Inventories (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Inventories
Raw materials	$ 19,355,000	$ 19,532,000
Work in process	16,759,000	16,007,000
Finished goods	2,617,000	2,473,000
Inventories, total	38,731,000	38,012,000
Inventory reserve	11,600,000	12,000,000
Excess and obsolete inventory	$ 297,000	$ 625,000