REAL ESTATE AND OTHER SECURITIES - Summary of Real Estate Securities in an Unrealized Loss Position (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 25,589,381
Weighted Average Life (Years)	1 year 1 month 6 days
Less than 12 Months
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 170,182
Before Credit Impairment - Amortized Cost Basis	156,345
Credit Impairment - Amortized Cost Basis	(5,670)
After Credit Impairment - Amortized Cost Basis	150,675
Gross Unrealized Losses - Less than 12 Months	(7,318)
Carrying Value - Less than 12 Months	$ 143,357
Number of Securities - Less than 12 Months | security	89
Weighted Average Coupon	3.20%
Weighted Average Yield	3.90%
Weighted Average Life (Years)	7 years 3 months 18 days
12 or More Months
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 222,735
Before Credit Impairment - Amortized Cost Basis	219,554
Credit Impairment - Amortized Cost Basis	(3,918)
After Credit Impairment - Amortized Cost Basis	215,636
Gross Unrealized Losses - 12 or More Months	(22,753)
Carrying Value - 12 or More Months	$ 192,883
Number of Securities - 12 or More Months | security	110
Weighted Average Coupon	3.80%
Weighted Average Yield	3.50%
Weighted Average Life (Years)	4 years 7 months 6 days
Total/Weighted Average
Debt Securities, Available-for-sale [Line Items]
Outstanding Face Amount	$ 392,917
Before Credit Impairment - Amortized Cost Basis	375,899
Credit Impairment - Amortized Cost Basis	(9,588)
After Credit Impairment - Amortized Cost Basis	366,311
Gross Unrealized Losses - Total	(30,071)
Carrying Value - Total	$ 336,240
Number of Securities - Total | security	199
Weighted Average Coupon	3.50%
Weighted Average Yield	3.70%
Weighted Average Life (Years)	5 years 9 months 18 days