Note 8 - Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2021	Sep. 30, 2021
Goodwill	$ 99,661	$ 133,076
Accumulated impairment losses	(89,288)	(89,288)
Goodwill	43,788	43,788
Goodwill acquired	33,415
Lighting Segment [Member]
Goodwill	70,971	70,971
Accumulated impairment losses	(61,763)	(61,763)
Goodwill	9,208	9,208
Goodwill acquired	0
Display Solutions Segment [Member]
Goodwill	28,690	62,105
Accumulated impairment losses	(27,525)	(27,525)
Goodwill	34,580	$ 34,580
Goodwill acquired	$ 33,415