Note 6 - Fair Value Measurements and Fair Value of Financial Instruments - Carrying Value and Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Securities available-for-sale	$ 623,629	$ 534,507
Reported Value Measurement [Member]
Cash and due from banks	333,844	265,536
Securities available-for-sale	623,629	534,507
Restricted investments in bank stocks	45,324	27,826
Equity securities	15,563	13,794
Net loans	7,808,733	6,749,849
Derivatives	54,041	3,347
Accrued interest receivable	38,940	34,152
Noninterest-bearing deposits	1,665,658	1,617,049
Interest-bearing deposits	5,644,852	4,715,904
Borrowings	829,953	468,193
Subordinated debentures	153,179	152,951
Accrued interest payable	5,733	2,716
Estimate of Fair Value Measurement [Member]
Cash and due from banks	333,844	265,536
Securities available-for-sale	623,629	534,507
Equity securities	15,563	13,794
Net loans	7,524,799	6,800,287
Derivatives	54,041	3,347
Accrued interest receivable	38,940	34,152
Noninterest-bearing deposits	1,665,658	1,617,049
Interest-bearing deposits	5,599,170	4,716,358
Borrowings	826,280	469,671
Subordinated debentures	153,170	163,995
Accrued interest payable	5,733	2,716
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and due from banks	333,844	265,536
Securities available-for-sale	134	195
Equity securities	9,701	11,081
Net loans	0	0
Derivatives	0	0
Accrued interest receivable	0	0
Noninterest-bearing deposits	1,665,658	1,617,049
Interest-bearing deposits	3,723,617	3,565,795
Borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	0	0
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and due from banks	0	0
Securities available-for-sale	616,118	525,747
Equity securities	5,862	2,713
Net loans	0	0
Derivatives	54,041	3,347
Accrued interest receivable	3,219	1,554
Noninterest-bearing deposits	0	0
Interest-bearing deposits	1,875,553	1,150,563
Borrowings	826,280	469,671
Subordinated debentures	153,170	163,995
Accrued interest payable	5,733	2,716
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and due from banks	0	0
Securities available-for-sale	7,377	8,565
Equity securities	0	0
Net loans	7,524,799	6,800,287
Derivatives	0	0
Accrued interest receivable	35,721	32,598
Noninterest-bearing deposits	0	0
Interest-bearing deposits	0	0
Borrowings	0	0
Subordinated debentures	0	0
Accrued interest payable	$ 0	$ 0