Retirement Plans (Schedule of Amounts Recognized in Balance Sheet) (Details) - USD ($) $ in Millions	Sep. 30, 2016	Sep. 25, 2015
Amounts recognized on the consolidated balance sheet:
Non-current liabilities	$ (144.9)	$ (114.2)
Pension Benefits
Amounts recognized on the consolidated balance sheet:
Non-current assets	4.0	3.9
Current liabilities	(5.2)	(2.9)
Non-current liabilities	(98.4)	(66.6)
Net amount recognized on the consolidated balance sheet	(99.6)	(65.6)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	(141.2)	(107.9)
Prior service credit	0.3	0.0
Net amount recognized in accumulated other comprehensive income	(140.9)	(107.9)
Postretirement Benefits
Amounts recognized on the consolidated balance sheet:
Non-current assets	0.0	0.0
Current liabilities	(4.3)	(4.6)
Non-current liabilities	(46.5)	(47.6)
Net amount recognized on the consolidated balance sheet	(50.8)	(52.2)
Amounts recognized in accumulated other comprehensive income consist of:
Net actuarial loss	(5.6)	(5.1)
Prior service credit	12.8	14.9
Net amount recognized in accumulated other comprehensive income	$ 7.2	$ 9.8