INVESTMENTS - Commercial Mortgage Loans by Key Credit Quality Indicators (Details) - Commercial mortgage loans $ in Millions	Mar. 31, 2022 USD ($)
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 0
2021	337
2020	47
2019	604
2018	154
Prior	737
Total Financing Receivable	$ 1,879
Weighted Average Debt Service Coverage Ratio	2.39
2022
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	0.00
2021
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	2.87
2020
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	1.93
2019
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	2.39
2018
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	2.10
Prior
Financing Receivable, Credit Quality Indicator [Line Items]
Weighted Average Debt Service Coverage Ratio	2.28
Loan to Value Ratio, Zero to Fifty-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 0
2021	303
2020	47
2019	518
2018	154
Prior	599
Total Financing Receivable	$ 1,621
Weighted Average Debt Service Coverage Ratio	2.48
Loan to Value Ratio, Sixty to Sixty-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 0
2021	34
2020	0
2019	86
2018	0
Prior	113
Total Financing Receivable	$ 233
Weighted Average Debt Service Coverage Ratio	1.87
Loan to Value Ratio, Seventy to Seventy-nine Point Nine-nine Percent
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 0
2021	0
2020	0
2019	0
2018	0
Prior	25
Total Financing Receivable	$ 25
Weighted Average Debt Service Coverage Ratio	1.78
Loan-to-Value Ratio Eighty Percent and Above
Financing Receivable, Credit Quality Indicator [Line Items]
2022	$ 0
2021	0
2020	0
2019	0
2018	0
Prior	0
Total Financing Receivable	$ 0
Weighted Average Debt Service Coverage Ratio	0.00