Accrued Expenses (Schedule of Components of Accrued Expenses) (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Jun. 30, 2014
Payables And Accruals [Abstract]
Accrued compensation	$ 6,942	$ 7,940
Accrued environmental remediation costs-current portion	8,084	1,828
Reserve for price concessions	$ 35,965	24,884
Accrued income taxes payable		6,403
Other accrued expenses	$ 8,850	20,409
Accrued expenses	$ 59,841	$ 61,464