Defined Benefit Pension Plans Schedule of Net Periodic Pension Benefit Costs (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Schedule of Net Periodic Pension Benefit Costs [Line Items]
Service Cost	$ 738	$ 617
Interest Cost	926	917
Expected Return on Plan Assets	(85)	(80)
Amortization of Actuarial Net Loss (Gains)	2	14
Amortization of Unrecognized Prior Service Costs	17	18
Net Periodic Benefit Cost	$ 1,598	$ 1,486