Defined Benefit Pension Obligation - Components of Net Periodic Benefit Cost and Other Amounts Recognized in Other Comprehensive Loss (Details) - Defined benefit pension plan - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Net Periodic Benefit Costs:
Service cost	$ 1,887	$ 1,996	$ 1,903
Interest cost	97	49	76
Expected returns on assets	(156)	(132)	(102)
Amortization of prior service cost	(44)	(46)
Amortization of net loss	11	114	53
Net periodic benefit costs	1,795	1,981	1,930
Other Amounts Recognized in Other Comprehensive Loss:
Net (gain) loss arising during the year	(901)	(881)	1,093
Prior service cost	(105)	46	(491)
Amortization of prior service cost	44
Amortization of net gain	(11)	(114)	(53)
Total recognized in other comprehensive gain (loss)	(973)	(949)	549
Total recognized in net periodic benefit costs and other comprehensive loss	822	$ 1,032	$ 2,479
Amounts in accumulated other comprehensive loss that are expected to be recognized as components of net periodic benefit cost during fiscal year 2019
Net loss	631
Prior service credit	(505)
Accumulated other comprehensive loss	$ 126