LOANS HELD FOR INVESTMENT - Loans held for Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Carrying Amount	$ 2,014,500		$ 2,126,524
Outstanding Principal	$ 2,044,948		2,158,045
Weighted Average Unleveraged Effective Yield, Including Non-accrual Loans	7.90%	7.50%
Weighted Average Unleveraged Effective Yield, Excluding Non-accrual Loans	9.30%	9.40%
Weighted Average Remaining Life (Years)	1 year	1 year 1 month 6 days
Senior mortgage loans
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Carrying Amount	$ 1,970,558		2,090,146
Outstanding Principal	$ 1,996,099		2,118,947
Weighted Average Unleveraged Effective Yield, Including Non-accrual Loans	8.00%	7.50%
Weighted Average Unleveraged Effective Yield, Excluding Non-accrual Loans	9.20%	9.30%
Weighted Average Remaining Life (Years)	1 year	1 year 1 month 6 days
Subordinated debt and preferred equity investments
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
Carrying Amount	$ 43,942		36,378
Outstanding Principal	$ 48,849		$ 39,098
Weighted Average Unleveraged Effective Yield, Including Non-accrual Loans	6.40%	8.10%
Weighted Average Unleveraged Effective Yield, Excluding Non-accrual Loans	15.30%	15.30%
Weighted Average Remaining Life (Years)	1 year 10 months 24 days	1 year 9 months 18 days