Employee Benefit Plans (Schedule Of Components Of Net Periodic Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Employee Benefit Plans [Abstract]
Service cost
Interest cost	9,838	10,466	9,006
Expected return on plan assets	(9,336)	(8,039)	(6,291)
Net periodic pension cost	$ 502	$ 2,427	$ 2,715