BORROWINGS - Schedule of Short-Term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2026	Dec. 31, 2025
Short-term Debt [Line Items]
Short-term borrowings	$ 6,066	$ 1,261
Securities sold under agreements to repurchase
Short-term Debt [Line Items]
Short-term borrowings	0	22
FHLB advances
Short-term Debt [Line Items]
Short-term borrowings	5,500	1,000
Other borrowings
Short-term Debt [Line Items]
Short-term borrowings	$ 566	$ 239

Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer.

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Name:	us-gaap_ShortTermBorrowings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant