Securities - Amortized Cost and Fair Value, Held to Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 1,221,496	$ 1,324,072
Gross Unrealized Gains	74	17
Gross Unrealized Losses	(99,740)	(117,549)
Fair Value	1,121,830	1,206,540
Allowance for credit losses - held to maturity securities	(32)	(32)
Held-to-maturity securities, net of allowance for credit losses	1,221,464	1,324,040
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	288,154	291,886
Gross Unrealized Gains	74	17
Gross Unrealized Losses	(33,688)	(48,325)
Fair Value	254,540	243,578
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	387,208	423,315
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(31,670)	(30,706)
Fair Value	355,538	392,609
Other debt securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	58,373	62,875
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(4,119)	(4,266)
Fair Value	54,254	58,609
Government agency mortgage-backed securities | Residential mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	426,264	483,560
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(20,314)	(24,432)
Fair Value	405,950	459,128
Government agency mortgage-backed securities | Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	16,983	17,006
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2,972)	(3,261)
Fair Value	14,011	13,745
Government agency collateralized mortgage obligations | Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	44,514	45,430
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6,977)	(6,559)
Fair Value	$ 37,537	$ 38,871