Derivative Instruments and Hedging Activities Part 2 (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jul. 02, 2011	Jun. 30, 2012	Jul. 02, 2011
Derivative Instruments, Gain (Loss) [Line Items]
Restricted cash related to open futures contracts	$ 1,100,000		$ 1,100,000
Commodity contracts [Member] | Cash Flow Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in Accumulated OCI (Effective Portion), Net of Tax	(1,394,000)	961,000	(107,000)	793,000
Commodity contracts [Member] | Cash Flow Hedges [Member] | Cost of goods sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
(Gain) Loss Reclassified from Accumulated OCI into Income (Effective Portion), Net of Tax	$ 804,000	$ (417,000)	$ 430,000	$ (1,026,000)