Note 3 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance				$ 9,617,024				$ 7,608,000	$ 9,617,024	$ 7,608,000	$ 7,996,000
Provision charged to expense	$ 0	$ 100,000	$ 300,000	400,000	$ 1,400,000	$ 950,000	$ 750,000	500,000	800,000	3,600,000	200,000
Losses charged off									(378,000)	(1,710,000)	(1,055,000)
Recoveries									550,000	119,000	467,000
Balance	10,588,562				9,617,024				10,588,562	9,617,024	7,608,000
Ending balance: individually evaluated for impairment	851,000				420,000				851,000	420,000	1,094,000
Ending balance: collectively evaluated for impairment	9,738,000				9,196,000				9,738,000	9,196,000	6,514,000
Ending balance: loans acquired with deteriorated credit quality	0				1,000				0	1,000	0
Ending balance: individually evaluated for impairment	7,783,000				16,472,000				7,783,000	16,472,000	9,133,000
Ending balance: collectively evaluated for impairment	812,578,000				734,394,000				812,578,000	734,394,000	716,946,000
Ending balance: loans acquired with deteriorated credit quality	2,225,000				2,542,000				2,225,000	2,542,000	2,835,000
Real Estate, Construction [Member]
Balance				1,132,000				1,749,000	1,132,000	1,749,000	2,306,000
Provision charged to expense									1,242,000	121,000	(809,000)
Losses charged off									(121,000)	(738,000)	0
Recoveries									285,000	0	252,000
Balance	2,538,000				1,132,000				2,538,000	1,132,000	1,749,000
Ending balance: individually evaluated for impairment	656,000				114,000				656,000	114,000	553,000
Ending balance: collectively evaluated for impairment	1,882,000				1,018,000				1,882,000	1,018,000	1,196,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	2,891,000				6,239,000				2,891,000	6,239,000	4,742,000
Ending balance: collectively evaluated for impairment	121,958,000				64,608,000				121,958,000	64,608,000	72,567,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Commercial Real Estate Portfolio Segment [Member]
Balance				3,624,000				2,267,000	3,624,000	2,267,000	2,093,000
Provision charged to expense									781,000	1,350,000	265,000
Losses charged off									(1,000)	0	(122,000)
Recoveries									3,000	7,000	31,000
Balance	4,407,000				3,624,000				4,407,000	3,624,000	2,267,000
Ending balance: individually evaluated for impairment	85,000				117,000				85,000	117,000	24,000
Ending balance: collectively evaluated for impairment	4,322,000				3,507,000				4,322,000	3,507,000	2,243,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	1,334,000				1,810,000				1,334,000	1,810,000	650,000
Ending balance: collectively evaluated for impairment	377,649,000				301,453,000				377,649,000	301,453,000	297,318,000
Ending balance: loans acquired with deteriorated credit quality	2,136,000				2,410,000				2,136,000	2,410,000	2,651,000
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Balance				1,445,000				1,001,000	1,445,000	1,001,000	1,297,000
Provision charged to expense									(310,000)	440,000	(32,000)
Losses charged off									(27,000)	(2,000)	(272,000)
Recoveries									4,000	6,000	8,000
Balance	1,112,000				1,445,000				1,112,000	1,445,000	1,001,000
Ending balance: individually evaluated for impairment	49,000				112,000				49,000	112,000	197,000
Ending balance: collectively evaluated for impairment	1,063,000				1,333,000				1,063,000	1,333,000	804,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	1,452,000				3,110,000				1,452,000	3,110,000	2,613,000
Ending balance: collectively evaluated for impairment	101,339,000				112,689,000				101,339,000	112,689,000	116,211,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Balance				1,058,000				746,000	1,058,000	746,000	641,000
Provision charged to expense									(308,000)	312,000	105,000
Losses charged off									0	0	0
Recoveries									0	0	0
Balance	750,000				1,058,000				750,000	1,058,000	746,000
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	750,000				1,058,000				750,000	1,058,000	746,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	76,565,000				90,029,000				76,565,000	90,029,000	87,448,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Commercial Portfolio Segment [Member]
Balance				1,129,000				1,129,000	1,129,000	1,129,000	1,160,000
Provision charged to expense									(116,000)	669,000	225,000
Losses charged off									(36,000)	(709,000)	(381,000)
Recoveries									200,000	40,000	125,000
Balance	1,177,000				1,129,000				1,177,000	1,129,000	1,129,000
Ending balance: individually evaluated for impairment	46,000				62,000				46,000	62,000	299,000
Ending balance: collectively evaluated for impairment	1,131,000				1,066,000				1,131,000	1,066,000	830,000
Ending balance: loans acquired with deteriorated credit quality	0				1,000				0	1,000	0
Ending balance: individually evaluated for impairment	1,935,000				5,111,000				1,935,000	5,111,000	908,000
Ending balance: collectively evaluated for impairment	113,770,000				139,083,000				113,770,000	139,083,000	112,956,000
Ending balance: loans acquired with deteriorated credit quality	89,000				132,000				89,000	132,000	184,000
Consumer Portfolio Segment [Member]
Balance				571,000				443,000	571,000	443,000	373,000
Provision charged to expense									(103,000)	323,000	299,000
Losses charged off									(193,000)	(261,000)	(280,000)
Recoveries									58,000	66,000	51,000
Balance	333,000				571,000				333,000	571,000	443,000
Ending balance: individually evaluated for impairment	15,000				15,000				15,000	15,000	21,000
Ending balance: collectively evaluated for impairment	318,000				556,000				318,000	556,000	422,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	171,000				202,000				171,000	202,000	220,000
Ending balance: collectively evaluated for impairment	21,297,000				26,532,000				21,297,000	26,532,000	30,446,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Unallocated Financing Receivables [Member]
Balance				$ 658,000				$ 273,000	658,000	273,000	126,000
Provision charged to expense									(386,000)	385,000	147,000
Losses charged off									0	0	0
Recoveries									0	0	0
Balance	272,000				658,000				272,000	658,000	273,000
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	272,000				658,000				272,000	658,000	273,000
Ending balance: loans acquired with deteriorated credit quality	0				0				0	0	0
Ending balance: individually evaluated for impairment	0				0				0	0	0
Ending balance: collectively evaluated for impairment	0				0				0	0	0
Ending balance: loans acquired with deteriorated credit quality	$ 0				$ 0				$ 0	$ 0	$ 0