LOANS HELD FOR INVESTMENT, NET - Credit Quality Indicators (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Credit Risk Profile of Real Estate Loans [Abstract]
Total	$ 10,886,387		$ 10,886,387		$ 10,766,837
Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	419,631		419,631		922,902
2023/2022	911,305		911,305		2,700,103
2022/2021	2,643,194		2,643,194		1,582,274
2021/2020	1,482,599		1,482,599		954,855
2020/2019	935,051		935,051		960,030
2019/2018 and Prior	2,954,119		2,954,119		2,257,567
Revolving	905,684		905,684		704,128
Revolving-Term	87,373		87,373		60,048
Total	10,338,956		10,338,956		10,141,907
Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	141		141		481
2023/2022	531		531		53,182
2022/2021	17,876		17,876		45,366
2021/2020	32,339		32,339		92,825
2020/2019	92,249		92,249		27,827
2019/2018 and Prior	111,019		111,019		70,219
Revolving	17,266		17,266		21,267
Revolving-Term	9,459		9,459		26,082
Total	280,880		280,880		337,249
Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2023/2022	335		335		1,857
2022/2021	9,039		9,039		2,196
2021/2020	21,804		21,804		96,805
2020/2019	65,772		65,772		14,483
2019/2018 and Prior	124,464		124,464		130,103
Revolving	6,798		6,798		15,567
Revolving-Term	31,670		31,670		20,167
Total	259,882		259,882		281,178
Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2019/2018 and Prior	611		611		748
Total	611		611		748
Business Loans
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	248,482		248,482		259,180
2023/2022	248,518		248,518		434,299
2022/2021	383,036		383,036		200,169
2021/2020	211,346		211,346		165,092
2020/2019	177,262		177,262		160,799
2019/2018 and Prior	427,992		427,992		339,404
Revolving	863,375		863,375		670,394
Revolving-Term	91,718		91,718		78,834
Total	2,651,729		2,651,729		2,308,171
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs 2022/2021			158		77
YTD Gross Charge-Offs 2021/2020			116		38
YTD Gross Charge-Offs 2020/2019			267		4,166
YTD Gross Charge-Offs 2019/2018 and Prior			584		2,229
YTD Gross Charge-Offs Revolving					5,464
YTD Gross Charge-Offs Revolving-Term			3,940		3,390
YTD Gross Charge-Offs	3,090	$ 5,147	5,065	$ 10,921	15,364
Business Loans | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	248,341		248,341		258,699
2023/2022	247,652		247,652		390,760
2022/2021	357,323		357,323		196,790
2021/2020	204,733		204,733		144,796
2020/2019	169,319		169,319		150,871
2019/2018 and Prior	394,679		394,679		305,258
Revolving	840,224		840,224		633,719
Revolving-Term	52,024		52,024		35,079
Total	2,514,295		2,514,295		2,115,972
Business Loans | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	141		141		481
2023/2022	531		531		41,682
2022/2021	16,674		16,674		1,199
2021/2020	4,318		4,318		13,567
2020/2019	3,090		3,090		7,125
2019/2018 and Prior	10,468		10,468		3,150
Revolving	17,107		17,107		21,108
Revolving-Term	9,459		9,459		25,306
Total	61,788		61,788		113,618
Business Loans | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2023/2022	335		335		1,857
2022/2021	9,039		9,039		2,180
2021/2020	2,295		2,295		6,729
2020/2019	4,853		4,853		2,803
2019/2018 and Prior	22,234		22,234		30,248
Revolving	6,044		6,044		15,567
Revolving-Term	30,235		30,235		18,449
Total	75,035		75,035		77,833
Business Loans | Doubtful
Credit Risk Profile of Real Estate Loans [Abstract]
2019/2018 and Prior	611		611		748
Total	611		611		748
One-to-Four Family Residential and Cooperative/Condominium Apartment
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	93,307		93,307		170,601
2023/2022	162,376		162,376		213,479
2022/2021	206,691		206,691		102,684
2021/2020	98,996		98,996		70,529
2020/2019	65,503		65,503		62,693
2019/2018 and Prior	266,891		266,891		221,875
Revolving	28,630		28,630		31,364
Revolving-Term	10,373		10,373		14,330
Total	932,767		932,767		887,555
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs Revolving-Term					14
YTD Gross Charge-Offs				14	14
One-to-Four Family Residential and Cooperative/Condominium Apartment | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	93,307		93,307		170,601
2023/2022	162,376		162,376		213,479
2022/2021	206,691		206,691		102,684
2021/2020	98,996		98,996		69,524
2020/2019	64,514		64,514		62,356
2019/2018 and Prior	257,747		257,747		213,131
Revolving	27,717		27,717		31,205
Revolving-Term	9,595		9,595		12,493
Total	920,943		920,943		875,473
One-to-Four Family Residential and Cooperative/Condominium Apartment | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2019/2018 and Prior	719		719		33
Revolving	159		159		159
Revolving-Term					776
Total	878		878		968
One-to-Four Family Residential and Cooperative/Condominium Apartment | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2021/2020					1,005
2020/2019	989		989		337
2019/2018 and Prior	8,425		8,425		8,711
Revolving	754		754
Revolving-Term	778		778		1,061
Total	10,946		10,946		11,114
Multifamily Residential and Residential Mixed-Use
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	21,942		21,942		256,822
2023/2022	254,215		254,215		1,340,197
2022/2021	1,319,836		1,319,836		587,686
2021/2020	561,366		561,366		316,312
2020/2019	302,652		302,652		393,912
2019/2018 and Prior	1,397,202		1,397,202		1,113,081
Revolving	3,892		3,892		4,841
Revolving-Term	5,373		5,373		4,325
