Note 20 - Parent Company Only Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash and due from banks	$ 37,490	$ 61,329
Interest-bearing deposits at financial institutions	75,292	86,596
Securities available for sale, at fair value	337,830	361,966
Loans/leases receivable held for investment	4,676,304	4,247,371
Premises and equipment, net	78,530	72,693
Other assets	93,412	83,548
Total assets	6,096,132	5,705,043	$ 4,909,050
Subordinated notes	113,850	118,691
Junior subordinated debentures	38,155	37,993
Other liabilities	100,410	105,729
Total liabilities	5,419,122	5,111,250
Common stock	15,613	15,806
Additional paid-in capital	273,768	275,807
Retained earnings	386,077	300,804
Total stockholders' equity	677,010	593,793	$ 535,351	$ 473,138
Total liabilities and stockholders' equity	6,096,132	5,705,043
Reportable Legal Entities [Member] | Parent Company [Member]
Cash and due from banks	41,531	88,610
Interest-bearing deposits at financial institutions	5,750	7,200
Premises and equipment, net	8,632	9,242
Other assets	7,716	16,268
Total assets	838,598	781,092
Subordinated notes	113,850	113,691
Junior subordinated debentures	38,155	37,993
Other liabilities	9,583	35,615
Total liabilities	161,588	187,299
Common stock	15,613	15,806
Additional paid-in capital	273,768	275,807
Retained earnings	386,077	300,804
Accumulated other comprehensive income	1,552	1,376
Total stockholders' equity	677,010	593,793
Total liabilities and stockholders' equity	838,598	781,092
Reportable Legal Entities [Member] | Parent Company [Member] | Bank Subsidiaries [Member]
Investment in bank subsidiaries	769,628	655,232
Reportable Legal Entities [Member] | Parent Company [Member] | Non-bank Subsidiaries [Member]
Investment in bank subsidiaries	$ 5,341	$ 4,540