Retirement And Benefit Plans (Weighted Average Assumptions Used In The Measurement Of Company's Benefit Obligations) (Details)	Dec. 31, 2011	Dec. 25, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.93%	5.64%
United States [Member] | Other Defined Benefits Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.70%	4.50%
Canada [Member] | Other Defined Benefits Postretirement [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.50%	5.30%