Income Taxes - Components of the Temporary Differences (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Deferred Tax Assets: [Abstract]
Postretirement benefits	$ 19,800	$ 26,014	$ 27,568
Accrued liabilities	6,156	4,477	3,958
Net operating loss carryforward	40,275	44,607	44,736
Intangible assets	1,126	694	919
Other	7,253	8,945	5,945
Total deferred tax assets	74,610	84,737	83,126
Deferred tax liabilities: [Abstract]
Fixed assets	(1,902)	(2,641)	(4,117)
Other	(1,538)	(882)	(794)
Total deferred tax liabilities	(3,440)	(3,523)	(4,911)
Valuation allowance	(72,613)	(82,522)	(79,448)
Net deferred tax liability	$ (1,443)	$ (1,308)	$ (1,233)