Equity (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009	Aug. 16, 2011	Aug. 23, 2010
Equity [Abstract]
Shares authorized for repurchase				1,000,000	2,000,000
Remaining shares available for repurchase under August 16, 2011 authorization	516,551
Common stock repurchased during period, shares	1,206,111
Total cost of repurchase of common stock	$ 50,450	$ 102,736	$ 55,757
Preferred stock, shares authorized and unissued	2,000,000
Preferred stock, shares issued	0