Net Income Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Net income per common share amounts
Income from continuing operations	$ 64.3	$ 44.4	$ 135.9	$ 116.0
Loss from discontinued operations, net of tax	(1.0)	(1.9)	(1.0)	(2.3)
Net income	$ 63.3	$ 42.5	$ 134.9	$ 113.7
Weighted-average number of common shares outstanding	91.2	94.9	90.9	95.4
Dilutive shares (additional common shares issuable under stock-based awards)	1.8	1.8	1.9	1.9
Weighted-average number of common shares outstanding, assuming dilution	93.0	96.7	92.8	97.3
Net income (loss) per common share:
Continuing operations (in dollars per share)	$ 0.70	$ 0.47	$ 1.49	$ 1.22
Discontinued operations (in dollars per share)	(0.01)	(0.02)	(0.01)	(0.03)
Net income per common share (in dollars per share)	0.69	0.45	1.48	1.19
Net income (loss) per common share, assuming dilution:
Continuing operations (in dollars per share)	0.69	0.46	1.46	1.19
Discontinued operations (in dollars per share)	(0.01)	(0.02)	(0.01)	(0.02)
Net income per common share, assuming dilution (in dollars per share)	$ 0.68	$ 0.44	$ 1.45	$ 1.17
Stock-based compensation awards excluded from the computation of net income per common share, assuming dilution	1.0	3.0	1.0	4.0