Note 12 - Segment Information (Details) - Segment Information (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	$ 11,218	$ 13,576	$ 20,191	$ 24,307
Earnings (loss) before income tax expense (benefit):
Earnings (loss) before income tax expense (benefit)	1,487	1,994	1,857	1,923
Net earnings (loss):
Net earnings (loss)	1,003	1,334	1,295	1,291
Intersegment sales	11,218	13,576	20,191	24,307
Thermal Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	5,772	6,503	11,670	12,614
Net earnings (loss):
Intersegment sales	5,772	6,503	11,670	12,614
Thermal Products [Member]
Earnings (loss) before income tax expense (benefit):
Earnings (loss) before income tax expense (benefit)	1,078	1,055	2,236	1,372
Net earnings (loss):
Net earnings (loss)	727	706	1,641	896
Mechanical Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	3,812	3,086	5,608	5,600
Net earnings (loss):
Intersegment sales	3,812	3,086	5,608	5,600
Mechanical Products [Member] | Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	14		17	10
Net earnings (loss):
Intersegment sales	14		17	10
Mechanical Products [Member]
Earnings (loss) before income tax expense (benefit):
Earnings (loss) before income tax expense (benefit)	290	(380)	(396)	(932)
Net earnings (loss):
Net earnings (loss)	196	(254)	(346)	(585)
Electrical Products [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	1,648	3,987	2,930	6,103
Net earnings (loss):
Intersegment sales	1,648	3,987	2,930	6,103
Electrical Products [Member]
Earnings (loss) before income tax expense (benefit):
Earnings (loss) before income tax expense (benefit)	207	1,374	199	1,739
Net earnings (loss):
Net earnings (loss)	140	919	134	1,138
Intersegment Sales [Member] | Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	(14)		(17)	(10)
Net earnings (loss):
Intersegment sales	(14)		(17)	(10)
Corporate Segment [Member]
Earnings (loss) before income tax expense (benefit):
Earnings (loss) before income tax expense (benefit)	(88)	(55)	(182)	(256)
Net earnings (loss):
Net earnings (loss)	(59)	(37)	(133)	(158)
UNITED STATES
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	3,504	3,733	6,718	7,929
Net earnings (loss):
Intersegment sales	3,504	3,733	6,718	7,929
Foreign [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	7,714	9,843	13,473	16,378
Net earnings (loss):
Intersegment sales	7,714	9,843	13,473	16,378
Net Revenues from Unaffiliated Customers [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	11,218	13,576	20,191	24,307
Net earnings (loss):
Intersegment sales	11,218	13,576	20,191	24,307
Intersegment Sales [Member]
Segment Reporting Information [Line Items]
Net revenues from unaffiliated customers	14		17	10
Net earnings (loss):
Intersegment sales	$ 14		$ 17	$ 10