Note 5 - Loans and Allowance for Loan Losses - Loans by Aging (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Loans receivable, past due	$ 11,026,000	$ 10,554,000
Loans receivable, current	757,940,000	776,341,000
Loans receivable	768,965,653	786,894,894
Loans receivable, past due and accruing
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	2,102,000	2,670,000
Loans receivable, current	125,230,000	129,741,000
Loans receivable	127,332,191	132,410,810
Loans receivable, past due and accruing
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	5,930,000	5,952,000
Loans receivable, current	86,116,000	84,596,000
Loans receivable	92,045,496	90,548,265
Loans receivable, past due and accruing
Real Estate, Construction [Member]
Loans receivable, past due	159,000
Loans receivable, current	89,446,000	88,554,000
Loans receivable	89,605,230	88,553,995
Loans receivable, past due and accruing
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	1,818,000	1,081,000
Loans receivable, current	308,558,000	321,840,000
Loans receivable	310,375,931	322,921,323
Loans receivable, past due and accruing
Commercial Portfolio Segment [Member]
Loans receivable, past due	899,000	732,000
Loans receivable, current	117,396,000	118,638,000
Loans receivable	118,295,271	119,369,484
Loans receivable, past due and accruing
Consumer and Other Loans [Member]
Loans receivable, past due	118,000	119,000
Loans receivable, current	31,194,000	32,972,000
Loans receivable	31,311,534	33,091,017
Loans receivable, past due and accruing
Financial Asset, 30 to 59 Days Past Due [Member]
Loans receivable, past due	7,898,000	7,464,000
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	82,000	177,000
Financial Asset, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due	5,930,000	5,952,000
Financial Asset, 30 to 59 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due	89,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	852,000	1,000,000
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	898,000	228,000
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	47,000	107,000
Financial Asset, 60 to 89 Days Past Due [Member]
Loans receivable, past due	588,000	855,000
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	27,000	329,000
Financial Asset, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due
Financial Asset, 60 to 89 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due	70,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	419,000	81,000
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	1,000	433,000
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	71,000	12,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Loans receivable, past due	2,540,000	2,235,000
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	1,993,000	2,164,000
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
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	547,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due		71,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due