Note 5 - Loans - Components of Loans in Consolidated Balance Sheets (Details) - USD ($) $ in Thousands |
Jun. 30, 2026 |
Mar. 31, 2026 |
Dec. 31, 2025 |
Jun. 30, 2025 |
Mar. 31, 2025 |
Dec. 31, 2024 |
|---|---|---|---|---|---|---|
| Loans held for investment | $ 20,621,332 | $ 20,147,202 | ||||
| Less: Allowance for loan losses | (218,896) | $ (208,786) | (195,911) | $ (173,531) | $ (173,936) | $ (161,765) |
| Unamortized deferred loan fees, net | (14,606) | (14,903) | ||||
| Loans held for investment, net | 20,387,830 | 19,936,388 | ||||
| Commercial Portfolio Segment [Member] | ||||||
| Loans held for investment | 3,524,945 | 3,184,556 | ||||
| Less: Allowance for loan losses | (46,374) | (46,720) | (39,123) | (40,842) | (69,023) | (57,796) |
| Real Estate Construction Portfolio Segment [Member] | ||||||
| Loans held for investment | 248,375 | 337,550 | ||||
| Less: Allowance for loan losses | (15,153) | (15,404) | (6,475) | (5,434) | (8,540) | (8,185) |
| Commercial Real Estate Portfolio Segment [Member] | ||||||
| Loans held for investment | 10,779,326 | 10,564,744 | ||||
| Less: Allowance for loan losses | (134,102) | (122,349) | (125,665) | (106,773) | (80,901) | (79,597) |
| Residential Portfolio Segment [Member] | ||||||
| Loans held for investment | 5,832,159 | 5,832,094 | ||||
| Equity Lines Portfolio Segment [Member] | ||||||
| Loans held for investment | 234,265 | 226,444 | ||||
| Installment and Other Loans [Member ] | ||||||
| Loans held for investment | 2,262 | 1,814 | ||||
| Less: Allowance for loan losses | $ (7) | $ (16) | $ (7) | $ (17) | $ (17) | $ (6) |