FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Fair Value (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	$ 75,741	$ 98,696
Equity securities	1,091	1,603
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	24,158	32,532
Equity securities	822	1,340
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	49,805	64,866
Equity securities	60	90
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	1,778	1,298
Equity securities	209	173
Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	882	1,430
Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	822	1,340
Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	60	90
Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	209	173
Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	209	173
Government and agencies
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	25,114	33,820
Government and agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	24,158	32,532
Government and agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	956	1,288
Government and agencies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Government and agencies | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	24,740	33,340
Government and agencies | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	24,158	32,532
Government and agencies | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	582	808
Government and agencies | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Government and agencies | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	374	480
Government and agencies | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Government and agencies | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	374	480
Government and agencies | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,320	3,036
Municipalities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,320	3,036
Municipalities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,021	2,222
Municipalities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,021	2,222
Municipalities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	299	814
Municipalities | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Municipalities | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	299	814
Municipalities | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Mortgage- and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,146	1,246
Mortgage- and asset-backed securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Mortgage- and asset-backed securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	1,803	955
Mortgage- and asset-backed securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	343	291
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	1,798	955
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	1,798	955
Mortgage- and asset-backed securities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Mortgage- and asset-backed securities | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	343	291
Mortgage- and asset-backed securities | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3
Mortgage- and asset-backed securities | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0
Mortgage- and asset-backed securities | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3
Mortgage- and asset-backed securities | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0
Mortgage- and asset-backed securities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	345	291
Mortgage- and asset-backed securities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Mortgage- and asset-backed securities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2	0
Mortgage- and asset-backed securities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	343	291
Public utilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	7,666	10,051
Public utilities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	7,169	9,558
Public utilities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	497	493
Public utilities | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,786	4,527
Public utilities | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,786	4,527
Public utilities | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Discounted cash flow technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	497	493
Public utilities | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,383	5,031
Public utilities | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,383	5,031
Public utilities | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	497	493
Public utilities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Public utilities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	497	493
Sovereign and supranational
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	834	1,115
Sovereign and supranational | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	797	1,072
Sovereign and supranational | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	37	43
Sovereign and supranational | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	232	273
Sovereign and supranational | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	232	273
Sovereign and supranational | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	37	43
Sovereign and supranational | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	565	799
Sovereign and supranational | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	565	799
Sovereign and supranational | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	37	43
Sovereign and supranational | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Sovereign and supranational | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	37	43
Banks/financial institutions
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	9,299	11,591
Banks/financial institutions | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	9,140	11,546
Banks/financial institutions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	159	45
Banks/financial institutions | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	4,622	5,237
Banks/financial institutions | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	4,622	5,237
Banks/financial institutions | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Consensus pricing valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities		45
Banks/financial institutions | Discounted cash flow technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	159
Banks/financial institutions | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	4,623	6,309
Banks/financial institutions | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	4,518	6,309
Banks/financial institutions | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	105	0
Banks/financial institutions | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	54	45
Banks/financial institutions | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Banks/financial institutions | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	54	45
Other corporate
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	28,362	37,837
Other corporate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	27,620	37,411
Other corporate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	742	426
Other corporate | Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	22,268	29,495
Other corporate | Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	22,268	29,495
Other corporate | Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Discounted cash flow technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	742	426
Other corporate | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	5,552	7,916
Other corporate | Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	5,352	7,916
Other corporate | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	200	0
Other corporate | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	542	426
Other corporate | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0	0
Other corporate | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	$ 542	$ 426