Note 9 - Segment Information (Details) - Identifiable Assets - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Identifiable assets:
Identifiable assets	$ 41,072	$ 38,738
Thermal Products [Member]
Identifiable assets:
Identifiable assets	16,631	26,211
Mechanical Products [Member]
Identifiable assets:
Identifiable assets	20,472	7,801
Electrical Products [Member]
Identifiable assets:
Identifiable assets	$ 3,969	$ 4,726