INVESTMENTS - Middle Market Loans by Key Credit Quality Indicators (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 13,133	$ 13,688
Middle market loans
Financing Receivable, Credit Quality Indicator [Line Items]
2023	53
2022	599
2021	1,230
2020	766
2019	744
Prior	579
Revolving Loans	878
Total	4,849
Middle market loans | BBB Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	7
2022	57
2021	128
2020	68
2019	37
Prior	27
Revolving Loans	146
Total	470
Middle market loans | BB Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	31
2022	321
2021	466
2020	297
2019	170
Prior	111
Revolving Loans	388
Total	1,784
Middle market loans | B Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	15
2022	216
2021	615
2020	362
2019	420
Prior	291
Revolving Loans	285
Total	2,204
Middle market loans | CCC Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	5
2021	21
2020	39
2019	110
Prior	134
Revolving Loans	56
Total	365
Middle market loans | CC Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	7
Prior	10
Revolving Loans	0
Total	17
Middle market loans | C and Lower Credit Rating
Financing Receivable, Credit Quality Indicator [Line Items]
2023	0
2022	0
2021	0
2020	0
2019	0
Prior	6
Revolving Loans	3
Total	$ 9