Note 2 - Business Segment Information - Identifiable Assets by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Identifiable Assets:
Identifiable assets	$ 229,517	$ 256,680	$ 195,560	$ 180,690	$ 168,688
Corporate and Eliminations [Member]
Identifiable Assets:
Identifiable assets	16,837	9,466
Lighting Segment [Member] | Operating Segments [Member]
Identifiable Assets:
Identifiable assets	172,799	214,070
Graphics Segment [Member] | Operating Segments [Member]
Identifiable Assets:
Identifiable assets	$ 39,881	$ 33,144