Securities - Gross Unrealized Losses and Fair Value by Investment Category (Details) $ in Thousands	Sep. 30, 2025 USD ($) security	Dec. 31, 2024 USD ($) security
Available for Sale:
Number of positions, Less than 12 Months | security	61	16
Fair Value, Less than 12 Months	$ 553,009	$ 95,216
Unrealized Losses, Less than 12 Months	$ (4,592)	$ (1,120)
Number of positions, 12 Months or More | security	117	122
Fair value, 12 Months or More	$ 583,825	$ 606,628
Unrealized Losses, 12 Months or More	$ (97,891)	$ (137,488)
Number of positions | security	178	138
Fair Value	$ 1,136,834	$ 701,844
Unrealized Losses	$ (102,483)	$ (138,608)
Held to Maturity:
Number of positions, Less than 12 Months | security	6	0
Fair Value, Less than 12 Months	$ 15,151	$ 0
Unrealized Losses, Less than 12 Months	$ (1,272)	$ 0
Number of positions, 12 Months or More | security	223	235
Fair value, 12 Months or More	$ 959,886	$ 1,000,874
Unrealized Losses, 12 Months or More	$ (73,980)	$ (123,603)
Number of positions | security	229	235
Fair Value	$ 975,037	$ 1,000,874
Unrealized Losses	$ (75,252)	$ (123,603)
Obligations of states and political subdivisions
Available for Sale:
Number of positions, Less than 12 Months | security	19	0
Fair Value, Less than 12 Months	$ 33,281	$ 0
Unrealized Losses, Less than 12 Months	$ (702)	$ 0
Number of positions, 12 Months or More | security	7	7
Fair value, 12 Months or More	$ 13,309	$ 12,841
Unrealized Losses, 12 Months or More	$ (1,663)	$ (2,269)
Number of positions | security	26	7
Fair Value	$ 46,590	$ 12,841
Unrealized Losses	$ (2,365)	$ (2,269)
Held to Maturity:
Number of positions, Less than 12 Months | security	6	0
Fair Value, Less than 12 Months	$ 15,151	$ 0
Unrealized Losses, Less than 12 Months	$ (1,272)	$ 0
Number of positions, 12 Months or More | security	119	128
Fair value, 12 Months or More	$ 229,928	$ 240,394
Unrealized Losses, 12 Months or More	$ (32,313)	$ (42,491)
Number of positions | security	125	128
Fair Value	$ 245,079	$ 240,394
Unrealized Losses	$ (33,585)	$ (42,491)
Other debt securities
Available for Sale:
Number of positions, Less than 12 Months | security	16	2
Fair Value, Less than 12 Months	$ 269,566	$ 22,357
Unrealized Losses, Less than 12 Months	$ (1,983)	$ (218)
Number of positions, 12 Months or More | security	10	17
Fair value, 12 Months or More	$ 18,286	$ 30,801
Unrealized Losses, 12 Months or More	$ (1,256)	$ (2,437)
Number of positions | security	26	19
Fair Value	$ 287,852	$ 53,158
Unrealized Losses	$ (3,239)	$ (2,655)
Held to Maturity:
Number of positions, Less than 12 Months | security	0	0
Fair Value, Less than 12 Months	$ 0	$ 0
Unrealized Losses, Less than 12 Months	$ 0	$ 0
Number of positions, 12 Months or More | security	10	10
Fair value, 12 Months or More	$ 45,854	$ 49,603
Unrealized Losses, 12 Months or More	$ (2,440)	$ (4,080)
Number of positions | security	10	10
Fair Value	$ 45,854	$ 49,603
Unrealized Losses	$ (2,440)	$ (4,080)
Mortgage backed securities issued by U.S. Government agencies or sponsored enterprises | Residential mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	5	7
Fair Value, Less than 12 Months	$ 122,812	$ 11,051
Unrealized Losses, Less than 12 Months	$ (1,316)	$ (259)
Number of positions, 12 Months or More | security	36	34
Fair value, 12 Months or More	$ 137,171	$ 141,321
Unrealized Losses, 12 Months or More	$ (16,192)	$ (24,208)
Number of positions | security	41	41
