Basis of Presentation (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2017	Dec. 30, 2016	Jan. 01, 2016	Mar. 31, 2017
Other Non-current Assets
Basis Of Presentation [Line Items]
Restricted investments	$ 7.7			$ 7.7
Employee loans receivable	2.2			2.2
Selling, General and Administrative Expense
Basis Of Presentation [Line Items]
One-time, non-cash benefit	$ 9.9			$ 9.9
Goodwill Adjustment
Basis Of Presentation [Line Items]
Overstatement adjustment of financial statements line item		$ 209.9
Accumulated Other Comprehensive Income Adjustment
Basis Of Presentation [Line Items]
Overstatement adjustment of financial statements line item		209.9
Overall Translation Adjustment
Basis Of Presentation [Line Items]
Overstatement adjustment of financial statements line item		$ 287.5
Other Comprehensive Income Adjustment
Basis Of Presentation [Line Items]
Overstatement adjustment of financial statements line item			$ 18.4