Retirement Plans (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 25, 2015	Sep. 26, 2014
Amounts recognized on the consolidated balance sheet:
Non-current liabilities	$ (116.7)	$ (116.2)
Pension Benefits
Amounts recognized on the consolidated balance sheet:
Non-current assets	20.1	9.8
Current liabilities	(6.6)	(2.7)
Non-current liabilities	(69.1)	(71.9)
Net amount recognized on the consolidated balance sheet	(55.6)	(64.8)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	(104.1)	(115.1)
Prior service credit	5.5	6.9
Net amount recognized in accumulated other comprehensive income	(98.6)	(108.2)
Postretirement Benefits
Amounts recognized on the consolidated balance sheet:
Non-current assets	0.0	0.0
Current liabilities	(4.6)	(4.8)
Non-current liabilities	(47.6)	(47.2)
Net amount recognized on the consolidated balance sheet	(52.2)	(52.0)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	(5.1)	(2.9)
Prior service credit	14.9	18.8
Net amount recognized in accumulated other comprehensive income	$ 9.8	$ 15.9