Inventories (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Inventory, Net [Abstract]
Raw materials	$ 8,458,000		$ 9,219,000
Work-in-process	681,000		1,195,000
Finished goods	9,251,000		10,762,000
Inventory, Gross	18,390,000		21,176,000
Less: inventory valuation allowance	(2,663,000)		(2,701,000)
Inventories, net	15,727,000		18,475,000
Other Inventory, Materials, Supplies and Merchandise under Consignment, Gross	2,100,000		2,600,000
Inventory Charges, Inventory Valuation, Deposit And Adverse Purchase Commitment Liability	(40,000)	1,162,000
Adverse Purchase Commitments	$ 576,000	$ (127,000)