FAIR VALUE MEASUREMENTS - Changes in Investments Carried at Fair Value Classified as Level 3 (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 3,517	$ 2,224
Net investment gains (losses) included in earnings	10	1
Unrealized gains (losses) included in other comprehensive income (loss)	(63)	19
Purchases	313	547
Issuances	0	0
Sales	0	(1)
Settlements	(94)	(20)
Transfers into Level 3	119	15
Transfers out of Level 3	(5)	(95)
Balance, end of period	3,797	2,690
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ 0	$ 1
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Other Comprehensive Income (Loss), before Tax	Other Comprehensive Income (Loss), before Tax
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment gains (losses), Other Comprehensive Income (Loss), before Tax	Net investment gains (losses), Other Comprehensive Income (Loss), before Tax
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment gains (losses)	Net investment gains (losses)
Fixed maturity securities \| Mortgage- and asset-backed securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 2,294	$ 1,156
Net investment gains (losses) included in earnings	2	0
Unrealized gains (losses) included in other comprehensive income (loss)	(32)	10
Purchases	302	434
Issuances	0	0
Sales	0	0
Settlements	(30)	(12)
Transfers into Level 3	119	15
Transfers out of Level 3	0	0
Balance, end of period	2,655	1,603
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	1	0
Fixed maturity securities \| Public utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	876	647
Net investment gains (losses) included in earnings	4	0
Unrealized gains (losses) included in other comprehensive income (loss)	(23)	6
Purchases	10	110
Issuances	0	0
Sales	0	0
Settlements	(42)	(7)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	825	756
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	0	0
Fixed maturity securities \| Sovereign and supranational
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	19	23
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	0	1
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	19	24
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	0	0
Fixed maturity securities \| Banks/financial institutions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	9	10
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(5)	0
Balance, end of period	4	10
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	0	0
Fixed maturity securities \| Other corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	159	231
Net investment gains (losses) included in earnings	6	0
Unrealized gains (losses) included in other comprehensive income (loss)	(8)	2
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	(22)	(1)
Transfers into Level 3	0	0
Transfers out of Level 3	0	(95)
Balance, end of period	135	137
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	0	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	160	157
Net investment gains (losses) included in earnings	(2)	1
Unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases	1	3
Issuances	0	0
Sales	0	(1)
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	159	160
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ (1)	$ 1

Indicates line item in statement of income or comprehensive income that includes unrealized gain (loss) from asset measured at fair value using unobservable input (level 3) and still held.

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Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in other comprehensive income (OCI) from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Indicates line item in statement of income or comprehensive income that includes gain (loss) from asset measured at fair value using unobservable input (level 3).

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