Schedule of Net Periodic Pension Costs (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2016	Mar. 31, 2015
Defined Benefit Plan Net Periodic Benefit Cost [Abstract]
Service cost	$ 658	$ 680	$ 1,978	$ 2,033
Interest cost	107	181	321	541
Expected return on plan assets	(269)	(270)	(810)	(807)
Net amortization	(22)	28	41	(481)
Net periodic pension costs	$ 474	$ 619	$ 1,530	$ 1,286