Foreign Revenues (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	$ 14,619	$ 20,037
China [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	3,802	5,984
Malaysia [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	4,651	7,035
Thailand [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	1,681	1,907
All other foreign countries [Member]
Frequency Control Devices - Significant Foreign Revenues:
Total foreign revenues	$ 4,485	$ 5,111