Note 4 - Loans and Allowance for Loan Losses - Acquired Impaired Loans Accretable Yield (Details) - USD ($)		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017
Balance at beginning of period		$ 1,404,000	$ 1,726,000
Additions		0	223,000
Accretion income		(490,000)	(562,000)
Net reclassification from nonaccretable to accretable		437,000	367,000
Reductions (1)	[1]	(77,000)	(350,000)
Balance at end of period		$ 1,274,000	$ 1,404,000

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