Note 5 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015
Beginning balance				$ 3,415				$ 4,846	$ 3,415	$ 4,846
Provision for loan losses	$ 220	$ 200	$ 150	75	$ 0	$ 0	$ 50	0	645	50
Charge-offs									(918)	(1,679)
Recoveries									244	198
Ending balance	3,386				3,415				3,386	3,415
Individually evaluated for impairment											$ 85	$ 166
Collectively evaluated for impairment											3,301	3,249
Allowance for loan losses	3,386			3,415	3,415			4,846	3,386	3,415	3,386	3,415
Individually evaluated for impairment											3,707	5,946
Collectively evaluated for impairment											381,427	356,646
Loans											385,764	363,942
Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											630	1,350
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member]
Beginning balance				527				609	527	609
Provision for loan losses									(87)	35
Charge-offs									(118)	(128)
Recoveries									58	11
Ending balance	380				527				380	527
Individually evaluated for impairment											23	6
Collectively evaluated for impairment											357	521
Allowance for loan losses	380			527	527			609	527	527	380	527
Individually evaluated for impairment											2,083	1,996
Collectively evaluated for impairment											135,904	145,695
Loans											138,377	148,575
Real Estate Mortgage Portfolio Segment [Member] | Residential Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											390	884
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member]
Beginning balance				157				201	157	201
Provision for loan losses									(92)	(44)
Charge-offs									(9)	0
Recoveries									0	0
Ending balance	56				157				56	157
Individually evaluated for impairment											0	0
Collectively evaluated for impairment											56	157
Allowance for loan losses	56			157	157			201	157	157	56	157
Individually evaluated for impairment											0	24
Collectively evaluated for impairment											13,951	13,014
Loans											13,951	13,038
Real Estate Mortgage Portfolio Segment [Member] | Land Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											0	0
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member]
Beginning balance				47				60	47	60
Provision for loan losses									33	(13)
Charge-offs									0	0
Recoveries									0	0
Ending balance	80				47				80	47
Individually evaluated for impairment											0	0
Collectively evaluated for impairment											80	47
Allowance for loan losses	80			47	47			60	47	47	80	47
Individually evaluated for impairment											0	0
Collectively evaluated for impairment											19,489	12,616
Loans											19,489	12,616
Real Estate Mortgage Portfolio Segment [Member] | Construction Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											0	0
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Beginning balance				1,541				1,501	1,541	1,501
Provision for loan losses									157	6
Charge-offs									(82)	0
Recoveries									54	34
Ending balance	1,670				1,541				1,670	1,541
Individually evaluated for impairment											0	49
Collectively evaluated for impairment											1,670	1,492
Allowance for loan losses	1,670			1,541	1,541			1,501	1,541	1,541	1,670	1,541
Individually evaluated for impairment											1,217	3,623
Collectively evaluated for impairment											95,212	80,639
Loans											96,669	84,728
Real Estate Mortgage Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											240	466
Commercial Portfolio Segment [Member]
Beginning balance				261				1,480	261	1,480
Provision for loan losses									187	(23)
Charge-offs									(264)	(1,205)
Recoveries									14	9
Ending balance	198				261				198	261
Individually evaluated for impairment											43	100
Collectively evaluated for impairment											155	161
Allowance for loan losses	198			261	261			1,480	261	261	198	261
Individually evaluated for impairment											143	167
Collectively evaluated for impairment											23,983	22,986
Loans											24,126	23,153
Commercial Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											0	0
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member]
Beginning balance				626				720	626	720
Provision for loan losses									79	(49)
Charge-offs									(36)	(78)
Recoveries									14	33
Ending balance	683				626				683	626
Individually evaluated for impairment											13	11
Collectively evaluated for impairment											670	615
Allowance for loan losses	683			626	626			720	626	626	683	626
Individually evaluated for impairment											244	136
Collectively evaluated for impairment											43,587	39,041
Loans											43,831	39,177
Consumer Portfolio Segment [Member] | Home Equity and Second Mortgage [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	0			0	0				0	0	0	0
Loans											0	0
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member]
Beginning balance				256				275	256	275
Provision for loan losses									368	138
Charge-offs									(409)	(268)
Recoveries									104	111
Ending balance	319				256				319	256
Individually evaluated for impairment											6	0
Collectively evaluated for impairment											313	256
Allowance for loan losses	319			256	256			$ 275	256	256	319	256
Individually evaluated for impairment											20	0
Collectively evaluated for impairment											49,301	42,655
Loans											49,321	42,655
Consumer Portfolio Segment [Member] | Other Consumer Loan [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Beginning balance				0					0
Ending balance	0				0				0	0
Allowance for loan losses	$ 0			$ 0	$ 0				$ 0	$ 0	0	0
Loans											$ 0	$ 0