FAIR VALUE MEASUREMENTS - Fair Value Hierarchy Levels of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Assets:
Fixed maturity securities, available-for-sale	$ 64,121	$ 65,269
Equity securities	887	796
Other investments	1,373	1,599
Cash and cash equivalents	6,245	6,229
Asset derivatives	179	240
Total assets	72,805	74,133
Liabilities:
Liability derivatives	972	933
Total liabilities	972	933
Foreign currency swaps
Assets:
Asset derivatives	45	55
Liabilities:
Liability derivatives	765	604
Foreign currency forwards
Assets:
Asset derivatives	120	185
Liabilities:
Liability derivatives	18
Interest rate swaps
Assets:
Asset derivatives	14
Liabilities:
Liability derivatives	189	329
Government and agencies
Assets:
Fixed maturity securities, available-for-sale	14,607	17,846
Municipalities
Assets:
Fixed maturity securities, available-for-sale	1,930	2,034
Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	4,366	3,563
Public utilities
Assets:
Fixed maturity securities, available-for-sale	7,174	7,045
Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	402	416
Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	9,244	8,956
Other corporate
Assets:
Fixed maturity securities, available-for-sale	26,398	25,409
Level 1
Assets:
Fixed maturity securities, available-for-sale	13,921	17,088
Equity securities	727	639
Other investments	1,373	1,599
Cash and cash equivalents	6,245	6,229
Asset derivatives	0	0
Total assets	22,266	25,555
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 | Interest rate swaps
Assets:
Asset derivatives	0
Liabilities:
Liability derivatives	0	0
Level 1 | Government and agencies
Assets:
Fixed maturity securities, available-for-sale	13,921	17,088
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	46,843	46,114
Equity securities	0	0
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	179	240
Total assets	47,022	46,354
Liabilities:
Total liabilities	972	933
Level 2 | Foreign currency swaps
Assets:
Asset derivatives	45	55
Liabilities:
Liability derivatives	765	604
Level 2 | Foreign currency forwards
Assets:
Asset derivatives	120	185
Liabilities:
Liability derivatives	18
Level 2 | Interest rate swaps
Assets:
Asset derivatives	14
Liabilities:
Liability derivatives	189	329
Level 2 | Government and agencies
Assets:
Fixed maturity securities, available-for-sale	686	758
Level 2 | Municipalities
Assets:
Fixed maturity securities, available-for-sale	1,930	2,034
Level 2 | Mortgage- and asset-backed securities
Assets:
Fixed maturity securities, available-for-sale	2,072	2,407
Level 2 | Public utilities
Assets:
Fixed maturity securities, available-for-sale	6,298	6,398
Level 2 | Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	383	393
Level 2 | Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	9,235	8,946
Level 2 | Other corporate
Assets:
Fixed maturity securities, available-for-sale	26,239	25,178
Level 3
Assets:
Fixed maturity securities, available-for-sale	3,357	2,067
Equity securities	160	157
Other investments	0	0
Cash and cash equivalents	0	0
Asset derivatives	0	0
Total assets	3,517	2,224
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 | 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	2,294	1,156
Level 3 | Public utilities
Assets:
Fixed maturity securities, available-for-sale	876	647
Level 3 | Sovereign and supranational
Assets:
Fixed maturity securities, available-for-sale	19	23
Level 3 | Banks/financial institutions
Assets:
Fixed maturity securities, available-for-sale	9	10
Level 3 | Other corporate
Assets:
Fixed maturity securities, available-for-sale	$ 159	$ 231