LOANS HELD FOR INVESTMENT, NET - Past Due Status (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	$ 10,566,831	$ 9,244,661
Non-accrual	28,162
Aggregate outstanding balance		3,000
Non-accrual	34,237	40,307
Principal balances outstanding	10,566,831	9,244,661
Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Principal balances outstanding	58,496	116,696
30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Principal balances outstanding	23,517	61,242
60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Principal balances outstanding	742	12,146
Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Principal balances outstanding		3,001
Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Principal balances outstanding	10,508,335	9,127,965
Total real estate loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	9,487,440	8,294,204
Non-accrual	12,192	12,676
Total real estate loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	31,884	77,109
Total real estate loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	19,692	57,385
Total real estate loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		5,103
Total real estate loans | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		1,945
Total real estate loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	9,455,556	8,217,095
One-to-four family residential and cooperative/condominium apartment
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	773,321	669,282
Non-accrual	3,203	7,623
One-to-four family residential and cooperative/condominium apartment | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	3,889	13,739
One-to-four family residential and cooperative/condominium apartment | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	686	3,294
One-to-four family residential and cooperative/condominium apartment | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		877
One-to-four family residential and cooperative/condominium apartment | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		1,945
One-to-four family residential and cooperative/condominium apartment | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	769,432	655,543
Multifamily residential and residential mixed-use
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,026,826	3,356,346
Multifamily residential and residential mixed-use | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,817	34,322
Multifamily residential and residential mixed-use | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,817	30,983
Multifamily residential and residential mixed-use | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		3,339
Multifamily residential and residential mixed-use | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,022,009	3,322,024
Commercial real estate ("CRE")
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,457,630	3,945,948
Non-accrual	8,332	5,053
Commercial real estate ("CRE") | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	22,521	29,048
Commercial real estate ("CRE") | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	14,189	23,108
Commercial real estate ("CRE") | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		887
Commercial real estate ("CRE") | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	4,435,109	3,916,900
Acquisition, development, and construction
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	229,663	322,628
Non-accrual	657
Acquisition, development, and construction | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	657
Acquisition, development, and construction | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	229,006	322,628
Commercial and Industrial ("C&I") Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	1,071,712	933,559
Non-accrual	21,946	27,266
Commercial and Industrial ("C&I") Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	26,248	39,115
Commercial and Industrial ("C&I") Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	3,561	3,753
Commercial and Industrial ("C&I") Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	741	7,040
Commercial and Industrial ("C&I") Loans | Loans 90 Days or More Past Due and Still Accruing Interest
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans		1,056
Commercial and Industrial ("C&I") Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	1,045,464	894,444
Other Loans
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	7,679	16,898
Non-accrual	99	365
Other Loans | Total Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	364	472
Other Loans | 30 to 59 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	264	104
Other Loans | 60 to 89 Days Past Due
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	1	3
Other Loans | Current
Financing Receivable, Recorded Investment, Aging [Abstract]
Total Loans	$ 7,315	$ 16,426