Foreign Revenues (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	$ 23,013	$ 26,201
Portion of foreign sales (in hundredths)	10.00%
China [Member]
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	2,604	3,504
Hong Kong [Member}
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	604	1,448
Malaysia [Member]
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	3,018	4,079
All other foreign countries [Member]
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	3,231	3,373
Foreign [Member]
Frequency Control Devices - Significant Foreign Revenues:
Revenues from Operations	$ 9,457	$ 12,404