INVESTMENTS - Accrued Investment Income (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Net Investment Income [Line Items]
Total accrued investment income	$ 65	$ 60
Retained Business
Net Investment Income [Line Items]
Total accrued investment income	53	51
Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	12	9
Fixed maturity securities
Net Investment Income [Line Items]
Total accrued investment income	62	56
Fixed maturity securities | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	50	48
Fixed maturity securities | Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	12	8
Mortgage loans
Net Investment Income [Line Items]
Total accrued investment income	2	3
Mortgage loans | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	2	3
Mortgage loans | Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	0	0
Short-term investments and cash equivalents
Net Investment Income [Line Items]
Total accrued investment income	1	1
Short-term investments and cash equivalents | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	1	0
Short-term investments and cash equivalents | Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	$ 0	$ 1