Note 11 - Borrowings - Contractual Maturities of Repurchase Agreements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Repurchase agreements	$ 1,601	$ 29,370
Maturity Overnight and Continuous [Member]
Repurchase agreements	1,601
Maturity Less than 30 Days [Member]
Repurchase agreements
Maturity 30 to 90 Days [Member]
Repurchase agreements
Maturity Greater than 90 Days [Member]
Repurchase agreements
US Treasury Securities [Member]
Repurchase agreements
US Treasury Securities [Member] | Maturity Overnight and Continuous [Member]
Repurchase agreements
US Treasury Securities [Member] | Maturity Less than 30 Days [Member]
Repurchase agreements
US Treasury Securities [Member] | Maturity 30 to 90 Days [Member]
Repurchase agreements
US Treasury Securities [Member] | Maturity Greater than 90 Days [Member]
Repurchase agreements
US States and Political Subdivisions Debt Securities [Member]
Repurchase agreements	871
US States and Political Subdivisions Debt Securities [Member] | Maturity Overnight and Continuous [Member]
Repurchase agreements	871
US States and Political Subdivisions Debt Securities [Member] | Maturity Less than 30 Days [Member]
Repurchase agreements
US States and Political Subdivisions Debt Securities [Member] | Maturity 30 to 90 Days [Member]
Repurchase agreements
US States and Political Subdivisions Debt Securities [Member] | Maturity Greater than 90 Days [Member]
Repurchase agreements
Mortgage-backed Agency Securities [Member]
Repurchase agreements	730
Mortgage-backed Agency Securities [Member] | Maturity Overnight and Continuous [Member]
Repurchase agreements	730
Mortgage-backed Agency Securities [Member] | Maturity Less than 30 Days [Member]
Repurchase agreements
Mortgage-backed Agency Securities [Member] | Maturity 30 to 90 Days [Member]
Repurchase agreements
Mortgage-backed Agency Securities [Member] | Maturity Greater than 90 Days [Member]
Repurchase agreements