Note 5 - Past Due and Nonaccrual Loans (Details) - USD ($)	Jun. 30, 2016	Dec. 31, 2015
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	$ 929,000	$ 1,419,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	3,037,000	6,051,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	2,293,000	2,868,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	2,778,000	3,363,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Nonaccrual [Member]
Loans receivable, current	4,561,000	2,168,000
Loans receivable, gross	7,783,000	6,455,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member]
Loans receivable, current	384,251,000	391,622,000
Loans receivable, gross	390,066,000	401,036,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	0	0
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	0	125,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	0	67,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	0	67,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Nonaccrual [Member]
Loans receivable, current	149,000	163,000
Loans receivable, gross	149,000	230,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member]
Loans receivable, current	80,334,000	74,034,000
Loans receivable, gross	80,334,000	74,226,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	344,000	136,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	574,000	1,060,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	3,576,000	1,742,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	4,354,000	2,646,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Nonaccrual [Member]
Loans receivable, current	1,699,000	4,760,000
Loans receivable, gross	5,619,000	6,638,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Loans receivable, current	472,350,000	483,978,000
Loans receivable, gross	477,278,000	487,684,000
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	0	0
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	19,000	42,000
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	671,000	668,000
Real Estate Portfolio Segment [Member] | Farmland [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	671,000	668,000
Real Estate Portfolio Segment [Member] | Farmland [Member] | Nonaccrual [Member]
Loans receivable, current	144,000	305,000
Loans receivable, gross	815,000	973,000
Real Estate Portfolio Segment [Member] | Farmland [Member]
Loans receivable, current	91,762,000	93,525,000
Loans receivable, gross	92,452,000	94,235,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	15,000	6,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	133,000	148,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	479,000	432,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	572,000	510,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Nonaccrual [Member]
Loans receivable, current	7,000	184,000
Loans receivable, gross	501,000	622,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Loans receivable, current	123,664,000	115,357,000
Loans receivable, gross	124,369,000	116,015,000
Commercial Portfolio Segment [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	270,000	23,000
Commercial Portfolio Segment [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	500,000	1,722,000
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	3,446,000	325,000
Commercial Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	3,605,000	336,000
Commercial Portfolio Segment [Member] | Nonaccrual [Member]
Loans receivable, current	480,000	3,887,000
Loans receivable, gross	4,196,000	4,235,000
Commercial Portfolio Segment [Member]
Loans receivable, current	277,769,000	244,246,000
Loans receivable, gross	281,874,000	246,304,000
Consumer Portfolio Segment [Member] | Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	40,000	14,000
Consumer Portfolio Segment [Member] | Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	243,000	489,000
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	85,000	132,000
Consumer Portfolio Segment [Member] | Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	87,000	140,000
Consumer Portfolio Segment [Member] | Nonaccrual [Member]
Loans receivable, current	114,000	41,000
Loans receivable, gross	239,000	187,000
Consumer Portfolio Segment [Member]
Loans receivable, current	36,009,000	37,965,000
Loans receivable, gross	36,339,000	38,594,000
Financing Receivables 30 to 89 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	1,598,000	1,598,000
Financing Receivables 30 to 89 Days Past Due [Member]
Loans receivable, past due	4,506,000	9,637,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member] | Nonaccrual [Member]
Loans receivable, past due	10,550,000	6,234,000
Financing Receivables, Equal to Greater than 90 Days Past Due [Member]
Loans receivable, past due	12,067,000	7,730,000
Nonaccrual [Member]
Loans receivable, current	7,154,000	11,508,000
Loans receivable, gross	19,302,000	19,340,000
Loans receivable, current	1,466,139,000	1,440,727,000
Loans receivable, gross	$ 1,482,712,000	$ 1,458,094,000