Note 6 - Accounting for Certain Loans Acquired (Details Textual) - USD ($)	9 Months Ended	12 Months Ended
Sep. 30, 2020	Dec. 31, 2019
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Provision for Loan Losses	$ 1,409	$ 2,391

Amount of expense related to loan loss not accounted for as debt securities, with evidence of deterioration of credit quality.

No definition available.

Name:	us-gaap_CertainLoansAcquiredInTransferNotAccountedForAsDebtSecuritiesProvisionForLoanLosses1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration