Employee Benefits - Components of Net Pension Expense for All Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 55	$ 54
Weighted-average assumptions:
Discount rate	3.80%	3.50%
Expected return on plan assets	4.00%	4.00%
Rate of compensation increase	0.00%	0.00%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0
Interest cost	55	54
Expected return on assets	(36)	(34)
Amortization of prior service cost	125	129
Settlement cost	15	0
Net pension expense	$ 159	$ 149