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, 2025	Mar. 31, 2024
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	$ 2,224	$ 2,029
Net investment gains (losses) included in earnings	1	(4)
Unrealized gains (losses) included in other comprehensive income (loss)	19	(19)
Purchases	547	220
Issuances	0	0
Sales	(1)	0
Settlements	(20)	(142)
Transfers into Level 3	15	226
Transfers out of Level 3	(95)	(233)
Balance, end of period	2,690	2,077
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ 1	$ (2)
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)
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
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	$ 1,156	$ 772
Net investment gains (losses) included in earnings	0	1
Unrealized gains (losses) included in other comprehensive income (loss)	10	(4)
Purchases	434	118
Issuances	0	0
Sales	0	0
Settlements	(12)	(28)
Transfers into Level 3	15	0
Transfers out of Level 3	0	0
Balance, end of period	1,603	859
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
Fixed maturity securities | Public utilities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, beginning of period	647	253
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	6	(10)
Purchases	110	60
Issuances	0	0
Sales	0	0
Settlements	(7)	(22)
Transfers into Level 3	0	226
Transfers out of Level 3	0	0
Balance, end of period	756	507
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	23	30
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	1	(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	24	28
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	10	78
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	0	(4)
Purchases	0	5
Issuances	0	0
Sales	0	0
Settlements	0	(5)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	10	74
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	231	648
Net investment gains (losses) included in earnings	0	0
Unrealized gains (losses) included in other comprehensive income (loss)	2	1
Purchases	0	37
Issuances	0	0
Sales	0	0
Settlements	(1)	(3)
Transfers into Level 3	0	0
Transfers out of Level 3	(95)	(233)
Balance, end of period	137	450
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	157	248
Net investment gains (losses) included in earnings	1	(5)
Unrealized gains (losses) included in other comprehensive income (loss)	0	0
Purchases	3	0
Issuances	0	0
Sales	(1)	0
Settlements	0	(84)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Balance, end of period	160	159
Changes in unrealized gains (losses) relating to Level 3 assets and liabilities still held at the end of the period included in earnings	$ 1	$ (3)