Note 3 - Loans and Allowance for Loan Losses - Acquired Impaired Loans Accretable Yield (Details) - USD ($)		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Balance at beginning of period		$ 1,270,000	$ 1,319,000	$ 1,274,000	$ 1,404,000
Additions		7,000	0	9,000	0
Accretion income		(106,000)	(123,000)	(225,000)	(254,000)
Net reclassification from nonaccretable to accretable		83,000	86,000	204,000	172,000
Reductions (1)	[1]	(19,000)	(35,000)	(27,000)	(75,000)
Balance at end of period		$ 1,235,000	$ 1,247,000	$ 1,235,000	$ 1,247,000

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