Income Taxes - Tax effects of significant temporary differences of deferred tax assets and liabilities (Details 3) - USD ($) $ in Thousands	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2013
Deferred tax assets:
Employee related accruals	$ 12,603	$ 9,778
Inventory	2,573	3,889
Environmental remediation	2,208	2,155
Net operating loss carry forwards-domestic	13,768	13,641
Net operating loss carry forwards-foreign	4,346	4,127
Other	7,566	5,418
Deferred tax assets, gross	43,064	39,008
Valuation allowance	(4,614)	(26,622)	$ (32,892)	$ (27,753)
Deferred tax assets, net of valuation allowance	38,450	12,386
Deferred tax liabilities:
Property, plant and equipment and intangible assets	(9,725)	(11,088)
Other	(1,956)	(461)
Deferred tax liabilities, net	(11,681)	(11,549)
Net deferred tax asset	$ 26,769	$ 837