Employee Benefits - Components of Net Pension Expense for All Plans (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 54	$ 65
Weighted-average assumptions:
Discount rate	3.50%	4.50%	4.50%
Expected return on plan assets	4.00%	4.00%	4.00%
Rate of compensation increase	0.00%	0.00%	0.00%
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0
Interest cost	54	65	60
Expected return on assets	(34)	(35)	(34)
Amortization of prior service cost	129	113	100
Settlement cost	0	38	0
Net pension expense	$ 149	$ 181	$ 126