INVESTMENTS - Held-to-Maturity Debt Securities (Detail) - USD ($) $ in Millions	Dec. 31, 2023		Dec. 31, 2022
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 17,824		$ 19,063
Allowance for Credit Losses	5		7
Total fixed maturity securities held to maturity	17,819	[1]	19,056
Gross Unrealized Gains	1,838		2,154
Gross Unrealized Losses	0		0
Fair Value	19,657		21,210
Municipalities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	266		287
Fair Value	307		335
Public utilities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	34		37
Fair Value	38		41
Sovereign and supranational
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	418		446
Fair Value	462		500
Other corporate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	18		19
Fair Value	21		22
Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	17,824		19,063
Allowance for Credit Losses	5		7
Total fixed maturity securities held to maturity	17,819		19,056
Gross Unrealized Gains	1,838		2,154
Gross Unrealized Losses	0		0
Fair Value	19,657		21,210
Yen-denominated | Japan government and agencies
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	17,085		18,269
Allowance for Credit Losses	2		2
Total fixed maturity securities held to maturity	17,083		18,267
Gross Unrealized Gains	1,746		2,045
Gross Unrealized Losses	0		0
Fair Value	18,829		20,312
Yen-denominated | Municipalities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	266		287
Allowance for Credit Losses	0		0
Total fixed maturity securities held to maturity	266		287
Gross Unrealized Gains	41		48
Gross Unrealized Losses	0		0
Fair Value	307		335
Yen-denominated | Public utilities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	34		38
Allowance for Credit Losses	0		1
Total fixed maturity securities held to maturity	34		37
Gross Unrealized Gains	4		4
Gross Unrealized Losses	0		0
Fair Value	38		41
Yen-denominated | Sovereign and supranational
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	421		450
Allowance for Credit Losses	3		4
Total fixed maturity securities held to maturity	418		446
Gross Unrealized Gains	44		54
Gross Unrealized Losses	0		0
Fair Value	462		500
Yen-denominated | Other corporate
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	18		19
Allowance for Credit Losses	0		0
Total fixed maturity securities held to maturity	18		19
Gross Unrealized Gains	3		3
Gross Unrealized Losses	0		0
Fair Value	$ 21		$ 22

[1] Net of allowance for credit losses