Note 5 - Loans and Allowance for Loan Losses - Loans by Aging (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019
Loans receivable, past due	$ 12,105,000	$ 1,356,000
Loans receivable, current	771,369,000	727,558,000
Loans receivable	783,474,229	728,914,025
Loans receivable, past due and accruing	0	0
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	2,201,000	645,000
Loans receivable, current	124,987,000	118,179,000
Loans receivable	127,187,806	118,823,731
Loans receivable, past due and accruing	0	0
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	0	0
Loans receivable, current	85,824,000	87,448,000
Loans receivable	85,824,232	87,448,418
Loans receivable, past due and accruing	0	0
Real Estate, Construction [Member]
Loans receivable, past due	5,355,000	338,000
Loans receivable, current	60,999,000	76,971,000
Loans receivable	66,354,401	77,308,551
Loans receivable, past due and accruing	0	0
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	162,000	43,000
Loans receivable, current	306,538,000	300,576,000
Loans receivable	306,700,011	300,619,387
Loans receivable, past due and accruing	0	0
Commercial Portfolio Segment [Member]
Loans receivable, past due	4,238,000	256,000
Loans receivable, current	164,141,000	113,792,000
Loans receivable	168,378,978	114,047,753
Loans receivable, past due and accruing	0	0
Consumer and Other Loans [Member]
Loans receivable, past due	149,000	74,000
Loans receivable, current	28,880,000	30,592,000
Loans receivable	29,028,801	30,666,185
Loans receivable, past due and accruing	0	0
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, past due	7,488,000	603,000
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	1,185,000	83,000
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due	5,355,000	338,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	162,000	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	685,000	134,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	101,000	48,000
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, past due	4,021,000	568,000
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	467,000	437,000
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	3,553,000	105,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	1,000	26,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, past due	596,000	185,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	549,000	125,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	0	43,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	0	17,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	$ 47,000	$ 0