Note 5 - Loans and Allowance for Loan Losses - Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018		Dec. 31, 2017
Beginning balance				$ 4,774				$ 4,856	$ 4,774	$ 4,856
Charge-offs									(3,117)	(2,991)
Recoveries									776	922
Provision for loan and lease losses	$ 473	$ 789	$ 702	658	$ 523	$ 373	$ 576	515	2,622	1,987
Ending balance	5,055				4,774				5,055	4,774
Allowance for loan losses individually evaluated for impairment											$ 166		$ 98
Allowance for loan losses collectively evaluated for impairment											4,889		4,676
Loans, allowance for loan losses	5,055			4,774	4,774			4,856	5,055	4,774	5,055		4,774
Loans individually evaluated for impairment											1,042		791
Loans collectively evaluated for impairment											524,331		356,667
Loans											525,870		357,458
Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											497
Real Estate [Member] | Construction, Land Development and Other Land Loans [Member]
Beginning balance				203				535	203	535
Charge-offs
Recoveries
Provision for loan and lease losses									37	(332)
Ending balance	240				203				240	203
Allowance for loan losses individually evaluated for impairment											28
Allowance for loan losses collectively evaluated for impairment											212		203
Loans, allowance for loan losses	240			203	203			535	203	203	240		203
Loans individually evaluated for impairment											153
Loans collectively evaluated for impairment											41,114		26,143
Loans											41,340		26,143
Real Estate [Member] | Construction, Land Development and Other Land Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											73
Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Beginning balance				290				411	290	411
Charge-offs									(101)	(28)
Recoveries									74	135
Provision for loan and lease losses									83	(228)
Ending balance	346				290				346	290
Allowance for loan losses individually evaluated for impairment											50		5
Allowance for loan losses collectively evaluated for impairment											296		285
Loans, allowance for loan losses	346			290	290			411	290	290	346		290
Loans individually evaluated for impairment											268		187
Loans collectively evaluated for impairment											110,064		44,886
Loans											110,756		45,073
Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											424
Real Estate [Member] | Secured by Multi-family Residential Properties [Member]
Beginning balance				116				88	116	88
Charge-offs
Recoveries
Provision for loan and lease losses									12	28
Ending balance	128				116				128	116
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											128		116
Loans, allowance for loan losses	128			116	116			88	116	116	128		116
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											23,009		16,579
Loans											23,009		16,579
Real Estate [Member] | Secured by Multi-family Residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member]
Beginning balance				777				903	777	903
Charge-offs
Recoveries									4	69
Provision for loan and lease losses									50	(195)
Ending balance	831				777				831	777
Allowance for loan losses individually evaluated for impairment											1		21
Allowance for loan losses collectively evaluated for impairment											830		756
Loans, allowance for loan losses	831			777	777			903	777	777	831		777
Loans individually evaluated for impairment											511		532
Loans collectively evaluated for impairment											155,651		104,601
Loans											156,162		105,133
Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Real Estate [Member] | Other Real Estate Loans [Member]
Beginning balance				2				2	2	2
Charge-offs
Recoveries
Provision for loan and lease losses									(1)
Ending balance	1				2				1	2
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											1		2
Loans, allowance for loan losses	1			2	2			2	2	2	1		2
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											1,308		190
Loans											1,308		190
Real Estate [Member] | Other Real Estate Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Commercial and Industrial Loans [Member]
Beginning balance				1,049				527	1,049	527
Charge-offs									(3)	(16)
Recoveries									11	19
Provision for loan and lease losses									81	519
Ending balance	1,138				1,049				1,138	1,049
Allowance for loan losses individually evaluated for impairment											67		72
Allowance for loan losses collectively evaluated for impairment											1,071		977
Loans, allowance for loan losses	1,138			1,049	1,049			527	1,049	1,049	1,138		1,049
Loans individually evaluated for impairment											67		72
Loans collectively evaluated for impairment											85,712		69,897
Loans											85,779	[1]	69,969
Commercial and Industrial Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Consumer Portfolio Segment [Member] | Consumer Loans [Member]
Beginning balance				1,715				1,767	1,715	1,767
Charge-offs									(2,482)	(2,360)
Recoveries									568	601
Provision for loan and lease losses									1,998	1,707
Ending balance	1,799				1,715				1,799	1,715
Allowance for loan losses individually evaluated for impairment											20
Allowance for loan losses collectively evaluated for impairment											1,779		1,715
Loans, allowance for loan losses	1,799			1,715	1,715			1,767	1,715	1,715	1,799		1,715
Loans individually evaluated for impairment											43
Loans collectively evaluated for impairment											38,540		39,300
Loans											38,583		39,300
