Note 17 - Fair Value Disclosure - Assets and Liabilities Reported Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale	$ 225,409	$ 123,583
Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	225,409	123,583
US Government Agencies Debt Securities [Member]
Debt Securities, Available-for-sale	80,579	65,888
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-sale	44,601	38,988
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Debt Securities, Available-for-sale	97,771	16,978
Equity Securities - Mutual Funds [Member]
Debt Securities, Available-for-sale	968	503
Equity Securities [Member]
Debt Securities, Available-for-sale	1,490	1,226
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	80,579	65,888
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	44,601	38,988
Fair Value, Inputs, Level 2 [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] | Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	97,771	16,978
Fair Value, Inputs, Level 1 [Member] | Equity Securities - Mutual Funds [Member] | Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	968	503
Fair Value, Inputs, Level 1 [Member] | Equity Securities [Member] | Fair Value, Measurements, Recurring [Member]
Debt Securities, Available-for-sale	$ 1,490	$ 1,226