Summary of Significant Accounting Policies (Net Income Per Common Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 28, 2019	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Accounting Policies [Abstract]
Net income (loss)	$ (71.7)	$ 7.8	$ 39.4	$ 36.9	$ 17.3	$ 39.1	$ 63.8	$ 35.7	$ 12.4	$ 155.9	$ (265.4)
Weighted average shares of common stock outstanding									48.8	49.9	50.8
Common equivalent shares:
Assumed exercise of dilutive options, restricted shares, restricted stock units and performance share units									0.2	0.3	0.0
Weighted average common and common equivalent shares outstanding									49.0	50.2	50.8
Basic earnings (loss) per share	$ (1.47)	$ 0.16	$ 0.81	$ 0.76	$ 0.36	$ 0.79	$ 1.26	$ 0.70	$ 0.26	$ 3.12	$ (5.22)
Diluted earnings (loss) per share	$ (1.47)	$ 0.16	$ 0.81	$ 0.76	$ 0.35	$ 0.79	$ 1.26	$ 0.70	$ 0.25	$ 3.11	$ (5.22)
Shares excluded from the determination of potential common stock because inclusion would have been anti-dilutive									3.9	3.0	3.1