Note 17 - Quarterly Consolidated Financial Data - Quarterly Consolidated Financial Data (Details) - USD ($) $ / shares in Units, $ 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
Gross margin	9,745		8,796		8,421	7,728	5,405	5,577	5,329	4,067	34,690	20,378
Earnings (loss) before income tax expense	(4,511)		2,841		2,336	3,172	1,613	1,721	749	124	3,838	4,207
Income tax expense	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
Net earnings (loss)per common share - basic (in dollars per share)	$ (0.44)		$ 0.20		$ 0.14	$ 0.20	$ 0.10	$ 0.11	$ 0.05	$ 0.01	$ 0.09	$ 0.26
Weighted average common shares outstanding - basic (in shares)	10,308,243		10,288,325		10,277,155	10,264,565	10,273,702	10,295,447	10,295,836	10,390,002	10,284,572	10,313,747
Net earnings (loss) per common share - diluted (in dollars per share)	$ (0.44)		$ 0.19		$ 0.14	$ 0.20	$ 0.10	$ 0.11	$ 0.05	$ 0.01	$ 0.09	$ 0.26
Weighted average common shares outstanding - diluted (in shares)	10,308,243		10,351,009		10,334,894	10,295,337	10,297,439	10,318,715	10,310,692	10,404,244	10,339,313	10,332,920

[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.