INVESTMENTS - Held-to-Maturity Debt Securities (Detail) - USD ($) $ in Millions	Dec. 31, 2024		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 15,971		$ 17,824
Allowance for Credit Losses	5		5	$ 7	$ 8
Total fixed maturity securities held to maturity	15,966	[1]	17,819
Gross Unrealized Gains	815		1,838
Gross Unrealized Losses	9		0
Fair Value	16,772		19,657
Municipalities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	235		266
Fair Value	257		307
Public utilities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	32		34
Fair Value	33		38
Sovereign and supranational
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	374		418
Fair Value	405		462
Other corporate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	16		18
Fair Value	18		21
Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	15,971		17,824
Allowance for Credit Losses	5		5
Total fixed maturity securities held to maturity	15,966		17,819
Gross Unrealized Gains	815		1,838
Gross Unrealized Losses	9		0
Fair Value	16,772		19,657
Yen-denominated | Japan government and agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	15,311		17,085
Allowance for Credit Losses	2		2
Total fixed maturity securities held to maturity	15,309		17,083
Gross Unrealized Gains	759		1,746
Gross Unrealized Losses	9		0
Fair Value	16,059		18,829
Yen-denominated | Municipalities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	235		266
Allowance for Credit Losses	0		0
Total fixed maturity securities held to maturity	235		266
Gross Unrealized Gains	22		41
Gross Unrealized Losses	0		0
Fair Value	257		307
Yen-denominated | Public utilities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	32		34
Allowance for Credit Losses	0		0
Total fixed maturity securities held to maturity	32		34
Gross Unrealized Gains	1		4
Gross Unrealized Losses	0		0
Fair Value	33		38
Yen-denominated | Sovereign and supranational
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	377		421
Allowance for Credit Losses	3		3
Total fixed maturity securities held to maturity	374		418
Gross Unrealized Gains	31		44
Gross Unrealized Losses	0		0
Fair Value	405		462
Yen-denominated | Other corporate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	16		18
Allowance for Credit Losses	0		0
Total fixed maturity securities held to maturity	16		18
Gross Unrealized Gains	2		3
Gross Unrealized Losses	0		0
Fair Value	$ 18		$ 21

[1] Net of allowance for credit losses