Note 15 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Thermal Products [Member]
Net revenues from unaffiliated customers	$ 24,084	$ 23,446
Depreciation/amorization	581	720
Operating Income (Loss)	4,517	4,740
Earnings (loss) before income tax expense (benefit)	4,479	4,699
Income tax expense (benefit)	1,252	1,407
Net earnings (loss)	3,227	3,292
Capital expenditures	389	595
Mechanical Products [Member]
Net revenues from unaffiliated customers	7,539	11,245
Depreciation/amorization	79	87
Operating Income (Loss)	(1,902)	(18)
Earnings (loss) before income tax expense (benefit)	(1,874)	(5)
Income tax expense (benefit)	(524)	(2)
Net earnings (loss)	(1,350)	(3)
Capital expenditures	101	96
Electrical Products [Member]
Net revenues from unaffiliated customers	7,266	7,105
Depreciation/amorization	94	72
Operating Income (Loss)	673	781
Earnings (loss) before income tax expense (benefit)	704	802
Income tax expense (benefit)	197	240
Net earnings (loss)	507	562
Capital expenditures	109	140
Corporate Segment [Member]
Operating Income (Loss)	(726)	(587)
Earnings (loss) before income tax expense (benefit)	(726)	(587)
Income tax expense (benefit)	(203)	(175)
Net earnings (loss)	(523)	(412)
Net revenues from unaffiliated customers	38,889	41,796
Depreciation/amorization	754	879
Operating Income (Loss)	2,562	4,916
Earnings (loss) before income tax expense (benefit)	2,583	4,909
Income tax expense (benefit)	722	1,470
Net earnings (loss)	1,861	3,439
Capital expenditures	$ 599	$ 831