Borrowings and Credit Arrangements - Interest Expense Credit Agreement (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Line of Credit Facility [Line Items]
Interest expense	$ 15.7	$ 15.7	$ 47.1	$ 47.1
Credit Agreement
Line of Credit Facility [Line Items]
Interest expense	$ 11.4	$ 16.4	$ 38.0	$ 51.9
Weighted average interest rate	1.68%	3.85%	2.52%	3.84%
Interest rate at end of period	1.55%	3.78%	1.55%	3.78%