INVESTMENTS - Held-to-Maturity Debt Securities (Details) - USD ($) $ in Millions	Sep. 30, 2022		Dec. 31, 2021
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	$ 17,472		$ 22,008
Allowance for Credit Loss	6		8
Total fixed maturity securities, held to maturity, amortized cost	17,466	[1]	22,000
Gross Unrealized Gains	2,619		4,869
Gross Unrealized Losses	0		0
Fair Value	20,085		26,869
Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	17,472		22,008
Allowance for Credit Loss	6		8
Total fixed maturity securities, held to maturity, amortized cost	17,466		22,000
Gross Unrealized Gains	2,619		4,869
Gross Unrealized Losses	0		0
Fair Value	20,085		26,869
Japan government and agencies | Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	16,745		21,089
Allowance for Credit Loss	3		3
Total fixed maturity securities, held to maturity, amortized cost	16,742		21,086
Gross Unrealized Gains	2,483		4,613
Gross Unrealized Losses	0		0
Fair Value	19,225		25,699
Municipalities
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	264		335
Fair Value	321		436
Municipalities | Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	264		335
Allowance for Credit Loss	0		0
Total fixed maturity securities, held to maturity, amortized cost	264		335
Gross Unrealized Gains	57		101
Gross Unrealized Losses	0		0
Fair Value	321		436
Public utilities
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	34		43
Fair Value	41		55
Public utilities | Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	34		44
Allowance for Credit Loss	0		1
Total fixed maturity securities, held to maturity, amortized cost	34		43
Gross Unrealized Gains	7		12
Gross Unrealized Losses	0		0
Fair Value	41		55
Sovereign and supranational
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	409		514
Fair Value	477		650
Sovereign and supranational | Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	412		518
Allowance for Credit Loss	3		4
Total fixed maturity securities, held to maturity, amortized cost	409		514
Gross Unrealized Gains	68		136
Gross Unrealized Losses	0		0
Fair Value	477		650
Other corporate
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	17		22
Fair Value	21		29
Other corporate | Yen-denominated
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, fixed maturity securities, amortized cost	17		22
Allowance for Credit Loss	0		0
Total fixed maturity securities, held to maturity, amortized cost	17		22
Gross Unrealized Gains	4		7
Gross Unrealized Losses	0		0
Fair Value	$ 21		$ 29

[1] Net of allowance for credit losses