REAL ESTATE AND OTHER SECURITIES - Summary of Real Estate Securities in an Unrealized Loss Position (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 25,859,938
Weighted Average Life (Years)	1 year
Less than 12 Months
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 79,960
Before Credit Impairment - Amortized Cost Basis	69,392
Credit Impairment - Amortized Cost Basis	0
After Credit Impairment - Amortized Cost Basis	69,392
Gross Unrealized Losses - Less than 12 Months	(6,770)
Carrying Value - Less than 12 Months	$ 62,622
Number of Securities - Less than 12 Months | security	72
Weighted Average Coupon	3.10%
Weighted Average Yield	4.00%
Weighted Average Life (Years)	4 years 8 months 12 days
12 or More Months
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 306,044
Before Credit Impairment - Amortized Cost Basis	288,367
Credit Impairment - Amortized Cost Basis	(14,421)
After Credit Impairment - Amortized Cost Basis	273,946
Gross Unrealized Losses - 12 or More Months	(26,153)
Carrying Value - 12 or More Months	$ 247,793
Number of Securities - 12 or More Months | security	130
Weighted Average Coupon	3.70%
Weighted Average Yield	3.70%
Weighted Average Life (Years)	7 years 2 months 12 days
Total/Weighted Average
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 386,004
Before Credit Impairment - Amortized Cost Basis	357,759
Credit Impairment - Amortized Cost Basis	(14,421)
After Credit Impairment - Amortized Cost Basis	343,338
Gross Unrealized Losses - Total	(32,923)
Carrying Value - Total	$ 310,415
Number of Securities - Total | security	202
Weighted Average Coupon	3.60%
Weighted Average Yield	3.80%
Weighted Average Life (Years)	6 years 8 months 12 days