Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 29, 2017	Dec. 30, 2016
Income Tax Disclosure [Abstract]
United States income taxes	$ 304.9	$ 56.5
Foreign income taxes	10.3	6.8
Provision for income taxes	$ 315.2	$ 63.3
Effective tax rate	81.70%	19.70%