CURRENT EXPECTED CREDIT LOSSES - Narrative (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 12, 2024	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	$ 138,500
Allowance for credit loss (basis points)	6.61%
Commitments	$ 2,094,034			$ 2,274,584
Outstanding Principal	2,007,435			2,158,045
Other Assets
Financing Receivable, Allowance for Credit Loss [Line Items]
Interest receivable	11,000			13,000
Office | Senior Mortgage Loans | CA
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal		$ 33,200
Office | Senior Mortgage Loans | NJ | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	15,700
Office | Senior Mortgage Loans | NC | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	5,600
Office | Senior Mortgage Loans | NC | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss | SOFR Plus 4.35% Due May 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal	68,600
Office | Subordinated debt and preferred equity investments | CA
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal	20,600
Office | Subordinated debt and preferred equity investments | NJ | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal	18,500
Industrial | Senior Mortgage Loans | CA | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	10,900
Industrial | Senior Mortgage Loans | CA | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss | SOFR Plus 3.00% Due Jul 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal	19,600
Multifamily | Senior Mortgage Loans | TX | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	6,500
Multifamily | Senior Mortgage Loans | TX | 5 - Impaired/Loss Likely: A loan that has significantly increased probability of default or principal loss | SOFR Plus 3.00% Due Jul 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Outstanding Principal	97,500
Loans Held for Investment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	137,403		$ 139,763	159,885
Unfunded Loan Commitment
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing receivable, allowance for credit loss, excluding accrued interest	$ 1,087		$ 1,101	$ 3,248