Securities - Fair Value and Age of Gross Unrealized Losses of Debt Securities (Details) $ in Thousands	Sep. 30, 2024 USD ($) security	Dec. 31, 2023 USD ($) security
Number of Securities
Less Than 12 Months | security	17	15
12 Months or More | security	97	118
Total | security	114	133
Fair Value
Less Than 12 Months	$ 88,746	$ 45,297
12 Months or More	630,352	794,365
Total	719,098	839,662
Unrealized Losses
Less Than 12 Months	(652)	(371)
12 Months or More	(57,282)	(83,380)
Total	$ (57,934)	$ (83,751)
U.S. Treasury securities
Number of Securities
Less Than 12 Months | security	2	1
12 Months or More | security	8	13
Total | security	10	14
Fair Value
Less Than 12 Months	$ 20,311	$ 10,036
12 Months or More	77,622	123,750
Total	97,933	133,786
Unrealized Losses
Less Than 12 Months	(60)	(52)
12 Months or More	(4,840)	(10,454)
Total	$ (4,900)	$ (10,506)
Obligations of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	0	0
12 Months or More | security	2	5
Total | security	2	5
Fair Value
Less Than 12 Months	$ 0	$ 0
12 Months or More	15,026	32,513
Total	15,026	32,513
Unrealized Losses
Less Than 12 Months	0	0
12 Months or More	(256)	(829)
Total	$ (256)	$ (829)
Collateralized mortgage obligations of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	3	4
12 Months or More | security	56	57
Total | security	59	61
Fair Value
Less Than 12 Months	$ 29,281	$ 35,161
12 Months or More	339,367	351,220
Total	368,648	386,381
Unrealized Losses
Less Than 12 Months	(238)	(318)
12 Months or More	(37,119)	(47,753)
Total	$ (37,357)	$ (48,071)
Residential mortgage-backed securities of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	8	10
12 Months or More | security	13	14
Total | security	21	24
Fair Value
Less Than 12 Months	$ 40	$ 100
12 Months or More	35,429	37,877
Total	35,469	37,977
Unrealized Losses
Less Than 12 Months	0	(1)
12 Months or More	(5,422)	(6,536)
Total	$ (5,422)	$ (6,537)
Commercial mortgage-backed securities of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	2	0
12 Months or More | security	18	29
Total | security	20	29
Fair Value
Less Than 12 Months	$ 19,448	$ 0
12 Months or More	162,908	249,005
Total	182,356	249,005
Unrealized Losses
Less Than 12 Months	(153)	0
12 Months or More	(9,645)	(17,808)
Total	$ (9,798)	$ (17,808)
Obligations of states and political subdivisions
Number of Securities
Less Than 12 Months | security	2
12 Months or More | security	0
Total | security	2
Fair Value
Less Than 12 Months	$ 19,666
12 Months or More	0
Total	19,666
Unrealized Losses
Less Than 12 Months	(201)
12 Months or More	0
Total	$ (201)