Note 16 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2017	[1],[2]	Sep. 30, 2017	[3]	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Net revenues	$ 19,381		$ 17,352		$ 15,888	$ 14,180	$ 10,272	$ 10,823	$ 10,485	$ 8,647	$ 66,801	$ 40,227
Depreciation/amortization											1,779	599
Operating income (loss)											3,611	4,146
Earnings (loss) before income tax expense (benefit)	(4,511)		2,841		2,336	3,172	1,613	1,721	749	124	3,838	4,207
Income tax expense (benefit)	55		823		891	1,094	612	631	263	43	2,863	1,549
Net earnings (loss)	$ (4,566)		$ 2,018		$ 1,445	$ 2,078	$ 1,001	$ 1,090	$ 486	$ 81	975	2,658
Capital expenditures											745	339
Corporate, Non-Segment [Member]
Operating income (loss)											(2,397)	(1,053)
Earnings (loss) before income tax expense (benefit)											(2,345)	(1,007)
Income tax expense (benefit)											(621)	(371)
Net earnings (loss)											(1,724)	(636)
Thermal Products [Member] | Operating Segments [Member]
Net revenues											42,233	24,033
Depreciation/amortization											1,628	440
Operating income (loss)											(822)	4,210
Earnings (loss) before income tax expense (benefit)											(686)	4,193
Income tax expense (benefit)											1,665	1,544
Net earnings (loss)											(2,351)	2,649
Capital expenditures											659	262
EMS [Member] | Operating Segments [Member]
Net revenues											24,568	16,194
Depreciation/amortization											151	159
Operating income (loss)											6,830	989
Earnings (loss) before income tax expense (benefit)											6,869	1,021
Income tax expense (benefit)											1,819	376
Net earnings (loss)											5,050	645
Capital expenditures											$ 86	$ 77

[1] 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.

[2] The quarter ended December 31, 2017 includes adjustments related to tax legislation enacted in December 2017, as discussed in Note 2 and 11.

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