Earnings (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 26, 2015	Jun. 27, 2014	Jun. 26, 2015	Jun. 27, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive equity awards excluded from calculation	0.0		0.0
Income (loss) from continuing operations attributable to common shareholders before allocation of earnings to participating securities	$ 57.5	$ (24.3)	$ 226.1	$ 33.8
Undistributed Earnings (Loss) Allocated to Participating Securities, Basic	0.4	0.0	2.0	0.0
Income (loss) from continuing operations attributable to common shareholders, after earnings allocated to participating securities	57.1	(24.3)	224.1	33.8
Income (loss) from discontinued operations, net of income taxes	0.5	0.2	23.4	(0.7)
Less: earnings from discontinued operations allocated to participating securities	0.0	0.0	0.2	0.0
Income (loss) from discontinued operations attributable to common shareholders, after allocation of earnings to participating securities	0.5	0.2	23.2	(0.7)
Net income (loss) attributable to common shareholders, after allocation of earnings to participating securities	$ 57.6	$ (24.1)	$ 247.3	$ 33.1
Weighted-average shares outstanding - basic (in shares)	116.3	58.5	115.5	58.2
Impact of dilutive securities (in shares)	1.5	0.0	1.6	0.8
Weighted-average shares outstanding - diluted (in shares)	117.8	58.5	117.1	59.0
Income from continuing operations (in usd per share)	$ 0.49	$ (0.42)	$ 1.94	$ 0.58
Loss from discontinued operations (in usd per share)	0.00	0.00	0.20	(0.01)
Net income (in usd per share)	0.50	(0.41)	2.14	0.57
Income from continuing operations (in usd per share)	0.48	(0.42)	1.91	0.57
Loss from discontinued operations (in usd per share)	0.00	0.00	0.20	(0.01)
Net income attributable to common shareholders (in usd per share)	$ 0.49	$ (0.41)	$ 2.11	$ 0.56
Dilutive Securities, Effect on Basic Earnings Per Share		$ 1.0
Stock Compensation Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive equity awards excluded from calculation		3.4		0.1