INVESTMENTS - Allowance for Loan Losses by Portfolio Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period	$ (274)
(Addition to) release of allowance for credit losses	(7)	$ (31)
Balance, end of period	(232)
Balance, beginning of period	(5)	(7)
(Addition to) release of allowance for credit losses	0	1
Write-offs, net of recoveries	0	0
Change in foreign exchange	0	0
Balance, end of period	(5)	(6)
Balance, beginning of period	0	0
(Addition to) release of allowance for credit losses	0	0
Write-offs, net of recoveries	0	0
Change in foreign exchange	0	0
Balance, end of period	0	0
Balance, beginning of period	(295)	(223)
(Addition to) release of allowance for credit losses	(7)	(27)
Write-offs, net of recoveries	50	0
Change in foreign exchange	0	0
Balance, end of period	(252)	(250)
Transitional real estate loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period	(112)	(54)
(Addition to) release of allowance for credit losses	(2)	(11)
Write-offs, net of recoveries	0	0
Change in foreign exchange	0	0
Balance, end of period	(114)	(65)
Commercial mortgage loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period	(16)	(9)
(Addition to) release of allowance for credit losses	(3)	0
Write-offs, net of recoveries	0	0
Change in foreign exchange	0	0
Balance, end of period	(19)	(9)
Middle market loans
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period	(146)	(129)
(Addition to) release of allowance for credit losses	(3)	(20)
Write-offs, net of recoveries	50	0
Change in foreign exchange	0	0
Balance, end of period	(99)	(149)
Other loans and loan commitments
Allowance for Loan Losses by Portfolio Segment [Roll Forward]
Balance, beginning of period	(16)	(24)
(Addition to) release of allowance for credit losses	1	3
Write-offs, net of recoveries	0	0
Change in foreign exchange	0	0
Balance, end of period	$ (15)	$ (21)