Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 26, 2020	Sep. 28, 2019
Statement of Financial Position [Abstract]
Accounts receivable, reserves	$ 31.6	$ 17.8
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	1,623,000	1,623,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares issued (in shares)	295,107,000	292,323,000
Treasury stock (in shares)	37,609,000	24,639,000