Note 5 - Loans - Internal Classification of the Loan Portfolio (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Loans receivable	$ 618,031	$ 514,247
Performing Financial Instruments [Member]
Loans receivable	614,264	513,270
Restructured Loans [Member]
Loans receivable	22
Nonperforming Financial Instruments [Member]
Loans receivable	3,745	977
One-to-Four Family Loans [Member]
Loans receivable		135,217
Residential Portfolio Segment [Member]
Loans receivable	144,107	135,217
Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	116,939	109,911
Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member] | Performing Financial Instruments [Member]
Loans receivable	116,556	109,436
Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member] | Restructured Loans [Member]
Loans receivable
Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	383	475
Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	27,168	25,306
Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member] | Performing Financial Instruments [Member]
Loans receivable	26,534	25,306
Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member] | Restructured Loans [Member]
Loans receivable
Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	634
Commercial Real Estate Portfolio Segment [Member]
Loans receivable	328,438	244,783
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	256,784	194,805
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Performing Financial Instruments [Member]
Loans receivable	255,005	194,805
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Restructured Loans [Member]
Loans receivable
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	1,779
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	41,739	38,351
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Performing Financial Instruments [Member]
Loans receivable	41,726	38,351
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Restructured Loans [Member]
Loans receivable
Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	13
Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	29,915	11,627
Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member] | Performing Financial Instruments [Member]
Loans receivable	29,915	11,627
Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member] | Restructured Loans [Member]
Loans receivable
Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member] | Nonperforming Financial Instruments [Member]
Loans receivable
Home Equity Portfolio Segment [Member]
Loans receivable	52,159	52,672
Home Equity Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans receivable	51,668	52,430
Home Equity Portfolio Segment [Member] | Restructured Loans [Member]
Loans receivable	22
Home Equity Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	469	242
Consumer Portfolio Segment [Member]
Loans receivable	16,565	15,712
Consumer Portfolio Segment [Member] | Performing Financial Instruments [Member]
Loans receivable	16,438	15,559
Consumer Portfolio Segment [Member] | Restructured Loans [Member]
Loans receivable
Consumer Portfolio Segment [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	127	153
Commercial Portfolio Segment [Member]
Loans receivable	76,762	65,863
Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	59,053	63,300
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Performing Financial Instruments [Member]
Loans receivable	58,745	63,193
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Restructured Loans [Member]
Loans receivable
Commercial Portfolio Segment [Member] | Commercial Loans [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	308	107
Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	17,709	2,563
Commercial Portfolio Segment [Member] | Agricultural Loan [Member] | Performing Financial Instruments [Member]
Loans receivable	17,677	2,563
Commercial Portfolio Segment [Member] | Agricultural Loan [Member] | Restructured Loans [Member]
Loans receivable
Commercial Portfolio Segment [Member] | Agricultural Loan [Member] | Nonperforming Financial Instruments [Member]
Loans receivable	32
Pass [Member]
Loans receivable	610,115	512,204
Pass [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	116,065	109,167
Pass [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	26,533	24,850
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	252,731	194,502
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	41,726	38,351
Pass [Member] | Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	29,915	11,627
Pass [Member] | Home Equity Portfolio Segment [Member]
Loans receivable	51,668	52,430
Pass [Member] | Consumer Portfolio Segment [Member]
Loans receivable	16,394	15,549
Pass [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	57,778	63,165
Pass [Member] | Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	17,305	2,563
Special Mention [Member]
Loans receivable	2,681	0
Special Mention [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	0	0
Special Mention [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	1,731	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	0	0
Special Mention [Member] | Home Equity Portfolio Segment [Member]
Loans receivable	0	0
Special Mention [Member] | Consumer Portfolio Segment [Member]
Loans receivable	0	0
Special Mention [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	950	0
Special Mention [Member] | Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	0	0
Substandard [Member]
Loans receivable	5,154	1,994
Substandard [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	874	744
Substandard [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	635	456
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	2,322	303
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	13	0
Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	0	0
Substandard [Member] | Home Equity Portfolio Segment [Member]
Loans receivable	491	242
Substandard [Member] | Consumer Portfolio Segment [Member]
Loans receivable	171	136
Substandard [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	244	113
Substandard [Member] | Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	404	0
Doubtful [Member]
Loans receivable	81	0
Doubtful [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	0	0
Doubtful [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	0	0
Doubtful [Member] | Home Equity Portfolio Segment [Member]
Loans receivable	0	0
Doubtful [Member] | Consumer Portfolio Segment [Member]
Loans receivable	0	0
Doubtful [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	81	0
Doubtful [Member] | Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member]
Loans receivable	0	49
Unlikely to be Collected Financing Receivable [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Loans [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Residential Portfolio Segment [Member] | One-to-Four Family Construction [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Loan [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Farmland Loan [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Home Equity Portfolio Segment [Member]
Loans receivable	0	0
Unlikely to be Collected Financing Receivable [Member] | Consumer Portfolio Segment [Member]
Loans receivable	0	27
Unlikely to be Collected Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Commercial Loans [Member]
Loans receivable	0	22
Unlikely to be Collected Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Agricultural Loan [Member]
Loans receivable	$ 0	$ 0