Note 5 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Balance, beginning of period	$ 7,847,000	$ 7,103,000	$ 7,995,569	$ 7,107,000
Provision for loan losses	100,000	500,000	100,000	725,000
Losses charged off	(373,000)	(59,000)	(661,000)	(322,000)
Recoveries	97,000	29,000	236,000	63,000
Balance, end of period	7,670,666	7,573,000	7,670,666	7,573,000
Ending balance: individually evaluated for impairment	1,265,000		1,265,000		$ 1,612,000
Ending balance: collectively evaluated for impairment	6,403,000		6,403,000		6,384,000
Ending balance: loans acquired with deteriorated credit quality	3,000		3,000
Ending balance: individually evaluated for impairment	14,454,000		14,454,000		17,379,000
Ending balance: collectively evaluated for impairment	741,937,000		741,937,000		766,343,000
Ending balance: loans acquired with deteriorated credit quality	3,059,000		3,059,000		3,173,000
Real Estate, Construction [Member]
Balance, beginning of period	1,936,000	2,223,000	2,306,000	2,244,000
Provision for loan losses	212,000	248,000	(278,000)	208,000
Losses charged off
Recoveries	21,000	13,000	141,000	32,000
Balance, end of period	2,169,000	2,484,000	2,169,000	2,484,000
Ending balance: individually evaluated for impairment	551,000		551,000		552,000
Ending balance: collectively evaluated for impairment	1,618,000		1,618,000		1,754,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment	3,921,000		3,921,000		4,088,000
Ending balance: collectively evaluated for impairment	96,441,000		96,441,000		84,507,000
Ending balance: loans acquired with deteriorated credit quality
Commercial Real Estate Portfolio Segment [Member]
Balance, beginning of period	2,137,000	1,876,000
Provision for loan losses	31,000	(90,000)
Losses charged off
Recoveries	20,000	1,000
Balance, end of period	2,188,000	1,787,000	2,188,000	1,787,000
Ending balance: individually evaluated for impairment	173,000		173,000		106,000
Ending balance: collectively evaluated for impairment	2,015,000		2,015,000		1,987,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment	1,272,000		1,272,000		1,588,000
Ending balance: collectively evaluated for impairment	296,388,000		296,388,000		317,488,000
Ending balance: loans acquired with deteriorated credit quality	2,713,000		2,713,000		2,782,000
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Balance, beginning of period			2,093,000	1,789,000
Provision for loan losses			75,000	(3,000)
Losses charged off
Recoveries			20,000	1,000
Balance, end of period	2,188,000	1,787,000	2,188,000	1,787,000
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Balance, beginning of period	1,386,000	1,113,000	1,297,000	946,000
Provision for loan losses	(168,000)	123,000	(81,000)	290,000
Losses charged off	(271,000)		(271,000)
Recoveries	1,000	1,000	3,000	1,000
Balance, end of period	948,000	1,237,000	948,000	1,237,000
Ending balance: individually evaluated for impairment	167,000		167,000		573,000
Ending balance: collectively evaluated for impairment	781,000		781,000		724,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment	2,215,000		2,215,000		4,520,000
Ending balance: collectively evaluated for impairment	122,627,000		122,627,000		128,258,000
Ending balance: loans acquired with deteriorated credit quality
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Balance, beginning of period	694,000	487,000	641,000	464,000
Provision for loan losses	(21,000)	66,000	32,000	89,000
Losses charged off	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	673,000	553,000	673,000	553,000
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment	673,000		673,000		641,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment	5,930,000		5,930,000		5,952,000
Ending balance: collectively evaluated for impairment	82,526,000		82,526,000		84,663,000
Ending balance: loans acquired with deteriorated credit quality
Commercial Portfolio Segment [Member]
Balance, beginning of period	974,000	958,000	1,160,000	1,031,000
Provision for loan losses	262,000	122,000	301,000	142,000
Losses charged off	(41,000)		(275,000)	(96,000)
Recoveries	41,000	5,000	50,000	8,000
Balance, end of period	1,236,000	1,085,000	1,236,000	1,085,000
Ending balance: individually evaluated for impairment	345,000		345,000		363,000
Ending balance: collectively evaluated for impairment	891,000		891,000		797,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment	892,000		892,000		1,062,000
Ending balance: collectively evaluated for impairment	112,899,000		112,899,000		118,459,000
Ending balance: loans acquired with deteriorated credit quality	196,000		196,000		216,000
Consumer Portfolio Segment [Member]
Balance, beginning of period	368,000	291,000	373,000	454,000
Provision for loan losses	76,000	126,000	117,000	118,000
Losses charged off	(61,000)	(59,000)	(115,000)	(226,000)
Recoveries	14,000	9,000	22,000	21,000
Balance, end of period	397,000	367,000	397,000	367,000
Consumer and Other Loans [Member]
Ending balance: individually evaluated for impairment	29,000		29,000		18,000
Ending balance: collectively evaluated for impairment	365,000		365,000		355,000
Ending balance: loans acquired with deteriorated credit quality	3,000		3,000
Ending balance: individually evaluated for impairment	224,000		224,000		169,000
Ending balance: collectively evaluated for impairment	31,056,000		31,056,000		32,968,000
Ending balance: loans acquired with deteriorated credit quality	150,000		150,000		175,000
Unallocated Financing Receivables [Member]
Balance, beginning of period	352,000	155,000	126,000	179,000
Provision for loan losses	(292,000)	(95,000)	(66,000)	(119,000)
Losses charged off	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	60,000	$ 60,000	60,000	$ 60,000
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment	60,000		60,000		126,000
Ending balance: loans acquired with deteriorated credit quality
Ending balance: individually evaluated for impairment
Ending balance: collectively evaluated for impairment
Ending balance: loans acquired with deteriorated credit quality