Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Liabilities, Other than Long-term Debt, Noncurrent [Abstract]
Deferred income taxes	$ 23,568	$ 24,400
Pension and post retirement liabilities	10,526	10,714
Liability for Uncertain Tax Positions, Noncurrent	2,744	2,798
Environmental liabilities	1,100	1,100
Other liabilities	2,920	2,444
Other Liabilities, Noncurrent	$ 40,858	$ 41,456