Pensions and Other Postretirement Benefits - Components of net periodic benefits cost and other amounts recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Net Periodic Benefit Cost
Interest cost	$ 60	$ 73
Expected return on plan assets	(5)	(9)
Recognized actuarial loss	64	65
Net periodic benefit cost	$ 119	$ 129