DERIVATIVE INSTRUMENTS - Offsetting of Financial Assets and Derivative Assets (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	$ 63	$ 187
Gross amount of liabilities offset in balance sheet	0	0
Net amount of derivative assets presented in balance sheet	63	187
Financial instruments, amount not offset	(26)	0
Derivative, collateral, obligation to return securities	0	(45)
Derivative, collateral, obligation to return cash	(30)	(135)
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement	7	7
Derivative asset, not subject to master netting arrangement	44	53
Derivative asset, fair value, gross asset including not subject to master netting arrangement	107	240
Net amount of derivative assets presented in balance sheet	107	240
Derivative asset, fair value, amount offset against collateral	51	60
Securities lending, gross amounts of recognized financial instruments	5,377	2,001
Securities lending, gross amounts offset in balance sheet	0	0
Securities lending, net amounts of assets presented in balance sheet	5,377	2,001
Securities lending, carrying value of financial instruments not offset in balance sheet	0	0
Securities lending, securities collateral, not offset in balance sheet	0	0
Securities lending, cash collateral, not offset in balance sheet	(5,377)	(2,001)
Securities lending, financial instruments, amount of assets offset against collateral	0	0
Gross amount of recognized assets	5,484	2,241
Gross amounts offset in balance sheet	0	0
Net amounts of assets presented in balance sheet	5,484	2,241
Carrying value of financial instruments not offset in balance sheet	(26)	0
Securities collateral, not offset in balance sheet	0	(45)
Cash collateral, not offset in balance sheet	(5,407)	(2,136)
Financial instruments, amount of assets offset against collateral	51	60
OTC - Bilateral
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	47	187
Gross amount of liabilities offset in balance sheet	0	0
Net amount of derivative assets presented in balance sheet	47	187
Financial instruments, amount not offset	(10)	0
Derivative, collateral, obligation to return securities	0	(45)
Derivative, collateral, obligation to return cash	(30)	(135)
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement	7	7
Derivative asset, not subject to master netting arrangement	44	$ 53
OTC- Cleared
Offsetting Assets [Line Items]
Gross amount of recognized derivative assets	16
Gross amount of liabilities offset in balance sheet	0
Net amount of derivative assets presented in balance sheet	16
Financial instruments, amount not offset	(16)
Derivative, collateral, obligation to return securities	0
Derivative, collateral, obligation to return cash	0
Derivative asset, fair value, amount offset against collateral, subject to master netting agreement	$ 0