Note 9 - Segment Information (Details) - Identifiable Assets (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Identifiable assets:
Identifiable assets	$ 38,395	$ 35,481
Thermal Products [Member]
Identifiable assets:
Identifiable assets	25,410	23,934
Mechanical Products [Member]
Identifiable assets:
Identifiable assets	7,866	7,093
Electrical Products [Member]
Identifiable assets:
Identifiable assets	$ 5,119	$ 4,454