Defined Benefit Pension Plans Schedule of Amounts Recognized in the Consolidated Balance Sheets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Schedule of Amounts Recognized in the Consolidated Balance Sheets [Line Items]
Plan Assets in Other Long Term Assets	$ (477)	$ (449)
Current Portion of Pension Plan Liability in Wages and Benefits Payable	2,626	2,621
Long-term portion of pension plan liability	64,432	62,449
Net Penison Plan Benefit Liability	$ 66,581	$ 64,621