Note 6 - Allocation of Allowance for Loan Losses and the Related Loans Receivable, Disaggregated By Impairment Method (Details) - USD ($)	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	$ 288,000		$ 381,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	2,951,000		3,189,000
Real Estate Portfolio Segment [Member] | One-to-Four-Family Residential [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	77,000		83,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	3,815,000		3,787,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	3,892,000	$ 3,795,000	3,870,000	$ 4,165,000	$ 4,219,000	$ 4,488,000
Loan Balances Individually Evaluated for Impairment	7,985,000		6,660,000
Loan Balances Collectively Evaluated for Impairment	379,130,000		391,187,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	2,951,000		3,189,000	4,049,000
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	0		0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	0		0
Real Estate Portfolio Segment [Member] | Multifamily Residential [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	0		0
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	779,000		665,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	779,000	787,000	665,000	581,000	633,000	791,000
Loan Balances Individually Evaluated for Impairment	149,000		230,000
Loan Balances Collectively Evaluated for Impairment	80,185,000		73,996,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	425,000		552,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	9,446,000		9,886,000
Real Estate Portfolio Segment [Member] | Nonfarm Nonresidential [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	131,000		522,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	3,015,000		3,077,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	3,146,000	3,306,000	3,599,000	3,880,000	3,970,000	4,243,000
Loan Balances Individually Evaluated for Impairment	5,619,000		6,638,000
Loan Balances Collectively Evaluated for Impairment	462,213,000		471,160,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	9,446,000		9,886,000	9,299,000
Real Estate Portfolio Segment [Member] | Farmland [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	0		0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	62,000		70,000
Real Estate Portfolio Segment [Member] | Farmland [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	0		112,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	716,000		602,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	716,000	665,000	714,000	518,000	487,000	342,000
Loan Balances Individually Evaluated for Impairment	815,000		972,000
Loan Balances Collectively Evaluated for Impairment	91,575,000		93,193,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	62,000		70,000	84,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	21,000		21,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	1,932,000		2,127,000
Real Estate Portfolio Segment [Member] | Construction Loans [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	0		89,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	1,569,000		1,367,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	1,569,000	1,571,000	1,456,000	1,121,000	1,070,000	1,023,000
Loan Balances Individually Evaluated for Impairment	578,000		701,000
Loan Balances Collectively Evaluated for Impairment	121,859,000		113,187,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	1,932,000		2,127,000	3,212,000
Commercial Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	138,000		561,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	586,000		1,012,000
Commercial Portfolio Segment [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	685,000		250,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	2,918,000		2,315,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	3,603,000	3,145,000	2,565,000	1,765,000	1,659,000	2,315,000
Loan Balances Individually Evaluated for Impairment	4,196,000		4,235,000
Loan Balances Collectively Evaluated for Impairment	277,092,000		241,057,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	586,000		1,012,000	1,130,000
Consumer Portfolio Segment [Member] | Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	0		0
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	62,000		63,000
Consumer Portfolio Segment [Member]
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	5,000		5,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	169,000		161,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	174,000	176,000	166,000	121,000	107,000	101,000
Loan Balances Individually Evaluated for Impairment	239,000		188,000
Loan Balances Collectively Evaluated for Impairment	36,038,000		38,343,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	62,000		63,000	84,000
Receivables Acquired with Deteriorated Credit Quality [Member]
Allowance for Loan and Lease Losses Purchased Credit Impaired	872,000	1,421,000	1,515,000	1,703,000	1,617,000	357,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	15,039,000		16,347,000
Allowance for Loan and Lease Losses Individually Evaluated for Impairment	898,000		1,061,000
Allowance for Loan and Lease Losses Collectively Evaluated for Impairment	12,981,000		11,974,000
Allowance for Loan and Lease Losses Purchased Credit Impaired	14,751,000	$ 14,866,000	14,550,000	13,854,000	$ 13,762,000	$ 13,660,000
Loan Balances Individually Evaluated for Impairment	19,581,000		19,624,000
Loan Balances Collectively Evaluated for Impairment	1,448,092,000		1,422,123,000
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	$ 15,039,000		$ 16,347,000	$ 17,858,000