Note 3 - Segment Reporting Information (Details) - Inter-segment Revenues - USD ($) $ in Thousands		3 Months Ended
		Sep. 30, 2015	Sep. 30, 2014
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	[1]	$ 85,925	$ 78,466
Lighting Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		59,075	55,721
Lighting Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		614	1,052
Graphics Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		21,753	16,024
Graphics Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		444	131
Technology Segment [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		5,097	6,680
Technology Segment [Member] | Intersegment Eliminations [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales		$ 9,384	7,272
All Other Category [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales			41
All Other Category [Member] | Intersegment Eliminations [Member]
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales			$ 308

[1] Net sales are attributed to geographic areas based upon the location of the operation making the sale.