Net Income Per Share - Computation of Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020	Jun. 27, 2021	Jun. 28, 2020
Earnings Per Share, Basic and Diluted [Abstract]
Net income	$ 82.9	$ 33.2	$ 155.4	$ 77.9
Shares outstanding
Weighted average common shares outstanding (in shares)	134.8	133.8	134.7	133.9
Effect of dilutive stock awards (in shares)	0.5	0.8	0.6	1.0
Weighted average common shares outstanding and potential common shares (in shares)	135.3	134.6	135.3	134.9
Net income per share
Basic (in dollars per share)	$ 0.61	$ 0.25	$ 1.15	$ 0.58
Diluted (in dollars per share)	$ 0.61	$ 0.25	$ 1.15	$ 0.58