Accumulated Other Comprehensive Income (Loss) (Details) $ in Thousands	12 Months Ended
	Jun. 30, 2019 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at June 30, 2018	$ (2,313)
Adoption of ASU No. 2016-01	(318)
Other comprehensive income before reclassifications	(3,948)
Net current period other comprehensive income (loss)	(4,266)
Balance at June 30, 2019	(6,579)
Unrealized Gain / (Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at June 30, 2018	(1,373)
Adoption of ASU No. 2016-01	(318)
Other comprehensive income before reclassifications	(3,677)
Net current period other comprehensive income (loss)	(3,995)
Balance at June 30, 2019	(5,368)
Pension and Postretirement Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at June 30, 2018	(1,372)
Other comprehensive income before reclassifications	(335)
Net current period other comprehensive income (loss)	(335)
Balance at June 30, 2019	(1,707)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance at June 30, 2018	432
Adoption of ASU No. 2016-01	0
Other comprehensive income before reclassifications	64
Net current period other comprehensive income (loss)	64
Balance at June 30, 2019	$ 496