Note 3 - Segment Reporting Information - Intersegment Revenues (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Inter-segment Revenues	$ 70,006	$ 88,701
Lighting Segment [Member]
Inter-segment Revenues	45,405	63,191
Graphics Segment [Member]
Inter-segment Revenues	24,601	25,510
Intersegment Eliminations [Member] | Lighting Segment [Member]
Inter-segment Revenues	4,080	811
Intersegment Eliminations [Member] | Graphics Segment [Member]
Inter-segment Revenues	$ 38	$ 24