FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Assets:
Available for sale, fixed maturity securities	$ 73,290	$ 75,741
Equity securities	1,088	1,091
Other investments	1,304	1,532
Cash and cash equivalents	4,306	3,943
Asset derivatives	$ 337	$ 617
Asset derivatives ext list	Other	Other
Total assets	$ 80,325	$ 82,924
Liabilities:
Liability derivatives	1,430	1,698
Total liabilities	1,430	1,698
Foreign currency swaps
Assets:
Asset derivatives	86	128
Liabilities:
Liability derivatives	507	390
Foreign currency forwards
Assets:
Asset derivatives	238	400
Liabilities:
Liability derivatives	504	725
Foreign currency options
Assets:
Asset derivatives	2	82
Interest rate swaps
Assets:
Asset derivatives	11	7
Liabilities:
Liability derivatives	419	583
Government and agencies
Assets:
Available for sale, fixed maturity securities	22,600	25,114
Municipalities
Assets:
Available for sale, fixed maturity securities	2,298	2,320
Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	3,086	2,146
Public utilities
Assets:
Available for sale, fixed maturity securities	7,592	7,666
Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	537	834
Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	8,835	9,299
Other corporate
Assets:
Available for sale, fixed maturity securities	28,342	28,362
Level 1
Assets:
Available for sale, fixed maturity securities	21,700	24,158
Equity securities	840	822
Other investments	1,304	1,532
Cash and cash equivalents	4,306	3,943
Asset derivatives	0	0
Total assets	28,150	30,455
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	0
Level 1 | Foreign currency options
Assets:
Asset derivatives	0	0
Level 1 | Interest rate swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 1 | Government and agencies
Assets:
Available for sale, fixed maturity securities	21,700	24,158
Level 1 | Municipalities
Assets:
Available for sale, fixed maturity securities	0	0
Level 1 | Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	0	0
Level 1 | Public utilities
Assets:
Available for sale, fixed maturity securities	0	0
Level 1 | Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	0	0
Level 1 | Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	0	0
Level 1 | Other corporate
Assets:
Available for sale, fixed maturity securities	0	0
Level 2
Assets:
Available for sale, fixed maturity securities	49,809	49,805
Equity securities	0	60
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	337	617
Total assets	50,146	50,482
Liabilities:
Total liabilities	1,430	1,698
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	86	128
Liabilities:
Liability derivatives	507	390
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	238	400
Liabilities:
Liability derivatives	504	725
Level 2 | Foreign currency options
Assets:
Asset derivatives	2	82
Level 2 | Interest rate swaps
Assets:
Asset derivatives	11	7
Liabilities:
Liability derivatives	419	583
Level 2 | Government and agencies
Assets:
Available for sale, fixed maturity securities	900	956
Level 2 | Municipalities
Assets:
Available for sale, fixed maturity securities	2,298	2,320
Level 2 | Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	2,314	1,803
Level 2 | Public utilities
Assets:
Available for sale, fixed maturity securities	7,339	7,169
Level 2 | Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	507	797
Level 2 | Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	8,757	9,140
Level 2 | Other corporate
Assets:
Available for sale, fixed maturity securities	27,694	27,620
Level 3
Assets:
Available for sale, fixed maturity securities	1,781	1,778
Equity securities	248	209
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	0
Total assets	2,029	1,987
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	0
Level 3 | Foreign currency options
Assets:
Asset derivatives	0	0
Level 3 | Interest rate swaps
Assets:
Asset derivatives	0	0
Liabilities:
Liability derivatives	0	0
Level 3 | Government and agencies
Assets:
Available for sale, fixed maturity securities	0	0
Level 3 | Municipalities
Assets:
Available for sale, fixed maturity securities	0	0
Level 3 | Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	772	343
Level 3 | Public utilities
Assets:
Available for sale, fixed maturity securities	253	497
Level 3 | Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	30	37
Level 3 | Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	78	159
Level 3 | Other corporate
Assets:
Available for sale, fixed maturity securities	$ 648	$ 742