Investment Securities - Available-for-sale Securities with Unrealized Loss (Details) $ in Thousands	Dec. 31, 2023 USD ($) security	Dec. 31, 2022 USD ($) security
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	$ 107,930	$ 299,453
Less than 12 months, unrealized loss	$ 1,532	$ 12,051
Less than 12 months, Number of securities | security	132	254
12 months or more, fair value	$ 831,720	$ 803,481
12 months or more, unrealized loss	$ 137,674	$ 158,373
12 months or more, Number of securities | security	420	308
Total fair value	$ 939,650	$ 1,102,934
Total unrealized loss	139,206	170,424
U.S. Treasury and government agencies
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	8,568	112,730
Less than 12 months, unrealized loss	$ 83	$ 2,772
Less than 12 months, Number of securities | security	22	13
12 months or more, fair value	$ 11,631	$ 39,692
12 months or more, unrealized loss	$ 912	$ 3,279
12 months or more, Number of securities | security	5	11
Total fair value	$ 20,199	$ 152,422
Total unrealized loss	995	6,051
U.S. government sponsored agencies
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	14,439	15,166
Less than 12 months, unrealized loss	$ 35	$ 249
Less than 12 months, Number of securities | security	4	17
12 months or more, fair value	$ 74,211	$ 66,706
12 months or more, unrealized loss	$ 10,497	$ 13,407
12 months or more, Number of securities | security	15	18
Total fair value	$ 88,650	$ 81,872
Total unrealized loss	10,532	13,656
States and political subdivisions
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	18,268	60,324
Less than 12 months, unrealized loss	$ 136	$ 714
Less than 12 months, Number of securities | security	32	114
12 months or more, fair value	$ 167,346	$ 156,900
12 months or more, unrealized loss	$ 26,959	$ 35,028
12 months or more, Number of securities | security	138	117
Total fair value	$ 185,614	$ 217,224
Total unrealized loss	27,095	35,742
Residential mortgage-backed securities
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	58,671	104,959
Less than 12 months, unrealized loss	$ 1,150	$ 8,087
Less than 12 months, Number of securities | security	66	105
12 months or more, fair value	$ 529,895	$ 488,452
12 months or more, unrealized loss	$ 89,517	$ 95,302
12 months or more, Number of securities | security	238	139
Total fair value	$ 588,566	$ 593,411
Total unrealized loss	90,667	103,389
Commercial mortgage-backed securities
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	6,000	1,874
Less than 12 months, unrealized loss	$ 112	$ 129
Less than 12 months, Number of securities | security	7	2
12 months or more, fair value	$ 44,656	$ 48,175
12 months or more, unrealized loss	$ 9,270	$ 10,913
12 months or more, Number of securities | security	21	21
Total fair value	$ 50,656	$ 50,049
Total unrealized loss	9,382	11,042
Bank-issued trust preferred securities
Available-for-sale securities that had an unrealized loss:
Less than 12 months, fair value	1,984	4,400
Less than 12 months, unrealized loss	$ 16	$ 100
Less than 12 months, Number of securities | security	1	3
12 months or more, fair value	$ 3,981	$ 3,556
12 months or more, unrealized loss	$ 519	$ 444
12 months or more, Number of securities | security	3	2
Total fair value	$ 5,965	$ 7,956
Total unrealized loss	$ 535	$ 544