Note 8 - Loans and Allowance for Credit Losses - Nonaccrual Loans and Loans Past Due Over 90 Days (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Nonaccrual Loans	$ 1,106,444	$ 1,503,940
Loans Past Due Over 90 Days Still Accruing		0
Residential Portfolio Segment [Member] | One- to Four-family Loan [Member]
Nonaccrual Loans	662,122	1,048,744
Loans Past Due Over 90 Days Still Accruing		0
Residential Portfolio Segment [Member] | Multi-family Loans [Member]
Nonaccrual Loans	0	0
Loans Past Due Over 90 Days Still Accruing	0	0
Nonresidential Real Estate Portfolio Segment [Member]
Nonaccrual Loans	444,322	455,196
Loans Past Due Over 90 Days Still Accruing		0
Commercial Portfolio Segment [Member]
Nonaccrual Loans
Loans Past Due Over 90 Days Still Accruing	0	0
Consumer Portfolio Segment [Member]
Nonaccrual Loans	0	0
Loans Past Due Over 90 Days Still Accruing	0	0
Purchased Auto Loans [Member]
Nonaccrual Loans
Loans Past Due Over 90 Days Still Accruing	$ 0	$ 0