LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Allowance for Credit Losses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 141,465	$ 132,099	$ 167,279
Provision for Loan and Lease Losses	11,097	8,158	(33,112)
Recoveries	2,788	3,921	4,615
Charge-offs	(5,707)	(2,713)	(6,683)
Ending balance	$ 149,643	$ 141,465	$ 132,099
Net loan charge-offs as a percent of average outstanding loans during the period	(0.03%)	0.01%	(0.02%)
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 44,086	$ 52,995	$ 57,791
Provision for Loan and Lease Losses	259	9,299	(2,758)
Recoveries	557	392	1,729
Charge-offs	0	(2)	(3,767)
Ending balance	$ 44,384	$ 44,086	$ 52,995
Net loan charge-offs as a percent of average outstanding loans during the period	0.01%	0.00%	(0.02%)
Multifamily Real Estate [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 7,734	$ 7,043	$ 3,893
Provision for Loan and Lease Losses	1,592	691	3,209
Recoveries	0	0	0
Charge-offs	0	0	(59)
Ending balance	$ 9,326	$ 7,734	$ 7,043
Net loan charge-offs as a percent of average outstanding loans during the period	0.00%	0.00%	0.00%
Construction and Land [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 29,171	$ 27,294	$ 41,295
Provision for Loan and Lease Losses	(16)	1,523	(14,101)
Recoveries	29	384	100
Charge-offs	(1,089)	(30)	0
Ending balance	$ 28,095	$ 29,171	$ 27,294
Net loan charge-offs as a percent of average outstanding loans during the period	(0.01%)	0.00%	0.00%
Commercial business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 33,299	$ 26,421	$ 35,007
Provision for Loan and Lease Losses	3,532	6,654	(8,621)
Recoveries	1,283	1,923	1,797
Charge-offs	(1,161)	(1,699)	(1,762)
Ending balance	$ 35,464	$ 33,299	$ 26,421
Net loan charge-offs as a percent of average outstanding loans during the period	(0.01%)	0.00%	0.00%
Agricultural Business [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 3,475	$ 3,190	$ 4,914
Provision for Loan and Lease Losses	808	148	1,573
Recoveries	146	475	30
Charge-offs	(564)	(42)	(181)
Ending balance	$ 3,865	$ 3,475	$ 3,190
Net loan charge-offs as a percent of average outstanding loans during the period	0.00%	0.00%	0.00%
One- to four-family residential [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 14,729	$ 8,205	$ 9,913
Provision for Loan and Lease Losses	4,354	6,343	1,907
Recoveries	230	181	199
Charge-offs	(42)	0	0
Ending balance	$ 19,271	$ 14,729	$ 8,205
Net loan charge-offs as a percent of average outstanding loans during the period	0.00%	0.00%	0.00%
Consumer [Member]
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 8,971	$ 6,951	$ 14,466
Provision for Loan and Lease Losses	1,086	2,394	(7,361)
Recoveries	543	566	760
Charge-offs	(1,362)	(940)	(914)
Ending balance	$ 9,238	$ 8,971	$ 6,951
Net loan charge-offs as a percent of average outstanding loans during the period	(0.01%)	0.00%	0.00%
Commercial and Small Business Scored
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs	$ (2,650)