Retirement And Benefit Plans (Weighted Average Assumptions Used In The Measurement Of Net Periodic Benefit Cost) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.64%	6.15%	6.20%
Expected long-term return on plan assets	8.20%	8.20%	7.50%
Other Defined Benefits Postretirement [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.50%	5.10%	6.10%
Expected long-term return on plan assets
Other Defined Benefits Postretirement [Member] | Canada [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.30%	6.40%	7.30%
Expected long-term return on plan assets