Note 3 - Loans and Allowance for Loan Losses - Activity in Allowance for Loan Losses and the Recorded Investments in Loans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Beginning balance	$ 37,967,000		$ 23,889,000		$ 22,380,000
Provision (benefit) for loan losses	(4,300,000)		14,050,000		1,750,000
Charge-offs	(1,044,000)		(838,000)		(883,000)
Recoveries	2,740,000		866,000		642,000
Ending balance	35,363,000		37,967,000		23,889,000
Ending balance: individually evaluated for impairment	546,000		551,000		1,623,000
Ending balance: collectively evaluated for impairment	34,817,000		37,416,000		22,266,000
Ending balance	3,413,349,000	[1]	2,828,211,000	[2]	2,856,667,000
Ending balance: individually evaluated for impairment	19,366,000	[1]	26,958,000	[2]	14,622,000
Ending balance: collectively evaluated for impairment	3,393,983,000	[1]	2,801,253,000	[2]	2,842,045,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Beginning balance	9,424,000		6,659,000		6,168,000
Provision (benefit) for loan losses	2,030,000		2,921,000		764,000
Charge-offs	(882,000)		(247,000)		(393,000)
Recoveries	210,000		91,000		120,000
Ending balance	10,782,000		9,424,000		6,659,000
Ending balance: individually evaluated for impairment	266,000		53,000		202,000
Ending balance: collectively evaluated for impairment	10,516,000		9,371,000		6,457,000
Ending balance	1,097,309,000	[1]	780,164,000	[2]	846,551,000
Ending balance: individually evaluated for impairment	5,010,000	[1]	6,585,000	[2]	8,587,000
Ending balance: collectively evaluated for impairment	1,092,299,000	[1]	773,579,000	[2]	837,964,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning balance	679,000		466,000		337,000
Provision (benefit) for loan losses	(618,000)		289,000		105,000
Charge-offs	(15,000)		(113,000)		(12,000)
Recoveries	374,000		37,000		36,000
Ending balance	420,000		679,000		466,000
Ending balance: individually evaluated for impairment	0		0		0
Ending balance: collectively evaluated for impairment	420,000		679,000		466,000
Ending balance	43,239,000		55,055,000		56,119,000
Ending balance: individually evaluated for impairment	0		0		85,000
Ending balance: collectively evaluated for impairment	43,239,000		55,055,000		56,034,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Beginning balance	8,246,000		6,291,000		5,866,000
Provision (benefit) for loan losses	(3,308,000)		1,881,000		331,000
Charge-offs	(12,000)		(235,000)		(48,000)
Recoveries	1,119,000		309,000		142,000
Ending balance	6,045,000		8,246,000		6,291,000
Ending balance: individually evaluated for impairment	84,000		77,000		982,000
Ending balance: collectively evaluated for impairment	5,961,000		8,169,000		5,309,000
Ending balance	565,758,000		529,953,000		579,003,000
Ending balance: individually evaluated for impairment	10,435,000		15,327,000		1,745,000
Ending balance: collectively evaluated for impairment	555,323,000		514,626,000		577,258,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning balance	13,611,000		6,761,000		6,408,000
Provision (benefit) for loan losses	(310,000)		6,837,000		342,000
Charge-offs	0		0		(2,000)
Recoveries	0		13,000		13,000
Ending balance	13,301,000		13,611,000		6,761,000
Ending balance: individually evaluated for impairment	0		8,000		0
Ending balance: collectively evaluated for impairment	13,301,000		13,603,000		6,761,000
Ending balance	1,027,415,000		917,436,000		835,346,000
Ending balance: individually evaluated for impairment	146,000		503,000		178,000
Ending balance: collectively evaluated for impairment	1,027,269,000		916,933,000		835,168,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning balance	1,819,000		893,000		840,000
Provision (benefit) for loan losses	(150,000)		907,000		36,000
Charge-offs	0		(18,000)		0
Recoveries	26,000		37,000		17,000
Ending balance	1,695,000		1,819,000		893,000
Ending balance: individually evaluated for impairment	4,000		0		0
Ending balance: collectively evaluated for impairment	1,691,000		1,819,000		893,000
Ending balance	176,593,000		146,095,000		124,525,000
Ending balance: individually evaluated for impairment	91,000		0		9,000
Ending balance: collectively evaluated for impairment	176,502,000		146,095,000		124,516,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Beginning balance	889,000		861,000		883,000
Provision (benefit) for loan losses	(301,000)		58,000		(19,000)
Charge-offs	(43,000)		(96,000)		(66,000)
Recoveries	81,000		66,000		63,000
Ending balance	626,000		889,000		861,000
Ending balance: individually evaluated for impairment	123,000		241,000		356,000
Ending balance: collectively evaluated for impairment	503,000		648,000		505,000
Ending balance	60,488,000		61,620,000		75,374,000
Ending balance: individually evaluated for impairment	1,247,000		1,270,000		1,694,000
Ending balance: collectively evaluated for impairment	59,241,000		60,350,000		73,680,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Beginning balance	3,240,000		1,888,000		1,834,000
Provision (benefit) for loan losses	(1,629,000)		1,168,000		165,000
Charge-offs	(92,000)		(129,000)		(362,000)
Recoveries	930,000		313,000		251,000
Ending balance	2,449,000		3,240,000		1,888,000
Ending balance: individually evaluated for impairment	69,000		172,000		83,000
Ending balance: collectively evaluated for impairment	2,380,000		3,068,000		1,805,000
Ending balance	442,547,000		337,888,000		339,749,000
Ending balance: individually evaluated for impairment	2,437,000		3,273,000		2,324,000
Ending balance: collectively evaluated for impairment	440,110,000		334,615,000		337,425,000
Unallocated Financing Receivables [Member]
Beginning balance	59,000		70,000		44,000
Provision (benefit) for loan losses	(14,000)		(11,000)		26,000
Charge-offs	0		0		0
Recoveries	0		0		0
Ending balance	45,000		59,000		70,000
Ending balance: individually evaluated for impairment	0		0		0
Ending balance: collectively evaluated for impairment	$ 45,000		$ 59,000		$ 70,000

[1] Excludes $40.1 million in loans originated under the Paycheck Protection Program.

[2] Excludes $365 million in loans originated under the Paycheck Protection Program.