Note 13 - Derivative Financial Instruments - Offset Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Gross amount of recognized assets	$ 3,986	$ 1,544
Gross amounts offset in the statements of financial condition
Net amount of assets presented in the statement of financial condition	3,986	1,544
Financial instruments
Cash collateral received
Net amount	3,986	1,544
Interest Rate Swap [Member]
Gross amount of recognized assets	3,282	1,358
Gross amounts offset in the statements of financial condition
Net amount of assets presented in the statement of financial condition	3,282	1,358
Financial instruments
Cash collateral received
Net amount	3,282	1,358
Loan Commitments [Member]
Gross amount of recognized assets	704	186
Gross amounts offset in the statements of financial condition
Net amount of assets presented in the statement of financial condition	704	186
Financial instruments
Cash collateral received
Net amount	$ 704	$ 186