Note 21 - Disclosures About Fair Value of Financial Instruments - Fair Value of Financial Instruments Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	$ 421,145	$ 285,252
Fair Value, Recurring [Member] \| Reported Value Measurement [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	421,145	285,252
Mortgage loans held for sale	18,179	7,484
Derivative, fair value	328	335
Bank owned life insurance	31,762	30,952
Total assets	471,414	324,023
Mortgage banking derivatives	23	88
Total liabilities	23	88
Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Mortgage loans held for sale	0	0
Derivative, fair value	0	0
Bank owned life insurance	0	0
Total assets	0	0
Mortgage banking derivatives	0	0
Total liabilities	0	0
Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	421,145	285,252
Mortgage loans held for sale	18,179	7,484
Derivative, fair value	328	335
Bank owned life insurance	0	0
Total assets	439,652	293,071
Mortgage banking derivatives	23	88
Total liabilities	23	88
Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Mortgage loans held for sale	0	0
Derivative, fair value	0	0
Bank owned life insurance	31,762	30,952
Total assets	31,762	30,952
Mortgage banking derivatives	0	0
Total liabilities	0	0
US Government-sponsored Enterprises Debt Securities [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	59,579	68,467
US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Recurring [Member] \| Reported Value Measurement [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	59,579	68,467
US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	59,579	68,467
US Government-sponsored Enterprises Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Collateralized Mortgage Backed Securities [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	267,313	147,510
Collateralized Mortgage Backed Securities [Member] \| Fair Value, Recurring [Member] \| Reported Value Measurement [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	267,313	147,510
Collateralized Mortgage Backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Collateralized Mortgage Backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	267,313	147,510
Collateralized Mortgage Backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Asset-backed Securities [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	27,229	21,700
Asset-backed Securities [Member] \| Fair Value, Recurring [Member] \| Reported Value Measurement [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	27,229	21,700
Asset-backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
Asset-backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	27,229	21,700
Asset-backed Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	67,024	47,575
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member] \| Reported Value Measurement [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	67,024	47,575
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	0	0
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	67,024	47,575
US States and Political Subdivisions Debt Securities [Member] \| Fair Value, Recurring [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale securities, at market (amortized cost $420,207 and $295,683, respectively)	$ 0	$ 0

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 security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value portion of the amount that could be realized under a life insurance contract or contracts owned by the entity, commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

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Fair value, before effects of master netting arrangements, of a financial asset or other 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 assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Fair value, before 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 elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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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 loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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