Commitments And Guarantees (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 25, 2010	Dec. 26, 2009
Commitments And Guarantees [Abstract]
Expiration date of supply contract	Dec. 31, 2017
Purchases under agreement	$ 630.1	$ 615.6	$ 633.9
Percentage of minority owner's interest in joint venture	49.00%
Estimated purchase price of minority owner's interest	27.6
Number of operating leases	6
Expiration date of operating leases assuming exercise of renewal options	2019
Payments for rent	$ 3.0