Retirement Plans (Schedule of Fair Value of Plan Assets) (Details) - USD ($) $ in Millions		12 Months Ended
		Sep. 30, 2016	Sep. 25, 2015
Recurring
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		$ 309.9
Fair value of plan assets at end of year		309.5	$ 309.9
Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		308.6
Fair value of plan assets at end of year		309.5	308.6
Recurring | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		1.3
Fair value of plan assets at end of year		0.0	1.3
Recurring | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year		0.0	0.0
Recurring | U.S. Small Mid Cap
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		15.1
Fair value of plan assets at end of year			15.1
Recurring | U.S. Small Mid Cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		15.1
Fair value of plan assets at end of year			15.1
Recurring | U.S. Small Mid Cap | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | U.S. Small Mid Cap | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | U.S. Large Cap
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		46.2
Fair value of plan assets at end of year		1.4	46.2
Recurring | U.S. Large Cap | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		46.2
Fair value of plan assets at end of year		1.4	46.2
Recurring | U.S. Large Cap | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year		0.0	0.0
Recurring | U.S. Large Cap | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year		0.0	0.0
Recurring | International
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		22.9
Fair value of plan assets at end of year			22.9
Recurring | International | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		22.7
Fair value of plan assets at end of year			22.7
Recurring | International | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.2
Fair value of plan assets at end of year			0.2
Recurring | International | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | Diversified Fixed Income Funds
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	197.2
Fair value of plan assets at end of year	[1]	296.1	197.2
Recurring | Diversified Fixed Income Funds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	196.9
Fair value of plan assets at end of year	[1]	296.1	196.9
Recurring | Diversified Fixed Income Funds | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	0.3
Fair value of plan assets at end of year	[1]	0.0	0.3
Recurring | Diversified Fixed Income Funds | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	[1]	0.0
Fair value of plan assets at end of year	[1]	0.0	0.0
Recurring | High Yield Bonds
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		11.3
Fair value of plan assets at end of year			11.3
Recurring | High Yield Bonds | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		11.3
Fair value of plan assets at end of year			11.3
Recurring | High Yield Bonds | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | High Yield Bonds | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | Emerging Market Fund
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		7.4
Fair value of plan assets at end of year			7.4
Recurring | Emerging Market Fund | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		7.4
Fair value of plan assets at end of year			7.4
Recurring | Emerging Market Fund | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | Emerging Market Fund | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year			0.0
Recurring | Other
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		9.8
Fair value of plan assets at end of year		12.0	9.8
Recurring | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		9.0
Fair value of plan assets at end of year		12.0	9.0
Recurring | Other | Significant Other Observable Inputs (Level 2)
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.8
Fair value of plan assets at end of year		0.0	0.8
Recurring | Other | Level 3
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		0.0
Fair value of plan assets at end of year		0.0	0.0
Pension Benefits
Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year		309.9	339.0
Currency translation		0.0	0.0
Fair value of plan assets at end of year		$ 309.5	$ 309.9

[1] Diversified fixed income funds consist of U.S. Treasury bonds, mortgage-backed securities, corporate bonds, asset-backed securities and U.S. agency bonds.