FAIR VALUE MEASUREMENT - FV of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Dec. 31, 2023
Assets:
Other assets - GNMA EBO loans	$ 6,193,053	$ 7,382,404
Carrying Value
Assets:
Cash and cash equivalents	406,600	215,664
Investment securities HTM	2,301	2,371
Single family LHFI	6,191,766	7,381,124
Federal Home Loan Bank stock	50,676	55,293
Liabilities:
Certificates of deposit	3,267,772	3,227,954
Borrowings	1,000,000	1,745,000
Long-term debt	225,131	224,766
Estimate of Fair Value Measurement
Assets:
Cash and cash equivalents		215,664
Investment securities HTM	2,273	2,331
Single family LHFI	5,864,426	7,002,028
Federal Home Loan Bank stock	50,676	55,293
Liabilities:
Certificates of deposit	3,262,350	3,216,665
Borrowings	1,001,873	1,750,023
Long-term debt	184,124	132,996
Level 1 \| Estimate of Fair Value Measurement
Assets:
Cash and cash equivalents	406,600	215,664
Investment securities HTM	0	0
Single family LHFI	0	0
Federal Home Loan Bank stock	0	0
Liabilities:
Certificates of deposit	0	0
Borrowings	0	0
Long-term debt	0	0
Level 2 \| Estimate of Fair Value Measurement
Assets:
Cash and cash equivalents	0	0
Investment securities HTM	2,273	2,331
Single family LHFI	0	0
Federal Home Loan Bank stock	50,676	55,293
Liabilities:
Certificates of deposit	3,262,350	3,216,665
Borrowings	1,001,873	1,750,023
Long-term debt	184,124	132,996
Level 3 \| Estimate of Fair Value Measurement
Assets:
Cash and cash equivalents	0	0
Investment securities HTM	0	0
Single family LHFI	5,864,426	7,002,028
Federal Home Loan Bank stock	0	0
Liabilities:
Certificates of deposit	0	0
Borrowings	0	0
Long-term debt	0	0
Multifamily \| Carrying Value
Assets:
LHFS – multifamily and other		6,788
Mortgage servicing rights – multifamily and SBA	26,565	29,987
Multifamily \| Estimate of Fair Value Measurement
Assets:
LHFS – multifamily and other		6,871
Mortgage servicing rights – multifamily and SBA	32,361	35,292
Multifamily \| Level 1 \| Estimate of Fair Value Measurement
Assets:
LHFS – multifamily and other		0
Mortgage servicing rights – multifamily and SBA	0	0
Multifamily \| Level 2 \| Estimate of Fair Value Measurement
Assets:
LHFS – multifamily and other		6,871
Mortgage servicing rights – multifamily and SBA	0	0
Multifamily \| Level 3 \| Estimate of Fair Value Measurement
Assets:
LHFS – multifamily and other		0
Mortgage servicing rights – multifamily and SBA	32,361	35,292
Ginnie Mae Early Buyout Loans \| Carrying Value
Assets:
Other assets - GNMA EBO loans	5,111	5,617
Ginnie Mae Early Buyout Loans \| Estimate of Fair Value Measurement
Assets:
Other assets - GNMA EBO loans	5,111	5,617
Ginnie Mae Early Buyout Loans \| Level 1 \| Estimate of Fair Value Measurement
Assets:
Other assets - GNMA EBO loans	0	0
Ginnie Mae Early Buyout Loans \| Level 2 \| Estimate of Fair Value Measurement
Assets:
Other assets - GNMA EBO loans	0	0
Ginnie Mae Early Buyout Loans \| Level 3 \| Estimate of Fair Value Measurement
Assets:
Other assets - GNMA EBO loans	$ 5,111	$ 5,617

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Amortized cost excluding accrued interest, after allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Fair value of investment in debt security measured at amortized cost (held-to-maturity).

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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