Note 3 - Revenue From Contracts With Customers - Revenue From Contracts With Customers (Details) - USD ($)	3 Months Ended				6 Months Ended
	Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2019		Dec. 31, 2018
Net sales	$ 56,864,000	[1]	$ 56,532,000	[2]	$ 108,978,000	[3]	$ 108,433,000	[4]
North American Segment [Member]
Net sales	33,098,000	[1]	34,628,000	[2]	64,106,000	[3]	64,828,000	[4]
International Segment [Member]
Net sales	23,766,000		21,904,000		44,872,000		43,605,000
UNITED STATES | North American Segment [Member]
Net sales	31,085,000		32,413,000		59,708,000		60,360,000
Canada and Mexico [Member] | North American Segment [Member]
Net sales	2,013,000		2,215,000		4,398,000		4,468,000
BRAZIL | International Segment [Member]
Net sales	15,000,000		12,519,000		27,822,000		24,886,000
UNITED KINGDOM | International Segment [Member]
Net sales	5,372,000		5,657,000		10,603,000		11,673,000
CHINA | International Segment [Member]
Net sales	1,653,000		2,052,000		3,167,000		3,761,000
Australia and New Zealand [Member] | International Segment [Member]
Net sales	$ 1,741,000		$ 1,676,000		$ 3,280,000		$ 3,285,000

[1] Excludes $1,049 of North American segment intercompany sales to the International segment, and $3,855 of International segment intercompany sales to the North American segment.

[2] Excludes $1,047 of North American segment intercompany sales to the International segment, and $3,744 of International segment intercompany sales to the North American segment.

[3] Excludes $2,016 of North American segment intercompany sales to the International segment, and $8,097 of International segment intercompany sales to the North American segment.

[4] Excludes $2,180 of North American segment intercompany sales to the International segment, and $7,063 of International segment intercompany sales to the North American segment.