Consumer Portfolio Segment [Member] | Consumer Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Consumer Portfolio Segment [Member] | Branch Retail [Member]
Beginning balance				393				467	393	467
Charge-offs									(415)	(538)
Recoveries									113	98
Provision for loan and lease losses									336	366
Ending balance	427				393				427	393
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											427		393
Loans, allowance for loan losses	427			393	393			467	393	393	427		393
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											28,324		26,434
Loans											28,324		26,434
Consumer Portfolio Segment [Member] | Branch Retail [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
Consumer Portfolio Segment [Member] | Indirect Sales [Member]
Beginning balance				229				156	229	156
Charge-offs									(116)	(49)
Recoveries									6
Provision for loan and lease losses									26	122
Ending balance	145				229				145	229
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											145		229
Loans, allowance for loan losses	145			229	229			156	229	229	145		229
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											40,609		28,637
Loans											40,609		28,637
Consumer Portfolio Segment [Member] | Indirect Sales [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member]
Beginning balance				2,447				2,409	2,447	2,409
Charge-offs									(16)	(79)
Recoveries									89	247
Provision for loan and lease losses									215	(130)
Ending balance	2,735				2,447				2,735	2,447
Allowance for loan losses individually evaluated for impairment											166		98
Allowance for loan losses collectively evaluated for impairment											2,569		2,349
Loans, allowance for loan losses	2,735			2,447	2,447			2,409	2,735	2,447	2,735		2,447
Loans individually evaluated for impairment											831		791
Loans collectively evaluated for impairment											416,168		256,712
Loans											417,496		257,503
FUSB [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											497
FUSB [Member] | Real Estate [Member] | Construction, Land Development and Other Land Loans [Member]
Beginning balance				203				535	203	535
Charge-offs
Recoveries
Provision for loan and lease losses									37	(332)
Ending balance	240				203				240	203
Allowance for loan losses individually evaluated for impairment											28
Allowance for loan losses collectively evaluated for impairment											212		203
Loans, allowance for loan losses	240			203	203			535	203	203	240		203
Loans individually evaluated for impairment											153
Loans collectively evaluated for impairment											41,114		26,143
Loans											41,340		26,143
FUSB [Member] | Real Estate [Member] | Construction, Land Development and Other Land Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											73
FUSB [Member] | Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Beginning balance				238				304	238	304
Charge-offs									(9)
Recoveries									51	103
Provision for loan and lease losses									42	(169)
Ending balance	322				238				322	238
Allowance for loan losses individually evaluated for impairment											50		5
Allowance for loan losses collectively evaluated for impairment											272		233
Loans, allowance for loan losses	322			238	238			304	238	238	322		238
Loans individually evaluated for impairment											57		187
Loans collectively evaluated for impairment											102,490		34,085
Loans											102,971		34,272
FUSB [Member] | Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans											424
FUSB [Member] | Real Estate [Member] | Secured by Multi-family Residential Properties [Member]
Beginning balance				116				88	116	88
Charge-offs
Recoveries
Provision for loan and lease losses									12	28
Ending balance	128				116				128	116
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											128		116
Loans, allowance for loan losses	128			116	116			88	116	116	128		116
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											23,009		16,579
Loans											23,009		16,579
FUSB [Member] | Real Estate [Member] | Secured by Multi-family Residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member]
Beginning balance				777				903	777	903
Charge-offs
Recoveries									4	69
Provision for loan and lease losses									50	(195)
Ending balance	831				777				831	777
Allowance for loan losses individually evaluated for impairment											1		21
Allowance for loan losses collectively evaluated for impairment											830		756
Loans, allowance for loan losses	831			777	777			903	777	777	831		777
Loans individually evaluated for impairment											511		532
Loans collectively evaluated for impairment											155,651		104,601
Loans											156,162		105,133
FUSB [Member] | Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Real Estate [Member] | Other Real Estate Loans [Member]
Beginning balance				2				2	2	2
Charge-offs
Recoveries
Provision for loan and lease losses									(1)
Ending balance	1				2				1	2
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											1		2
Loans, allowance for loan losses	1			2	2			2	2	2	1		2
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											1,308		190
Loans											1,308		190
FUSB [Member] | Real Estate [Member] | Other Real Estate Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Commercial and Industrial Loans [Member]
Beginning balance				1,049				527	1,049	527
Charge-offs									(3)	(16)
Recoveries									11	19
Provision for loan and lease losses									81	519
Ending balance	1,138				1,049				1,138	1,049
Allowance for loan losses individually evaluated for impairment											67		72
