Note 15 - Fair Value Measurements and Fair Values of Financial Instruments - Financial Assets Measured at on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Investment securities available for sale, at fair value	$ 369,739	$ 284,795
SBA Servicing Assets	5,352	4,886	$ 4,099	$ 3,477
Collateralized Mortgage Obligations [Member]
Investment securities available for sale, at fair value	224,765	178,145
Agency Mortgage-backed Securities [Member]
Investment securities available for sale, at fair value	36,710	10,171
US States and Political Subdivisions Debt Securities [Member]
Investment securities available for sale, at fair value	26,547	23,344
Corporate Debt Securities [Member]
Investment securities available for sale, at fair value	64,748	54,129
Asset-backed Securities [Member]
Investment securities available for sale, at fair value	15,149	17,005
Collateralized Debt Obligations [Member]
Investment securities available for sale, at fair value	1,820	1,883
Other Debt Obligations [Member]
Investment securities available for sale, at fair value		118
Fair Value, Measurements, Recurring [Member]
Investment securities available for sale, at fair value	369,739	284,795
Mortgage Loans Held for Sale	23,911
SBA Servicing Assets	5,352	4,886
Fair Value, Measurements, Recurring [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Asset	103
Fair Value, Measurements, Recurring [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Asset	229
Fair Value, Measurements, Recurring [Member] | Interest Rate Lock Commitments [Member]
Derivative Asset	439
Derivative Liability	55
Fair Value, Measurements, Recurring [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Liability	125
Fair Value, Measurements, Recurring [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Liability	38
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Mortgage Loans Held for Sale
SBA Servicing Assets
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Asset
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Asset
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Interest Rate Lock Commitments [Member]
Derivative Asset
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	364,948	280,078
Mortgage Loans Held for Sale	23,911
SBA Servicing Assets
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Asset	103
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Asset	229
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Interest Rate Lock Commitments [Member]
Derivative Asset	439
Derivative Liability	55
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Liability	125
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Liability	38
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value	4,791	4,717
Mortgage Loans Held for Sale
SBA Servicing Assets	5,352	4,886
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Asset
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Asset
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Interest Rate Lock Commitments [Member]
Derivative Asset
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Best Efforts Forward Loan sales Commitments [Member]
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Mandatory Forward Loan Sales Commitments [Member]
Derivative Liability
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member]
Investment securities available for sale, at fair value	224,765	178,145
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	224,765	178,145
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Agency Mortgage-backed Securities [Member]
Investment securities available for sale, at fair value	36,710	10,171
Fair Value, Measurements, Recurring [Member] | Agency Mortgage-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Agency Mortgage-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	36,710	10,171
Fair Value, Measurements, Recurring [Member] | Agency Mortgage-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member]
Investment securities available for sale, at fair value	26,547	23,344
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	26,547	23,344
Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member]
Investment securities available for sale, at fair value	64,748	54,129
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	61,777	51,295
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value	2,971	2,834
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member]
Investment securities available for sale, at fair value	15,149	17,005
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value	15,149	17,005
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Collateralized Debt Obligations [Member]
Investment securities available for sale, at fair value	1,820	1,883
Fair Value, Measurements, Recurring [Member] | Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Collateralized Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value	$ 1,820	1,883
Fair Value, Measurements, Recurring [Member] | Other Debt Obligations [Member]
Investment securities available for sale, at fair value		118
Fair Value, Measurements, Recurring [Member] | Other Debt Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Investment securities available for sale, at fair value
Fair Value, Measurements, Recurring [Member] | Other Debt Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Investment securities available for sale, at fair value		118
Fair Value, Measurements, Recurring [Member] | Other Debt Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Investment securities available for sale, at fair value