FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Jun. 30, 2023	Dec. 31, 2022
Assets:
Available for sale, fixed maturity securities	$ 74,505	$ 75,741
Equity securities	965	1,091
Other investments	2,706	1,532
Cash and cash equivalents	4,720	3,943
Asset derivatives	668	617
Total assets	83,564	82,924
Liabilities:
Liability derivatives	1,481	1,698
Total liabilities	1,481	1,698
Foreign currency swaps
Assets:
Asset derivatives	107	128
Liabilities:
Liability derivatives	450	390
Foreign currency forwards
Assets:
Asset derivatives	552	400
Liabilities:
Liability derivatives	440	725
Foreign currency options
Assets:
Asset derivatives	0	82
Interest rate swaps
Assets:
Asset derivatives	9	7
Liabilities:
Liability derivatives	591	583
Government and agencies
Assets:
Available for sale, fixed maturity securities	23,953	25,114
Municipalities
Assets:
Available for sale, fixed maturity securities	2,323	2,320
Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	2,855	2,146
Public utilities
Assets:
Available for sale, fixed maturity securities	7,569	7,666
Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	674	834
Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	8,849	9,299
Other corporate
Assets:
Available for sale, fixed maturity securities	28,282	28,362
Level 1
Assets:
Available for sale, fixed maturity securities	23,022	24,158
Equity securities	752	822
Other investments	2,706	1,532
Cash and cash equivalents	4,720	3,943
Asset derivatives	0	0
Total assets	31,200	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	23,022	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	49,856	49,805
Equity securities	0	60
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	668	617
Total assets	50,524	50,482
Liabilities:
Total liabilities	1,481	1,698
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	107	128
Liabilities:
Liability derivatives	450	390
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	552	400
Liabilities:
Liability derivatives	440	725
Level 2 | Foreign currency options
Assets:
Asset derivatives	0	82
Level 2 | Interest rate swaps
Assets:
Asset derivatives	9	7
Liabilities:
Liability derivatives	591	583
Level 2 | Government and agencies
Assets:
Available for sale, fixed maturity securities	931	956
Level 2 | Municipalities
Assets:
Available for sale, fixed maturity securities	2,323	2,320
Level 2 | Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	2,203	1,803
Level 2 | Public utilities
Assets:
Available for sale, fixed maturity securities	7,267	7,169
Level 2 | Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	642	797
Level 2 | Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	8,780	9,140
Level 2 | Other corporate
Assets:
Available for sale, fixed maturity securities	27,710	27,620
Level 3
Assets:
Available for sale, fixed maturity securities	1,627	1,778
Equity securities	213	209
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	0
Total assets	1,840	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	652	343
Level 3 | Public utilities
Assets:
Available for sale, fixed maturity securities	302	497
Level 3 | Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	32	37
Level 3 | Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	69	159
Level 3 | Other corporate
Assets:
Available for sale, fixed maturity securities	$ 572	$ 742