Other Long Term Liabilities (Other Long-Term Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Other Long Term-Liabilities [Abstract]
Billings in Excess of Cost	$ 3,394	$ 3,654
Pension and Post Retirement	10,577	10,778
Alabama Lease Incentive	4,304	4,591
Insurance Reserves	4,800	4,674
Derivatives	183	121
Deferred Tax Liability		309
Other	1,081	1,141
Other Long-Term Liabilities	$ 24,339	$ 25,268