Investment Securities - Amortized Cost and Estimated Fair Values of Investment Securities by Contractual Final Maturity (Details) $ in Thousands	Dec. 31, 2025 USD ($)
Investment Securities [Abstract]
Available-for-sale, Amortized cost, One year or less	$ 5,670
Available-for-sale, Fair value, One year or less	5,672
Held-to-maturity, Amortized cost, One year or less	1,918
Held-to-maturity, Fair value, One year or less	1,911
Available-for-sale, Amortized cost, After one year through five years	25,577
Available-for-sale, Fair value, After one year through five years	25,733
Held-to-maturity, Amortized cost, After one year through five years	18,411
Held-to-maturity, Fair value, After one year through five years	18,389
Available-for-sale, Amortized cost, After five years through ten years	24,394
Available-for-sale, Fair value, After five years through ten years	25,778
Held-to-maturity, Amortized cost, After five years through ten years	18,653
Held-to-maturity, Fair value, After five years through ten years	17,843
Available-for-sale, Amortized cost, After ten years	899,562
Available-for-sale, Fair value, After ten years	893,971
Held-to-maturity, Amortized cost, After ten years	679,659
Held-to-maturity, Fair value, After ten years	554,593
Available-for-sale, Amortized cost, Total	955,203
Available-for-sale, Fair value, Total	951,154
Held-to-maturity, Amortized cost, Total	718,641
Held-to-maturity, Fair value, Total	$ 592,736