Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2016 USD ($) Bank	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2001 USD ($)	Mar. 20, 2015 USD ($)	Dec. 31, 2013 USD ($)
Business acquisition:
Net foreign translation and transaction activity	$ 89,000	$ 54,000	$ (108,000)
Goodwill	2,403,000	2,403,000
Goodwill, Impairment Loss	0	0	0
Asset Impairment Charges	0	0	0
Billed contracts receivable	11,052,000	21,967,000
Costs incurred on uncompleted contracts	9,968,000	19,696,000
Tooling in progress	$ 1,084,000	2,271,000
Number of banks in which cash is held | Bank	1
Cash and cash equivalents	$ 28,285,000	8,943,000	2,312,000			$ 2,266,000
Allowance for doubtful accounts	0	40,000
Allowance for chargebacks	309,000	523,000
Allowance for slow moving and obsolete inventory	770,000	863,000
Self-insurance reserve	1,139,000	1,074,000
Postemployment Benefits Liability	8,667,000	9,006,000
Research and development expense	$ 965,000	719,000	$ 475,000
CPI [Member]
Business acquisition:
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Assets, Other than Goodwill					$ 650,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment					$ 12,474,000
Goodwill, acquired during period		$ 1,306,000
Airshield Corporation
Business acquisition:
Goodwill, acquired during period				$ 1,097,000