Accrued Liabilities (Narrative) (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities [Abstract]
Accrued product liability	$ 5,172,000	$ 5,370,000
Accrued payroll liability	4,948,000	4,576,000
Environmental accrued liability	1,010,000	1,180,000
Other accrued liabilities	$ 1,114,000	$ 1,444,000