Note 21 - Parent Company Only Financial Statements - Condensed Statements of Cash Flows (Details) - USD ($) $ in Thousands				1 Months Ended	3 Months Ended								12 Months Ended
	Nov. 30, 2020	Sep. 14, 2020	Feb. 12, 2019	Nov. 30, 2020	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income					$ 18,271	$ 17,344	$ 13,739	$ 11,228	$ 15,891	$ 15,095	$ 13,504	$ 12,918	$ 60,582	$ 57,408	$ 43,120
Deferred income taxes													(14,530)	6,364	6,292
Accretion of acquisition fair value adjustments, net													(3,271)	(4,344)	(5,527)
Depreciation													5,333	5,225	4,451
Stock-based compensation expense													2,150	2,469	1,443
Loss on sale of subsidiary													(158)	12,286
Securities gains, net													(2,484)	30
Goodwill impairment	$ 0			$ 0									500	3,000
Loss on liability extinguishment, net											$ 50		3,907	436
Net increase in interest-bearing deposits at financial institutions													61,295	(69,984)	(14,508)
Purchases													(356,127)	(71,963)	(84,045)
Calls, maturities and redemptions													53,007	25,193	23,931
Sales													38,562	30,055	1,938
Net cash received in dissolution of subsidiary													(154)	42,587
Net cash paid for acquisition															(5,183)
Purchase of premises and equipment													(4,268)	(12,429)	(11,457)
Net cash provided by (used in) investing activities													(704,482)	(308,664)	(333,648)
Proceeds from other borrowings															9,000
Paydown of revolving line of credit														9,000
Prepayments														(46,313)
Calls, maturities and scheduled principal payments														(11,937)	(12,550)
Proceeds from subordinated notes		$ 50,000	$ 63,400										50,000	63,393
Proceeds from issuance of common stock, net													1,360	1,926	1,279
Repurchase and cancellation of shares													(3,779)
Net cash provided by (used in) financing activities													577,380	222,901	279,178
Net increase (decrease) in cash and due from banks													(14,925)	(9,269)	9,801
Parent Company [Member] | Reportable Legal Entities [Member]
Net income													60,582	57,408	43,120
Deferred income taxes													6,909	2,498	1,292
Accretion of acquisition fair value adjustments, net													378	305	183
Depreciation													454	327	249
Stock-based compensation expense													2,150	2,469	1,443
Loss on sale of subsidiary													(158)
Goodwill impairment													500	3,000
Decrease (increase) in other assets													1,663	(2,472)	940
Increase (decrease) in other liabilities													(14,966)	7,814	(7,226)
Net cash provided by (used in) operating activities													(21,495)	39,644	19,791
Net increase in interest-bearing deposits at financial institutions													(1,599)	(4,600)	(1,000)
Net cash received in dissolution of subsidiary													8,450
Net cash paid for acquisition															(5,183)
Net cash received in sale of subsidiary													195
Purchase of premises and equipment													(272)	(2,861)	(2,257)
Net cash provided by (used in) investing activities													6,774	(16,161)	(11,940)
Proceeds from other borrowings															9,000
Paydown of revolving line of credit														(9,000)
Prepayments														(21,313)
Calls, maturities and scheduled principal payments														(1,799)	(12,550)
Proceeds from subordinated notes													50,000	63,393
Payment of cash dividends on common and preferred stock													(3,779)	(3,767)	(3,300)
Proceeds from issuance of common stock, net													1,360	1,926	1,279
Repurchase and cancellation of shares													(3,779)
Net cash provided by (used in) financing activities													43,802	29,440	(5,571)
Net increase (decrease) in cash and due from banks													29,081	52,923	2,280
Cash and due from banks, beginning								$ 59,529				$ 6,606	59,529	6,606	4,326
Cash and due from banks, ending					$ 88,610				$ 59,529				88,610	59,529	6,606
Parent Company [Member] | Reportable Legal Entities [Member] | Bank Subsidiaries [Member]
Earnings of bank subsidiaries													(79,624)	(69,966)	(55,209)
Parent Company [Member] | Reportable Legal Entities [Member] | Non-bank Subsidiaries [Member]
Earnings of bank subsidiaries													261	(6,797)	436
Distributions from bank subsidiaries													$ 40	45,058	63
Parent Company [Member] | Reportable Legal Entities [Member] | Bank Subsidiaries [Member]
Capital infusion to subsidiaries														(8,600)	(3,500)
Parent Company [Member] | Reportable Legal Entities [Member] | Bank Subsidiaries [Member] | Bank Subsidiaries [Member]
Distributions from bank subsidiaries															$ 34,500
Parent Company [Member] | Reportable Legal Entities [Member] | Non-bank Subsidiaries [Member]
Capital infusion to subsidiaries														$ (100)