Allowance for loan losses collectively evaluated for impairment											1,071		977
Loans, allowance for loan losses	1,138			1,049	1,049			527	1,049	1,049	1,138		1,049
Loans individually evaluated for impairment											67		72
Loans collectively evaluated for impairment											85,712		69,897
Loans											85,779	[1]	69,969
FUSB [Member] | Commercial and Industrial Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Consumer Portfolio Segment [Member]
Loans											6,927		5,217
FUSB [Member] | Consumer Portfolio Segment [Member] | Consumer Loans [Member]
Beginning balance				62				50	62	50
Charge-offs									(4)	(63)
Recoveries									23	56
Provision for loan and lease losses									(6)	19
Ending balance	75				62				75	62
Allowance for loan losses individually evaluated for impairment											20
Allowance for loan losses collectively evaluated for impairment											55		62
Loans, allowance for loan losses	75			62	62			50	62	62	75		62
Loans individually evaluated for impairment											43
Loans collectively evaluated for impairment											6,884		5,217
Loans											6,927		5,217
FUSB [Member] | Consumer Portfolio Segment [Member] | Consumer Loans [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Consumer Portfolio Segment [Member] | Branch Retail [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
FUSB [Member] | Consumer Portfolio Segment [Member] | Branch Retail [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
FUSB [Member] | Consumer Portfolio Segment [Member] | Indirect Sales [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
FUSB [Member] | Consumer Portfolio Segment [Member] | Indirect Sales [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Ending balance
Loans, allowance for loan losses
Loans
ALC [Member]
Beginning balance				2,327				2,447	2,327	2,447
Charge-offs									(3,101)	(2,912)
Recoveries									687	675
Provision for loan and lease losses									2,407	2,117
Ending balance	2,320				2,327				2,320	2,327
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											2,320		2,327
Loans, allowance for loan losses	2,320			2,327	2,327			2,447	2,320	2,327	2,320		2,327
Loans individually evaluated for impairment											211
Loans collectively evaluated for impairment											108,163		99,955
Loans											108,374		99,955
ALC [Member] | Real Estate [Member] | Construction, Land Development and Other Land Loans [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
ALC [Member] | Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member]
Beginning balance				52				107	52	107
Charge-offs									(92)	(28)
Recoveries									23	32
Provision for loan and lease losses									41	(59)
Ending balance	24				52				24	52
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											24		52
Loans, allowance for loan losses	24			52	52			107	52	52	24		52
Loans individually evaluated for impairment											211
Loans collectively evaluated for impairment											7,574		10,801
Loans											7,785		10,801
ALC [Member] | Real Estate [Member] | Secured by Multi-family Residential Properties [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
ALC [Member] | Real Estate [Member] | Secured by Non-farm, Non-residential Properties [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
ALC [Member] | Real Estate [Member] | Other Real Estate Loans [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans
ALC [Member] | Commercial and Industrial Loans [Member]
Beginning balance
Charge-offs
Recoveries
Provision for loan and lease losses
Ending balance
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment
Loans, allowance for loan losses
Loans individually evaluated for impairment
Loans collectively evaluated for impairment
Loans												[1]
ALC [Member] | Consumer Portfolio Segment [Member] | Consumer Loans [Member]
Beginning balance				1,653				1,717	1,653	1,717
Charge-offs									(2,478)	(2,297)
Recoveries									545	545
Provision for loan and lease losses									2,004	1,688
Ending balance	1,724				1,653				1,724	1,653
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											1,724		1,653
Loans, allowance for loan losses	1,724			1,653	1,653			1,717	1,653	1,653	1,724		1,653
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											31,656		34,083
Loans											31,656		34,083
ALC [Member] | Consumer Portfolio Segment [Member] | Branch Retail [Member]
Beginning balance				393				467	393	467
Charge-offs									(415)	(538)
Recoveries									113	98
Provision for loan and lease losses									336	366
Ending balance	427				393				427	393
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											427		393
Loans, allowance for loan losses	427			393	393			467	393	393	427		393
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											28,324		26,434
Loans											28,324		26,434
ALC [Member] | Consumer Portfolio Segment [Member] | Indirect Sales [Member]
Beginning balance				229				156	229	156
Charge-offs									(116)	(49)
Recoveries									6
Provision for loan and lease losses									26	122
Ending balance	145				229				145	229
Allowance for loan losses individually evaluated for impairment
Allowance for loan losses collectively evaluated for impairment											145		229
Loans, allowance for loan losses	$ 145			$ 229	$ 229			$ 156	$ 229	$ 229	145		229
Loans individually evaluated for impairment
Loans collectively evaluated for impairment											40,609		28,637
Loans											$ 40,609		$ 28,637

[1] Includes equipment financing leases.