Income Taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016
Deferred tax assets:
Net operating loss carryforwards	$ 20,439	$ 15,704
Alternative minimum tax credit carryforwards	857	857
Accrued expenses and other timing	1,344	1,473
Total gross deferred tax assets	22,640	18,034
Less — valuation allowance	(22,195)	(17,939)
Net deferred tax assets	445	95
Deferred tax liabilities:
Property and equipment, principally due to differences in depreciation	(445)	(95)
Total gross deferred tax liabilities	(445)	(95)
Net deferred tax assets (liabilities)	$ 0	$ 0