Note 9 - Fair Value and Interest Rate Risk - Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financial Assets:
Available-for-sale securities, at fair value	$ 29,586	$ 24,428
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financial Assets:
Available-for-sale securities, at fair value	8,036	10,441
Corporate Debt Securities [Member]
Financial Assets:
Available-for-sale securities, at fair value	13,905	8,961
Subordinated Notes [Member]
Financial Assets:
Available-for-sale securities, at fair value	7,645	5,026
Reported Value Measurement [Member]
Financial Assets:
Financial assets, total	778,658	708,593
Financial Liabilities:
Financial liabilities, total	757,342	688,918
Estimate of Fair Value Measurement [Member]
Financial Assets:
Financial assets, total	774,526	708,368
Financial Liabilities:
Financial liabilities, total	756,565	687,463
Fair Value, Inputs, Level 1 [Member] \| Reported Value Measurement [Member] \| Brokered Deposits [Member]
Financial Liabilities:
Deposits	94,011	63,932
Fair Value, Inputs, Level 1 [Member] \| Reported Value Measurement [Member] \| Cash and Due from Banks [Member]
Financial Assets:
Cash and cash equivalents	3,337	2,596
Fair Value, Inputs, Level 1 [Member] \| Reported Value Measurement [Member] \| Interest-bearing Deposits [Member]
Financial Assets:
Cash and cash equivalents	25,075	89,693
Fair Value, Inputs, Level 1 [Member] \| Estimate of Fair Value Measurement [Member] \| Brokered Deposits [Member]
Financial Liabilities:
Deposits	93,950	63,897
Fair Value, Inputs, Level 1 [Member] \| Estimate of Fair Value Measurement [Member] \| Cash and Due from Banks [Member]
Financial Assets:
Cash and cash equivalents	3,337	2,596
Fair Value, Inputs, Level 1 [Member] \| Estimate of Fair Value Measurement [Member] \| Interest-bearing Deposits [Member]
Financial Assets:
Cash and cash equivalents	25,075	89,693
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member]
Financial Assets:
Other investments	4,450	4,450
Federal Reserve Bank stock	2,460	2,109
Federal Home Loan Bank stock	6,353	5,609
Accrued interest receivable	3,501	2,726
Financial Liabilities:
FHLB and correspondent bank borrowings	130,000	138,000
Senior notes	11,684	11,628
Subordinated debentures	8,085	8,079
Accrued interest payable	532	118
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Demand Deposits [Member]
Financial Liabilities:
Deposits	76,875	76,772
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Savings Deposits [Member]
Financial Liabilities:
Deposits	141,256	131,429
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Money Market Deposits [Member]
Financial Liabilities:
Deposits	13,477	15,593
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Negotiable Order of Withdrawal (NOW) Accounts [Member]
Financial Liabilities:
Deposits	27,420	29,912
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Time Deposits [Member]
Financial Liabilities:
Deposits	252,375	211,686
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financial Assets:
Available-for-sale securities, at fair value	8,036	10,441
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Corporate Debt Securities [Member]
Financial Assets:
Available-for-sale securities, at fair value	13,905	8,961
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member] \| Subordinated Notes [Member]
Financial Assets:
Available-for-sale securities, at fair value	5,610	3,026
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member]
Financial Assets:
Other investments	4,450	4,450
Federal Reserve Bank stock	2,460	2,109
Federal Home Loan Bank stock	6,353	5,609
Accrued interest receivable	3,501	2,726
Financial Liabilities:
FHLB and correspondent bank borrowings	130,214	138,149
Senior notes	11,324	11,628
Subordinated debentures	8,085	8,079
Accrued interest payable	532	118
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Demand Deposits [Member]
Financial Liabilities:
Deposits	76,875	76,772
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Savings Deposits [Member]
Financial Liabilities:
Deposits	141,256	131,429
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Money Market Deposits [Member]
Financial Liabilities:
Deposits	13,477	15,593
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Negotiable Order of Withdrawal (NOW) Accounts [Member]
Financial Liabilities:
Deposits	27,420	29,912
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Time Deposits [Member]
Financial Liabilities:
Deposits	251,966	210,321
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Financial Assets:
Available-for-sale securities, at fair value	8,036	10,441
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Corporate Debt Securities [Member]
Financial Assets:
Available-for-sale securities, at fair value	13,905	8,961
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member] \| Subordinated Notes [Member]
Financial Assets:
Available-for-sale securities, at fair value	5,610	3,026
Fair Value, Inputs, Level 3 [Member] \| Reported Value Measurement [Member]
Financial Assets:
Loans receivable, net	703,896	576,982
Financial Liabilities:
Note payable	1,627	1,769
Fair Value, Inputs, Level 3 [Member] \| Reported Value Measurement [Member] \| Subordinated Notes [Member]
Financial Assets:
Available-for-sale securities, at fair value	2,035	2,000
Fair Value, Inputs, Level 3 [Member] \| Estimate of Fair Value Measurement [Member]
Financial Assets:
Loans receivable, net	699,764	576,757
Financial Liabilities:
Note payable	1,466	1,565
Fair Value, Inputs, Level 3 [Member] \| Estimate of Fair Value Measurement [Member] \| Subordinated Notes [Member]
Financial Assets:
Available-for-sale securities, at fair value	$ 2,035	$ 2,000

Fair value portion of the Federal Reserve Bank Stock.

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Fair value portion of interest receivable.

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Fair value portion of investments classified as other.

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Fair value portion of senior notes.

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Fair value portion of accrued expenses.

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Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Fair value of subordinated debt obligations including, but not limited to, subordinated loan, subordinated bond, subordinated debenture or junior debt.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Fair value portion of notes payable.

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