LOANS HELD FOR INVESTMENT, NET - Performance of Modified Loans, After 12 Months (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	$ 109,075	$ 3,325
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	149,376	3,325
Current
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	100,451	3,325
30 to 59 Days Past Due
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	12,651
60 to 89 Days Past Due
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	21,790
Non-Accrual
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	14,484
Business loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	3,429	475
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	16,074	475
Business loans | Current
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	13,694	475
Business loans | 60 to 89 Days Past Due
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	240
Business loans | Non-Accrual
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	2,140
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	404	2,850
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	3,353	2,850
One-to-four family residential and cooperative/condominium apartment | Current
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	3,262	$ 2,850
One-to-four family residential and cooperative/condominium apartment | Non-Accrual
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	91
Multifamily residential and residential mixed-use
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	61,832
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	61,832
Multifamily residential and residential mixed-use | Current
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	27,631
Multifamily residential and residential mixed-use | 30 to 59 Days Past Due
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	12,651
Multifamily residential and residential mixed-use | 60 to 89 Days Past Due
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	21,550
Non-owner-occupied commercial real estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	31,157
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	55,864
Non-owner-occupied commercial real estate | Current
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	55,864
Acquisition, development, and construction ("ADC")
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans that have been modified	12,253
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	12,253
Acquisition, development, and construction ("ADC") | Non-Accrual
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans that defaulted during the quarter and were modified in the 12 months before default to borrowers experiencing financial difficulty	$ 12,253