Fair Value	$ 259,983	$ 152,372
Unrealized Losses	$ (17,508)	$ (24,467)
Held to Maturity:
Number of positions, Less than 12 Months | security	0	0
Fair Value, Less than 12 Months	$ 0	$ 0
Unrealized Losses, Less than 12 Months	$ 0	$ 0
Number of positions, 12 Months or More | security	66	69
Fair value, 12 Months or More	$ 324,998	$ 347,154
Unrealized Losses, 12 Months or More	$ (11,384)	$ (25,251)
Number of positions | security	66	69
Fair Value	$ 324,998	$ 347,154
Unrealized Losses	$ (11,384)	$ (25,251)
Mortgage backed securities issued by U.S. Government agencies or sponsored enterprises | Commercial mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	9	2
Fair Value, Less than 12 Months	$ 71,211	$ 5,248
Unrealized Losses, Less than 12 Months	$ (396)	$ (122)
Number of positions, 12 Months or More | security	2	2
Fair value, 12 Months or More	$ 5,581	$ 5,375
Unrealized Losses, 12 Months or More	$ (403)	$ (629)
Number of positions | security	11	4
Fair Value	$ 76,792	$ 10,623
Unrealized Losses	$ (799)	$ (751)
Held to Maturity:
Number of positions, Less than 12 Months | security	0	0
Fair Value, Less than 12 Months	$ 0	$ 0
Unrealized Losses, Less than 12 Months	$ 0	$ 0
Number of positions, 12 Months or More | security	1	1
Fair value, 12 Months or More	$ 14,758	$ 14,002
Unrealized Losses, 12 Months or More	$ (2,185)	$ (2,958)
Number of positions | security	1	1
Fair Value	$ 14,758	$ 14,002
Unrealized Losses	$ (2,185)	$ (2,958)
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises | Residential mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	3	3
Fair Value, Less than 12 Months	$ 27,820	$ 48,879
Unrealized Losses, Less than 12 Months	$ (155)	$ (482)
Number of positions, 12 Months or More | security	37	37
Fair value, 12 Months or More	$ 306,995	$ 311,964
Unrealized Losses, 12 Months or More	$ (59,748)	$ (86,389)
Number of positions | security	40	40
Fair Value	$ 334,815	$ 360,843
Unrealized Losses	$ (59,903)	$ (86,871)
Held to Maturity:
Number of positions, Less than 12 Months | security	0	0
Fair Value, Less than 12 Months	$ 0	$ 0
Unrealized Losses, Less than 12 Months	$ 0	$ 0
Number of positions, 12 Months or More | security	18	18
Fair value, 12 Months or More	$ 308,063	$ 313,376
Unrealized Losses, 12 Months or More	$ (19,529)	$ (41,506)
Number of positions | security	18	18
Fair Value	$ 308,063	$ 313,376
Unrealized Losses	$ (19,529)	$ (41,506)
Collateralized mortgage obligations issued by U.S. Government agencies or sponsored enterprises | Commercial mortgage backed securities:
Available for Sale:
Number of positions, Less than 12 Months | security	9	2
Fair Value, Less than 12 Months	$ 28,319	$ 7,681
Unrealized Losses, Less than 12 Months	$ (40)	$ (39)
Number of positions, 12 Months or More | security	25	25
Fair value, 12 Months or More	$ 102,483	$ 104,326
Unrealized Losses, 12 Months or More	$ (18,629)	$ (21,556)
Number of positions | security	34	27
Fair Value	$ 130,802	$ 112,007
Unrealized Losses	$ (18,669)	$ (21,595)
Held to Maturity:
Number of positions, Less than 12 Months | security	0	0
Fair Value, Less than 12 Months	$ 0	$ 0
Unrealized Losses, Less than 12 Months	$ 0	$ 0
Number of positions, 12 Months or More | security	9	9
Fair value, 12 Months or More	$ 36,285	$ 36,345
Unrealized Losses, 12 Months or More	$ (6,129)	$ (7,317)
Number of positions | security	9	9
Fair Value	$ 36,285	$ 36,345
Unrealized Losses	$ (6,129)	$ (7,317)