Note 3 - Segment Reporting Information - Summarized Financial Information by Reportable Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Net Sales	$ 72,204	$ 71,010	$ 218,597	$ 242,088
Operating income (loss)	2,096	2,631	6,984	11,230
Capital expenditures	637	419	1,517	1,538
Depreciation and amortization	1,920	2,080	5,943	6,631
Segment Reconciling Items [Member]
Operating income (loss)	(2,931)	(2,486)	(8,731)	(8,575)
Capital expenditures	15	59	184	246
Depreciation and amortization	76	83	208	435
Lighting Segment [Member]
Net Sales	45,740	49,013	136,271	165,640
Lighting Segment [Member] | Operating Segments [Member]
Operating income (loss)	3,797	1,102	9,519	13,411
Capital expenditures	605	126	1,249	1,013
Depreciation and amortization	1,566	1,650	4,795	5,089
Graphics Segment [Member]
Net Sales	26,464	21,997	82,326	76,448
Graphics Segment [Member] | Operating Segments [Member]
Operating income (loss)	1,230	4,015	6,196	6,394
Capital expenditures	17	234	84	279
Depreciation and amortization	$ 278	$ 347	$ 940	$ 1,107