INVESTMENTS - Transitional Real Estate Loans by Key Credit Quality Indicators (Details) - Transitional real estate loans $ in Millions	Mar. 31, 2022 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 600
2021	2,446
2020	329
2019	1,435
2018	730
Prior	51
Total Financing Receivable	5,591
Loan to Value Ratio, Zero to Fifty-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	294
2021	598
2020	36
2019	318
2018	86
Prior	0
Total Financing Receivable	1,332
Loan to Value Ratio, Sixty to Sixty-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	161
2021	693
2020	137
2019	624
2018	417
Prior	50
Total Financing Receivable	2,082
Loan to Value Ratio, Seventy to Seventy-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	145
2021	1,031
2020	156
2019	493
2018	227
Prior	1
Total Financing Receivable	2,053
Loan-to-Value Ratio Eighty Percent and Above
Financing Receivable, Credit Quality Indicator [Line Items]
2022	0
2021	124
2020	0
2019	0
2018	0
Prior	0
Total Financing Receivable	$ 124