Derivative Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Jul. 01, 2012	Jan. 01, 2012	Jul. 03, 2011
Summary of fair values and classification in the consolidated balance sheets of derivative instruments
Total	$ 0	$ 0	$ 6,292
Fuel hedges [Member] | Unamortized cost [Member] | Prepaid expenses and other current assets [Member]
Summary of fair values and classification in the consolidated balance sheets of derivative instruments
Total	0	0	526
Aluminum hedges [Member] | Fair market value [Member] | Prepaid expenses and other current assets [Member]
Summary of fair values and classification in the consolidated balance sheets of derivative instruments
Total	0	0	4,450
Aluminum hedges [Member] | Unamortized cost [Member] | Prepaid expenses and other current assets [Member]
Summary of fair values and classification in the consolidated balance sheets of derivative instruments
Total	$ 0	$ 0	$ 1,316