Total	3,866,478		3,866,478		4,017,176
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs 2020/2019			1,292
YTD Gross Charge-Offs 2019/2018 and Prior			2,553		2
YTD Gross Charge-Offs	1,294	2	3,845	2	2
Multifamily Residential and Residential Mixed-Use | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	21,942		21,942		256,822
2023/2022	254,215		254,215		1,340,197
2022/2021	1,318,634		1,318,634		578,352
2021/2020	548,979		548,979		283,633
2020/2019	288,401		288,401		384,937
2019/2018 and Prior	1,259,803		1,259,803		981,820
Revolving	3,892		3,892		4,841
Revolving-Term	5,373		5,373		4,325
Total	3,701,239		3,701,239		3,834,927
Multifamily Residential and Residential Mixed-Use | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2022/2021	1,202		1,202		9,334
2021/2020	12,387		12,387		3,880
2020/2019	14,251		14,251		3,886
2019/2018 and Prior	73,409		73,409		64,273
Total	101,249		101,249		81,373
Multifamily Residential and Residential Mixed-Use | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2021/2020					28,799
2020/2019					5,089
2019/2018 and Prior	63,990		63,990		66,988
Total	63,990		63,990		100,876
Non-Owner-Occupied Commercial Real Estate
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	45,208		45,208		220,045
2023/2022	216,058		216,058		738,133
2022/2021	728,276		728,276		665,134
2021/2020	626,752		626,752		582,652
2020/2019	547,655		547,655		370,018
2019/2018 and Prior	1,095,528		1,095,528		783,840
Revolving	12,328		12,328		11,919
Revolving-Term	8,251		8,251		7,926
Total	3,280,056		3,280,056		3,379,667
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs Revolving-Term			96
YTD Gross Charge-Offs	96		96
Non-Owner-Occupied Commercial Real Estate | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	45,208		45,208		220,045
2023/2022	216,058		216,058		738,133
2022/2021	728,276		728,276		645,246
2021/2020	606,580		606,580		447,002
2020/2019	412,817		412,817		359,201
2019/2018 and Prior	1,039,290		1,039,290		756,921
Revolving	12,328		12,328		11,919
Revolving-Term	8,251		8,251		7,926
Total	3,068,808		3,068,808		3,186,393
Non-Owner-Occupied Commercial Real Estate | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2022/2021					19,872
2021/2020	663		663		75,378
2020/2019	74,908		74,908		4,563
2019/2018 and Prior	26,423		26,423		2,763
Total	101,994		101,994		102,576
Non-Owner-Occupied Commercial Real Estate | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
2022/2021					16
2021/2020	19,509		19,509		60,272
2020/2019	59,930		59,930		6,254
2019/2018 and Prior	29,815		29,815		24,156
Total	109,254		109,254		90,698
Non-Owner-Occupied Commercial Real Estate | Real estate loan
Credit Risk Profile of Real Estate Loans [Abstract]
Total	3,280,056		3,280,056		3,379,667
Acquisition, development, and construction ("ADC")
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	10,833		10,833		16,735
2023/2022	31,004		31,004		29,034
2022/2021	32,270		32,270		74,163
2021/2020	38,282		38,282		9,900
2020/2019					14,918
2019/2018 and Prior	2,600		2,600		437
Revolving	21,523		21,523		22,444
Revolving-Term	12,787		12,787		882
Total	149,299		149,299		168,513
Acquisition, development, and construction ("ADC") | Pass
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	10,833		10,833		16,735
2023/2022	31,004		31,004		17,534
2022/2021	32,270		32,270		59,202
2021/2020	23,311		23,311		9,900
2020/2019					2,665
2019/2018 and Prior	2,600		2,600		437
Revolving	21,523		21,523		22,444
Revolving-Term	12,130		12,130		225
Total	133,671		133,671		129,142
Acquisition, development, and construction ("ADC") | Special Mention
Credit Risk Profile of Real Estate Loans [Abstract]
2023/2022					11,500
2022/2021					14,961
2021/2020	14,971		14,971
2020/2019					12,253
Total	14,971		14,971		38,714
Acquisition, development, and construction ("ADC") | Substandard
Credit Risk Profile of Real Estate Loans [Abstract]
Revolving-Term	657		657		657
Total	657		657		657
Other Loans
Credit Risk Profile of Real Estate Loans [Abstract]
Total	6,058		6,058		5,755
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs	14	$ 26	59	$ 60
Other Loans | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Total	6,058		6,058		5,755
Other Loans | Performing | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Total	6,052		6,052		5,755
Other Loans | Non-accrual | Credit Risk Profile
Credit Risk Profile of Real Estate Loans [Abstract]
Total	6		6
Excludes Other Loans
Credit Risk Profile of Real Estate Loans [Abstract]
2024/2023	419,772		419,772		923,383
2023/2022	912,171		912,171		2,755,142
2022/2021	2,670,109		2,670,109		1,629,836
2021/2020	1,536,742		1,536,742		1,144,485
2020/2019	1,093,072		1,093,072		1,002,340
2019/2018 and Prior	3,190,213		3,190,213		2,458,637
Revolving	929,748		929,748		740,962
Revolving-Term	128,502		128,502		106,297
Total	$ 10,880,329		10,880,329		10,761,082
Financing Receivable, Excluding Accrued Interest, Allowance for Credit Loss, Writeoff, by Origination Year [Abstract]
YTD Gross Charge-Offs 2022/2021			158		77
YTD Gross Charge-Offs 2021/2020			116		38
YTD Gross Charge-Offs 2020/2019			1,559		4,166
YTD Gross Charge-Offs 2019/2018 and Prior			3,137		2,231
YTD Gross Charge-Offs Revolving					5,464
YTD Gross Charge-Offs Revolving-Term			4,036		3,404
YTD Gross Charge-Offs			$ 9,006		$ 15,380