Quarterly report [Sections 13 or 15(d)]

Note 4 - Securities - Amortized Cost and Fair Value of Available-for-sale and Held-to-maturity Securities (Details)

v3.26.1
Note 4 - Securities - Amortized Cost and Fair Value of Available-for-sale and Held-to-maturity Securities (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Available for sale, amortized cost $ 1,000,285 $ 1,073,313
Available for sale, gross unrealized gain 4,047 6,128
Available for sale, gross unrealized loss (9,281) (10,616)
Available for sale, fair value 995,051 1,068,825
Held to maturity, amortized cost 635,480 660,076
Held to maturity, gross unrealized gain 445 743
Held to maturity, gross unrealized loss (45,645) (44,284)
Held to maturity debt securities, fair value 590,280 616,535
US Treasury Securities [Member]    
Available for sale, amortized cost 430,267 520,100
Available for sale, gross unrealized gain 655 2,823
Available for sale, gross unrealized loss 0 0
Available for sale, fair value 430,922 522,923
Held to maturity, amortized cost 249,730 249,621
Held to maturity, gross unrealized gain 0 0
Held to maturity, gross unrealized loss (9,020) (9,589)
Held to maturity debt securities, fair value 240,710 240,032
Collateralized Mortgage-Backed Securities [Member]    
Available for sale, amortized cost 163,452 133,126
Available for sale, gross unrealized gain 268 1,030
Available for sale, gross unrealized loss (1,589) (852)
Available for sale, fair value 162,131 133,304
Held to maturity, amortized cost 376,735 402,097
Held to maturity, gross unrealized gain 445 743
Held to maturity, gross unrealized loss (36,333) (34,395)
Held to maturity debt securities, fair value 340,847 368,445
US States and Political Subdivisions Debt Securities [Member]    
Available for sale, amortized cost 10,357 10,362
Available for sale, gross unrealized gain 1 1
Available for sale, gross unrealized loss (541) (554)
Available for sale, fair value 9,817 9,809
Held to maturity, amortized cost 9,015 8,358
Held to maturity, gross unrealized gain 0 0
Held to maturity, gross unrealized loss (292) (300)
Held to maturity debt securities, fair value 8,723 8,058
Corporate Debt Securities [Member]    
Available for sale, amortized cost 396,209 409,725
Available for sale, gross unrealized gain 3,123 2,274
Available for sale, gross unrealized loss (7,151) (9,210)
Available for sale, fair value $ 392,181 $ 402,789