Note 18 - Summary of Quarterly Results (Unaudited) - Quarterly Results (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016		Jun. 30, 2015	Jun. 30, 2014
Net sales	$ 83,409	$ 78,843	$ 92,305	$ 87,466	$ 83,419	$ 78,156	$ 85,658	$ 84,159	$ 80,844	$ 70,740	$ 84,687	$ 85,925	$ 342,023	$ 331,392	$ 322,196		$ 307,857	$ 299,463
Gross profit	20,306	19,918	25,307	23,703	21,236	18,399	21,407	20,835	19,847	16,549	23,926	23,349	89,234	81,877	83,671
Net income (loss)	$ (2,664)	$ 220	$ (1,468)	$ (15,629)	$ 696	$ (531)	$ 2,006	$ 829	$ 1,428	$ 522	$ 3,782	$ 3,750	$ (19,541)	$ 3,000	$ 9,482		$ 5,151	$ 930
Basic (in dollars per share)	$ (0.10)	$ (0.01)	$ (0.06)	$ (0.61)	$ 0.03	$ (0.02)	$ 0.08	$ 0.03	$ 0.06	$ 0.02	$ 0.15	$ 0.15	$ (0.76)	$ 0.12	$ 0.38		$ 0.21	$ 0.04
Diluted (in dollars per share)	(0.10)	(0.01)	(0.06)	(0.61)	0.03	(0.02)	0.08	0.03	0.06	0.02	0.15	0.15	$ (0.76)	$ 0.12	$ 0.37		$ 0.21	$ 0.04
Maximum [Member]
Share prices (in dollars per share)	8.11	8.88	7.49	9.27	10.21	10.68	11.23	11.64	13.45	12.22	12.80	10.48
Minimum [Member]
Share prices (in dollars per share)	$ 4.91	$ 6.70	$ 6.07	$ 4.99	$ 8.26	$ 8.31	$ 8.12	$ 9.41	$ 10.29	$ 9.85	$ 7.89	$ 8.33
Fiscal Year [Member]
Net sales													$ 342,023	$ 331,392	$ 322,196
Gross profit													89,234	81,877	83,671
Net income (loss)													$ (19,541)	$ 3,000	$ 9,482
Basic (in dollars per share)													$ (0.76)	$ 0.12	$ 0.38
Diluted (in dollars per share)													(0.76)	0.12	0.37	[1]
Fiscal Year [Member] | Maximum [Member]
Share prices (in dollars per share)													9.27	11.64	13.45
Fiscal Year [Member] | Minimum [Member]
Share prices (in dollars per share)													$ 4.91	$ 8.12	$ 7.89

[1] The total of the earnings per share for each of the four quarters does not equal the total earnings per share for the full year because the calculations are based on the average shares outstanding during each of the individual periods.