FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Assets:
Fixed maturity securities, available-for-sale	$ 65,269	$ 73,290
Equity securities	796	1,088
Other investments	1,599	1,304
Cash and cash equivalents	6,229	4,306
Asset derivatives	240	337
Total assets	74,133	80,325
Liabilities:
Liability derivatives	933	1,430
Total liabilities	933	1,430
Foreign currency swaps
Assets:
Asset derivatives	55	86
Liabilities:
Liability derivatives	604	507
Foreign currency forwards
Assets:
Asset derivatives	185	238
Liabilities:
Liability derivatives		504
Foreign currency options
Assets:
Asset derivatives		2
Interest rate swaps
Assets:
Asset derivatives		11
Liabilities:
Liability derivatives	329	419
Government and agencies
Assets:
Fixed maturity securities, available-for-sale	17,846	22,600
Municipalities
Assets:
Fixed maturity securities, available-for-sale	2,034	2,298
Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	3,563	3,086
Public utilities
Assets:
Fixed maturity securities, available-for-sale	7,045	7,592
Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	416	537
Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	8,956	8,835
Other corporate
Assets:
Fixed maturity securities, available-for-sale	25,409	28,342
Level 1
Assets:
Fixed maturity securities, available-for-sale	17,088	21,700
Equity securities	639	840
Other investments	1,599	1,304
Cash and cash equivalents	6,229	4,306
Asset derivatives	0	0
Total assets	25,555	28,150
Liabilities:
Total liabilities	0	0
Level 1 | Foreign currency swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives		0
Level 1 | Foreign currency options
Assets:
Asset derivatives		0
Level 1 | Interest rate swaps
Assets:
Asset derivatives		0
Liabilities:
Liability derivatives	0	0
Level 1 | Government and agencies
Assets:
Fixed maturity securities, available-for-sale	17,088	21,700
Level 1 | Municipalities
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 1 | Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 1 | Public utilities
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 1 | Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 1 | Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 1 | Other corporate
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 2
Assets:
Fixed maturity securities, available-for-sale	46,114	49,809
Equity securities	0	0
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	240	337
Total assets	46,354	50,146
Liabilities:
Total liabilities	933	1,430
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	55	86
Liabilities:
Liability derivatives	604	507
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	185	238
Liabilities:
Liability derivatives		504
Level 2 | Foreign currency options
Assets:
Asset derivatives		2
Level 2 | Interest rate swaps
Assets:
Asset derivatives		11
Liabilities:
Liability derivatives	329	419
Level 2 | Government and agencies
Assets:
Fixed maturity securities, available-for-sale	758	900
Level 2 | Municipalities
Assets:
Fixed maturity securities, available-for-sale	2,034	2,298
Level 2 | Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	2,407	2,314
Level 2 | Public utilities
Assets:
Fixed maturity securities, available-for-sale	6,398	7,339
Level 2 | Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	393	507
Level 2 | Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	8,946	8,757
Level 2 | Other corporate
Assets:
Fixed maturity securities, available-for-sale	25,178	27,694
Level 3
Assets:
Fixed maturity securities, available-for-sale	2,067	1,781
Equity securities	157	248
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	0
Total assets	2,224	2,029
Liabilities:
Total liabilities	0	0
Level 3 | Foreign currency swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 3 | Foreign currency forwards
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives		0
Level 3 | Foreign currency options
Assets:
Asset derivatives		0
Level 3 | Interest rate swaps
Assets:
Asset derivatives		0
Liabilities:
Liability derivatives	0	0
Level 3 | Government and agencies
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 3 | Municipalities
Assets:
Fixed maturity securities, available-for-sale	0	0
Level 3 | Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	1,156	772
Level 3 | Public utilities
Assets:
Fixed maturity securities, available-for-sale	647	253
Level 3 | Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	23	30
Level 3 | Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	10	78
Level 3 | Other corporate
Assets:
Fixed maturity securities, available-for-sale	$ 231	$ 648