Net Income Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Net income (loss) per common share was computed as follows:
Income from continuing operations	$ 51.3	$ 53.1	$ 97.6	$ 90.0
Income from discontinued operations	12.9	20.2	10.5	28.1
Net income available to common shareholders	$ 64.2	$ 73.3	$ 108.1	$ 118.1
Weighted-average number of common shares outstanding	103.4	105.7	104.6	105.6
Dilutive shares (additional common shares issuable under employee stock-based awards)	0.9	1.2	0.7	1.2
Weighted-average number of common shares outstanding, assuming dilution	104.3	106.9	105.3	106.8
Net income per common share:
Continuing operations	$ 0.50	$ 0.50	$ 0.93	$ 0.85
Discontinued operations	$ 0.12	$ 0.19	$ 0.10	$ 0.27
Net income per common share	$ 0.62	$ 0.69	$ 1.03	$ 1.12
Net income per common share, assuming dilution:
Continuing operations	$ 0.49	$ 0.50	$ 0.93	$ 0.84
Discontinued operations	$ 0.13	$ 0.19	$ 0.10	$ 0.27
Net income per common share, assuming dilution	$ 0.62	$ 0.69	$ 1.03	$ 1.11
Net Income Per Share (Textual) [Abstract]
Employee stock-based awards excluded from the computation of net income per common share, assuming dilution	11	10	12	11