Note 9 - Segment Information (Details) - Segment Information (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenues	$ 8,797	$ 8,973
Long-lived Assets	1,323	1,254	1,254
Earnings (Loss) Before Income Tax Expense (Benefit)	411	370
Net earnings (loss)	286	292
Identifiable Assets	35,935	35,481	35,481
Thermal Products [Member]
Segment Reporting Information [Line Items]
Revenues	5,243	5,898
Earnings (Loss) Before Income Tax Expense (Benefit)	811	1,158
Net earnings (loss)	564	914
Identifiable Assets	24,423	23,934
Mechanical Products [Member]
Segment Reporting Information [Line Items]
Revenues	2,047	1,793
Earnings (Loss) Before Income Tax Expense (Benefit)	(283)	(686)
Net earnings (loss)	(197)	(542)
Identifiable Assets	6,941	7,093
Electrical Products [Member]
Segment Reporting Information [Line Items]
Revenues	1,507	1,282
Earnings (Loss) Before Income Tax Expense (Benefit)	5	(8)
Net earnings (loss)	4	(6)
Identifiable Assets	4,571	4,454
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) Before Income Tax Expense (Benefit)	(122)	(94)
Net earnings (loss)	(85)	(74)
UNITED STATES
Segment Reporting Information [Line Items]
Revenues	3,149	3,214
Long-lived Assets	747	700
Foreign [Member]
Segment Reporting Information [Line Items]
Revenues	5,648	5,759
Long-lived Assets	$ 576	$ 554