Note 13 - Income Taxes (Details Textual) - USD ($)	6 Months Ended		12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2018	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Income (Loss) from Continuing Operations before Income Taxes, Domestic	$ (4,551,000)			$ (29,005,000)	$ (17,789,000)
Income (Loss) from Continuing Operations before Income Taxes, Foreign	(457,000)			(763,000)	(799,000)
Income Tax Expense (Benefit)	$ (2,238,000)			(673,000)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	35.00%
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)	(2,238,000)			(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)			$ 2,209,000	$ 3,484,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards	123,046,000
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	1,509,000
State and Local Jurisdiction [Member]
Operating Loss Carryforwards	44,467,000
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax Credit Carryforward, Amount	$ 1,466,000
Scenario, Forecast [Member]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent			21.00%