Note 4 - Goodwill and Core Deposit Intangibles (Details Textual) - USD ($)	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	May 01, 2019	Dec. 31, 2013	Dec. 31, 1996
Goodwill, Ending Balance	$ 12,513,000	$ 12,513,000	$ 12,513,000	$ 12,513,000
King Bancorp Inc. [Member]
Goodwill, Ending Balance					$ 11,800,000
King Bancorp Inc. [Member] | Core Deposits [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles					$ 1,500,000
Indiana Bank [Member] | Commercial Banking [Member]
Goodwill, Ending Balance							$ 682,000
THE BANCorp [Member] | Core Deposits [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles						$ 2,500,000