FAIR VALUE MEASUREMENTS - Changes in Investments and Derivatives Carried at Fair Value Classified as Level 3 (Detail) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2024	Mar. 31, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 2,029	$ 1,987
Net investment gains (losses) included in earnings	(4)	2
Unrealized gains (losses) included in other comprehensive income (loss)	(19)	45
Purchases	220	277
Issuances	0	0
Sales	0	0
Settlements	(142)	(129)
Transfers into Level 3	226	18
Transfers out of Level 3	(233)	(260)
Balance, end of period	2,077	1,940
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ (2)	3
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net investment gains (losses)
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
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	$ 772	343
Net investment gains (losses) included in earnings	1	0
Unrealized gains (losses) included in other comprehensive income (loss)	(4)	3
Purchases	118	192
Issuances	0	0
Sales	0	0
Settlements	(28)	(120)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	859	418
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	253	497
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	(10)	10
Purchases	60	0
Issuances	0	0
Sales	0	0
Settlements	(22)	(7)
Transfers into Level 3	226	18
Transfers out of Level 3	0	(168)
Balance, end of period	507	350
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	30	37
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	(2)	0
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	28	37
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	78	159
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	(4)	2
Purchases	5	0
Issuances	0	0
Sales	0	0
Settlements	(5)	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	74	161
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	648	742
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	1	30
Purchases	37	75
Issuances	0	0
Sales	0	0
Settlements	(3)	(2)
Transfers into Level 3	0	0
Transfers out of Level 3	(233)	(92)
Balance, end of period	450	753
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	248	209
Net investment gains (losses) included in earnings	(5)	2
Unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases	0	10
Issuances	0	0
Sales	0	0
Settlements	(84)	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	159	221
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ (3)	$ 3

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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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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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

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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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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- Definition

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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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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-SubTopic 10
-Topic 820
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-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

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Indicates line item in statement in which net income is reported that includes gain (loss) from asset measured at fair value using unobservable input (level 3).

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Indicates line item in statement in which other comprehensive income (OCI) is reported that includes gain (loss) from asset measured at fair value using unobservable input (level 3).

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