Note 3 - Revenue from Contracts with Customers - Revenue from Contracts with Customers (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Mar. 31, 2019		Mar. 31, 2018		Mar. 31, 2019		Mar. 31, 2018
Net sales	$ 58,498	[1]	$ 54,834	[2]	$ 166,931	[3]	$ 158,776	[4]
North American Segment [Member]
Net sales	36,069	[1]	34,119	[2]	100,897	[3]	94,937	[4]
International Segment [Member]
Net sales	22,429		20,715		66,034		63,839
UNITED STATES | North American Segment [Member]
Net sales	33,915		31,793		94,275		88,151
Canada and Mexico [Member] | North American Segment [Member]
Net sales	2,154		2,326		6,622		6,786
BRAZIL | International Segment [Member]
Net sales	13,107		11,310		37,993		35,755
UNITED KINGDOM | International Segment [Member]
Net sales	6,559		6,175		18,232		18,502
CHINA | International Segment [Member]
Net sales	1,609		1,949		5,370		5,338
Australia and New Zealand [Member] | International Segment [Member]
Net sales	$ 1,154		$ 1,281		$ 4,439		$ 4,244

[1] Excludes $1,555 of North American segment intercompany sales to the International segment, and $3,922 of International segment intercompany sales to the North American segment.

[2] Excludes $1,527 of North American segment intercompany sales to the International segment, and $3,602 of International segment intercompany sales to the North American segment.

[3] Excludes $3,736 of North American segment intercompany sales to the International segment, and $10,985 of International segment intercompany sales to the North American segment.

[4] Excludes $4,804 of North American segment intercompany sales to the International segment, and $10,290 of International segment intercompany sales to the North American segment.