Retirement And Benefit Plans (Components Of Net Periodic Benefit Cost (Income)) (Details)) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,546	$ 3,164	$ 4,506
Interest cost	70,176	74,213	75,858
Expected return on plan assets	(79,289)	(83,494)	(76,623)
Recognized actuarial loss	17,371	13,239	10,330
Amortization of prior service credits
Other	80	149
Net periodic benefit cost (income)	10,884	7,271	14,071
Other Defined Benefits Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	227	263	184
Interest cost	1,006	1,213	1,137
Expected return on plan assets
Recognized actuarial loss	220	224	147
Amortization of prior service credits	(4,009)	(4,006)	(4,001)
Other
Net periodic benefit cost (income)	$ (2,556)	$ (2,306)	$ (2,533)