Note 5 - Loans Receivable - Troubled Debt Restructurings (Details) $ in Thousands	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Number of Loans	18	17
Financing Receivable, Modifications, Recorded Investment	$ 5,999	$ 1,713
Accrual [Member]
Number of Loans	5	3
Financing Receivable, Modifications, Recorded Investment	$ 4,804	$ 284
Nonaccrual [Member]
Number of Loans	13	14
Financing Receivable, Modifications, Recorded Investment	$ 1,195	$ 1,429
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member]
Number of Loans	8	8
Financing Receivable, Modifications, Recorded Investment	$ 512	$ 655
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Accrual [Member]
Number of Loans	2	2
Financing Receivable, Modifications, Recorded Investment	$ 197	$ 205
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Nonaccrual [Member]
Number of Loans	6	6
Financing Receivable, Modifications, Recorded Investment	$ 315	$ 450
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Number of Loans	4	3
Financing Receivable, Modifications, Recorded Investment	$ 4,654	$ 461
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Accrual [Member]
Number of Loans	1	0
Financing Receivable, Modifications, Recorded Investment	$ 4,244	$ 0
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Nonaccrual [Member]
Number of Loans	3	3
Financing Receivable, Modifications, Recorded Investment	$ 410	$ 461
Real Estate Portfolio Segment [Member] | Farmland [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 250	$ 250
Real Estate Portfolio Segment [Member] | Farmland [Member] | Accrual [Member]
Number of Loans	0	0
Financing Receivable, Modifications, Recorded Investment	$ 0	$ 0
Real Estate Portfolio Segment [Member] | Farmland [Member] | Nonaccrual [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 250	$ 250
Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Number of Loans	3	3
Financing Receivable, Modifications, Recorded Investment	$ 291	$ 321
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Accrual [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 76	$ 79
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Nonaccrual [Member]
Number of Loans	2	2
Financing Receivable, Modifications, Recorded Investment	$ 215	$ 242
Commercial Portfolio Segment [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 287	$ 21
Commercial Portfolio Segment [Member] | Accrual [Member]
Number of Loans	1	0
Financing Receivable, Modifications, Recorded Investment	$ 287	$ 0
Commercial Portfolio Segment [Member] | Nonaccrual [Member]
Number of Loans	0	1
Financing Receivable, Modifications, Recorded Investment	$ 0	$ 21
Consumer Portfolio Segment [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 5	$ 5
Consumer Portfolio Segment [Member] | Accrual [Member]
Number of Loans	0	0
Financing Receivable, Modifications, Recorded Investment	$ 0	$ 0
Consumer Portfolio Segment [Member] | Nonaccrual [Member]
Number of Loans	1	1
Financing Receivable, Modifications, Recorded Investment	$ 5	$ 5