COMMERCIAL MORTGAGE LOAN HELD-FOR-INVESTMENT - Summary of Concentration of Credit Risk (Details) - Commercial loans held-for-investment - Commercial real estate portfolio segment	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	100.00%	100.00%
Collateral Property Type
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	100.00%	100.00%
Multifamily | Collateral Property Type
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	92.30%	94.00%
Healthcare | Collateral Property Type
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	7.10%	5.50%
Self-Storage | Collateral Property Type
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	0.60%	0.50%
South | Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	36.60%	43.50%
Southwest | Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	32.90%	29.40%
Mid-Atlantic | Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	16.10%	15.00%
Midwest | Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	7.70%	7.90%
West | Geography
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk (as a percentage)	6.70%	4.20%