Note 3 - Segment Reporting Information - Summarized Financial Information by Reportable Business Segments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Net Sales:
Net sales	$ 92,305	$ 85,658	$ 179,771	$ 169,817
Operating Income (Loss):
Operating income (loss)	4,547	2,818	(20,267)	3,884
Capital Expenditures:
Capital expenditures	692	784	1,190	2,744
Depreciation and Amortization:
Depreciation and amortization	2,552	1,770	5,124	3,605
Corporate and Eliminations [Member]
Operating Income (Loss):
Operating income (loss)	(2,983)	(2,117)	(6,343)	(5,159)
Capital Expenditures:
Capital expenditures	36	120	91	618
Depreciation and Amortization:
Depreciation and amortization	283	279	575	562
Lighting Segment [Member]
Net Sales:
Net sales	69,174	65,076	137,602	130,341
Lighting Segment [Member] | Operating Segments [Member]
Operating Income (Loss):
Operating income (loss)	5,275	3,761	(17,655)	6,852
Capital Expenditures:
Capital expenditures	499	205	760	1,301
Depreciation and Amortization:
Depreciation and amortization	1,885	1,115	3,786	2,307
Graphics Segment [Member]
Net Sales:
Net sales	23,131	20,582	42,169	39,476
Graphics Segment [Member] | Operating Segments [Member]
Operating Income (Loss):
Operating income (loss)	2,255	1,174	3,731	2,191
Capital Expenditures:
Capital expenditures	157	459	339	825
Depreciation and Amortization:
Depreciation and amortization	$ 384	$ 376	$ 763	$ 736