Note 11 - Segment Information (Details) - Segment Information (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	$ 9,900	$ 10,799	$ 30,091	$ 35,106
Earnings (loss) before income tax expense (benefit)	1,114	1,012	2,971	2,935
Net earnings (loss)	1,090	664	2,385	1,955
Thermal Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	5,844	6,037	17,514	18,651
Thermal Products [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income tax expense (benefit)	1,232	895	3,468	2,267
Net earnings (loss)	1,206	587	2,847	1,483
Mechanical Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	2,193	2,677	7,784	8,267
Mechanical Products [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income tax expense (benefit)	(346)	(324)	(742)	(1,256)
Net earnings (loss)	(339)	(212)	(686)	(797)
Electrical Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	1,863	2,085	4,793	8,188
Electrical Products [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income tax expense (benefit)	294	376	493	2,115
Net earnings (loss)	288	246	422	1,384
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Earnings (loss) before income tax expense (benefit)	(66)	65	(248)	(191)
Net earnings (loss)	(65)	43	(198)	(115)
UNITED STATES
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	3,098	4,123	9,816	12,052
Foreign [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	6,802	6,676	20,275	23,054
Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	$ 9,900	$ 10,799	$ 30,091	$ 35,106