LOANS HELD FOR INVESTMENT, NET - Past Due Status (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	$ 10,763,265	$ 10,766,837
Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	86,176	42,366
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	26,197	11,977
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	25,152	1,290
Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	34,827	29,099
90 days or more past due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	0	0
Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	10,677,089	10,724,471
Business loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	2,326,962	2,308,171
Business loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	25,013	26,930
Business loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,246	7,139
Business loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,554	1,217
Business loans | Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	18,213	18,574
Business loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	2,301,949	2,281,241
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	873,335	887,555
One-to-four family residential and cooperative/condominium apartment | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	7,629	7,392
One-to-four family residential and cooperative/condominium apartment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,892	4,071
One-to-four family residential and cooperative/condominium apartment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	48	73
One-to-four family residential and cooperative/condominium apartment | Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,689	3,248
One-to-four family residential and cooperative/condominium apartment | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	865,706	880,163
Multifamily residential and residential mixed-use
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,996,548	4,017,176
Multifamily residential and residential mixed-use | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	40,030
Multifamily residential and residential mixed-use | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	18,480
Multifamily residential and residential mixed-use | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	21,550
Multifamily residential and residential mixed-use | Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	0
Multifamily residential and residential mixed-use | 90 days or more past due
Financing Receivable, Recorded Investment, Aging [Abstract]
Loans 90 Days or More Past Due and Still Accruing Interest	0
Multifamily residential and residential mixed-use | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,956,518	4,017,176
Non-owner-occupied commercial real estate
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,385,898	3,379,667
Non-owner-occupied commercial real estate | Total real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,385,898	3,379,667
Non-owner-occupied commercial real estate | Total real estate loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	592	6,957
Non-owner-occupied commercial real estate | Total real estate loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	577	337
Non-owner-occupied commercial real estate | Total real estate loans | Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	15	6,620
Non-owner-occupied commercial real estate | Total real estate loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	3,385,306	3,372,710
Acquisition, development, and construction ("ADC")
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	175,352	168,513
Acquisition, development, and construction ("ADC") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	12,910	1,087
Acquisition, development, and construction ("ADC") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total		430
Acquisition, development, and construction ("ADC") | Non-Accrual
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	12,910	657
Acquisition, development, and construction ("ADC") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	162,442	167,426
Other Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	5,170	5,755
Other Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	2
Other Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	2
Other Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total	$ 5,168	$ 5,755