Note 17 - Financial Information by Segment and Geographic Area (Details Textual) $ in Thousands	3 Months Ended								12 Months Ended
	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2019 USD ($)		Jun. 30, 2018 USD ($)		Jun. 30, 2017 USD ($)
Number of Reportable Segments									2
Revenues, Total	$ 61,091	$ 58,498	$ 56,532	$ 51,901	$ 57,552	$ 54,834	$ 52,124	$ 51,818	$ 228,022	[1]	$ 216,328	[2]	$ 207,023	[3]
North American Segment [Member]
Revenues, Total									136,387	[1]	128,442	[2]	124,606	[3]
North American Segment [Member] | Intersegment Eliminations [Member]
Revenues, Total									(4,879)		(6,468)		(7,902)
International Segment [Member]
Revenues, Total									91,635	[1]	87,886	[2]	82,417	[3]
International Segment [Member] | Intersegment Eliminations [Member]
Revenues, Total									$ (16,187)		$ (14,239)		$ (11,677)

[1] Excludes $4,879 of North American segment intercompany sales to the International segment and $16,187 intercompany sales of the International segment to the North American segment.

[2] Excludes $6,468 of North American segment intercompany sales to the International segment and $14,239 intercompany sales of the International segment to the North American segment.

[3] Excludes $7,902 of North American segment intercompany sales to the International segment and $11,677 intercompany sales of the International segment to the North American segment.