Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Beginning Balance	$ 10,067,000	$ 24,134,000	$ 8,587,000	$ 14,138,000
Charge-Offs	0	0	0	0
Payments	(3,537,000)	(85,000)	(8,512,000)	(4,899,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	7,000	2,000	6,462,000	14,812,000
Ending Balance	6,537,000	24,051,000	6,537,000	24,051,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Beginning Balance	80,000	0	85,000	0
Charge-Offs	0	0	0	0
Payments	(80,000)	0	(85,000)	0
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	87,000	0	87,000
Ending Balance	0	87,000	0	87,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Beginning Balance	3,791,000	2,498,000	1,145,000	3,100,000
Charge-Offs	0	0	0	0
Payments	(827,000)	(827,000)	(1,836,000)	(3,252,000)
Transfers to ORE	0	0	0	(97,000)
Net Additions/Deletions	55,000	102,000	3,710,000	2,022,000
Ending Balance	3,019,000	1,773,000	3,019,000	1,773,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Beginning Balance	170,000	185,000	178,000	210,000
Charge-Offs	0	0	0	0
Payments	(4,000)	(4,000)	(12,000)	(29,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	569,000	0	569,000	0
Ending Balance	735,000	181,000	735,000	181,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Beginning Balance	1,000	17,000	7,000	24,000
Charge-Offs	0	0	0	0
Payments	(1,000)	(5,000)	(7,000)	(12,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	0	0	0	0
Ending Balance	0	12,000	0	12,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member]
Beginning Balance	1,715,000	1,466,000	1,415,000	1,402,000
Charge-Offs	0	0	0	(18,000)
Payments	(220,000)	(45,000)	(423,000)	(137,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	82,000	60,000	585,000	234,000
Ending Balance	1,577,000	1,481,000	1,577,000	1,481,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member]
Beginning Balance	715,000	706,000	724,000	578,000
Charge-Offs	0	0	0	0
Payments	(17,000)	(13,000)	(46,000)	(38,000)
Transfers to ORE	0	0	0	0
Net Additions/Deletions	69,000	49,000	89,000	202,000
Ending Balance	$ 767,000	$ 742,000	$ 767,000	$ 742,000