Stockholders' Equity (Details) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended			12 Months Ended
	Feb. 29, 2012	Aug. 31, 2011	Feb. 28, 2011	Dec. 25, 2012	Dec. 27, 2011
Stockholders' Equity
Repurchase of common stock authorized by board of directors	$ 100.0		$ 50.0
Increase in amount of stock repurchase		50.0
Amount paid for repurchase of common stock				$ 29.4	$ 59.1
Number of shares repurchased				1,786,855	3,972,100