FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Assets:
Available for sale, fixed maturity securities	$ 73,643	$ 98,696
Equity securities	1,064	1,603
Other investments	1,816	1,726
Cash and cash equivalents	4,710	5,051
Asset derivatives	1,146	936
Total assets	82,379	108,012
Liabilities:
Liability derivatives	2,088	1,619
Total liabilities	2,088	1,619
Foreign currency swaps
Assets:
Asset derivatives	146	137
Liabilities:
Liability derivatives	462	427
Foreign currency forwards
Assets:
Asset derivatives	995	791
Liabilities:
Liability derivatives	1,035	1,138
Foreign currency options
Assets:
Asset derivatives	5	8
Interest rate swaps
Liabilities:
Liability derivatives	590	54
Forward bond purchase commitment
Liabilities:
Liability derivatives	1
Government and agencies
Assets:
Available for sale, fixed maturity securities	23,910	33,820
Municipalities
Assets:
Available for sale, fixed maturity securities	2,276	3,036
Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	2,009	1,246
Public utilities
Assets:
Available for sale, fixed maturity securities	7,350	10,051
Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	862	1,115
Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	9,031	11,591
Other corporate
Assets:
Available for sale, fixed maturity securities	28,205	37,837
Level 1
Assets:
Available for sale, fixed maturity securities	22,987	32,532
Equity securities	801	1,340
Other investments	1,816	1,726
Cash and cash equivalents	4,710	5,051
Asset derivatives	0	0
Total assets	30,314	40,649
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
Liabilities:
Liability derivatives	0	0
Level 1 \| Forward bond purchase commitment
Liabilities:
Liability derivatives	0
Level 1 \| Government and agencies
Assets:
Available for sale, fixed maturity securities	22,987	32,532
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	49,036	64,866
Equity securities	66	90
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	1,146	936
Total assets	50,248	65,892
Liabilities:
Total liabilities	2,088	1,619
Level 2 \| Foreign currency swaps
Assets:
Asset derivatives	146	137
Liabilities:
Liability derivatives	462	427
Level 2 \| Foreign currency forwards
Assets:
Asset derivatives	995	791
Liabilities:
Liability derivatives	1,035	1,138
Level 2 \| Foreign currency options
Assets:
Asset derivatives	5	8
Level 2 \| Interest rate swaps
Liabilities:
Liability derivatives	590	54
Level 2 \| Forward bond purchase commitment
Liabilities:
Liability derivatives	1
Level 2 \| Government and agencies
Assets:
Available for sale, fixed maturity securities	923	1,288
Level 2 \| Municipalities
Assets:
Available for sale, fixed maturity securities	2,276	3,036
Level 2 \| Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	1,699	955
Level 2 \| Public utilities
Assets:
Available for sale, fixed maturity securities	6,843	9,558
Level 2 \| Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	828	1,072
Level 2 \| Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	8,883	11,546
Level 2 \| Other corporate
Assets:
Available for sale, fixed maturity securities	27,584	37,411
Level 3
Assets:
Available for sale, fixed maturity securities	1,620	1,298
Equity securities	197	173
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	0
Total assets	1,817	1,471
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
Liabilities:
Liability derivatives	0	0
Level 3 \| Forward bond purchase commitment
Liabilities:
Liability derivatives	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	310	291
Level 3 \| Public utilities
Assets:
Available for sale, fixed maturity securities	507	493
Level 3 \| Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	34	43
Level 3 \| Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	148	45
Level 3 \| Other corporate
Assets:
Available for sale, fixed maturity securities	$ 621	$ 426

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