Note 6 - Fair Value of Financial Instruments - Fair Value of Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-Sale	$ 663,503	$ 673,413
Investment securities available-for-sale, at fair value	663,503	673,413
Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	663,503	673,413
Investment securities available-for-sale, at fair value	663,503	673,413
Assets, Fair Value Disclosure	669,529
Assets, Fair Value Disclosure	669,529
Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Derivative assets, fair value	6,026
US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale	132,595	305,247
Investment securities available-for-sale, at fair value	132,595	305,247
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale		305,247
Investment securities available-for-sale, at fair value		305,247
Passthrough Mortgage Securities [Member]
Debt Securities, Available-for-Sale	133,032	148,520
Investment securities available-for-sale, at fair value	133,032	148,520
Passthrough Mortgage Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	133,032	148,520
Investment securities available-for-sale, at fair value	133,032	148,520
Collateralized Debt Obligations [Member]
Debt Securities, Available-for-Sale	163,912	113,394
Investment securities available-for-sale, at fair value	163,912	113,394
Collateralized Debt Obligations [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	163,912	113,394
Investment securities available-for-sale, at fair value	163,912	113,394
Company Agency Obligations [Member]
Debt Securities, Available-for-Sale	129,719
Investment securities available-for-sale, at fair value	129,719
Company Agency Obligations [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	129,719
Investment securities available-for-sale, at fair value	129,719
Corporate Bond Securities [Member]
Debt Securities, Available-for-Sale	104,245	106,252
Investment securities available-for-sale, at fair value	104,245	106,252
Corporate Bond Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	104,245	106,252
Investment securities available-for-sale, at fair value	104,245	106,252
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	112	567
Investment securities available-for-sale, at fair value	112	567
Assets, Fair Value Disclosure	112
Assets, Fair Value Disclosure	112
Fair Value, Inputs, Level 3 [Member] | Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Derivative assets, fair value	0
Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member]
Debt Securities, Available-for-Sale	132,595
Investment securities available-for-sale, at fair value	132,595
Fair Value, Inputs, Level 3 [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	112
Investment securities available-for-sale, at fair value	112
Assets, Fair Value Disclosure		567
Assets, Fair Value Disclosure		567
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	663,391	672,846
Investment securities available-for-sale, at fair value	663,391	672,846
Derivative assets, fair value	669,417
Fair Value, Inputs, Level 2 [Member] | Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Derivative assets, fair value	6,026
Fair Value, Inputs, Level 2 [Member] | US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	132,483	304,680
Investment securities available-for-sale, at fair value	132,483	304,680
Fair Value, Inputs, Level 2 [Member] | Passthrough Mortgage Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	133,032	148,520
Investment securities available-for-sale, at fair value	133,032	148,520
Fair Value, Inputs, Level 2 [Member] | Collateralized Debt Obligations [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	163,912	113,394
Investment securities available-for-sale, at fair value	163,912	113,394
Fair Value, Inputs, Level 2 [Member] | Company Agency Obligations [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	129,719
Investment securities available-for-sale, at fair value	129,719
Fair Value, Inputs, Level 2 [Member] | Corporate Bond Securities [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	104,245	106,252
Investment securities available-for-sale, at fair value	104,245	106,252
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member]
Debt Securities, Available-for-Sale	0	0
Investment securities available-for-sale, at fair value	0	$ 0
Assets, Fair Value Disclosure	0
Assets, Fair Value Disclosure	0
Fair Value, Inputs, Level 1 [Member] | Fair Value, Recurring [Member] | Interest Rate Swap [Member]
Derivative assets, fair value	$ 0