Note 6 - Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019
Amortized intangible assets, gross	$ 54,625	$ 54,625
Accumulated amortization	28,087	25,400
Amortized intangible assets, net	26,538	29,225
Indefinite-lived intangible assets, gross	3,422	3,422
Total other intangible assets, gross	58,047	58,047
Total other intangible assets, net	29,960	32,647
Trademarks and Trade Names [Member]
Indefinite-lived intangible assets, gross	3,422	3,422
Customer Relationships [Member]
Amortized intangible assets, gross	35,563	35,563
Accumulated amortization	14,129	12,070
Amortized intangible assets, net	21,434	23,493
Patents [Member]
Amortized intangible assets, gross	338	338
Accumulated amortization	277	247
Amortized intangible assets, net	61	91
Technology-Based Intangible Assets [Member]
Amortized intangible assets, gross	16,066
Accumulated amortization	12,852
Amortized intangible assets, net	3,214
LED Technology Firmware Software [Member]
Amortized intangible assets, gross		16,066
Accumulated amortization		12,364
Amortized intangible assets, net		3,702
Trade Names [Member]
Amortized intangible assets, gross	2,658	2,658
Accumulated amortization	829	719
Amortized intangible assets, net	$ 1,829	$ 1,939