Note 7 - Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jun. 30, 2018
Balance as of June 30, 2018
Goodwill, net	$ 30,538	$ 30,538
Lighting Segment [Member]
Balance as of June 30, 2018
Goodwill	94,564	94,564
Accumulated impairment losses	(65,191)	(65,191)
Goodwill, net	29,373	29,373
Graphics Segment [Member]
Balance as of June 30, 2018
Goodwill	28,690	28,690
Accumulated impairment losses	(27,525)	(27,525)
Goodwill, net	1,165	1,165
Technology Segment [Member]
Balance as of June 30, 2018
Goodwill	123,254	123,254
Accumulated impairment losses	(92,716)	(92,716)
Goodwill, net	$ 30,538	$ 30,538