Note 8 - Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal, current	$ (1,174)		$ (7,780)
Federal, deferred	3,976	14,117	(28,055)
State, current	1,077	1,410	(1,737)
State, deferred	(415)	(20)	5,430
Income tax expense (benefit)	$ 3,464	$ 15,507	$ (32,142)