INVESTMENTS - Accrued Investment Income (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Net Investment Income [Line Items]
Total accrued investment income	$ 53	$ 52
Retained Business
Net Investment Income [Line Items]
Total accrued investment income	42	41
Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	11	11
Fixed maturity securities
Net Investment Income [Line Items]
Total accrued investment income	49	47
Fixed maturity securities | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	40	37
Fixed maturity securities | Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	9	10
Mortgage and other loans
Net Investment Income [Line Items]
Total accrued investment income	1	1
Mortgage and other loans | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	1	1
Mortgage and other 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	3	4
Short-term investments and cash equivalents | Retained Business
Net Investment Income [Line Items]
Total accrued investment income	1	3
Short-term investments and cash equivalents | Ceded Business
Net Investment Income [Line Items]
Total accrued investment income	$ 2	$ 1