Fair Value of Financial Instruments and Non-Financial Assets and Liabilities (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Dec. 31, 2011
Estimated fair value of long-term debt
Long-term debt (including current portion)	$ 640,815	$ 612,418
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Estimated fair value of long-term debt
Long-term debt (including current portion)
Significant Other Observable Inputs (Level 2) [Member]
Estimated fair value of long-term debt
Long-term debt (including current portion)	640,815	612,418
Unobservable Inputs (Level 3) [Member]
Estimated fair value of long-term debt
Long-term debt (including current portion)