Note 7 - Goodwill and Other Intangible Assets (Details Textual)		3 Months Ended			6 Months Ended	9 Months Ended
	Mar. 01, 2018 USD ($)	Mar. 31, 2018 USD ($)	Sep. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Mar. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Number of Reporting Units						3
Goodwill, Impairment Loss				$ 479,000		$ 28,000,000	$ 479,000
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	$ 0
Intangible Assets, Indefinite-lived, Amount of Fair Value in Excess of Carrying Amount	$ 20,600,000
Intangible Assets, Indefinite-lived, Percentage of Fair Value in Excess of Carrying Amount	604.00%
Lighting Segment [Member]
Number of Reporting Units						2
Goodwill, Impairment Loss			$ 28,000,000		$ 28,000,000
Good will Impairment Testing Value Above Carrying Value	$ 21,400,000
Good will Impairment Testing Percent Value Above Carrying Value	15.00%
Graphics Segment [Member]
Number of Reporting Units					1
Goodwill, Impairment Loss
Good will Impairment Testing Value Above Carrying Value	$ 3,300,000
Good will Impairment Testing Percent Value Above Carrying Value	319.00%
Second Lighting Segment [Member]
Good will Impairment Testing Value Above Carrying Value	$ 16,100,000
Good will Impairment Testing Percent Value Above Carrying Value	69.00%