Note 2 - Business Segment Information - Intersegment Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Inter-segment Revenues	$ 305,558	$ 328,852
Lighting Segment [Member]
Inter-segment Revenues	206,199	235,114
Graphics Segment [Member]
Inter-segment Revenues	99,359	93,738
Intersegment Eliminations [Member] | Lighting Segment [Member]
Inter-segment Revenues	3,718	2,043
Intersegment Eliminations [Member] | Graphics Segment [Member]
Inter-segment Revenues	$ 552	$ 928