INVESTMENTS - Estimated Fair Values of Debt Securities by Contractual Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Fair Value
Total available-for-sale debt securities	$ 1,140,783	$ 1,102,681
Amortized Cost
Amortized Cost	1,254,321	1,220,819
Fair Value
Total held-to-maturity debt securities	177,854	200,411
Amortized Cost
Amortized Cost	215,747	236,165
U.S. treasuries and government agencies
Fair Value
One year or less	58,341	17,798
One to five years	23,973	79,129
Five to ten years	0	0
After ten years	0	0
Total available-for-sale debt securities	82,314	96,927
Amortized Cost
One year or less	59,634	17,979
One to five years	24,786	83,699
Five to ten years	0	0
After ten years	0	0
Amortized Cost	84,420	101,678
State and municipal
Fair Value
One year or less	19,285	22,345
One to five years	14,447	33,282
Five to ten years	56,396	46,355
After ten years	144,806	166,232
Total available-for-sale debt securities	234,934	268,214
Amortized Cost
One year or less	19,467	22,793
One to five years	15,286	34,288
Five to ten years	66,696	54,487
After ten years	180,388	199,937
Amortized Cost	281,837	311,505
Mortgage-backed and asset-backed
Fair Value
One year or less	9,493	20,814
One to five years	20,937	29,823
Five to ten years	273,282	256,924
After ten years	519,823	429,979
Total available-for-sale debt securities	823,535	737,540
Amortized Cost
One year or less	9,503	21,111
One to five years	21,347	30,666
Five to ten years	293,839	280,209
After ten years	563,375	475,650
Amortized Cost	888,064	807,636
Fair Value
One year or less	0	0
One to five years	0	0
Five to ten years	27,357	31,434
After ten years	150,497	168,977
Total held-to-maturity debt securities	177,854	200,411
Amortized Cost
One year or less	0	0
One to five years	0	0
Five to ten years	30,059	34,458
After ten years	185,688	201,707
Amortized Cost	$ 215,747	$ 236,165