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LOANS HELD FOR INVESTMENT, NET - Collateral Dependent Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans, net of fair value hedge basis point adjustments	$ 10,824,858		$ 10,773,428
Allowance for credit losses	77,812		71,743
Real Estate Collateral Dependent
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans, net of fair value hedge basis point adjustments	6,097		11,004
Allowance for credit losses	1,497		926
Business Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	37,115	$ 35,981	35,962	$ 39,700	$ 43,879	$ 47,029
Business Loans \| Real Estate Collateral Dependent
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans, net of fair value hedge basis point adjustments	5,440		3,742
Allowance for credit losses	1,210
One-to-Four Family Residential and Cooperative/Condominium Apartment
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	7,305	6,973	6,813	6,419	6,012	5,969
Multifamily Residential and Residential Mixed-Use
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	12,357	11,171	7,237	8,190	7,613	8,360
Non-Owner-Occupied Commercial Real Estate
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	18,340	19,445	19,623	18,440	18,076	20,153
Non-Owner-Occupied Commercial Real Estate \| Real Estate Collateral Dependent
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans, net of fair value hedge basis point adjustments			6,605
Allowance for credit losses			621
Acquisition, development, and construction ("ADC")
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	2,455	2,322	1,989	2,558	2,515	1,723
Acquisition, development, and construction ("ADC") \| Real Estate Collateral Dependent
Financing Receivable, Allowance for Credit Loss [Line Items]
Total loans, net of fair value hedge basis point adjustments	657		657
Allowance for credit losses	287		305
Other Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for credit losses	$ 240	$ 176	$ 119	$ 339	$ 240	$ 273