Pensions and Other Postretirement Benefits - Obligations and funded status (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Change in benefit obligation:
Benefit obligation at beginning of year	$ 4,702	$ 4,581
Interest cost	30	60
Actuarial (gain) loss	79	(432)
Foreign currency exchange rate change	(60)	(123)
Benefits paid	(241)	(248)
Benefit obligation at end of year	4,352	4,702
Change in plan assets:
Fair value of plan assets at beginning of year	560	809
Actual return on plan assets	6	1
Employer contributions	21	13
Benefits paid	(235)	(242)
Foreign currency exchange rate change	(10)	(21)
Fair value of plan assets at end of year	342	560
Funded status at end of year	$ (4,010)	$ (4,142)