Note 4 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 2,989,000	$ 1,503,000	$ 2,028,000
Charge-Offs	(230,000)	0	0
Payments	(692,000)	(2,021,000)	(555,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	11,523,000	3,507,000	30,000
Ending Balance	13,590,000	2,989,000	1,503,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	383,000	1,488,000	2,086,000
Charge-Offs	0	0	0
Payments	(383,000)	(1,105,000)	(598,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	0	0	0
Ending Balance	0	383,000	1,488,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	1,599,000	906,000	1,400,000
Charge-Offs	0	0	0
Payments	(4,999,000)	(242,000)	(591,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	6,082,000	935,000	97,000
Ending Balance	2,682,000	1,599,000	906,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	0	5,110,000	10,657,000
Charge-Offs	0	0	0
Payments	0	(232,000)	(6,004,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	0	(4,878,000)	457,000
Ending Balance	0	0	5,110,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	0	716,000	476,000
Charge-Offs	0	0	0
Payments	0	(405,000)	(30,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	0	(311,000)	270,000
Ending Balance	0	0	716,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	1,001,000	1,125,000	1,686,000
Charge-Offs	(275,000)	0	(48,000)
Payments	(100,000)	(550,000)	(513,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	(78,000)	426,000	0
Ending Balance	548,000	1,001,000	1,125,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	0	0
Charge-Offs	0	0	0
Payments	0	(33,000)	0
Transfers to ORE	0	0	0
Net Additions/Deletions	0	33,000	0
Ending Balance	0	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	427,000	900,000	1,652,000
Charge-Offs	0	(249,000)	0
Payments	(1,664,000)	(257,000)	(1,514,000)
Transfers to ORE	(93,000)	0	0
Net Additions/Deletions	1,748,000	33,000	762,000
Ending Balance	418,000	427,000	900,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	237,000	728,000	647,000
Charge-Offs	0	0	0
Payments	(27,000)	(922,000)	(110,000)
Transfers to ORE	0	(291,000)	0
Net Additions/Deletions	0	722,000	191,000
Ending Balance	210,000	237,000	728,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	41,000	60,000	331,000
Charge-Offs	0	0	0
Payments	(17,000)	(1,084,000)	(278,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	0	1,065,000	7,000
Ending Balance	24,000	41,000	60,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Beginning Balance	1,127,000	385,000	146,000
Charge-Offs	0	0	0
Payments	(251,000)	(57,000)	(1,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	62,000	799,000	240,000
Ending Balance	938,000	1,127,000	385,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	146,000	157,000	128,000
Charge-Offs	0	0	0
Payments	(4,000)	(11,000)	(11,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	0	0	40,000
Ending Balance	142,000	146,000	157,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Beginning Balance	219,000	208,000	141,000
Charge-Offs	(30,000)	(25,000)	0
Payments	(72,000)	(121,000)	(30,000)
Transfers to ORE	(82,000)	0	0
Net Additions/Deletions	429,000	157,000	97,000
Ending Balance	464,000	219,000	208,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	393,000	326,000	316,000
Charge-Offs	0	0	0
Payments	(37,000)	(188,000)	(9,000)
Transfers to ORE	0	0	0
Net Additions/Deletions	80,000	255,000	19,000
Ending Balance	$ 436,000	$ 393,000	$ 326,000