LOANS HELD FOR INVESTMENT, NET - Credit Quality Indicators (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Credit Risk Profile of Real Estate Loans [Abstract]
Total Loans	$ 10,566,831	$ 9,244,661
Principal balances outstanding	10,566,831	9,244,661
Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	2,845,426
2021	1,733,872	1,828,115
2020	1,196,053	1,473,478
2019	1,024,753	1,174,655
2018	522,005	606,030
2017 and Prior	2,175,148	752,529
2016 and Prior		2,114,513
Revolving	726,711	552,538
Revolving-Term	59,850	29,902
Total Loans	10,283,818	8,531,760
Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2022	6,634
2021		6,003
2020	20,549	15,891
2019	17,365	54,365
2018	16,628	21,926
2017 and Prior	31,664	23,775
2016 and Prior		45,900
Revolving	9,641	4,071
Revolving-Term	1,204	2,033
Total Loans	103,685	173,964
Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2022	5,242
2021	2,052	4,833
2020	23,234	11,011
2019	19,143	50,235
2018	22,819	97,994
2017 and Prior	66,232	91,019
2016 and Prior		196,506
Revolving	11,290	30,823
Revolving-Term	10,505	14,491
Total Loans	160,517	496,912
Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2021		550
2020		1,621
2019	8,332	10,074
2018	752	775
2017 and Prior	2,048	11,107
Revolving		1,000
Total Loans	11,132	25,127
Total real estate loans
Credit Risk Profile of Real Estate Loans [Abstract]
Total Loans	9,487,440	8,294,204
Excludes Other Loans
Credit Risk Profile of Real Estate Loans [Abstract]
2022	2,857,302
2021	1,735,924	1,839,501
2020	1,239,836	1,502,001
2019	1,069,593	1,289,329
2018	562,204	726,725
2017 and Prior	2,275,092	878,430
2016 and Prior		2,356,919
Revolving	747,642	588,432
Revolving-Term	71,559	46,426
Total Loans	10,559,152	9,227,763
One-to-four family residential and cooperative/condominium apartment
Credit Risk Profile of Real Estate Loans [Abstract]
2022	225,031
2021	108,185	129,679
2020	73,758	89,096
2019	66,742	82,568
2018	67,180	76,726
2017 and Prior	176,292	80,365
2016 and Prior		145,946
Revolving	41,751	50,724
Revolving-Term	14,382	14,178
Total Loans	773,321	669,282
One-to-four family residential and cooperative/condominium apartment | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	225,031
2021	108,185	129,679
2020	72,732	86,028
2019	65,515	80,195
2018	66,038	75,354
2017 and Prior	164,338	77,829
2016 and Prior		129,276
Revolving	41,172	49,878
Revolving-Term	12,563	12,537
Total Loans	755,574	640,776
One-to-four family residential and cooperative/condominium apartment | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2020		1,124
2019		335
2018	735	752
2017 and Prior	1,175	334
2016 and Prior		2,158
Revolving	579	846
Revolving-Term	726	747
Total Loans	3,215	6,296
One-to-four family residential and cooperative/condominium apartment | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2020	1,026	1,944
2019	1,227	2,038
2018	407	597
2017 and Prior	10,779	2,202
2016 and Prior		14,512
Revolving-Term	1,093	894
Total Loans	14,532	22,187
One-to-four family residential and cooperative/condominium apartment | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2018		23
Total Loans		23
Multifamily residential and residential mixed-use
Credit Risk Profile of Real Estate Loans [Abstract]
2022	1,386,549
2021	582,393	590,462
2020	328,718	353,747
2019	414,117	505,089
2018	147,385	183,616
2017 and Prior	1,155,080	398,804
2016 and Prior		1,309,248
Revolving	12,584	14,555
Revolving-Term		825
Total Loans	4,026,826	3,356,346
Multifamily residential and residential mixed-use | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	1,386,549
2021	582,393	590,462
2020	316,424	341,206
2019	395,933	455,277
2018	127,074	151,226
2017 and Prior	1,107,281	332,749
2016 and Prior		1,145,609
Revolving	12,584	12,277
Revolving-Term		825
Total Loans	3,928,238	3,029,631
Multifamily residential and residential mixed-use | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2020		11,040
2019	11,183	14,486
2017 and Prior	14,168	11,817
2016 and Prior		26,252
Total Loans	25,351	63,595
Multifamily residential and residential mixed-use | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2020	12,294	1,501
