FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets by Pricing Source, Securities Carried at Fair Value (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	$ 65,269	$ 73,290
Equity securities	796	1,088
Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	17,088	21,700
Equity securities	639	840
Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	46,114	49,809
Equity securities	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,067	1,781
Equity securities	157	248
Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	639	800
Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	639	800
Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	26	216
Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	0
Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	26	216
Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	131	72
Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Equity securities	0	40
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	131	32
Government and agencies
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	17,846	22,600
Government and agencies | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	17,088	21,700
Government and agencies | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	758	900
Government and agencies | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Government and agencies | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	17,534	22,500
Government and agencies | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	17,088	21,692
Government and agencies | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	446	808
Government and agencies | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Government and agencies | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	312	60
Government and agencies | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Government and agencies | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	312	60
Government and agencies | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Government and agencies | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		40
Government and agencies | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		8
Government and agencies | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		32
Government and agencies | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		0
Municipalities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,034	2,298
Municipalities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,034	2,298
Municipalities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	1,791	1,426
Municipalities | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	1,791	1,426
Municipalities | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	243	256
Municipalities | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	243	256
Municipalities | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Municipalities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		616
Municipalities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		0
Municipalities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		616
Municipalities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale		0
Mortgage- and asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	3,563	3,086
Mortgage- and asset-backed securities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Mortgage- and asset-backed securities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,407	2,314
Mortgage- and asset-backed securities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	1,156	772
Mortgage- and asset-backed securities | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,352	2,277
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,352	2,277
Mortgage- and asset-backed securities | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Mortgage- and asset-backed securities | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	92	132
Mortgage- and asset-backed securities | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Mortgage- and asset-backed securities | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	55	27
Mortgage- and asset-backed securities | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	37	105
Mortgage- and asset-backed securities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	1,119	677
Mortgage- and asset-backed securities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Mortgage- and asset-backed securities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	10
Mortgage- and asset-backed securities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	1,119	667
Public utilities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	7,045	7,592
Public utilities | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	6,398	7,339
Public utilities | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	647	253
Public utilities | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	3,628	4,570
Public utilities | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	3,628	4,570
Public utilities | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,770	2,677
Public utilities | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	2,770	2,677
Public utilities | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	647	345
Public utilities | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Public utilities | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	92
Public utilities | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	647	253
Sovereign and supranational
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	416	537
Sovereign and supranational | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	393	507
Sovereign and supranational | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	23	30
Sovereign and supranational | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	78	118
Sovereign and supranational | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	78	118
Sovereign and supranational | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	315	330
Sovereign and supranational | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	315	330
Sovereign and supranational | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	23	89
Sovereign and supranational | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Sovereign and supranational | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	59
Sovereign and supranational | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	23	30
Banks/financial institutions
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	8,956	8,835
Banks/financial institutions | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Banks/financial institutions | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	8,946	8,757
Banks/financial institutions | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	10	78
Banks/financial institutions | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	4,975	5,085
Banks/financial institutions | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Banks/financial institutions | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	4,975	5,085
Banks/financial institutions | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Banks/financial institutions | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	3,976	3,077
Banks/financial institutions | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Banks/financial institutions | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	3,971	3,008
Banks/financial institutions | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	5	69
Banks/financial institutions | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	5	673
Banks/financial institutions | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Banks/financial institutions | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	664
Banks/financial institutions | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	5	9
Other corporate
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	25,409	28,342
Other corporate | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Other corporate | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	25,178	27,694
Other corporate | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	231	648
Other corporate | Third-party pricing vendor
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	20,051	18,092
Other corporate | Third-party pricing vendor | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Other corporate | Third-party pricing vendor | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	20,051	18,088
Other corporate | Third-party pricing vendor | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	4
Other corporate | Internal
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	5,243	4,440
Other corporate | Internal | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Other corporate | Internal | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	5,127	4,210
Other corporate | Internal | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	116	230
Other corporate | Broker/other
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	115	5,810
Other corporate | Broker/other | Level 1
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	0
Other corporate | Broker/other | Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	0	5,396
Other corporate | Broker/other | Level 3
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Fixed maturity securities, available-for-sale	$ 115	$ 414