Note 9 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Thermal Products [Member]
Net revenues:
Revenues	$ 6,259	$ 5,908	$ 18,635	$ 17,267
Earnings (loss) before income tax expense (benefit):
Income (Loss) From Continuing Operations	1,165	1,304	3,731	3,322
Net earnings (loss):
Net Income (Loss)	886	861	2,559	2,222
Mechanical Products [Member]
Net revenues:
Revenues	1,273	3,077	6,195	9,261
Earnings (loss) before income tax expense (benefit):
Income (Loss) From Continuing Operations	(759)	(109)	(1,240)	245
Net earnings (loss):
Net Income (Loss)	(577)	(72)	(891)	152
Electrical Products [Member]
Net revenues:
Revenues	1,671	1,809	6,120	5,406
Earnings (loss) before income tax expense (benefit):
Income (Loss) From Continuing Operations	79	203	875	608
Net earnings (loss):
Net Income (Loss)	60	134	579	402
Corporate Segment [Member]
Earnings (loss) before income tax expense (benefit):
Income (Loss) From Continuing Operations	(78)	(130)	(629)	(442)
Net earnings (loss):
Net Income (Loss)	(59)	(86)	(419)	(296)
Revenues	9,203	10,794	30,950	31,934
Income (Loss) From Continuing Operations	407	1,268	2,737	3,733
Net Income (Loss)	$ 310	$ 837	$ 1,828	$ 2,480