Note 3 - Allowance for Loan Losses, Nonperforming Assets and Impaired Loans - Impaired Loans and Associated Reserves (Details) - USD ($) $ in Thousands		Sep. 30, 2017		Dec. 31, 2016		Sep. 30, 2016
Principal balance		$ 12,550		$ 9,820
Total recorded investment		12,159	[1]	9,173	[1]	$ 9,910
Recorded investment for which there is no related allowance		10,522	[1]	8,269	[1]	9,290
Recorded investment for which there is a related allowance		1,637	[1]	904	[1]	620
Related allowance		186		26		$ 27
Real Estate Construction Portfolio Segment[Member] | Construction, Other [Member]
Principal balance	[2]	3,300
Total recorded investment	[1],[2]	3,300
Recorded investment for which there is no related allowance	[1],[2]	3,300
Recorded investment for which there is a related allowance	[1],[2]	0
Related allowance	[2]	0
Real Estate Construction Portfolio Segment[Member] | Construction, 1-4 Family Residential [Member]
Principal balance	[2]			280
Total recorded investment	[1],[2]			270
Recorded investment for which there is no related allowance	[1],[2]			270
Recorded investment for which there is a related allowance	[1],[2]			0
Related allowance	[2]			0
Consumer Real Estate Portfolio Segment [Member] | Closed End First Liens [Member]
Principal balance	[2]	804		648
Total recorded investment	[1],[2]	766		609
Recorded investment for which there is no related allowance	[1],[2]	440		267
Recorded investment for which there is a related allowance	[1],[2]	326		342
Related allowance	[2]	15		14
Consumer Real Estate Portfolio Segment [Member] | Closed End Junior Liens [Member]
Principal balance	[2]	180		195
Total recorded investment	[1],[2]	180		195
Recorded investment for which there is no related allowance	[1],[2]	0		0
Recorded investment for which there is a related allowance	[1],[2]	180		195
Related allowance	[2]	6		7
Consumer Real Estate Portfolio Segment [Member] | Investor Owned Residential Real Estate [Member]
Principal balance	[2]	349		73
Total recorded investment	[1],[2]	330		73
Recorded investment for which there is no related allowance	[1],[2]	330		0
Recorded investment for which there is a related allowance	[1],[2]	0		73
Related allowance	[2]	0		4
Commercial Real Estate Portfolio Segment [Member] | Multifamily Real Estate [Member]
Principal balance		307		1,364	[2]
Total recorded investment		307		1,091	[1],[2]
Recorded investment for which there is no related allowance		307		1,091	[1],[2]
Recorded investment for which there is a related allowance		0		0	[1],[2]
Related allowance		0		0	[2]
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate, Owner Occupied [Member]
Principal balance	[2]	3,390		4,005
Total recorded investment	[1],[2]	3,383		3,957
Recorded investment for which there is no related allowance	[1],[2]	3,383		3,663
Recorded investment for which there is a related allowance	[1],[2]	0		294
Related allowance	[2]	0		1
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Principal balance	[2]	2,936		2,997
Total recorded investment	[1],[2]	2,629		2,734
Recorded investment for which there is no related allowance	[1],[2]	2,629		2,734
Recorded investment for which there is a related allowance	[1],[2]	0		0
Related allowance	[2]	0		0
Commercial Non Real Estate Segment [Member] | Commercial and Industrial [Member]
Principal balance	[2]	1,268		255
Total recorded investment	[1],[2]	1,248		241
Recorded investment for which there is no related allowance	[1],[2]	131		241
Recorded investment for which there is a related allowance	[1],[2]	1,117		0
Related allowance	[2]	163		0
Consumer Non Real Estate Portfolio Segment [Member] | Automobile Loan [Member]
Principal balance	[2]	16		3
Total recorded investment	[1],[2]	16		3
Recorded investment for which there is no related allowance	[1],[2]	2		3
Recorded investment for which there is a related allowance	[1],[2]	14		0
Related allowance	[2]	$ 2		$ 0

[1] Recorded investment is net of charge-offs and interest paid while a loan is in nonaccrual status.

[2] Only classes with impaired loans are shown.