Note 17 - Fair Value - Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Securities available for sale	$ 165,580	$ 165,579
Securities held to maturity	25,084	47,266
FDIC indemnification asset	7,161	12,173	$ 20,844
Interest receivable	5,778	5,553
Derivative financial liabilities	90	167
Reported Value Measurement [Member]
Cash and cash equivalents	157,951	76,307
Securities available for sale	165,580	165,579
Securities held to maturity	25,149	47,133
Loans held for investment, net of allowance	1,797,908	1,835,000
FDIC indemnification asset	7,161	12,173
Interest receivable	5,778	5,553
Deferred compensation assets	4,002	3,224
Securities sold under agreements to repurchase	30,086	98,005
Interest payable	1,104	1,280
FHLB and other borrowings	50,000	80,708
Derivative financial liabilities	90	167
Deferred compensation liabilities	4,002	3,224
Reported Value Measurement [Member] \| Demand Deposits [Member]
Deposits fair value	454,143	427,705
Reported Value Measurement [Member] \| Interest-bearing Deposits [Member]
Deposits fair value	465,407	378,339
Reported Value Measurement [Member] \| Savings Deposits [Member]
Deposits fair value	512,795	523,260
Reported Value Measurement [Member] \| Bank Time Deposits [Member]
Deposits fair value	497,546	512,034
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	157,951	76,307
Securities available for sale	165,580	165,579
Securities held to maturity	25,084	47,266
Loans held for investment, net of allowance	1,760,606	1,805,999
FDIC indemnification asset	3,927	8,112
Interest receivable	5,778	5,553
Deferred compensation assets	4,002	3,224
Securities sold under agreements to repurchase	30,449	98,879
Interest payable	1,104	1,280
FHLB and other borrowings	52,702	83,551
Derivative financial liabilities	90	167
Deferred compensation liabilities	4,002	3,224
Estimate of Fair Value Measurement [Member] \| Demand Deposits [Member]
Deposits fair value	454,143	427,705
Estimate of Fair Value Measurement [Member] \| Interest-bearing Deposits [Member]
Deposits fair value	465,407	378,339
Estimate of Fair Value Measurement [Member] \| Savings Deposits [Member]
Deposits fair value	512,795	523,260
Estimate of Fair Value Measurement [Member] \| Bank Time Deposits [Member]
Deposits fair value	490,628	507,917
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	157,951	76,307
Securities available for sale	55	55
Securities held to maturity
Loans held for investment, net of allowance
FDIC indemnification asset
Interest receivable
Deferred compensation assets	4,002	3,224
Securities sold under agreements to repurchase
Interest payable
FHLB and other borrowings
Derivative financial liabilities
Deferred compensation liabilities	4,002	3,224
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Demand Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Interest-bearing Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Savings Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Bank Time Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents
Securities available for sale	165,525	165,524
Securities held to maturity	25,084	47,266
Loans held for investment, net of allowance	5,739	4,701
FDIC indemnification asset
Interest receivable	5,778	5,553
Deferred compensation assets
Securities sold under agreements to repurchase	30,449	98,879
Interest payable	1,104	1,280
FHLB and other borrowings	52,702	83,551
Derivative financial liabilities	90	167
Deferred compensation liabilities
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Demand Deposits [Member]
Deposits fair value	454,143	427,705
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Interest-bearing Deposits [Member]
Deposits fair value	465,407	378,339
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Savings Deposits [Member]
Deposits fair value	512,795	523,260
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Bank Time Deposits [Member]
Deposits fair value	490,628	507,917
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents
Securities available for sale
Securities held to maturity
Loans held for investment, net of allowance	1,754,867	1,801,298
FDIC indemnification asset	3,927	8,112
Interest receivable
Deferred compensation assets
Securities sold under agreements to repurchase
Interest payable
FHLB and other borrowings
Derivative financial liabilities
Deferred compensation liabilities
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Demand Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Interest-bearing Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Savings Deposits [Member]
Deposits fair value
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Bank Time Deposits [Member]
Deposits fair value

Fair value portion of deferred compensation assets.

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Fair value portion of deferred compensation liabilities.

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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, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Carrying amount of receivable assets originating from the indemnification agreement with the Federal Deposit Insurance Corporation (FDIC), in which the FDIC is to partially cover losses.

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No definition available.

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

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Fair value of investments in debt securities classified as held-to-maturity.

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Amount of interest payable on debt, including, but not limited to, trade payables.

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Carrying amount as of the balance sheet date of interest earned but not received. Also called accrued interest or accrued interest receivable.

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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 securities that an entity sells and agrees to repurchase at a specified date for a specified price.

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