Foreign Revenues (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	$ 12,404	$ 14,619
Portion of foreign sales (in hundredths)	10.00%
China [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	3,504	3,802
Hong Kong [Member}
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	1,448	0
Malaysia [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	4,079	4,651
Thailand [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	1,149	1,681
All other foreign countries [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	$ 2,224	$ 4,485