Note 2 - Business Segment Information - Identifiable Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Identifiable assets	$ 256,680	$ 195,560	$ 180,690	$ 168,688	$ 169,179
Corporate and Eliminations [Member]
Identifiable assets	9,131	38,554
Lighting Segment [Member] | Operating Segments [Member]
Identifiable assets	186,111	95,168
Graphics Segment [Member] | Operating Segments [Member]
Identifiable assets	33,144	33,490
Technology Segment [Member] | Operating Segments [Member]
Identifiable assets	$ 28,294	$ 28,348