GUARANTEES AND COMMITMENTS - Restricted Cash (Details) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Restricted Cash and Cash Equivalent Item [Line Items]
Total	$ 26,055	$ 24,418
Balance Sheet Location [Axis]: us-gaap:CashAndDueFromBanks
Restricted Cash and Cash Equivalent Item [Line Items]
Total	4,827	3,337
Balance Sheet Location [Axis]: c:DepositsWithBanksAndOtherFinancialInstitutionsNetOfAllowance
Restricted Cash and Cash Equivalent Item [Line Items]
Total	$ 21,228	$ 21,081

Amount of cash restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits.