Note 13 - Income Taxes - Income Tax Expense (Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current provision -
Federal	$ 31,819	$ 22,443	$ 15,236
State	6,291	4,030	2,300
Total current	38,110	26,473	17,536
Deferred provision -
Federal	6,082	(64,821)	8,260
State	(85)	2,618	71
Total deferred	5,997	(62,203)	8,331
Provision (benefit) for income taxes	$ 44,107	$ (35,730)	$ 25,867