Note 10 - Derivatives and Risk Management Activities - Amounts Recorded in Statement of Financial Condition (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Other Assets [Member] | Best Efforts Forward Loan sales Commitments [Member]
IRLCs	$ 5	$ 5
IRLCs	615	1,807
Other Assets [Member] | Mandatory Forward Loan Sales Commitments [Member]
IRLCs	9	19
IRLCs	2,647	4,566
Other Assets [Member] | Interest Rate Lock Commitments [Member]
IRLCs	634	363
IRLCs	25,566	16,366
Other Liabilities [Member] | Best Efforts Forward Loan sales Commitments [Member]
IRLCs	228	93
IRLCs	25,363	14,983
Other Liabilities [Member] | Mandatory Forward Loan Sales Commitments [Member]
IRLCs	148	195
IRLCs	16,276	36,223
Other Liabilities [Member] | Interest Rate Lock Commitments [Member]
IRLCs	1	1
IRLCs	$ 412	$ 424