Inventories (Details) (USD $)	Mar. 31, 2013	Dec. 31, 2012
Inventories [Abstract]
Raw materials	$ 18,937,000	$ 20,003,000
Work in process	15,119,000	15,608,000
Finished goods	4,712,000	4,741,000
Inventories, total	38,768,000	40,352,000	[1]
Inventory reserve	$ 9,700,000	$ 10,100,000

[1] The condensed consolidated balance sheet at December 31, 2012 has been derived from the audited consolidated financial statements at that date.