Note 22 - Parent Company Financial Information - Condensed Statements of Cash Flows (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income	$ 43,526,000	$ 30,045,000	$ 20,906,000
Net amortization of securities	(1,846,000)	(1,186,000)	(1,100,000)
Net change in other assets	245,000	29,000	11,137,000
Net change in other liabilities	146,000	(2,387,000)	(1,354,000)
Net cash operating activities	51,095,000	23,676,000	32,680,000
Purchases of securities available for sale	(433,690,000)	(295,109,000)	(155,746,000)
Proceeds from sales of equity securities	0	0	445,000
Cash paid in bank acquisition	0	0	(27,000)
Cash acquired in bank acquisition	0	0	26,283,000
Net cash provided by (used in) investing activities	(164,227,000)	(265,148,000)	(4,570,000)
Common stock dividends paid	(11,827,000)	(11,842,000)	(10,965,000)
Repurchase of common stock	(8,810,000)	(4,981,000)	(3,146,000)
Proceeds from exercise of stock options	89,000	43,000	688,000
Net cash used in financing activities	249,630,000	536,260,000	(12,783,000)
Net increase (decrease) in cash and cash equivalents	136,498,000	294,788,000	15,327,000
Cash and Cash Equivalents at Beginning of Period	374,370,000	79,582,000	64,255,000
Cash and Cash Equivalents at End of Period	510,868,000	374,370,000	79,582,000
Parent Company [Member]
Net income	43,526,000	30,045,000	20,906,000
(Equity in earnings) distributions in excess of earnings of subsidiary	(29,616,000)	(6,802,000)	1,286,000
Net amortization of securities	10,000	0	0
Net change in other assets	27,000	84,000	(382,000)
Net change in other liabilities	102,000	85,000	(35,000)
Net cash operating activities	14,049,000	23,412,000	21,775,000
Purchases of securities available for sale	0	0	(2,220,000)
Proceeds from sales of equity securities	6,800,000	0	445,000
Cash paid in bank acquisition	0	0	(27,000)
Cash acquired in bank acquisition	0	0	981,000
Net cash provided by (used in) investing activities	6,800,000	0	(821,000)
Common stock dividends paid	(11,827,000)	(11,842,000)	(10,965,000)
Repurchase of common stock	(8,810,000)	(4,981,000)	(3,146,000)
Proceeds from exercise of stock options	89,000	43,000	688,000
Net change in subordinated debt	(7,500,000)	0	0
Net cash used in financing activities	(28,048,000)	(16,780,000)	(13,423,000)
Net increase (decrease) in cash and cash equivalents	(7,199,000)	6,632,000	7,531,000
Cash and Cash Equivalents at Beginning of Period	17,759,000	11,127,000	3,596,000
Cash and Cash Equivalents at End of Period	$ 10,560,000	$ 17,759,000	$ 11,127,000