2019	7,001	35,326
2018	20,311	32,390
2017 and Prior	33,631	54,238
2016 and Prior		137,387
Revolving		2,278
Total Loans	73,237	263,120
Commercial real estate ("CRE")
Credit Risk Profile of Real Estate Loans [Abstract]
2022	1,024,486
2021	854,391	882,483
2020	777,757	851,450
2019	522,932	575,675
2018	323,768	370,839
2017 and Prior	895,167	341,690
2016 and Prior		874,440
Revolving	34,362	43,183
Revolving-Term	24,767	6,188
Total Loans	4,457,630	3,945,948
Commercial real estate ("CRE") | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	1,021,622
2021	854,240	872,049
2020	753,552	848,694
2019	510,332	529,182
2018	308,265	306,360
2017 and Prior	868,099	298,904
2016 and Prior		815,239
Revolving	34,362	43,183
Revolving-Term	24,767	6,188
Total Loans	4,375,239	3,719,799
Commercial real estate ("CRE") | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2022	2,864
2021		6,003
2020	19,655	1,024
2019	4,653	39,305
2018	14,372	18,983
2017 and Prior	15,478	11,039
2016 and Prior		17,438
Total Loans	57,022	93,792
Commercial real estate ("CRE") | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2021	151	4,431
2020	4,550	1,732
2019	7,947	7,082
2018	1,131	45,496
2017 and Prior	11,590	31,747
2016 and Prior		41,763
Total Loans	25,369	132,251
Commercial real estate ("CRE") | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2019		106
Total Loans		106
Acquisition, development, and construction
Credit Risk Profile of Real Estate Loans [Abstract]
2022	36,877
2021	153,200	142,123
2020	11,242	77,427
2019	15,943	56,885
2018		36,956
2017 and Prior	2,087	6,809
2016 and Prior		774
Revolving	10,033	1,066
Revolving-Term	281	588
Total Loans	229,663	322,628
Acquisition, development, and construction | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	36,877
2021	152,543	142,123
2020	11,242	76,259
2019	15,943	56,885
2018		23,456
2017 and Prior	2,087	6,809
2016 and Prior		774
Revolving	10,033	1,066
Revolving-Term	281	588
Total Loans	229,006	307,960
Acquisition, development, and construction | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2020		1,078
Total Loans		1,078
Acquisition, development, and construction | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2021	657
2020		90
2018		13,500
Total Loans	657	13,590
Commercial and Industrial ("C&I") Loans
Credit Risk Profile of Real Estate Loans [Abstract]
2022	184,359
2021	37,755	94,754
2020	48,361	130,281
2019	49,859	69,112
2018	23,871	58,588
2017 and Prior	46,466	50,762
2016 and Prior		26,511
Revolving	648,912	478,904
Revolving-Term	32,129	24,647
Total Loans	1,071,712	933,559
Commercial and Industrial ("C&I") Loans | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2022	175,347
2021	36,511	93,802
2020	42,103	121,291
2019	37,030	53,116
2018	20,628	49,634
2017 and Prior	33,343	36,238
2016 and Prior		23,615
Revolving	628,560	446,134
Revolving-Term	22,239	9,764
Total Loans	995,761	833,594
Commercial and Industrial ("C&I") Loans | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2022	3,770
2020	894	1,625
2019	1,529	239
2018	1,521	2,191
2017 and Prior	843	585
2016 and Prior		52
Revolving	9,062	3,225
Revolving-Term	478	1,286
Total Loans	18,097	9,203
Commercial and Industrial ("C&I") Loans | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2022	5,242
2021	1,244	402
2020	5,364	5,744
2019	2,968	5,789
2018	970	6,011
2017 and Prior	10,232	2,832
2016 and Prior		2,844
Revolving	11,290	28,545
Revolving-Term	9,412	13,597
Total Loans	46,722	65,764
Commercial and Industrial ("C&I") Loans | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2021		550
2020		1,621
2019	8,332	9,968
2018	752	752
2017 and Prior	2,048	11,107
Revolving		1,000
Total Loans	11,132	24,998
Other Loans
Credit Risk Profile of Real Estate Loans [Abstract]
Total Loans	7,679	16,898
Other Loans | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Principal balances outstanding	7,679	16,898
Other Loans | Performing | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Principal balances outstanding	7,580	16,533
Other Loans | Non-Accrual | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Principal balances outstanding	$ 99	$ 365