LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (portfolio of non-risk-rated loans by class and delinquency status) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Allowance for Credit Loss, Writeoff	$ 5,707	$ 2,713	$ 6,683
Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,767,291	10,114,353
30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, before Allowance for Credit Loss	15,936	15,814
60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, before Allowance for Credit Loss	10,280	7,429
90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, before Allowance for Credit Loss	16,948	9,128
Small Balance CRE [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	83,077	177,605
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	194,213	215,801
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	215,550	172,746
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	164,102	134,552
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	121,755	142,592
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	399,425	356,325
Financing Receivable, Revolving	378	630
Financing Receivable, before Allowance for Credit Loss	1,178,500	1,200,251
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	0
Small Balance CRE [Member] | Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	83,077	177,605
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	194,213	215,801
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	215,550	172,286
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	163,689	134,552
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	121,596	142,592
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	399,025	354,924
Financing Receivable, Revolving	378	630
Financing Receivable, before Allowance for Credit Loss	1,177,528	1,198,390
Small Balance CRE [Member] | 30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	460
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	159	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	400	1,399
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	559	1,859
Small Balance CRE [Member] | 60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	0	0
Small Balance CRE [Member] | 90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	413	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	2
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	413	2
Small Credit-Scored Business Loans [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	197,196	307,255
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	277,128	202,200
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	173,482	99,947
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	84,432	82,297
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	62,321	56,685
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	97,206	78,617
Financing Receivable, Revolving	130,389	120,091
Financing Receivable, before Allowance for Credit Loss	1,022,154	947,092
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	193
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	421
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	221
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	185
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	286
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	183
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	1,489
Small Credit-Scored Business Loans [Member] | Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	197,138	307,109
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	276,888	201,628
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	172,286	99,867
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	84,320	81,603
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	61,613	56,420
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	96,269	78,025
Financing Receivable, Revolving	129,998	119,281
Financing Receivable, before Allowance for Credit Loss	1,018,512	943,933
Small Credit-Scored Business Loans [Member] | 30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	16	146
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	171	518
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,048	54
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	52	262
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	169	46
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	287	280
Financing Receivable, Revolving	307	173
Financing Receivable, before Allowance for Credit Loss	2,050	1,479
Small Credit-Scored Business Loans [Member] | 60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	18	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	54
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	60	275
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	79	149
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	393	7
Financing Receivable, Revolving	83	176
Financing Receivable, before Allowance for Credit Loss	633	661
Small Credit-Scored Business Loans [Member] | 90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	24	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	69	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	148	26
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	157
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	460	70
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	257	305
Financing Receivable, Revolving	1	461
Financing Receivable, before Allowance for Credit Loss	959	1,019
One- to four-family residential [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	362,703	558,923
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	590,494	281,996
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	265,485	61,400
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	57,527	35,319
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	32,059	38,065
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	209,569	195,996
Financing Receivable, Revolving	209	1,413
Financing Receivable, before Allowance for Credit Loss	1,518,046	1,173,112
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	10
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	32
Financing Receivable, Revolving, Writeoff	0
Financing Receivable, Allowance for Credit Loss, Writeoff	42	0	$ 0
One- to four-family residential [Member] | Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	360,797	555,833
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	586,167	279,331
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	262,414	59,672
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	56,436	34,607
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	31,275	37,740
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	206,247	191,890
Financing Receivable, Revolving	209	1,335
Financing Receivable, before Allowance for Credit Loss	1,503,545	1,160,408
One- to four-family residential [Member] | 30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	846	2,030
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,087	846
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	979	755
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	511	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	116
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,441	1,462
Financing Receivable, Revolving	0	78
Financing Receivable, before Allowance for Credit Loss	6,864	5,287
One- to four-family residential [Member] | 60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	1,060
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	540	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	510	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	388	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	151	115
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	790	1,067
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	2,379	2,242
One- to four-family residential [Member] | 90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,060	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	700	1,819
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,582	973
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	192	712
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	633	94
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,091	1,577
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	5,258	5,175
Home Equity Line of Credit [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	5,003	7,491
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	3,010	1,193
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,933	477
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2,309	1,831
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,421	1,798
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,214	4,722
Financing Receivable, Revolving	568,813	548,779
Financing Receivable, before Allowance for Credit Loss	588,703	566,291
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	13
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	73
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	21
Financing Receivable, Revolving, Writeoff	3
Financing Receivable, Allowance for Credit Loss, Writeoff	104
Home Equity Line of Credit [Member] | Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	5,003	7,442
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,594	1,089
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,564	329
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,200	1,355
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,177	1,611
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,678	3,788
Financing Receivable, Revolving	566,249	547,068
Financing Receivable, before Allowance for Credit Loss	582,465	562,682
Home Equity Line of Credit [Member] | 30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	49
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	51	40
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	93	75
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	66	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	175	74
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	324	214
Financing Receivable, Revolving	2,063	1,372
Financing Receivable, before Allowance for Credit Loss	2,772	1,824
Home Equity Line of Credit [Member] | 60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	50
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	98	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	50	49
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	246	45
Financing Receivable, Revolving	445	59
Financing Receivable, before Allowance for Credit Loss	839	203
Home Equity Line of Credit [Member] | 90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	365	14
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	178	73
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,043	476
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	19	64
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	966	675
Financing Receivable, Revolving	56	280
Financing Receivable, before Allowance for Credit Loss	2,627	1,582
Consumer Loan [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	10,773	39,830
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	31,894	12,157
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,027	9,379
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,936	5,724
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,471	5,386
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	18,007	16,755
Financing Receivable, Revolving	28,573	25,401
Financing Receivable, before Allowance for Credit Loss	110,681	114,632
Financing Receivable, Year One, Originated, Current Fiscal Year, Writeoff	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year, Writeoff	55
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year, Writeoff	79
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year, Writeoff	37
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year, Writeoff	39
Financing Receivable, Originated, More than Five Years before Current Fiscal Year, Writeoff	159
Financing Receivable, Revolving, Writeoff	889
Financing Receivable, Allowance for Credit Loss, Writeoff	1,258
Consumer Loan [Member] | Financial Asset, Not Past Due
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	10,756	39,740
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	31,836	12,138
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	9,961	9,334
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	6,906	5,695
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,441	5,384
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	17,920	16,675
Financing Receivable, Revolving	28,207	25,219
Financing Receivable, before Allowance for Credit Loss	110,027	114,185
Consumer Loan [Member] | 30 to 59 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	5	49
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	62	16
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0	5
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0	2
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	81	67
Financing Receivable, Revolving	269	120
Financing Receivable, before Allowance for Credit Loss	417	259
Consumer Loan [Member] | 60 to 89 Days Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	12	41
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0	9
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	4	29
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	2	24
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	20	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6	13
Financing Receivable, Revolving	97	62
Financing Receivable, before Allowance for Credit Loss	141	178
Consumer Loan [Member] | 90 Days or More Past Due [Member]
Schedule non-risk-rated loans by class and delinquency status [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	58	10
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	28	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	10	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0	0
Financing Receivable, Revolving	0	0
Financing Receivable, before Allowance for Credit Loss	$ 96	$ 10