Fair Value of Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Jul. 01, 2012	Jan. 01, 2012	Jul. 03, 2011
Level 1 [Member]
Assets
Deferred compensation plan assets	$ 12,164	$ 10,709	$ 11,133
Cost and fair value aluminum hedging agreements
Liabilities
Public debt securities, fair value	579,386	576,127	569,324
Deferred Compensation Liability, Current and Noncurrent	12,164	10,709	11,133
Level 2 [Member]
Assets
Deferred compensation plan assets
Cost and fair value aluminum hedging agreements	0	0	4,450
Liabilities
Public debt securities, fair value
Deferred Compensation Liability, Current and Noncurrent