Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Oct. 12, 2016	Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ (10,000)
Deferred Tax Assets, Valuation Allowance, Total		74,150	$ 84,181
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax		393	$ 786
Proceeds From Deferred Tax Assets		400
Unrecognized Tax Benefits, Ending Balance		0
Domestic Tax Authority [Member]
Operating Loss Carryforwards, Total		846,600
Operating Loss Carryforwards, Available to Offset Future Taxable Income		215,600
Operating Loss Carryforwards, Increase (Decrease)	$ (630,700)
State and Local Jurisdiction [Member] | Louisiana Department of Revenue [Member]
Operating Loss Carryforwards, Increase (Decrease)		77,000
State and Local Jurisdiction [Member] | Mississippi Department of Revenue [Member]
Operating Loss Carryforwards, Increase (Decrease)		151,500
Current Year Activity [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		(5,500)
Deferred Tax Asset Which Carried a Full Valuation Allowance [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ (4,500)