Inventories (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Inventory, Net [Abstract]
Raw materials	$ 22,935,000		$ 22,416,000
Work-in-process	465,000		1,194,000
Finished goods	9,188,000		9,644,000
Inventory, Gross	32,588,000		33,254,000
Less: inventory valuation allowance	(8,697,000)		(7,845,000)
Inventories, net	23,891,000		25,409,000
Other Inventory, Materials, Supplies and Merchandise under Consignment, Gross, Contract Manufacturing Partner	10,800,000
Other Inventory, Materials, Supplies and Merchandise under Consignment, Gross	11,900,000		12,000,000
Inventory, net	1,162,000	397,000
Inventory Charges, Inventory Valuation, Deposit And Adverse Purchase Commitment Liability	1,162,000	1,038,000
Adverse Purchase Commitments	$ (127,000)	$ (32,000)