FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Assets:
Available for sale, fixed maturity securities	$ 98,696	$ 105,882
Equity securities	1,603	1,283
Other investments	1,726	1,139
Cash and cash equivalents	5,051	5,141
Asset derivatives	936	583
Total assets	108,012	114,028
Liabilities:
Liability derivatives	1,619	697
Total liabilities	1,619	697
Foreign currency swaps
Assets:
Asset derivatives	137	180
Liabilities:
Liability derivatives	427	312
Foreign currency forwards
Assets:
Asset derivatives	791	402
Liabilities:
Liability derivatives	1,138	385
Foreign currency options
Assets:
Asset derivatives	8	1
Interest rate swaps
Liabilities:
Liability derivatives	54
Government and agencies
Assets:
Available for sale, fixed maturity securities	33,820	37,350
Municipalities
Assets:
Available for sale, fixed maturity securities	3,036	3,018
Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	1,246	1,038
Public utilities
Assets:
Available for sale, fixed maturity securities	10,051	10,817
Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	1,115	1,382
Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	11,591	12,060
Other corporate
Assets:
Available for sale, fixed maturity securities	37,837	40,217
Level 1
Assets:
Available for sale, fixed maturity securities	32,532	36,032
Equity securities	1,340	1,095
Other investments	1,726	1,139
Cash and cash equivalents	5,051	5,141
Asset derivatives	0	0
Total assets	40,649	43,407
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
Level 1 \| Government and agencies
Assets:
Available for sale, fixed maturity securities	32,532	36,032
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	64,866	68,833
Equity securities	90	86
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	936	450
Total assets	65,892	69,369
Liabilities:
Total liabilities	1,619	466
Level 2 \| Foreign currency swaps
Assets:
Asset derivatives	137	47
Liabilities:
Liability derivatives	427	81
Level 2 \| Foreign currency forwards
Assets:
Asset derivatives	791	402
Liabilities:
Liability derivatives	1,138	385
Level 2 \| Foreign currency options
Assets:
Asset derivatives	8	1
Level 2 \| Interest rate swaps
Liabilities:
Liability derivatives	54
Level 2 \| Government and agencies
Assets:
Available for sale, fixed maturity securities	1,288	1,318
Level 2 \| Municipalities
Assets:
Available for sale, fixed maturity securities	3,036	3,018
Level 2 \| Mortgage- and asset-backed securities
Assets:
Available for sale, fixed maturity securities	955	814
Level 2 \| Public utilities
Assets:
Available for sale, fixed maturity securities	9,558	10,395
Level 2 \| Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	1,072	1,334
Level 2 \| Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	11,546	12,036
Level 2 \| Other corporate
Assets:
Available for sale, fixed maturity securities	37,411	39,918
Level 3
Assets:
Available for sale, fixed maturity securities	1,298	1,017
Equity securities	173	102
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	133
Total assets	1,471	1,252
Liabilities:
Total liabilities	0	231
Level 3 \| Foreign currency swaps
Assets:
Asset derivatives	0	133
Liabilities:
Liability derivatives	0	231
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
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	291	224
Level 3 \| Public utilities
Assets:
Available for sale, fixed maturity securities	493	422
Level 3 \| Sovereign and supranational
Assets:
Available for sale, fixed maturity securities	43	48
Level 3 \| Banks/financial institutions
Assets:
Available for sale, fixed maturity securities	45	24
Level 3 \| Other corporate
Assets:
Available for sale, fixed maturity securities	$ 426	$ 299

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