Note 13 - Fair Value Measurements and Fair Value of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Securities available-for-sale	$ 908,844	$ 1,036,550
Equity securities	20,993	23,744
Assets, fair value disclosure	936,359	1,068,382
Liabilities, fair value disclosure	14,666	12,486
Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	40,720	80,948
Equity securities	20,993	23,744
Assets, fair value disclosure	61,713	104,692
Liabilities, fair value disclosure	0	0
Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	868,124	955,602
Equity securities	0	0
Assets, fair value disclosure	874,630	963,669
Liabilities, fair value disclosure	14,666	12,486
Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Equity securities	0	0
Assets, fair value disclosure	16	21
Liabilities, fair value disclosure	0	0
US Treasury Securities [Member]
Securities available-for-sale	40,720	80,948
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	40,720	80,948
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	0	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
US Government Corporations and Agencies Securities [Member]
Securities available-for-sale	96,051	99,838
US Government Corporations and Agencies Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
US Government Corporations and Agencies Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	96,051	99,838
US Government Corporations and Agencies Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Commercial Mortgage Backed Securities [Member]
Securities available-for-sale	668,424	727,068
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	668,424	727,068
Commercial Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Collateralized Mortgage Obligations [Member]
Securities available-for-sale	10,127	10,324
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	10,127	10,324
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Corporate Debt Securities [Member]
Securities available-for-sale	93,522	118,372
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale	93,522	118,372
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale	0	0
Mutual Funds [Member]
Equity securities	6,301	6,413
Mutual Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities	6,301	6,413
Mutual Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities	0	0
Mutual Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Equity securities	0	0
Preferred Stock of Government Sponsored Entities [Member]
Equity securities	3,328	5,485
Preferred Stock of Government Sponsored Entities [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities	3,328	5,485
Preferred Stock of Government Sponsored Entities [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities	0	0
Preferred Stock of Government Sponsored Entities [Member] | Fair Value, Inputs, Level 3 [Member]
Equity securities	0	0
Other Equity Securities [Member]
Equity securities	11,364	11,846
Other Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Equity securities	11,364	11,846
Other Equity Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Equity securities	0	0
Other Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Equity securities	0	0
Warrant [Member]
Assets, fair value disclosure	16	21
Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, fair value disclosure	0	0
Warrant [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, fair value disclosure	0	0
Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, fair value disclosure	16	21
Interest Rate Swap [Member]
Assets, fair value disclosure	3,615	3,409
Liabilities, fair value disclosure	12,116	10,286
Interest Rate Swap [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	0	0
Interest Rate Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, fair value disclosure	3,615	3,409
Liabilities, fair value disclosure	12,116	10,286
Interest Rate Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	0	0
Foreign Exchange Contract [Member]
Assets, fair value disclosure	2,891	4,658
Liabilities, fair value disclosure	2,550	2,200
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	0	0
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Assets, fair value disclosure	2,891	4,658
Liabilities, fair value disclosure	2,550	2,200
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Assets, fair value disclosure	0	0
Liabilities, fair value disclosure	$ 0	$ 0