Defined Benefit Pension Obligation - Amounts Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Amounts recognized within the consolidated balance sheets:
Assets	$ 490,927	$ 438,181
Defined benefit pension plan
Amounts recognized within the consolidated balance sheets:
Long-term other liabilities	(4,468)	(3,349)
Net amount recognized	(4,468)	(3,349)
Amounts recognized in accumulated other comprehensive loss (before tax)
Net loss	(1,000)	(144)
Total recognized in other comprehensive income (loss)	(236)	(856)	$ 973
Accumulated other comprehensive loss	(1,236)	(1,000)
Accumulated benefit obligations in excess of fair value of plan assets:
Projected benefit obligation	18,426	17,577
Accumulated benefit obligation	16,175	15,506
Fair value of plan assets	$ 13,958	$ 14,228