Note 2 - Inter-segment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2016		Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2013	Jun. 30, 2012
Intersegment Eliminations [Member] | Lighting Segment [Member]
Net Sales													$ 2,935		$ 2,752		$ 3,534
Intersegment Eliminations [Member] | Graphics Segment [Member]
Net Sales													1,760		559		1,088
Intersegment Eliminations [Member] | Technology Segment [Member]
Net Sales													35,733		29,412		34,238
Intersegment Eliminations [Member] | All Other Category [Member]
Net Sales															308		2,286
Lighting Segment [Member]
Net Sales													226,889		219,920		222,604
Graphics Segment [Member]
Net Sales													77,039		64,895		50,970
Technology Segment [Member]
Net Sales													18,268		23,001		24,515
All Other Category [Member]
Net Sales															41		1,374
Net Sales	$ 80,844	$ 70,740	$ 84,687	$ 85,925	$ 76,073	$ 68,603	$ 84,715	$ 78,466	$ 73,858	$ 68,996	$ 76,123	$ 80,486	$ 322,196	[1]	$ 307,857	[1]	$ 299,463	[1]	$ 280,790	$ 268,402

[1] Net sales are attributed to geographic areas based upon the location of the operation making the sale.