Securities - Fair Value and Unrealized Losses on Debt Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Available-for-sale:
Estimated Fair Value	$ 5,406	$ 296,224
Unrealized Losses	(119)	(20,715)
Estimated Fair Value	490,586	239,756
Unrealized Losses	(74,098)	(40,391)
Estimated Fair Value	495,992	535,980
Unrealized Losses	$ (74,217)	$ (61,106)
Number of Securities | security	223	219
Held-to-maturity:
Estimated Fair Value	$ 464	$ 32,273
Unrealized Losses	(4)	(5,677)
Estimated Fair Value	30,307	401
Unrealized Losses	(6,614)	(15)
Estimated Fair Value	30,771	32,674
Unrealized Losses	$ (6,618)	$ (5,692)
Number of Securities | security	27	23
U.S. treasury
Available-for-sale:
Estimated Fair Value	$ 0	$ 25,702
Unrealized Losses	0	(967)
Estimated Fair Value	52,853	30,947
Unrealized Losses	(5,625)	(4,394)
Estimated Fair Value	52,853	56,649
Unrealized Losses	$ (5,625)	$ (5,361)
Number of Securities | security	9	10
U.S. agency
Available-for-sale:
Estimated Fair Value	$ 0	$ 0
Unrealized Losses	0	0
Estimated Fair Value	2,055	2,834
Unrealized Losses	(34)	(47)
Estimated Fair Value	2,055	2,834
Unrealized Losses	$ (34)	$ (47)
Number of Securities | security	7	7
Obligations of states and political subdivisions
Available-for-sale:
Estimated Fair Value	$ 0	$ 21,676
Unrealized Losses	0	(3,784)
Estimated Fair Value	24,488	2,753
Unrealized Losses	(5,453)	(1,214)
Estimated Fair Value	24,488	24,429
Unrealized Losses	$ (5,453)	$ (4,998)
Number of Securities | security	19	18
Held-to-maturity:
Estimated Fair Value	$ 329	$ 20,153
Unrealized Losses	(4)	(4,891)
Estimated Fair Value	19,698	0
Unrealized Losses	(5,469)	0
Estimated Fair Value	20,027	20,153
Unrealized Losses	$ (5,473)	$ (4,891)
Number of Securities | security	9	8
Mortgage backed - residential
Available-for-sale:
Estimated Fair Value	$ 320	$ 51,921
Unrealized Losses	(4)	(2,939)
Estimated Fair Value	100,233	63,691
Unrealized Losses	(18,418)	(10,887)
Estimated Fair Value	100,553	115,612
Unrealized Losses	$ (18,422)	$ (13,826)
Number of Securities | security	88	87
Held-to-maturity:
Estimated Fair Value	$ 135	$ 7,993
Unrealized Losses	0	(511)
Estimated Fair Value	6,888	0
Unrealized Losses	(815)	0
Estimated Fair Value	7,023	7,993
Unrealized Losses	$ (815)	$ (511)
Number of Securities | security	13	10
Collateralized mortgage obligations
Available-for-sale:
Estimated Fair Value	$ 0	$ 111,360
Unrealized Losses	0	(4,631)
Estimated Fair Value	184,457	92,905
Unrealized Losses	(24,492)	(16,663)
Estimated Fair Value	184,457	204,265
Unrealized Losses	$ (24,492)	$ (21,294)
Number of Securities | security	66	66
Held-to-maturity:
Estimated Fair Value	$ 0	$ 4,127
Unrealized Losses	0	(275)
Estimated Fair Value	3,721	401
Unrealized Losses	(330)	(15)
Estimated Fair Value	3,721	4,528
Unrealized Losses	$ (330)	$ (290)
Number of Securities | security	5	5
Mortgage backed - commercial
Available-for-sale:
Estimated Fair Value	$ 5,086	$ 70,710
Unrealized Losses	(115)	(6,475)
Estimated Fair Value	111,825	46,626
Unrealized Losses	(17,964)	(7,186)
Estimated Fair Value	116,911	117,336
Unrealized Losses	$ (18,079)	$ (13,661)
Number of Securities | security	25	22
Other debt
Available-for-sale:
Estimated Fair Value	$ 0	$ 14,855
Unrealized Losses	0	(1,919)
Estimated Fair Value	14,675	0
Unrealized Losses	(2,112)	0
Estimated Fair Value	14,675	14,855
Unrealized Losses	$ (2,112)	$ (1,919)
Number of Securities | security	9	9