Employee Benefit Plans - Other Changes in Plan Assets and Benefit Obligations Recognized in OCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total AOCI	$ 62,039	$ 61,493
Other Postretirement Benefits Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss subject to amortization	(8,005)	(8,775)
Transition obligation recognized in AOCI	(8,693)	(10,450)
Total AOCI	(16,698)	(19,225)
Unrecognized actuarial loss	70	2,377
Total recognized in OCI	2,527	10
Net periodic benefit cost (credit)	(1,154)	(798)	$ 629
Total recognized in net periodic benefit cost and OCI	$ 1,373	$ (788)