INVESTMENTS - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2023		Sep. 30, 2022	Sep. 30, 2023		Sep. 30, 2022
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period					$ (192)
(Addition to) release of allowance for credit losses		$ (30)		$ (12)	(63)		$ (8)
Balance, end of period		(260)			(260)
Balance, beginning of period					(7)
(Addition to) release of allowance for credit losses		0		0	1		0
Balance, end of period		(5)			(5)
Balance, beginning of period					0
Balance, end of period		0			0
Loan commitments, allowance for credit loss		19		26	19		26
Transitional real estate loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		(76)		(53)	(54)		(68)
(Addition to) release of allowance for credit losses		(35)	[1]	(2)	(57)	[1]	13
Write-offs, net of recoveries		0		0	0		0
Change in foreign exchange		0		0	0		0
Balance, end of period	[2]	(111)		(55)	(111)		(55)
Allowance for credit loss accounted for as purchased financial assets with credit deterioration		4			4
Commercial mortgage loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		(9)		(8)	(9)		(10)
(Addition to) release of allowance for credit losses		(3)		(2)	(3)		0
Write-offs, net of recoveries		0		0	0		0
Change in foreign exchange		0		0	0		0
Balance, end of period	[2]	(12)		(10)	(12)		(10)
Middle market loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		(140)		(109)	(129)		(96)
(Addition to) release of allowance for credit losses		3		(6)	(8)		(24)
Write-offs, net of recoveries		0		(2)	0		3
Change in foreign exchange		0		0	0		0
Balance, end of period	[2]	(137)		(117)	(137)		(117)
Held-to-maturity securities
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		(5)		(7)	(7)		(8)
(Addition to) release of allowance for credit losses		1		0	1		0
Write-offs, net of recoveries		0		0	0		0
Change in foreign exchange		(1)		1	1		2
Balance, end of period	[2]	(5)		(6)	(5)		(6)
Available-for-sale securities
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		0		0	0		0
(Addition to) release of allowance for credit losses		0		0	0		0
Write-offs, net of recoveries		0		0	0		0
Change in foreign exchange		0		0	0		0
Balance, end of period	[2]	0		0	0		0
Reinsurance recoverables
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period		(10)		(8)	(8)		(13)
(Addition to) release of allowance for credit losses)		0		0	(2)		2
Write-offs, net of recoveries		0		0	0		0
Change in foreign exchange		1		0	1		3
Balance, end of period	[2]	$ (9)		$ (8)	$ (9)		$ (8)

[1] Includes an allowance for credit losses of $4 recognized on financial assets accounted for as purchased financial assets with credit deterioration that is not recorded in earnings upon recognition.

[2] Excludes allowance on firm loan commitments of $19 and $26 as of September 30, 2023 and 2022, respectively.