Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																	12 Months Ended
	Dec. 29, 2017		Sep. 29, 2017		Jun. 30, 2017		Mar. 31, 2017		Dec. 30, 2016	Sep. 30, 2016		Jun. 24, 2016		Mar. 25, 2016		Dec. 25, 2015		Dec. 29, 2017	Sep. 30, 2016	Sep. 25, 2015
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 792.3		$ 793.9		$ 824.5		$ 810.9		$ 829.9	$ 887.2		$ 866.6		$ 815.8		$ 811.2		$ 3,221.6	$ 3,380.8	$ 2,923.1
Gross profit	421.0		400.6		416.1		418.6		445.8	490.2		488.8		425.1		450.9		1,656.3	1,855.0	1,622.9
Income (loss) from continuing operations	1,607.4		64.3		70.6		28.9		(176.8)	110.0		176.7		98.5		103.8		1,771.2	489.0	236.6
Income (loss) from discontinued operations, net of income taxes	1.3		(0.6)		(7.8)		370.3		23.6	5.0		22.6		19.8		107.3		363.2	154.7	88.1
Net income (loss)	$ 1,608.7		$ 63.7		$ 62.8		$ 399.2		$ (153.2)	$ 115.0		$ 199.3		$ 118.3		$ 211.1		$ 2,134.4	$ 643.7	$ 324.7
Basic earnings (loss) per share from continuing operations (in usd per share)	$ 17.43	[1]	$ 0.66	[1]	$ 0.72	[1]	$ 0.28	[1]	$ (1.67)	$ 1.02	[1]	$ 1.63	[1]	$ 0.89	[1]	$ 0.90	[1]	$ 18.13	$ 4.42	$ 2.03
Diluted earnings (loss) per share from continuing operations (in usd per share)	$ 17.40	[1]	$ 0.66	[1]	$ 0.72	[1]	$ 0.28	[1]	$ (1.67)	$ 1.01	[1]	$ 1.62	[1]	$ 0.88	[1]	$ 0.89	[1]	$ 18.09	$ 4.39	$ 2.00

[1] Quarterly and annual computations are prepared independently. Therefore, the sum of each quarter may not necessarily total the fiscal period amounts noted elsewhere within this Annual Report on Form 10-K.