Securities - Amortized Cost and Fair Value of Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 1,059,119	$ 1,051,313
Gross Unrealized Gains	5,672	1,746
Gross Unrealized Losses	(57,934)	(83,751)
Fair Value	1,006,857	969,308
Interest receivable	3,600	3,800
U.S. Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	122,960	144,292
Gross Unrealized Gains	49	0
Gross Unrealized Losses	(4,900)	(10,506)
Fair Value	118,109	133,786
Obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,282	33,342
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(256)	(829)
Fair Value	15,026	32,513
Collateralized mortgage obligations of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	598,762	507,942
Gross Unrealized Gains	3,907	1,068
Gross Unrealized Losses	(37,357)	(48,071)
Fair Value	565,312	460,939
Residential mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	41,069	44,707
Gross Unrealized Gains	6	7
Gross Unrealized Losses	(5,422)	(6,537)
Fair Value	35,653	38,177
Commercial mortgage-backed securities of U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	256,147	290,775
Gross Unrealized Gains	1,695	458
Gross Unrealized Losses	(9,798)	(17,808)
Fair Value	248,044	273,425
Obligations of states and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	24,899	30,255
Gross Unrealized Gains	15	213
Gross Unrealized Losses	(201)	0
Fair Value	$ 24,713	$ 30,468