DERIVATIVE INSTRUMENTS - Offsetting of Financial Liabilities and Derivative Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	$ 249	$ 329
Gross amount of assets offset in balance sheet	0	0
Derivative liability, fair value, amount not offset against collateral	249	329
Financial instruments, amount not offset	(26)	0
Derivative, collateral, right to reclaim securities	(26)	0
Derivative, collateral, right to reclaim cash	(196)	(329)
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	1	0
Derivative liability, not subject to master netting arrangement	685	604
Derivative liability, fair value, gross liability including not subject to master netting arrangement	934	933
Net amount of derivative liabilities presented in balance sheet	934	933
Derivative liability, fair value, amount offset against collateral	686	604
Securities lending, gross amounts of recognized financial instruments, offsetting liabilities	5,429	2,037
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	5,429	2,037
Securities lending, carrying value of financial instruments, liabilities not offset in balance sheet	(5,377)	(2,001)
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	52	36
Gross amounts of recognized financial instruments, offsetting liabilities	6,363	2,970
Gross amounts offset in statement of financial position, offsetting liabilities	0	0
Net amounts of financial instruments presented in balance sheet, offsetting liabilities	6,363	2,970
Carrying value of financial instruments, liabilities not offset in balance sheet	(5,403)	(2,001)
Securities collateral, liabilities not offset in balance sheet	(26)	0
Cash collateral, liabilities not offset in balance sheet	(196)	(329)
Financial instruments, amount of liabilities offset against collateral	738	640
OTC - Bilateral
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	18
Gross amount of assets offset in balance sheet	0
Derivative liability, fair value, amount not offset against collateral	18
Financial instruments, amount not offset	(10)
Derivative, collateral, right to reclaim securities	(7)
Derivative, collateral, right to reclaim cash	0
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	1
Derivative liability, not subject to master netting arrangement	685	604
OTC- Cleared
Offsetting Liabilities [Line Items]
Gross amount of recognized derivative liabilities	231	329
Gross amount of assets offset in balance sheet	0	0
Derivative liability, fair value, amount not offset against collateral	231	329
Financial instruments, amount not offset	(16)	0
Derivative, collateral, right to reclaim securities	(19)	0
Derivative, collateral, right to reclaim cash	(196)	(329)
Derivative liability, fair value, amount offset against collateral, subject to master netting agreement	$ 0	$ 0