Note 4 - Loans and Allowance for Credit Losses - Nonaccrual Loans and Loans Past Due Over 90 Days (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Nonaccrual Loans	$ 2,252,362	$ 1,503,940
Loans Past Due Over 90 Days Still Accruing
Residential Portfolio Segment [Member] | One- to Four-family Loan [Member]
Nonaccrual Loans	1,889,452	1,048,744
Loans Past Due Over 90 Days Still Accruing
Residential Portfolio Segment [Member] | Multi-family Loans [Member]
Nonaccrual Loans
Loans Past Due Over 90 Days Still Accruing
Nonresidential Real Estate Portfolio Segment [Member]
Nonaccrual Loans	343,720	455,196
Loans Past Due Over 90 Days Still Accruing
Commercial Portfolio Segment [Member]
Nonaccrual Loans
Loans Past Due Over 90 Days Still Accruing
Consumer Portfolio Segment [Member]
Nonaccrual Loans
Loans Past Due Over 90 Days Still Accruing
Purchased Auto Loans [Member]
Nonaccrual Loans	19,190
Loans Past Due Over 90 Days Still Accruing