Securities - Fair Value and Age of Gross Unrealized Losses of Debt Securities (Details) $ in Thousands	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Number of Securities
Less Than 12 Months | security	15	116
12 Months or More | security	118	31
Total | security	133	147
Fair Value
Less Than 12 Months	$ 45,297	$ 663,656
12 Months or More	794,365	308,067
Total	839,662	971,723
Unrealized Losses
Less Than 12 Months	(371)	(46,120)
12 Months or More	(83,380)	(56,462)
Total	$ (83,751)	$ (102,582)
U.S. Treasury securities
Number of Securities
Less Than 12 Months | security	1	6
12 Months or More | security	13	8
Total | security	14	14
Fair Value
Less Than 12 Months	$ 10,036	$ 57,057
12 Months or More	123,750	74,638
Total	133,786	131,695
Unrealized Losses
Less Than 12 Months	(52)	(3,363)
12 Months or More	(10,454)	(10,358)
Total	$ (10,506)	$ (13,721)
Obligations of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	0	6
12 Months or More | security	5	0
Total | security	5	6
Fair Value
Less Than 12 Months	$ 0	$ 41,811
12 Months or More	32,513	0
Total	32,513	41,811
Unrealized Losses
Less Than 12 Months	0	(1,668)
12 Months or More	(829)	0
Total	$ (829)	$ (1,668)
Collateralized mortgage obligations of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	4	47
12 Months or More | security	57	13
Total | security	61	60
Fair Value
Less Than 12 Months	$ 35,161	$ 296,509
12 Months or More	351,220	112,902
Total	386,381	409,411
Unrealized Losses
Less Than 12 Months	(318)	(28,153)
12 Months or More	(47,753)	(25,682)
Total	$ (48,071)	$ (53,835)
Residential mortgage-backed securities of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	10	25
12 Months or More | security	14	3
Total | security	24	28
Fair Value
Less Than 12 Months	$ 100	$ 7,143
12 Months or More	37,877	34,223
Total	37,977	41,366
Unrealized Losses
Less Than 12 Months	(1)	(589)
12 Months or More	(6,536)	(7,245)
Total	$ (6,537)	$ (7,834)
Commercial mortgage-backed securities of U.S. government corporations and agencies
Number of Securities
Less Than 12 Months | security	0	30
12 Months or More | security	29	7
Total | security	29	37
Fair Value
Less Than 12 Months	$ 0	$ 241,009
12 Months or More	249,005	86,304
Total	249,005	327,313
Unrealized Losses
Less Than 12 Months	0	(11,975)
12 Months or More	(17,808)	(13,177)
Total	$ (17,808)	$ (25,152)
Obligations of states and political subdivisions
Number of Securities
Less Than 12 Months | security	0	2
12 Months or More | security	0	0
Total | security	0	2
Fair Value
Less Than 12 Months	$ 0	$ 20,127
12 Months or More		0
Total	0	20,127
Unrealized Losses
Less Than 12 Months	0	(372)
12 Months or More		0
Total	$ 0	$ (372)