Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended																12 Months Ended
	Sep. 25, 2015		Jun. 26, 2015		Mar. 27, 2015		Dec. 26, 2014		Sep. 26, 2014		Jun. 27, 2014		Mar. 28, 2014		Dec. 27, 2013		Sep. 25, 2015	Sep. 26, 2014	Sep. 27, 2013
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 882.4		$ 877.3		$ 819.0		$ 768.2		$ 673.7		$ 530.1		$ 448.7		$ 429.5		$ 3,346.9	$ 2,082.0	$ 1,712.3
Gross profit	482.1		503.8		462.9		404.8		363.2		254.1		226.7		216.2		1,853.6	1,060.2	822.3
Income (loss) from continuing operations	90.0		55.6		75.2		87.4		(173.5)		(29.0)		20.2		38.5		308.2	(143.8)	8.2
Income (loss) from discontinued operations, net of income taxes	(14.8)		2.4		23.6		5.3		(178.9)		4.9		(8.6)		7.1		16.5	(175.5)	50.6
Net income (loss)	$ 75.2		$ 58.0		$ 98.8		$ 92.7		$ (352.4)		$ (24.1)		$ 11.6		$ 45.6		$ 324.7	$ (319.3)	$ 58.8
Basic earnings (loss) per share from continuing operations (in usd per share)	$ 0.77	[1]	$ 0.47	[1]	$ 0.64	[1]	$ 0.75	[1]	$ (2.04)	[1]	$ (0.50)	[1]	$ 0.35	[1]	$ 0.67	[1]	$ 2.64	$ (2.22)	$ 0.14
Diluted earnings (loss) per share from continuing operations (in usd per share)	$ 0.76	[1]	$ 0.47	[1]	$ 0.64	[1]	$ 0.74	[1]	$ (2.04)	[1]	$ (0.50)	[1]	$ 0.34	[1]	$ 0.66	[1]	$ 2.61	$ (2.22)	$ 0.14

[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.