Summary of Significant Accounting Policies (Net Income Per Common Share) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Accounting Policies [Abstract]
Net income	$ 82.3	$ 32.3	$ 47.6	$ 52.2	$ 89.8	$ 49.9	$ 76.3	$ 58.2	$ 214.4	$ 274.2	$ 193.0
Weighted-average shares of common stock outstanding									50.1	51.9	55.3
Common equivalent shares:
Assumed exercise of dilutive options, restricted shares, restricted stock units and performance share units									0.9	1.2	1.1
Weighted-average common and common equivalent shares outstanding									51.0	53.1	56.4
Basic earnings per share	$ 1.65	$ 0.64	$ 0.95	$ 1.04	$ 1.78	$ 0.97	$ 1.46	$ 1.09	$ 4.28	$ 5.28	$ 3.49
Diluted earnings per share	$ 1.63	$ 0.63	$ 0.93	$ 1.02	$ 1.74	$ 0.95	$ 1.43	$ 1.06	$ 4.20	$ 5.17	$ 3.42
Shares excluded from the determination of potential common stock because inclusion would have been anti-dilutive									0.4	0.1	0.4