Note 15 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	[1]	Sep. 30, 2018	[2]	Jun. 30, 2018	[3],[4]	Mar. 31, 2018	[5]	Dec. 31, 2019	Dec. 31, 2018
Net revenues	$ 13,614	$ 14,632	$ 14,352	$ 18,062	$ 18,435		$ 20,160		$ 21,097		$ 18,871		$ 60,660	$ 78,563
Depreciation/amortization													1,942	1,871
Operating income (loss)													2,549	5,180
Earnings (loss) before income tax expense (benefit)	648	794	(300)	1,462	(497)		162		4,396		982		2,604	5,043
Income tax expense (benefit)	(76)	147	(113)	324	295		728		382		601		282	2,006
Net earnings	$ 724	$ 647	$ (187)	$ 1,138	$ (792)		$ (566)		$ 4,014		$ 381		2,322	3,037
Capital expenditures													620	2,212
Corporate, Non-Segment [Member]
Depreciation/amortization													14	10
Operating income (loss)													(1,510)	(1,420)
Earnings (loss) before income tax expense (benefit)													(1,533)	(1,397)
Income tax expense (benefit)													(169)	(235)
Net earnings													(1,364)	(1,162)
Capital expenditures													73	13
Thermal Testing Products [Member] | Operating Segments [Member]
Net revenues													43,823	55,994
Depreciation/amortization													1,810	1,739
Operating income (loss)													2,334	1,218
Earnings (loss) before income tax expense (benefit)													2,370	1,024
Income tax expense (benefit)													257	1,331
Net earnings													2,113	(307)
Capital expenditures													501	2,149
EMS [Member] | Operating Segments [Member]
Net revenues													16,837	22,569
Depreciation/amortization													118	122
Operating income (loss)													1,725	5,382
Earnings (loss) before income tax expense (benefit)													1,767	5,416
Income tax expense (benefit)													194	910
Net earnings													1,573	4,506
Capital expenditures													$ 46	$ 50

[1] The quarter ended December 31, 2018 includes a $2,828 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[2] The quarter ended September 30, 2018 includes $3,057 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[3] The quarter ended June 30, 2018 includes a $710 reduction in the fair value of contingent consideration, which was not taxable.

[4] The quarter ended June 30, 2018 includes the reversal of certain adjustments originally recorded in the quarter ended December 31, 2017 which were related to tax legislation enacted in December 2017, as discussed in Note 10.

[5] The quarter ended March 31, 2018 includes a $1,726 increase in the fair value of contingent consideration, which was not deductible for tax purposes.