INVESTMENTS - Transitional Real Estate Loans by Key Credit Quality Indicators (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 12,592	$ 12,801
Transitional real estate loans
Financing Receivable, Credit Quality Indicator [Line Items]
2024	165
2023	226
2022	2,206
2021	2,295
2020	217
Prior	969
Total	6,078	$ 6,114
2024	0
2023	0
2022	0
2021	0
2020	0
Prior	0
Total	0
Transitional real estate loans | Loan to Value Ratio, 0.00% to 59.99%
Financing Receivable, Credit Quality Indicator [Line Items]
2024	131
2023	86
2022	609
2021	507
2020	36
Prior	125
Total	1,494
Transitional real estate loans | Loan to Value Ratio, 60.00% to 69.99%
Financing Receivable, Credit Quality Indicator [Line Items]
2024	34
2023	126
2022	496
2021	637
2020	18
Prior	552
Total	1,863
Transitional real estate loans | Loan to Value Ratio, 70.00% to 79.99%
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	14
2022	883
2021	900
2020	83
Prior	47
Total	1,927
Transitional real estate loans | Loan-to-Value Ratio, 80.00% or greater
Financing Receivable, Credit Quality Indicator [Line Items]
2024	0
2023	0
2022	218
2021	251
2020	80
Prior	245
Total	$ 794