Accrued Expenses (Schedule of Components of Accrued Expenses) (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015
Payables And Accruals [Abstract]
Accrued compensation	$ 6,880	$ 6,942
Accrued environmental remediation costs-current portion	9,180	8,084
Reserve for price concessions	31,342	35,965
Other accrued expenses	5,273	8,850
Accrued expenses	$ 52,675	$ 59,841