Earnings (Loss) per Share Schedule of Earnings per Share Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended																12 Months Ended
	Sep. 30, 2016		Jun. 24, 2016		Mar. 25, 2016		Dec. 25, 2015		Sep. 25, 2015		Jun. 26, 2015		Mar. 27, 2015		Dec. 26, 2014		Sep. 30, 2016	Sep. 25, 2015	Sep. 26, 2014
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 110.0		$ 176.7		$ 98.5		$ 103.8		$ 73.1		$ 34.6		$ 55.3		$ 73.6		$ 489.0	$ 236.6	$ (22.0)
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic																	0.0	2.0	0.0
Income (Loss) From Continuing Operations Attributable To Common Stockholders																	489.0	234.6	(22.0)
Income (loss) from discontinued operations, net of income taxes	$ 5.0		$ 22.6		$ 19.8		$ 107.3		$ 2.1		$ 23.4		$ 43.5		$ 19.1		154.7	88.1	(297.3)
Income (Loss) From Discontinued Operations Attributable To Common Stockholders																	0.0	0.7	0.0
Net Income (Loss) Available to Common Stockholders, Basic																	154.7	87.4	(297.3)
Net Income (Loss) Available to Common Stockholders, Basic																	$ 643.7	$ 322.0	$ (319.3)
Weighted Average Number of Shares Outstanding, Basic																	110.6	115.8	64.9
Weighted Average Number of Shares Outstanding, Diluted																	0.9	1.4	0.0
Weighted Average Number of Shares Outstanding, Diluted																	111.5	117.2	64.9
Income (Loss) from Continuing Operations, Per Basic Share	$ 1.02	[1]	$ 1.63	[1]	$ 0.89	[1]	$ 0.90	[1]	$ 0.62	[1]	$ 0.30	[1]	$ 0.47	[1]	$ 0.63	[1]	$ 4.42	$ 2.03	$ (0.34)
Income (Loss) from Discontinued Operations, Per Basic Share																	1.40	0.75	(4.58)
Earnings Per Share, Basic																	5.82	2.78	(4.92)
Income (Loss) from Continuing Operations, Per Diluted Share	$ 1.01	[1]	$ 1.62	[1]	$ 0.88	[1]	$ 0.89	[1]	$ 0.62	[1]	$ 0.29	[1]	$ 0.47	[1]	$ 0.63	[1]	4.39	2.00	(0.34)
Income (Loss) from Discontinued Operations, Per Diluted Share																	1.39	0.75	(4.58)
Earnings Per Share, Diluted																	$ 5.77	$ 2.75	$ (4.92)

[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.