Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 15,072,000	$ 1,982,000	$ 13,590,000	$ 2,989,000
Charge-Offs	0	0	0	(230,000)
Payments	(3,099,000)	(53,000)	(4,755,000)	(935,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	11,672,000	496,000	14,810,000	601,000
Ending Balance	23,645,000	2,425,000	23,645,000	2,425,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	338,000	0	383,000
Charge-Offs	0	0	0	0
Payments	0	(109,000)	0	(154,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	0	229,000	0	229,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	2,713,000	4,548,000	2,682,000	1,599,000
Charge-Offs	0	0	0	0
Payments	(2,311,000)	(2,764,000)	(2,350,000)	(3,619,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	1,180,000	0	1,250,000	3,804,000
Ending Balance	1,582,000	1,784,000	1,582,000	1,784,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	0	0	0	0
Charge-Offs	0	0	0	0
Payments	0	0	0	0
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	0	0	0	0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	0	0	0	0
Charge-Offs	0	0	0	0
Payments	0	0	0	0
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	0	0	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	538,000	716,000	548,000	1,001,000
Charge-Offs	0	0	0	(275,000)
Payments	(49,000)	(22,000)	(59,000)	(32,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	489,000	694,000	489,000	694,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	0	0	0
Charge-Offs	0	0	0	0
Payments	0	0	0	0
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	0	0	0	0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	982,000	2,007,000	418,000	427,000
Charge-Offs	0	0	0	0
Payments	(66,000)	(1,614,000)	(75,000)	(1,633,000)
Transfers to ORE	0	0	(97,000)	0
Net Additions/Deletions	0	0	670,000	1,599,000
Ending Balance	916,000	393,000	916,000	393,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	189,000	232,000	210,000	237,000
Charge-Offs	0	0	0	0
Payments	(4,000)	(7,000)	(25,000)	(12,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	185,000	225,000	185,000	225,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	21,000	36,000	24,000	41,000
Charge-Offs	0	0	0	0
Payments	(4,000)	(4,000)	(7,000)	(9,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	17,000	32,000	17,000	32,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Beginning Balance	915,000	1,169,000	938,000	1,127,000
Charge-Offs	0	0	0	0
Payments	(25,000)	(150,000)	(48,000)	(158,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	23,000	0	23,000	50,000
Ending Balance	913,000	1,019,000	913,000	1,019,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	142,000	144,000	142,000	146,000
Charge-Offs	0	0	0	0
Payments	(1,000)	(1,000)	(1,000)	(3,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	141,000	143,000	141,000	143,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Beginning Balance	529,000	240,000	464,000	219,000
Charge-Offs	(18,000)	(15,000)	(18,000)	(30,000)
Payments	(37,000)	(36,000)	(42,000)	(37,000)
Transfers to ORE	0	0	0	(82,000)
Net Additions/Deletions	79,000	113,000	149,000	232,000
Ending Balance	553,000	302,000	553,000	302,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	458,000	384,000	436,000	393,000
Charge-Offs	0	0	0	0
Payments	(13,000)	(8,000)	(23,000)	(17,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	120,000	24,000	152,000	24,000
Ending Balance	$ 565,000	$ 400,000	$ 565,000	$ 400,000