Note 8 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Elimination of AMT Operating Loss Carryforwards		$ 91,300
Income Tax Expense (Benefit), Total	$ 4,999	$ (4,999)
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Operating Loss Carryforwards that Do Not Expire	$ 3,700
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total	71,700
State and Local Jurisdiction [Member]
Operating Loss Carryforwards, Total	$ 85,700