Supplemental Financial Information - Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Accumulated Other Comprehensive Income (Loss)
Balance	$ 46,533
Balance	48,632	$ 46,533
Foreign Currency Items
Accumulated Other Comprehensive Income (Loss)
Balance	1,154	1,121
Other comprehensive income (loss)	83	33
Balance	1,237	1,154
Unrealized Gains and (Losses) on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss)
Balance	(89)	(15)
Other comprehensive income (loss)	89	(74)
Balance		(89)
Change in Defined Pension Benefit Obligation
Accumulated Other Comprehensive Income (Loss)
Balance	(1,117)	(2,066)
Other comprehensive income (loss)	973	949
Balance	(144)	(1,117)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance	(52)	(960)
Other comprehensive income (loss)	1,145	908
Balance	$ 1,093	$ (52)