INVESTMENTS - Other Invested Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	$ 211	$ 450
Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	85	440
Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	126	10
Partnership Interest | Fair Value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	33	354
Partnership Interest | Fair Value | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	24	344
Partnership Interest | Fair Value | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	9	10
Private equity | Partnership Interest | Fair Value
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	24	345
Private equity | Partnership Interest | Fair Value | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	24	344
Private equity | Partnership Interest | Fair Value | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	1
Derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	117	85
Derivatives | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	85
Derivatives | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	117	0
Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	61	11
Other | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	61	11
Other | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	0
Equity Method Investments | Partnership Interest
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	9	9
Equity Method Investments | Partnership Interest | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	0
Equity Method Investments | Partnership Interest | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	9	9
Equity Method Investments | Private equity | Partnership Interest
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	4	4
Equity Method Investments | Private equity | Partnership Interest | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	0
Equity Method Investments | Private equity | Partnership Interest | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	4	4
Equity Method Investments | Real estate-related | Partnership Interest
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	5	5
Equity Method Investments | Real estate-related | Partnership Interest | Retained Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	0	0
Equity Method Investments | Real estate-related | Partnership Interest | Ceded Business
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total other invested assets	$ 5	$ 5