Note 2 - Business Segment Information (Details) - Summarized Financial Information by Reportable Business Segments - USD ($) $ in Thousands	3 Months Ended												12 Months Ended
	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2015		Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2012	Jun. 30, 2011
Net Sales:
Net sales	$ 76,073	$ 68,603	$ 84,715	$ 78,466	$ 73,858	$ 68,996	$ 76,123	$ 80,486	$ 68,837	$ 66,152	$ 71,082	$ 74,719	$ 307,857	[1]	$ 299,463	[1]	$ 280,790	[1]	$ 268,402	$ 293,501
Operating Income (Loss):
Operating Income (Loss)													7,533		2,318		630		$ 6,331	$ 16,304
Capital Expenditures:
Capital Expenditures													4,754		5,245		7,571
Depreciation and Amortization:
Depreciation and Amortization													6,331		6,226		7,197
Lighting Segment [Member]
Net Sales:
Net sales													219,920		222,604		200,335
Operating Income (Loss):
Operating Income (Loss)													14,775		10,524		11,255
Capital Expenditures:
Capital Expenditures													1,905		3,294		2,023
Depreciation and Amortization:
Depreciation and Amortization													2,965		2,779		4,369
Graphics Segment [Member]
Net Sales:
Net sales													64,895		50,970		53,122
Operating Income (Loss):
Operating Income (Loss)													1,156		(2,086)		(950)
Capital Expenditures:
Capital Expenditures													1,100		461		350
Depreciation and Amortization:
Depreciation and Amortization													979		950		902
Technology Segment [Member]
Net Sales:
Net sales													23,001		24,515		26,361
Operating Income (Loss):
Operating Income (Loss)													2,949		1,633		(2,079)
Capital Expenditures:
Capital Expenditures													1,146		726		1,586
Depreciation and Amortization:
Depreciation and Amortization													1,341		1,563		1,422
All Other Category [Member]
Net Sales:
Net sales													41		1,374		972
Operating Income (Loss):
Operating Income (Loss)													(183)		(854)		(1,754)
Capital Expenditures:
Capital Expenditures													4		20		115
Depreciation and Amortization:
Depreciation and Amortization													31		161		185
Corporate and Eliminations [Member]
Operating Income (Loss):
Operating Income (Loss)													(11,164)		(6,899)		(5,842)
Capital Expenditures:
Capital Expenditures													599		744		3,497
Depreciation and Amortization:
Depreciation and Amortization													$ 1,015		$ 773		$ 319

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