Note 17 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended														12 Months Ended
	Dec. 31, 2018	[1]	Sep. 30, 2018	[2]	Jun. 30, 2018	[3],[4]	Mar. 31, 2018	[5]	Dec. 31, 2017	[6],[7]	Sep. 30, 2017	[8]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017
Net revenues	$ 18,435		$ 20,160		$ 21,097		$ 18,871		$ 19,381		$ 17,352		$ 15,888	$ 14,180	$ 78,563	$ 66,801
Depreciation/amortization															1,871	1,779
Operating income (loss)															5,180	3,611
Earnings (loss) before income tax expense (benefit)	(497)		162		4,396		982		(4,511)		2,841		2,336	3,172	5,043	3,838
Income tax expense (benefit)	295		728		382		601		55		823		891	1,094	2,006	2,863
Net earnings (loss)	$ (792)		$ (566)		$ 4,014		$ 381		$ (4,566)		$ 2,018		$ 1,445	$ 2,078	3,037	975
Capital expenditures															2,212	745
Corporate, Non-Segment [Member]
Operating income (loss)															(1,420)	(2,397)
Earnings (loss) before income tax expense (benefit)															(1,397)	(2,345)
Income tax expense (benefit)															(235)	(621)
Net earnings (loss)															(1,162)	(1,724)
Thermal Testing Products [Member] | Operating Segments [Member]
Net revenues															55,994	42,233
Depreciation/amortization															1,739	1,628
Operating income (loss)															1,218	(822)
Earnings (loss) before income tax expense (benefit)															1,024	(686)
Income tax expense (benefit)															1,331	1,665
Net earnings (loss)															(307)	(2,351)
Capital expenditures															2,149	659
EMS [Member] | Operating Segments [Member]
Net revenues															22,569	24,568
Depreciation/amortization															132	151
Operating income (loss)															5,382	6,830
Earnings (loss) before income tax expense (benefit)															5,416	6,869
Income tax expense (benefit)															910	1,819
Net earnings (loss)															4,506	5,050
Capital expenditures															$ 63	$ 86

[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 Notes 2 and 12.

[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.

[6] The quarter ended December 31, 2017 includes a $7,525 increase in the fair value of contingent consideration, which was not deductible for tax purposes.

[7] The quarter ended December 31, 2017 includes adjustments related to tax legislation enacted in December 2017, as discussed in Note 2 and 12.

[8] The quarter ended September 30, 2017 includes a $549 reduction in the fair value of contingent consideration, which was not taxable.