Note 9 - Segment Information (Details) - Identifiable Assets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Identifiable assets	$ 38,383	$ 35,481
Thermal Products [Member]
Segment Reporting Information [Line Items]
Identifiable assets	25,157	23,934
Mechanical Products [Member]
Segment Reporting Information [Line Items]
Identifiable assets	8,466	7,093
Electrical Products [Member]
Segment Reporting Information [Line Items]
Identifiable assets	$ 4,760	$ 4,454