Note 15 - Income Taxes - Summary of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Federal	$ 50,870	$ 47,547	$ 41,737
State	2,137	1,798	1,374
Total current	53,007	49,345	43,111
Federal	5,175	(2,755)	37,398
State	8,495	6,484	7,388
Total deferred	13,670	3,729	44,786
Provision for income taxes	$ 66,677	$ 53,074	$ 87,897