Note 13 - Income Taxes (Details Textual) - USD ($)	6 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ (4,551,000)	$ (45,458,000)	$ (29,005,000)
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(457,000)	(212,000)	(763,000)
Income Tax Expense (Benefit), Total	$ (2,238,000)	$ (4,730,000)	(673,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%	21.00%
Effective Income Tax Rate Reconciliation, Increase (Decrease) in Federal Statutory Income Tax Rate, Percent	(14.00%)
Deferred Tax Assets, Increase (Decrease) From Remeasurement Due to Change in Enacted Rate	$ (13,658,000)
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability	0
Deferred Income Tax Expense (Benefit), Total	(2,238,000)	$ (4,730,000)	(673,000)
Deferred Income Tax (Benefit) Due to Prior Years State Rate Changes			(559,000)	$ (157,000)	$ (402,000)
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ (14,296,000)	(2,266,000)	$ 2,209,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total		125,578,000
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount		1,604,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total		37,520,000
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount		1,475,000
Foreign Tax Authority [Member]
Operating Loss Carryforwards, Total		$ 2,430,000