FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	$ 73,290	$ 75,741
Equity securities	1,088	1,091
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	21,700	24,158
Equity securities	840	822
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	49,809	49,805
Equity securities	0	60
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	1,781	1,778
Equity securities	248	209
Third party pricing vendor valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	800	882
Third party pricing vendor valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	800	822
Third party pricing vendor valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	60
Third party pricing vendor valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	216
Internal valuation technique | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0
Internal valuation technique | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0
Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	216
Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	72	209
Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	40	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	32	209
Government and agencies
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	22,600	25,114
Government and agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	21,700	24,158
Government and agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	900	956
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	22,500	24,740
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	21,692	24,158
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	808	582
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	60	374
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	60	374
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
Government and agencies | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	40
Government and agencies | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	8
Government and agencies | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	32
Government and agencies | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0
Municipalities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,298	2,320
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	2,298	2,320
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	1,426	2,021
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	1,426	2,021
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	256	299
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	256	299
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
Municipalities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	616
Municipalities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	0
Municipalities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	616
Municipalities | Broker/other | 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
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,086	2,146
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	2,314	1,803
Mortgage- and asset-backed securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	772	343
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	2,277	1,798
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	2,277	1,798
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 | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	132	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	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	27	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	105	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	677	345
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	10	2
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	667	343
Public utilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	7,592	7,666
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	7,339	7,169
Public utilities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	253	497
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	4,570	3,786
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	4,570	3,786
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 | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	2,677	3,383
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	2,677	3,383
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	345	497
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	92	0
Public utilities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	253	497
Sovereign and supranational
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	537	834
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	507	797
Sovereign and supranational | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	30	37
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	118	232
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	118	232
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 | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	330	565
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	330	565
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	89	37
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	59	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	30	37
Banks/financial institutions
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	8,835	9,299
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	8,757	9,140
Banks/financial institutions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	78	159
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	5,085	4,622
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	5,085	4,622
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 | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	3,077	4,623
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	3,008	4,518
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	69	105
Banks/financial institutions | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	673	54
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	664	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	9	54
Other corporate
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	28,342	28,362
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	27,694	27,620
Other corporate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	648	742
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	18,092	22,268
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	18,088	22,268
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	4	0
Other corporate | Internal valuation technique
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	4,440	5,552
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	4,210	5,352
Other corporate | Internal valuation technique | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	230	200
Other corporate | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	5,810	542
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	5,396	0
Other corporate | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Available for sale, fixed maturity securities	$ 414	$ 542