Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2018	Jun. 30, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 15,976	$ 20,439
Alternative minimum tax credit carryforwards	857	857
Accrued expenses and other timing	983	1,344
Total gross deferred tax assets	17,816	22,640
Less — valuation allowance	(17,518)	(22,195)
Net deferred tax assets	298	445
Deferred tax liabilities:
Property and equipment, principally due to differences in depreciation	(298)	(445)
Total gross deferred tax liabilities	(298)	(445)
Net deferred tax assets (liabilities)	$ 0	$ 0