Investment Securities - Bond Ratings (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 1,258,640	$ 1,261,267
Aaa/AAA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	282,766
Aa/AA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	823,847
A
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	32,600
Not rated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	6,710
Agency backed
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	112,717
State and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	1,102,011	1,102,613
State and political subdivisions \| Aaa/AAA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	238,854
State and political subdivisions \| Aa/AA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	823,847
State and political subdivisions \| A
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	32,600
State and political subdivisions \| Not rated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	6,710
State and political subdivisions \| Agency backed
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored enterprises
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	43,912	$ 43,841
U.S. government-sponsored enterprises \| Aaa/AAA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	43,912
U.S. government-sponsored enterprises \| Aa/AA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored enterprises \| A
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored enterprises \| Not rated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored enterprises \| Agency backed
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	112,717
U.S. government-sponsored mortgage-backed securities \| Aaa/AAA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored mortgage-backed securities \| Aa/AA
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored mortgage-backed securities \| A
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored mortgage-backed securities \| Not rated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	0
U.S. government-sponsored mortgage-backed securities \| Agency backed
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 112,717