Summary of Significant Accounting Policies Net Income Per Common Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Dec. 25, 2010	Sep. 25, 2010	Jun. 26, 2010	Mar. 27, 2010	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Summary of Significant Accounting Policies [Abstract]
Excess tax benefits from share-based payment arrangements									$ (9.0)	$ (7.0)	$ (14.7)
Net income	86.9	10.5	65.1	55.8	80.7	39.9	57.9	47.1	218.3	225.6	175.1
Dividends Declared [Abstract]
To common shareholders									72.5	66.4	57.5
To participating security holders									0	0.2	0.2
Total undistributed earnings									145.8	159.0	117.4
Undistributed earnings to common shareholders									145.8	158.7	117.1
Undistributed earnings to participating security holders									0	0.3	0.3
Net income available to common shareholders for basic and diluted earnings per share									$ 218.3	$ 225.1	$ 174.6
Weighted-average shares of common stock outstanding									60.0	62.6	62.4
Common Equivalent Shares [Abstract]
Assumed exercise of dilutive options, restricted shares, restricted stock units and performance share units									1.4	1.2	1.0
Weighted-average common and common equivalent shares outstanding									61.4	63.8	63.4
Basic earnings per share	$ 1.53	$ 0.18	$ 1.05	$ 0.90	$ 1.29	$ 0.64	$ 0.92	$ 0.75	$ 3.63	$ 3.60	$ 2.80
Diluted earnings per share	$ 1.50	$ 0.17	$ 1.03	$ 0.88	$ 1.26	$ 0.62	$ 0.90	$ 0.73	$ 3.55	$ 3.53	$ 2.75
Shares excluded from the determination of potential common stock because inclusion would have been anti-dilutive									0.6	0.5	1.7
Participating Securities [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Unvested share-based payment awards outstanding									0	0.2	0.2