Accumulated Other Comprehensive Loss (Details) $ in Thousands	6 Months Ended
	Dec. 31, 2018 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance at June 30, 2018	$ (2,313)
Adoption of ASU No. 2016-01	(318)
Other comprehensive income (loss) before reclassifications	(2,582)
Amounts reclassified to accumulated other comprehensive income (loss)	0
Net current period other comprehensive income (loss)	(2,900)
Ending Balance at December 31, 2018	(5,213)
Unrealized Gain / (Loss) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance at June 30, 2018	(1,373)
Adoption of ASU No. 2016-01	(318)
Other comprehensive income (loss) before reclassifications	(2,690)
Amounts reclassified to accumulated other comprehensive income (loss)	0
Net current period other comprehensive income (loss)	(3,008)
Ending Balance at December 31, 2018	(4,381)
Pension and Postretirement Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance at June 30, 2018	(1,372)
Adoption of ASU No. 2016-01	0
Other comprehensive income (loss) before reclassifications	32
Amounts reclassified to accumulated other comprehensive income (loss)	28
Net current period other comprehensive income (loss)	60
Ending Balance at December 31, 2018	(1,312)
Currency Translation Adjustments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance at June 30, 2018	432
Adoption of ASU No. 2016-01	0
Other comprehensive income (loss) before reclassifications	76
Amounts reclassified to accumulated other comprehensive income (loss)	(28)
Net current period other comprehensive income (loss)	48
Ending Balance at December 31, 2018	$ 480