Note 13 - Income Taxes - Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income taxes at the federal statutory rate	$ 47,749	$ 23,255	$ 37,733
State income taxes, net of federal benefit	3,246	1,552	3,053
Tax effect of permanent differences	(4,097)	887	959
Revaluation of deferred taxes	(82,862)
Other, net	234	173	5
Provision (benefit) for income taxes	$ (35,730)	$ 25,867	$ 41,750