DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	$ 1,224	$ 1,308
Gross amount of assets offset in balance sheet	0	0
Derivative liability, fair value, amount not offset against collateral	1,224	1,308
Financial instruments, amount not offset	(189)	(174)
Derivative, collateral, right to reclaim securities	(365)	(506)
Derivative, collateral, right to reclaim cash	(669)	(629)
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	1	(1)
Derivative liability, not subject to master netting arrangement	442	390
Derivative liability, fair value, gross liability including not subject to master netting arrangement	1,666	1,698
Net amount of derivative liabilities presented in balance sheet	1,666	1,698
Derivative liability, fair value, amount offset against collateral	443	389
Securities lending, gross amounts of recognized financial instruments, offsetting liabilities	4,607	1,809
Securities lending, gross amounts offset in statement of financial position, offsetting liabilities	0	0
Securities lending, net amounts of financial instruments presented in balance sheet, offsetting liabilities	4,607	1,809
Securities lending, carrying value of financial instruments, liabilities not offset in balance sheet	(4,563)	(1,788)
Securities lending, securities collateral, liabilities not offset in balance sheet	0	0
Securities lending, cash collateral, liabilities not offset in balance sheet	0	0
Securities lending, financial instruments, amount of liabilities offset against collateral	44	21
Gross amounts of recognized financial instruments, offsetting liabilities	6,273	3,507
Gross amounts offset in statement of financial position, offsetting liabilities	0	0
Net amounts of financial instruments presented in balance sheet, offsetting liabilities	6,273	3,507
Carrying value of financial instruments, liabilities not offset in balance sheet	(4,752)	(1,962)
Securities collateral, liabilities not offset in balance sheet	(365)	(506)
Cash collateral, liabilities not offset in balance sheet	(669)	(629)
Financial instruments, amount of liabilities offset against collateral	487	410
OTC - Bilateral
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	588	725
Gross amount of assets offset in balance sheet	0	0
Derivative liability, fair value, amount not offset against collateral	588	725
Financial instruments, amount not offset	(189)	(167)
Derivative, collateral, right to reclaim securities	(362)	(506)
Derivative, collateral, right to reclaim cash	(36)	(52)
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	1	0
Derivative liability, not subject to master netting arrangement	442	390
OTC- Cleared
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	636	583
Gross amount of assets offset in balance sheet	0	0
Derivative liability, fair value, amount not offset against collateral	636	583
Financial instruments, amount not offset	0	(7)
Derivative, collateral, right to reclaim securities	(3)	0
Derivative, collateral, right to reclaim cash	(633)	(577)
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	$ 0	$ (1)