Note 9 - Allowance for Loan Losses and Credit Quality Information - Classified and Unclassified Loans (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
Classified [Member] | Special Mention [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	$ 916,000	$ 189,000
Classified [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	3,338,000	1,910,000
Classified [Member] | Special Mention [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	623,000	917,000
Classified [Member] | Special Mention [Member] | Consumer Portfolio Segment [Member]
Ending balance	0	0
Classified [Member] | Special Mention [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	0	4,082,000
Classified [Member] | Special Mention [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	3,938,000	841,000
Classified [Member] | Special Mention [Member]
Ending balance	8,815,000	7,939,000
Classified [Member] | Substandard [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	2,266,000	2,889,000
Classified [Member] | Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	7,207,000	4,827,000
Classified [Member] | Substandard [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	8,531,000	9,473,000
Classified [Member] | Substandard [Member] | Consumer Portfolio Segment [Member]
Ending balance	526,000	639,000
Classified [Member] | Substandard [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	4,001,000	18,000
Classified [Member] | Substandard [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	2,337,000	1,515,000
Classified [Member] | Substandard [Member]
Ending balance	24,868,000	19,361,000
Classified [Member] | Doubtful [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	48,000	55,000
Classified [Member] | Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	0	0
Classified [Member] | Doubtful [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	0	0
Classified [Member] | Doubtful [Member] | Consumer Portfolio Segment [Member]
Ending balance	84,000	52,000
Classified [Member] | Doubtful [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	0	0
Classified [Member] | Doubtful [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	0	0
Classified [Member] | Doubtful [Member]
Ending balance	132,000	107,000
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	0	0
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	0	0
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	0	0
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Consumer Portfolio Segment [Member]
Ending balance	305,000	286,000
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	0	0
Classified [Member] | Unlikely to be Collected Financing Receivable [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	0	0
Classified [Member] | Unlikely to be Collected Financing Receivable [Member]
Ending balance	305,000	286,000
Classified [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	3,230,000	3,133,000
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	10,545,000	6,737,000
Classified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	9,154,000	10,390,000
Classified [Member] | Consumer Portfolio Segment [Member]
Ending balance	915,000	977,000
Classified [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	4,001,000	4,100,000
Classified [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	6,275,000	2,356,000
Classified [Member]
Ending balance	34,120,000	27,693,000
Unclassified [Member] | One to Four Family Porfolio Segment [Member]
Ending balance	97,406,000	87,812,000
Unclassified [Member] | Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	150,078,000	118,639,000
Unclassified [Member] | Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	129,592,000	111,587,000
Unclassified [Member] | Consumer Portfolio Segment [Member]
Ending balance	75,152,000	63,438,000
Unclassified [Member] | Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	6,354,000	5,249,000
Unclassified [Member] | Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	57,885,000	58,401,000
Unclassified [Member]
Ending balance	516,467,000	445,126,000
One to Four Family Porfolio Segment [Member]
Ending balance	100,636,000	90,945,000
Commercial Real Estate Portfolio Segment [Member] | Real Estate Loan [Member]
Ending balance	160,623,000	125,376,000
Commercial Real Estate Portfolio Segment [Member] | Commercial Real Estate Other [Member]
Ending balance	138,746,000	121,977,000
Commercial Real Estate Portfolio Segment [Member]
Ending balance	299,369,000	247,353,000
Consumer Portfolio Segment [Member]
Ending balance	76,067,000	64,415,000
Commercial Portfolio Segment [Member] | Transportation Industry Loans [Member]
Ending balance	10,355,000	9,349,000
Commercial Portfolio Segment [Member] | Commercial Business Other [Member]
Ending balance	64,160,000	60,757,000
Commercial Portfolio Segment [Member]
Ending balance	74,515,000	70,106,000
Ending balance	$ 550,587,000	$ 472,819,000