Share-Based Payments Compensation Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 25, 2011	Jun. 30, 2012	Jun. 25, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
After-tax compensation expense (in dollars)	$ 3.7	$ 4.5	$ 7.1	$ 10.4
Options and SOSARs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense (in dollars)	0.7	1.1	2.6	3.9
Tax benefit (in dollars)	(0.2)	(0.3)	(0.8)	(1.1)
After-tax compensation expense (in dollars)	0.5	0.8	1.8	2.8
RSUs and DSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense (in dollars)	2.5	3.1	4.6	5.4
Tax benefit (in dollars)	(0.7)	(0.8)	(1.3)	(1.3)
After-tax compensation expense (in dollars)	1.8	2.3	3.3	4.1
PUs and PSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pre-tax compensation expense (in dollars)	1.9	2.0	2.9	5.0
Tax benefit (in dollars)	(0.5)	(0.6)	(0.9)	(1.5)
After-tax compensation expense (in dollars)	$ 1.4	$ 1.4	$ 2.0	$ 3.5