LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Nonperforming Loans (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 4,431,398	$ 4,468,476
1-4 Family Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2024	736	23,465
2023	19,157	14,915
2022	12,475	10,079
2021	10,031	1,206
2020	0	685
Prior	520	58
Revolving Loans Amortized Cost Basis	0	799
Revolving Loans Converted to Term	0	0
Total	42,919	51,207
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	0	0
Home equity lines of credit
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,487	27,110
2023	28,498	32,027
2022	30,033	11,437
2021	10,769	9,844
2020	8,399	6,781
Prior	34,905	30,481
Revolving Loans Amortized Cost Basis	6,853	7,479
Revolving Loans Converted to Term	6,346	5,541
Total	133,290	130,700
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	10
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	0	10
Residential Mortgages secured by first liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	13,262	135,019
2023	140,158	233,520
2022	230,114	200,784
2021	197,239	143,933
2020	141,860	77,785
Prior	264,057	196,746
Revolving Loans Amortized Cost Basis	2,854	3,199
Revolving Loans Converted to Term	0	0
Total	989,544	990,986
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	64	22
Revolving Loans Amortized Cost Basis	0	95
Revolving Loans Converted to Term	0	0
Total	64	117
Residential Mortgages secured by junior liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	5,304	28,685
2023	27,465	27,070
2022	26,141	14,027
2021	13,585	7,102
2020	6,867	3,888
Prior	11,958	8,875
Revolving Loans Amortized Cost Basis	1,294	1,416
Revolving Loans Converted to Term	0	0
Total	92,614	91,063
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	0	0
Other revolving credit plans
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,170	8,684
2023	9,889	8,056
2022	7,765	2,737
2021	2,362	11,274
2020	5,280	1,634
Prior	11,852	10,492
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	38,318	42,877
2024	0	0
2023	0	0
2022	0	50
2021	0	4
2020	0	16
Prior	15	49
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	15	119
Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,123	12,561
2023	11,474	6,851
2022	6,105	2,597
2021	2,077	1,479
2020	1,198	1,030
Prior	1,459	797
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	23,436	25,315
2024	0	18
2023	7	23
2022	0	0
2021	3	8
2020	0	7
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	10	56
Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,086	27,485
2023	23,383	12,591
2022	10,401	5,371
2021	4,402	3,119
2020	2,855	1,477
Prior	2,841	1,549
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	50,968	51,592
2024	0	210
2023	254	1,164
2022	205	467
2021	49	96
2020	4	33
Prior	5	12
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	517	1,982
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,363,290	1,376,380
Performing | 1-4 Family Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2024	736	23,465
2023	19,157	14,915
2022	12,475	10,079
2021	10,031	1,206
2020	0	685
Prior	520	58
Revolving Loans Amortized Cost Basis	0	799
Revolving Loans Converted to Term	0	0
Total	42,919	51,207
Performing | Home equity lines of credit
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,487	27,110
2023	28,498	32,027
2022	30,033	11,437
2021	10,769	9,844
2020	8,399	6,781
Prior	34,892	30,467
Revolving Loans Amortized Cost Basis	6,853	7,479
Revolving Loans Converted to Term	5,235	4,615
Total	132,166	129,760
Performing | Residential Mortgages secured by first liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	13,262	134,522
2023	139,680	233,346
2022	229,664	199,997
2021	196,357	143,318
2020	141,256	77,293
Prior	260,957	194,010
Revolving Loans Amortized Cost Basis	2,817	3,161
Revolving Loans Converted to Term	0	0
Total	983,993	985,647
Performing | Residential Mortgages secured by junior liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	5,304	28,685
2023	27,446	27,032
2022	26,004	14,027
2021	13,585	7,102
2020	6,867	3,888
Prior	11,921	8,833
Revolving Loans Amortized Cost Basis	1,251	1,373
Revolving Loans Converted to Term	0	0
Total	92,378	90,940
Performing | Other revolving credit plans
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,170	8,684
2023	9,889	8,027
2022	7,737	2,732
2021	2,323	11,274
2020	5,280	1,634
Prior	11,792	10,445
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	38,191	42,796
Performing | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
2024	1,123	12,545
2023	11,474	6,800
2022	6,056	2,597
2021	2,073	1,472
2020	1,182	1,025
Prior	1,455	797
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	23,363	25,236
Performing | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2024	7,086	27,202
2023	23,040	12,261
2022	10,206	5,255
2021	4,319	3,107
2020	2,845	1,471
Prior	2,784	1,498
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	50,280	50,794
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total	7,799	7,360
Nonperforming | 1-4 Family Construction
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	0	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	0	0
Nonperforming | Home equity lines of credit
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	0
2022	0	0
2021	0	0
2020	0	0
Prior	13	14
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	1,111	926
Total	1,124	940
Nonperforming | Residential Mortgages secured by first liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	497
2023	478	174
2022	450	787
2021	882	615
2020	604	492
Prior	3,100	2,736
Revolving Loans Amortized Cost Basis	37	38
Revolving Loans Converted to Term	0	0
Total	5,551	5,339
Nonperforming | Residential Mortgages secured by junior liens
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	19	38
2022	137	0
2021	0	0
2020	0	0
Prior	37	42
Revolving Loans Amortized Cost Basis	43	43
Revolving Loans Converted to Term	0	0
Total	236	123
Nonperforming | Other revolving credit plans
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	0
2023	0	29
2022	28	5
2021	39	0
2020	0	0
Prior	60	47
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	127	81
Nonperforming | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	16
2023	0	51
2022	49	0
2021	4	7
2020	16	5
Prior	4	0
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	73	79
Nonperforming | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0	283
2023	343	330
2022	195	116
2021	83	12
2020	10	6
Prior	57	51
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term	0	0
Total	$ 688	$ 798