Note 9 - Pension and Post-retirement Benefits - Net Periodic Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Pension Plan [Member]
Service cost
Interest cost	1,349	1,506
Expected return on plan assets	(1,294)	(1,284)
Amortization of net loss	10	7
Total	65	229
Post Retirement Medical Plan [Member]
Service cost	18	18
Interest cost	60	66
Amortization of net loss	21	7
Total	(35)	(43)
Amortization of prior service credit	$ (134)	$ (134)