Note 7 - Pension and Post-retirement Benefits - Net Periodic Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Pension Plan [Member]
Service cost		$ 791
Interest cost	1,511	1,552
Expected return on plan assets	(1,285)	(1,306)
Amortization of net loss	6	28
	232	1,065
Other Postretirement Benefits Plan [Member]
Service cost	21	23
Interest cost	67	68
Amortization of net loss	25	30
	(21)	(47)
Amortization of prior service credit	$ (134)	$ (168)