Note 4 - Loans and Allowance for Loan Losses - Acquired Impaired Loans Accretable Yield (Details) - USD ($)		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018
Balance at beginning of period		$ 1,274,000	$ 1,404,000
Additions		9,000	0
Accretion income		(407,000)	(490,000)
Net reclassification from nonaccretable to accretable		488,000	437,000
Reductions (1)	[1]	(88,000)	(77,000)
Balance at end of period		$ 1,276,000	$ 1,274,000

[1] Reductions primarily reflect the result of exit events, including loan payoffs and charge-offs.