Note 4 - Loans and Allowance for Loan Losses - Loans by Aging (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Loans receivable, past due	$ 3,100,000	$ 5,769,000
Loans receivable, current	642,606,000	631,606,000
Loans receivable	645,706,047	637,375,018
Loans receivable, past due and accruing
Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	2,527,000	3,736,000
Loans receivable, current	103,313,000	102,565,000
Loans receivable	105,840,035	106,300,790
Loans receivable, past due and accruing
Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due		775,000
Loans receivable, current	81,983,000	84,450,000
Loans receivable	81,982,799	85,225,074
Loans receivable, past due and accruing
Real Estate, Construction [Member]
Loans receivable, past due
Loans receivable, current	81,229,000	64,744,000
Loans receivable	81,228,819	64,743,582
Loans receivable, past due and accruing
Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	90,000	378,000
Loans receivable, current	254,626,000	261,488,000
Loans receivable	254,715,822	261,866,285
Loans receivable, past due and accruing
Commercial Portfolio Segment [Member]
Loans receivable, past due	381,000	864,000
Loans receivable, current	97,449,000	93,659,000
Loans receivable	97,830,737	94,522,840
Loans receivable, past due and accruing
Consumer and Other Loans [Member]
Loans receivable, past due	102,000	16,000
Loans receivable, current	24,006,000	24,700,000
Loans receivable	24,107,835	24,716,447
Loans receivable, past due and accruing
Financing Receivables, 30 to 59 Days Past Due [Member]
Loans receivable, past due	872,000	1,812,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	374,000	510,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due		775,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due	90,000	243,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	306,000	276,000
Financing Receivables, 30 to 59 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due	102,000	8,000
Financing Receivables, 60 to 89 Days Past Due [Member]
Loans receivable, past due	63,000	874,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	63,000	731,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due		135,000
Financing Receivables, 60 to 89 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due
Financing Receivables, 60 to 89 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due		8,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	2,165,000	3,083,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, One To Four Family Units [Member]
Loans receivable, past due	2,090,000	2,495,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Residential Portfolio Segment [Member] | Real Estate Residential, Multi Family Units [Member]
Loans receivable, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Real Estate, Construction [Member]
Loans receivable, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Real Estate Portfolio Segment [Member]
Loans receivable, past due
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Commercial Portfolio Segment [Member]
Loans receivable, past due	75,000	588,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Consumer and Other Loans [Member]
Loans receivable, past due