Securities - Amortized Cost and Fair Value, Held to Maturity (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 1,150,563	$ 1,221,496
Gross Unrealized Gains	52	74
Gross Unrealized Losses	(81,647)	(99,740)
Fair Value	1,068,968	1,121,830
Allowance for credit losses - held to maturity securities	(32)	(32)
Held to maturity securities, net of allowance for credit losses	1,150,531	1,221,464
Obligations of states and political subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	285,450	288,154
Gross Unrealized Gains	38	74
Gross Unrealized Losses	(34,861)	(33,688)
Fair Value	250,627	254,540
Residential mortgage backed securities:
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	363,095	387,208
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(23,736)	(31,670)
Fair Value	339,359	355,538
Residential mortgage backed securities: | Government agency mortgage backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	386,654	426,264
Gross Unrealized Gains	14	0
Gross Unrealized Losses	(11,742)	(20,314)
Fair Value	374,926	405,950
Commercial mortgage backed securities: | Government agency mortgage backed securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	16,966	16,983
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2,404)	(2,972)
Fair Value	14,562	14,011
Commercial mortgage backed securities: | Government agency collateralized mortgage obligations
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	43,966	44,514
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(6,326)	(6,977)
Fair Value	37,640	37,537
Other debt securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	54,432	58,373
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(2,578)	(4,119)
Fair Value	$ 51,854	$ 54,254