Computation Of Net Income Per Share (Computation Of Basic And Diluted Earnings Per Share) (Details) (USD $) In Millions, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 25, 2011	Sep. 26, 2010	Sep. 25, 2011	Sep. 26, 2010
Computation Of Net Income Per Share
Net income	$ 35.8	$ 35.8	$ 124.2	$ 102.2
Basic weighted average shares outstanding	126.9	124.5	127.0	124.8
Net income per share, basic	$ 0.28	$ 0.29	$ 0.98	$ 0.82
Assumed exercise of common stock equivalents	3.0	2.6	3.8	3.2
Diluted weighted average common and common equivalent shares	129.9	127.1	130.8	128.0
Net income per share, diluted	$ 0.28	$ 0.28	$ 0.95	$ 0.80
Anti-dilutive common stock equivalents, non-vested stock, DSUs, RSUs, and PUs	7.3	11.9	4.8	12.0