Schedule of Net Periodic Pension Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service cost	$ 874	$ 658	$ 2,642	$ 1,978
Interest cost	39	107	117	321
Expected return on plan assets	(176)	(269)	(532)	(810)
Net amortization	(189)	(22)	208	41
Net periodic pension costs	$ 548	$ 474	$ 2,435	$ 1,530