cash settlement	0.0
Ending Balance	8.1
Contract Termination Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	4.6
Provisions	6.6
Cash expenditures	(2.2)
Other non-cash settlement	(0.1)
Ending Balance	9.1
Other Associated Costs
Restructuring Reserve [Roll Forward]
Beginning Balance	0.4
Provisions	0.9
Cash expenditures	(0.1)
Other non-cash settlement	0.0
Ending Balance	$ 1.2