Note 12 - Derivatives and Risk Management Activities - Amounts Recorded in Statement of Financial Condition (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other Assets [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Asset, Fair Value	$ 0	$ 4
Derivative Asset, Notional Amount	0	875
Other Assets [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Asset, Fair Value	0	2
Derivative Asset, Notional Amount	0	288
Other Assets [Member] | Interest Rate Lock Commitments [Member]
Derivative Asset, Fair Value	1,451	362
Derivative Asset, Notional Amount	50,090	14,586
Other Liabilities [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Liability, Fair Value	554	133
Derivative Liability, Notional Amount	47,773	13,711
Other Liabilities [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Liability, Fair Value	525	83
Derivative Liability, Notional Amount	36,606	9,614
Other Liabilities [Member] | Interest Rate Lock Commitments [Member]
Derivative Liability, Fair Value	1	0
Derivative Liability, Notional Amount	$ 377	$ 0