Note 2 - Business Segment Information - Revenue by Geographic Region (Details) - USD ($) $ in Thousands		3 Months Ended												12 Months Ended
		Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2017		Jun. 30, 2016		Jun. 30, 2015		Jun. 30, 2014	Jun. 30, 2013
Inter-segment Revenues		$ 83,419	$ 78,156	$ 85,658	$ 84,159	$ 80,844	$ 70,740	$ 84,687	$ 85,925	$ 76,073	$ 68,603	$ 84,715	$ 78,466	$ 331,392	[1]	$ 322,196	[1]	$ 307,857	[1]	$ 299,463	$ 280,790
UNITED STATES
Inter-segment Revenues	[1]													331,392		322,196		307,816
CANADA
Inter-segment Revenues	[1]																	$ 41

[1] Net sales are attributed to geographic areas based upon the location of the operation making the sale.