Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 23,645,000	$ 2,425,000	$ 13,590,000	$ 2,989,000
Charge-Offs	0	0	0	(230,000)
Payments	(35,000)	0	(4,790,000)	(934,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	2,000	3,315,000	14,812,000	3,915,000
Ending Balance	23,612,000	5,740,000	23,612,000	5,740,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	0	229,000	0	383,000
Charge-Offs	0	0	0	0
Payments	0	(207,000)	0	(361,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	87,000	0	87,000	0
Ending Balance	87,000	22,000	87,000	22,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	1,582,000	1,784,000	2,682,000	1,599,000
Charge-Offs	0	0	0	0
Payments	(37,000)	(439,000)	(2,387,000)	(4,057,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	2,278,000	1,250,000	6,081,000
Ending Balance	1,545,000	3,623,000	1,545,000	3,623,000
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	489,000	694,000	548,000	1,001,000
Charge-Offs	0	0	0	(275,000)
Payments	(50,000)	(36,000)	(109,000)	(69,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	(80,000)	0	(79,000)
Ending Balance	439,000	578,000	439,000	578,000
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	916,000	393,000	418,000	427,000
Charge-Offs	0	0	0	0
Payments	(790,000)	(15,000)	(865,000)	(1,645,000)
Transfers to ORE	0	(93,000)	(97,000)	(92,000)
Net Additions/Deletions	102,000	151,000	772,000	1,746,000
Ending Balance	228,000	436,000	228,000	436,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	185,000	225,000	210,000	237,000
Charge-Offs	0	0	0	0
Payments	(4,000)	(8,000)	(29,000)	(20,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	181,000	217,000	181,000	217,000
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	17,000	32,000	24,000	41,000
Charge-Offs	0	0	0	0
Payments	(5,000)	(3,000)	(12,000)	(12,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	12,000	29,000	12,000	29,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member]
Beginning Balance	913,000	1,019,000	938,000	1,127,000
Charge-Offs	0	0	0	0
Payments	(35,000)	(81,000)	(84,000)	(238,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	13,000	0	37,000	49,000
Ending Balance	891,000	938,000	891,000	938,000
Retail Portfolio Segment [Member] | Originated Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	141,000	143,000	142,000	146,000
Charge-Offs	0	0	0	0
Payments	(1,000)	(1,000)	(2,000)	(4,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	140,000	142,000	140,000	142,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member]
Beginning Balance	553,000	302,000	464,000	219,000
Charge-Offs	0	0	(18,000)	(30,000)
Payments	(10,000)	(2,000)	(53,000)	(40,000)
Transfers to ORE	0	0	0	(82,000)
Net Additions/Deletions	47,000	0	197,000	233,000
Ending Balance	590,000	300,000	590,000	300,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | One to Four Family Mortgages [Member]
Beginning Balance	565,000	400,000	436,000	393,000
Charge-Offs	0	0	0	0
Payments	(12,000)	(9,000)	(36,000)	(26,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	49,000	13,000	202,000	37,000
Ending Balance	$ 602,000	$ 404,000	$ 602,000	$ 404,000