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, 2023	Mar. 31, 2022
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 1,987	$ 1,471
Net investment gains (losses) included in earnings	2	7
Unrealized gains (losses) included in other comprehensive income (loss)	45	(72)
Purchases	277	95
Issuances	0	0
Sales	0	0
Settlements	(129)	(21)
Transfers into Level 3	18	170
Transfers out of Level 3	(260)	(190)
Balance, end of period	1,940	1,460
Change in unrealized gains (losses) still held	3	4
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	343	291
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	3	(15)
Purchases	192	76
Issuances	0	0
Sales	0	0
Settlements	(120)	(2)
Transfers into Level 3	0	0
Transfers out of Level 3	0	(32)
Balance, end of period	418	318
Change in unrealized gains (losses) still held	0	0
Fixed maturity securities \| Public utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	497	493
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	10	(37)
Purchases	0	9
Issuances	0	0
Sales	0	0
Settlements	(7)	(8)
Transfers into Level 3	18	128
Transfers out of Level 3	(168)	0
Balance, end of period	350	585
Change in unrealized gains (losses) still held	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	37	43
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	0	(2)
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	37	41
Change in unrealized gains (losses) still held	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	159	45
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	(3)
Transfers into Level 3	0	18
Transfers out of Level 3	0	0
Balance, end of period	161	60
Change in unrealized gains (losses) still held	0	0
Fixed maturity securities \| Other corporate
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	742	426
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	30	(18)
Purchases	75	0
Issuances	0	0
Sales	0	0
Settlements	(2)	(1)
Transfers into Level 3	0	24
Transfers out of Level 3	(92)	(141)
Balance, end of period	753	290
Change in unrealized gains (losses) still held	0	0
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	209	173
Net investment gains (losses) included in earnings	2	7
Unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases	10	10
Issuances	0	0
Sales	0	0
Settlements	0	(7)
Transfers into Level 3	0	0
Transfers out of Level 3	0	(17)
Balance, end of period	221	166
Change in unrealized gains (losses) still held	$ 3	$ 4

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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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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.

+ References

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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).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
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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

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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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- 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
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
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-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-URI https://asc.fasb.org/extlink&oid=126976982&loc=d3e19207-110258

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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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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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