Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 29, 2019	Mar. 30, 2018	Mar. 29, 2019	Mar. 30, 2018
Income Tax Disclosure [Abstract]
United States income taxes	$ 21.3	$ 7.8	$ 50.9	$ 312.7
Foreign income taxes	6.0	8.5	15.4	18.8
Provision for income taxes	$ 27.3	$ 16.3	$ 66.3	$ 331.5
Effective tax rate	11.40%	5.60%	11.80%	48.90%