Note 20 - Commitments and Credit Risk (Details Textual) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Letters of Credit Outstanding, Amount	$ 12,218,000	$ 12,733,000
Commercial Loans [Member] | Unused lines of Credit [Member]
Other Commitment, Total	104,570,000	117,068,000
Open End Consumer Lines [Member] | Unused lines of Credit [Member]
Other Commitment, Total	22,254,000	15,929,000
Confirming Letters of Credit From FHLB [Member]
Letters of Credit Outstanding, Amount	$ 61,751,000	39,422,000
Standby Letters of Credit [Member] | Minimum [Member]
Debt Instrument, Term	1 year
Standby Letters of Credit [Member] | Maximum [Member]
Debt Instrument, Term	5 years
Commitments to Originate Fixed Rate Mortgages [Member]
Other Commitment, Total	$ 5,600,000	$ 7,261,000
Commitment, Mortgage Loan Origination, Disbursed Period	30 days