FAIR VALUE DISCLOSURES OF FINANCIAL ASSETS AND LIABILITIES - Schedule of Financial Instruments Carried at Fair Value (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	$ 3,651,913	$ 3,846,537
Collateralized mortgage obligation (CMO)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	449,398	464,619
Fannie Mae (FNMA) mortgage-backed securities (MBS)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	2,872,121	3,042,350
Freddie Mac (FHLMC) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	109,212	115,532
Ginnie Mae (GNMA) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	43,249	43,340
Government-sponsored enterprises (GSE) agency notes
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	177,933	180,696
Fair Value, Measurements, Recurring
Assets measured at fair value on a recurring basis:
Other assets, fair value	175,078	153,647
Liabilities measured at fair value on a recurring basis:
Other liabilities	169,775	151,642
Assets measured at fair value on a nonrecurring basis:
Total assets measured at fair value	3,826,991	4,000,184
Fair Value, Measurements, Recurring | Collateralized mortgage obligation (CMO)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	449,398	464,619
Fair Value, Measurements, Recurring | Fannie Mae (FNMA) mortgage-backed securities (MBS)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	2,872,121	3,042,350
Fair Value, Measurements, Recurring | Freddie Mac (FHLMC) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	109,212	115,532
Fair Value, Measurements, Recurring | Ginnie Mae (GNMA) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	43,249	43,340
Fair Value, Measurements, Recurring | Government-sponsored enterprises (GSE) agency notes
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	177,933	180,696
Fair Value, Measurements, Nonrecurring
Assets measured at fair value on a nonrecurring basis:
Other real estate owned	1,342	1,569
Total assets measured at fair value	70,270	46,043
Fair Value, Measurements, Nonrecurring | Other investments
Assets measured at fair value on a nonrecurring basis:
Other investments	14,320	15,206
Fair Value, Measurements, Nonrecurring | Loans held for sale
Assets measured at fair value on a nonrecurring basis:
Loans held for sale	54,608	29,268
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring
Assets measured at fair value on a recurring basis:
Other assets, fair value	0	0
Liabilities measured at fair value on a recurring basis:
Other liabilities	0	0
Assets measured at fair value on a nonrecurring basis:
Total assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring | Collateralized mortgage obligation (CMO)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring | Fannie Mae (FNMA) mortgage-backed securities (MBS)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring | Freddie Mac (FHLMC) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring | Ginnie Mae (GNMA) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Recurring | Government-sponsored enterprises (GSE) agency notes
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Nonrecurring
Assets measured at fair value on a nonrecurring basis:
Other real estate owned	0	0
Total assets measured at fair value	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Nonrecurring | Other investments
Assets measured at fair value on a nonrecurring basis:
Other investments	0	0
Quoted Prices in Active Markets for Identical Asset (Level 1) | Fair Value, Measurements, Nonrecurring | Loans held for sale
Assets measured at fair value on a nonrecurring basis:
Loans held for sale	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring
Assets measured at fair value on a recurring basis:
Other assets, fair value	175,035	153,569
Liabilities measured at fair value on a recurring basis:
Other liabilities	160,873	137,616
Assets measured at fair value on a nonrecurring basis:
Total assets measured at fair value	3,826,948	4,000,106
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Collateralized mortgage obligation (CMO)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	449,398	464,619
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Fannie Mae (FNMA) mortgage-backed securities (MBS)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	2,872,121	3,042,350
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Freddie Mac (FHLMC) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	109,212	115,532
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Ginnie Mae (GNMA) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	43,249	43,340
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Recurring | Government-sponsored enterprises (GSE) agency notes
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	177,933	180,696
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring
Assets measured at fair value on a nonrecurring basis:
Other real estate owned	0	0
Total assets measured at fair value	54,608	29,268
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring | Other investments
Assets measured at fair value on a nonrecurring basis:
Other investments	0	0
Significant Other Observable Inputs (Level 2) | Fair Value, Measurements, Nonrecurring | Loans held for sale
Assets measured at fair value on a nonrecurring basis:
Loans held for sale	54,608	29,268
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring
Assets measured at fair value on a recurring basis:
Other assets, fair value	43	78
Liabilities measured at fair value on a recurring basis:
Other liabilities	8,902	14,026
Assets measured at fair value on a nonrecurring basis:
Total assets measured at fair value	43	78
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Collateralized mortgage obligation (CMO)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Fannie Mae (FNMA) mortgage-backed securities (MBS)
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Freddie Mac (FHLMC) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Ginnie Mae (GNMA) MBS
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Recurring | Government-sponsored enterprises (GSE) agency notes
Assets measured at fair value on a recurring basis:
Investment securities available-for-sale	0	0
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring
Assets measured at fair value on a nonrecurring basis:
Other real estate owned	1,342	1,569
Total assets measured at fair value	15,662	16,775
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring | Other investments
Assets measured at fair value on a nonrecurring basis:
Other investments	14,320	15,206
Significant Unobservable Inputs (Level 3) | Fair Value, Measurements, Nonrecurring | Loans held for sale
Assets measured at fair value on a nonrecurring basis:
Loans held for sale	$ 0	$ 0